vvv— .. . fiafifi¢hqa§uaa .7. fiixéfllfis.‘ - -' um. & ~ g. find-Qvax‘v-z “fi‘i‘if‘tw-xgagf’ gait; w; .‘ iii-fig: @9.§..‘¥£‘“ ~ wamaflw :7. ”(1‘3 -< '7 flat“ 4 $93“ .7775“: manta-«,7? w - .~,' 7 v'r: ~' 32% ~ _ A”: - 7. . .4‘ .x 4mm:- JA: ‘5 - . u ,. ”19> a. 7 A ~U w «64.15... 1': ~ " 4‘ w 3;}, fl "REL'E; ¢~ ’ _ i“ n ,J I. ¢ ‘Dul fr “- v figanxgésxwh 7.13.. X‘I‘fi '~~.u . h \y‘g n“; .~ A“ ~ my: r uh— . . "r— u«.a_...v?- L. a 5%? "17% ' ‘2 ‘. " v » ‘ 3"”: Egg-:figfl‘ .fl'fifiv u ' :1;- - . at a.\ . “7.),7..,..--- » *C'sr W 15‘ ,figg’hfié’“ Ii 'R?Lé‘;‘ ‘ 1:1 A .n. hr-l . 31 J47 lllllllllll“Illllllllllllllll illllllll L 1293 0102 1 This is to certify that the thesis entitled THE PHOTODEGRADATION OF WOVEN POLYPROPYLENE USING ACCELERATED WEATHERING MACHINES WITH FLUORESCENT ULTRAVIOLET TUBES: CORRELATING THE QUV AND THE UVCON presented by David M. Powers has been accepted towards fulfillment of the requirements for Master ' Sdegree in Paclcaging Qua/ta Ix “(Y/(£213, Major professor Date June 28, 1994 0-7639 MS U is an Affirmative Action/Equal Opportunity Institution LIBRARY Mlchlgan State Unlverslty PLACE ll RETURN BOXtonmwodihdndtunflomyur-oud. TOAVOID FINES Mum onorbdonddoduo. ‘ DATE DUE DATE DUE DATE DUE 5 FEB 16 790 . MSU IOMWWVEMOWIMW W1 THE PHOTODEGRADATION OF WOVEN POLYPROPYLENE USING ACCELERATED WEATHERING MACHINES WITH FLUORESCENT ULTRAVIOLET TUBES: CORRELATING THE QUV AND THE UVCON BY David I! . Powers A THESIS Submitted to Michigan State University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE School of Packaging 1994 ABSTRACT THE PHOTODEGRADATIGN OF WOVEN POLYPROPYLENE USING ACCELERATED WEATHERINGIMACHINES WITH FLUORESCENT ULTRAVIOLET TUBES: CORRELATING THE QUV nan: TTUSlUVCIni BY David M. Powers This study explores the photodegradation that polymers experience when they are exposed to sunlight. Four different woven polypropylene fabrics used for bags were tested. The harmful ultraviolet rays were simulated using two different fluorescent weathering machines, under two different exposure conditions: a continuous ultraviolet light cycle without condensation, and a cycle consisting of 8 hours of ultraviolet light and 4 hours of condensation. After the fabrics were exposed to the harmful rays, tensile tests were performed to determine load strength. Correlation of the fabrics, machines, and test conditions was then established using linear regression. Positive correlation was determined between the machines, and test conditions. Overall, the amount of degradation was directly proportional to the length of ultraviolet exposure. The affect of a dark condensation cycle was determined to be statistically insignificant. Dedicated to my loving wife, Cindi, and daughter, Colleen. iii ACKNOWLEDGEMENTS Dr. Diana Twede, thank you for all of the advice, guidance, support, and pleasant leadership. Dr. Susan Selke, thank you for the technical advice you supplied, whenever it was needed. Dr. Charles Petty, thank you for increasing my knowledge while being a part of my committee. Dr. Houria Hassouna, thank.you for everything you did for me. Paul and Sandra Powers, thank you for everything. Special Thanks, to Phil and Mary Lynn, for the computer. Thanks to all my family and friends, for being so understanding during this time period. Thanks to MSU, the United States Department of Agriculture, Textile Bag Manufacturers, Q-Panel Company, and Atlas for making this research possible. iv TABLE OF CONTENTS LIST OF TABLES LIST OF FIGURES KEY TO ABBREVIATIONS AND NOMENCLATURE CHAPTER 1: INTRODUCTION Objectives CHAPTER 2: LITERATURE REVIEW DEGRADATION . . ULTRAVIOLET RADIATION TEST METHODS POLYPROPYLENE STABILIZATION CHAPTER 3: MATERIALS AND TEST METHODS MATERIALS . . ULTRAVIOLET TEST METHODS Sample Preparation Accelerated Weathering Tests Machine Comparison TENSILE TESTING . . Sample Preparation Tensile Tests . . STATISTICAL ANALYSIS OF DATA CHAPTER 4: RESULTS . . 8 HOUR UV - TEST 1 8 HOUR UV - TEST 2 . . CONTINUOUS UV - TEST 1 CONTINUOUS UV - TEST 2 RESULTS vs. CURRENT SPECIPICATION. T- TESTS . . COMBINED TESTS CORRELATION Correlation coefficient Fabrics Machines . Test Condition Equivalent Times ANOVA vii ix xii CHAPTER 5: SUMMARY AND CONCLUSIONS . . . . . . . . . . . 77 RECOMMENDATIONS . . . . . . . . . . . . . . . . . . 80 APPENDIX . . . . . . . . . . . . . . . . . . . . . . . . 82 LIST OF REFERENCES . . . . . . . . . . . . . . . . . . 188 vi 10 ll 12 13 14 15 16 17 18 19 20 21 LIST OF TABLES Fabric weight and yarns per inch Fabric thickness results Test Control (Original Fabrics) 8 Hour UV, Test 1 - Averages 8 Hour UV, Test 2 - Averages Continuous UV, Test 1 - Averages Continuous UV, Test 2 - Averages Fabric Rank by Retention T-test Results QUV (8 Hour UV) T-test Results - QUV (Continuous UV) T-test Results UVCON (8 Hour UV) T-test Results UVCON (Continuous UV) Load as a Function of Time (X) Linear Regression Correlations - Fabrics Linear Regression Correlations - Machines Equivalent test times ANOVA - 8 UV (Test 1) ANOVA - Continuous UV (Test 1) ANOVA - 8 UV (Test 1), Warp ANOVA - Continuous UV (Test 1), Warp ANOVA - 8 UV (Test 1), Fill vii 39 39 51 53 55 57 59 6O 63 63 64 64 67 7O 7O 73 82 83 84 85 86 22 23 24 25 26 27 28 29 3O 31 32 33 34 35 36 37 38 39 4O ANOVA - Continuous UV (Test 1), Fill ANOVA - 8 UV (Test 2) ANOVA - Continuous UV (Test 2) 8 Hour UV, 8 Hour UV, 8 Hour UV, 8 Hour UV, Continuous Continuous Continuous Continuous 8 Hour UV, 8 Hour UV, Continuous Continuous Test Temperatures Test Temperatures Test Temperatures Test Temperatures Test 1 Test 1 Test 2 TESL 2 UV, Test UV, Test UV, Test UV, Test QUV UVCON QUV UVCON 1 1 2 2 QUV UVCON QUV UVCON Test 1 (Test dates) Test 2 (Test dates) UV, Test 1 (Test dates) UV, Test 2 (Test dates) (8 UV - lst Test) (8 UV - 2nd Test) (Continuous UV - lst Test) (Continuous UV — 2nd Test) viii 87 88 89 9O 94 98 101 104 108 112 115 118 119 120 121 122 125 128 130 10 11 12 13 14 15 16 17 18 19 20 21 LIST OF FIGURES QUV, 8 Hour UV - Fabric A (warp) QUV, 8 Hour UV - Fabric B (warp) QUV, 8 Hour UV - Fabric C (warp) QUV, 8 Hour UV - Fabric D (warp) QUV, 8 Hour UV - Fabric A (fill) QUV, 8 Hour UV - Fabric B (fill) QUV, 8 Hour UV - Fabric C (fill) QUV, 8 Hour UV - Fabric D (fill) UVCON, 8 Hour UV - Fabric A (warp) UVCON, 8 Hour UV - Fabric B (warp) UVCON, 8 Hour UV - Fabric C (warp) UVCON, 8 Hour UV - Fabric D (warp) UVCON, 8 Hour UV - Fabric A (fill) UVCON, 8 Hour UV - Fabric B (fill) UVCON, 8 Hour UV - Fabric C (fill) UVCON, 8 Hour UV - Fabric D (fill) QUV, Continuous UV - Fabric A (warp) QUV, Continuous UV - Fabric B (warp) QUV, Continuous UV - Fabric C (warp) QUV, Continuous UV - Fabric D (warp) QUV, Continuous UV ~ Fabric A (fill) ix 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 4O 41 42 43 44 45 46 47 QUV, Continuous UV - QUV, Continuous UV - QUV, Continuous UV - UVCON, UVCON, UVCON, UVCON, UVCON, UVCON, UVCON, UVCON, Continuous Continuous Continuous Continuous Continuous Continuous Continuous Continuous 3322525 ‘2 Fabric B (fill) Fabric C (fill) Fabric D (fill) - Fabric A (warp) - Fabric B (warp) - Fabric C (warp) - Fabric D (warp) - Fabric A (fill) - Fabric B (fill) - Fabric C (fill) - Fabric D (fill) UVCON vs. QUV, 8 Hour UV - Warp UVCON vs. QUV, 8 Hour UV - Warp UVCON vs. QUV, Continuous UV — Warp UVCON vs. QUV, Continuous UV — Fill QUV (Continuous UV) vs. QUV (8 UV) - Warp QUV (Continuous UV) vs. UVCON (Continuous UV) vs. UVCON (Continuous UV) vs. 8 8 Hour Hour Hour Hour Hour Hour Hour UV- 3 35335! % % % % % % % Retention, Retention, Retention, Retention, Retention, Retention, Retention, QUV (8 UV) - Fill UVCON (8 UV) - Warp UVCON (8 UV) - Fill QUV - Test 1 (warp) UVCON-Test 1 (warp) QUV-Test I (fill) UVCON-Test I (fill) QUV-Test 2 (warp) UVCON-Test 2 (warp) QUV-Test 2 (fill) 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 48 49 50 51 52 53 54 55 56 8 Hour UV Continuous Continuous Continuous Continuous Continuous Continuous Continuous Continuous o\° 33333333 °\°0\°O\°0\° Retention, UVCON-Test 2 % % 0\° Retention, Retention, Retention, Retention, Retention, Retention, Retention, Retention, xi QUV - Test 1 UVCON - Test QUV - Test 1 UVCON - Test QUV - Test 2 UVCON - Test QUV - Test 2 UVCON — Test (fill) (warp) 1 (warp) (fill) I (fill) (warp) 2 (warp) (fill) 2 (fill) 179 180 181 182 183 184 185 186 187 QUV UVCON AVG STD lbf UV NA Warp (W) Fill (F) mil % Retention Cond Load Ext ° C irrad KEY TO ABBREVIATIONS AND NOMENCLATURE Accelerated weathering machine: made by The Q-Panel Company (Cleveland, Ohio) Accelerated weathering machine: made by Atlas Electric Devices Company (Chicago, Illinois) average standard deviation force (in pounds) ultraviolet light not applicable Parallel yarns, strung onto the loom first Interwoven perpendicular yarns 1/1000 of an inch Amount of original strength after tests Condensation (water cycle) measurement of force (in pounds) extension (in inches) degrees celsius irradiance xii CHAPTER 1 INTRODUCTION The purpose of this study was to compare two accelerated weathering machines using fluorescent ultraviolet (uv) tubes, under two different ultraviolet exposure conditions. The results were used to determine if either machine may be utilized to produce similar results, for a United States Department of Agriculture (USDA) specification for ultraviolet degradation resistance due to accelerated weathering. Four different woven polypropylene fabrics containing various stabilizers were used. The current USDA standard for degradation due to accelerated weathering, states that the fabric must maintain at least 70% of its original tensile strength after 200 hours of exposure to a carbon arc. However, carbon arc testing is costly and rarely performed. Most USDA fabric suppliers simply request that their resin be treated with enough ultraviolet stabilizer to meet the requirement. The USDA would like a less expensive quality control test. One objective of this study was to determine the amount of hours necessary to produce comparable results (e.g. how many hours would it take to reach 70% retention level with the QUV), for a new standard using fluorescent uv tubes. fl 2 The study investigated the photodegradation of woven polypropylene bags used by the USDA. The USDA is concerned with the stability of woven polypropylene bags, used to ship food, that may be stored outdoors. The USDA buys 40-60 million bags per year for use in its overseas food aid programs like those established under Public Law 480, Title II (U.S. Department of Agriculture 1954). One out of every seven Americans receive food assistance. The USDA is the world’s largest food buyer with over 70 million recipients overseas. This is the largest ongoing food assistance program that the world has ever known (Miteff 1993). Numerous studies have shown that ultraviolet light is the major cause of the degradation of polymers exposed to outdoor conditions. Heat, oxygen, humidity, and wetness can also contribute to degradation of polymeric fabrics. This study investigated the effects of continuous exposure of woven polypropylene fabrics to ultraviolet light (24 hour ultraviolet, no condensation cycle). This was done to establish correlation between continuous exposure to ultraviolet light, and a more common cycle used for testing (8 hour ultraviolet, 4 hour condensation) to enable a decrease in testing time. In addition, results from the two ultraviolet test machines (QUV supplied by Q-Panel and UVCON supplied by Altas Electric Devices Company) were compared. This study was requested by the USDA, and The Textile _— 3 Bag Manufacturers’ Association. The study was performed at Michigan State University (MSU), School of Packaging. The objectives of this study were to: 1. Compare the results for four different woven polypropylene fabrics. 2. Compare two accelerated weathering machines. 3. Compare two different exposure conditions. 4. Determine correlations between methods and machines. The major objective of this study was to determine whether there is a correlation between the two fluorescent accelerated weather machines and to recommend whether either machine could be used for quality control tests. Chapter 2 of this paper provides information pertaining to degradation of polymers, ultraviolet radiation, test methods, polypropylene, and stabilization methods. Chapter 3 describes the materials and test methods used in this study. Chapter 4 covers the results of the study. Conclusions and recommendations for further research can be found in Chapter 5. The appendix contains the experimental data. CHAPTER 2 LITERATURE REVIEW The use of polypropylene and other polymers in outdoor environments is increasing. However, when these polymers are exposed to harmful ultraviolet rays they will deteriorate rapidly unless stabilizers are added to prolong their lifetimes. Degradation can be affected by a number of circumstances; the primary factors are the wavelength of light, heat and moisture. The major mechanisms involved in polymer degradation are random chain scission and cross- linking. The ultraviolet rays in the 290-400 nanometer region have been shown to be the most energetic and damaging wavelengths of light. The damaging effects of photodegradation on a polymer’s mechanical and physical properties have lead to improved test methods in the area of photodegradation. Advances in polymer stabilization have also been a result of improved knowledge of the damaging effects of ultraviolet rays. This section reviews the literature pertaining to degradation, uv radiation, test methods, polypropylene, and stabilization. DEGRADATION Degradation that polymers experience while being used in outdoor environments leads to the loss of desired properties. "Photodegradation refers to the degradation of polymeric substances and other organic compounds when exposed to sunlight and other intense sources of light. The ultraviolet wavelengths are primarily responsible for the observed damage." (Plastics, Environmentally Degradable 1984) Oxidative degradation, which nearly all polymers undergo, is the degradation of polymeric chains through attack by oxygen and ozone. Oxidative degradation may be catalyzed by ultraviolet light, catalyst residues, or both (Plastics, Environmentally Degradable 1984). Nomenclature used to describe photosensitized reactions can be applied as follows: Photoinitiator is a compound which absorbs light and is excited by it to a higher energy state having a total energy content in excess of that required to effect a homolytic scission of some bonds in polymer molecule to form free radicals, which promote secondary reactions. Photosensitizer is a compound which by absorption of light is transferred to excited states and then donates the energy to another compound by inter- or intramolecular energy transfer. Photosensitized reactions are strictly speaking such reactions which are activated by photoinitiators or photosensitizers. (Rabek 1976) A chemical may behave as a photoinitiator or a photosensitizer, depending on the conditions of a particular reaction. 6 A major concern when using plastics is premature failure and possible product contamination (Johnson 1988). Unstabilized polyolefins are destroyed rapidly in sunlight which has limited their long—term use out-of—doors (Scott 1976b). Plastics must be able to provide their desired properties throughout their expected lifetime. These properties include chemical resistance, impact strength, tensile strength, modulus of elasticity, and other mechanical properties. Plastics must also be stable in order to eliminate package-to-product migration, which could result in product contamination. Photodegradation of polymers has become a concern because of their increased use in outdoor applications, including bags for agricultural commodities, carpeting, synthetic turf, agricultural film, and ring connectors for beverages. The United States Department of Agriculture, is concerned about the durability of woven polypropylene bags used to ship food to famine and disaster areas, where bags may be stored outdoors for a short period of time (Miteff 1993). In some cases, degradable plastics have become popular because plastic products are among some of the most visible forms of trash (Klemchuk 1989). Degradable plastics are plastics that deteriorate at a rate which is more rapid than normal while maintaining indoor stability for long time periods. Plastic ring connectors for beverage bottles are 7 now required to be degradable by law in some states. This law was developed to help prevent wildlife from being entrapped in the ring connectors. Other applications of degradable plastics that have been developed or proposed include shopping bags, trash bags, garbage bags, produce and fruit bags, snack bags, bread bags and frozen food bags. The problem with these applications is that if the packaging material is disposed of properly, for example, by being incinerated or buried in a landfill, the benefit of being photodegradable is not utilized. The photodegradability of the material is only a societal benefit if the packaging material is improperly discarded as litter (Plastics, Environmentally Degradable 1984). All synthetic polymers deteriorate upon exposure to ultraviolet light (Carlsson and Wiles 1976; Guillet 1972; Seppala, et al 1991; Wiles 1978; Tirrell 1981). These polymers can be classified into two groups with respect to their changes upon absorption of the harmful rays. The first category includes polymers such as polyvinyl chloride and polyacrylonitrile which tend to retain their physical properties but discolor rapidly. The discoloration is mainly a result of changes in the chemical structure of the polymer, but scission does not occur in the backbone of the polymer chain. The second category includes polymers such as polypropylene, polyethylene, and polystyrene which tend to embrittle after the absorption of ultraviolet light. E S. O C. U. r .3 8 Embrittlement can be caused by any one or a combination of the following (i) scission of the main chain, (ii) photoinduced crystallization, and (iii) crosslinking (Guillet 1972). Some of the effects of photodegradation include yellowing, bleaching, bond cleavage, destructive oxidation, charring, crazing, chalking and the loss of physical properties. Sunlight causes yellowing and weakening of fibers, which results in brittleness and loss of strength (Hardy 1983a). Bleaching is most common in the long wavelength region and in thick specimens; yellowing is more common in the short wavelength region. Yellowing, which is the result of short wavelength irradiation, tends to be destroyed by energy in the long wavelength region (Hirt and Searle 1967). Long wavelength radiation penetrates the bulk of the polymer, while short wavelength radiation will have a greater effect on surface properties (Searle 1984). Greying or whitening of the surface is an occurrence generally referred to as chalking. Chalking is independent of the degraded upper layer depth; this phenomenon depends on the concentration of exposed filler particles that reflect the incident light (Rysavy and Tkadleckova 1992). The excellent properties of plastics result from their long molecular chains. When photodegradable plastics are exposed to sunlight their molecular chains are cleaved and the plastic articles lose desired properties. Discoloration and surface 9 cracking are visible indications of degradation (Hawkins 1984b, Johnson 1988). Environmental stress cracking is a special type of degradation which occurs in polymers at a stress concentration lower than the polymer’s ultimate strength. This phenomenon occurs at critical stress levels with certain surface-active agents (Hawkins 1984a). Factors influencing the degradation of polymers include natural weather conditions, thermal history, and the physical form of the polymer. The major factor responsible for the degradation of plastics is ultraviolet radiation. Heat is primarily responsible for secondary reactions. Measurement of degradative effects at high temperatures does not always reflect the conditions found at lower temperatures. Oxygen, humidity, and wetness can also influence reactions (Hirt and Searle 1967, Freedman 1976, Swasey 1980). Atmospheric contaminants, including oxides of sulfur and nitrogen, have been suggested to catalyze oxidation (Hawkins 1984a). Geography can influence degradation because of variations in weather conditions. For example, exposure in Arizona, where there are more sunlight-hours per year, would be more destructive than exposure in New Hampshire (Swasey 1980). A polymer's thermal history has been shown to have a marked effect on its subsequent photostability (Crewdson 1993, Rabek 1976). If processing periods are extended, 10 substantial amounts of hydroperoxides may develop which can serve as initiators in the degradation of polypropylene (Hardy 1982). Therefore, while processing plastics it is critical to minimize the formation of radicals that may serve as photoinitiation sites. Drawing of polymers under high shear conditions (high draw speeds and low temperatures) produces appreciable amounts of hydroperoxide groups, which increases the rate of degradation. These hydroperoxide groups result from mechanically induced thermal oxidation (Carlsson, Garton and Wiles 1979). The physical form and chemical makeup of the specimen can influence the degradation of a polymer. The rate of hydrogen abstraction from hydrogen chains increases in the order of primary < secondary < tertiary bonded. This order is the same regardless if the attack is by singlet oxygen or a free radical process because it is due to the strength of the C-H bond being broken (Ranby and Rabek 1976). Primary bonds occur when a carbon atom is attached to one other carbon atom; these bonds appear at the end of a polymer chain, secondary bonds occur when a carbon atom is attached to two other carbon atoms, and tertiary bonds occur when a carbon atom is attached to three other carbon atoms. Polypropylene's structure contains many tertiary carbon atoms and linear polyethylene contains primarily secondary carbon atoms; this results in polypropylene being more susceptible to degradation than polyethylene. 11 Experimental results have shown that the wavelength having the maximum effect on a polymer is dependent on the sample thickness, decreasing as the sample thickness decreases (Hirt and Searle 1964). Since the degradation of polypropylene proceeds from the exposed surface inward, it is expected that thicker samples will survive longer than thin samples (Hardy 1982, McTigue and Blumberg 1967). The shape of a polymer may also influence degradation. "Curved surfaces are much more susceptible to initiation of degradation and cracking than flat surfaces." (Swasey 1980) Polymer morphology (i.e. crystallinity, orientation, etc.) can effect the photodegradation of polymers. Improvement in light resistance due to orientation is not completely understood, but it may be attributed to a combination of increased transparency, more uniform crystalline order, and reduced oxygen permeability (Carlsson and Wiles 1976, McTigue and Blumberg 1967). The number of degradation reactions that will result from a single quantum of ultraviolet radiation is a function of the chain length, which is an attribute of each respective polymer. The major mechanisms involved in the photodegradation of polymers are cross-linking and chain scission reactions. Most degradation processes begin with cross-linking reactions. However, chain scission (C-C bond destruction) becomes more prevalent as sites for C-H scission decrease (Bremer 1982). "Chain-scission reactions generate free 12 radicals, hydroperoxide groups form, and volatile products such as aldehydes, esters, ketones, alcohols, and hydrocarbons are produced in addition to cellulosic monomers and oligomers" (Plastics, Environmentally Degradable 1984). Chain-scission reactions shorten molecular chains rapidly, while cross-linking lengthens the molecular chains. When photodegradable polymers are exposed to sunlight, bond cleavage and destructive oxidation occur, resulting in decreases in molecular weight and consequently a shortened service life of the plastic (Hardy 1983a). For polypropylene, the primary photoinitiation steps all involve backbone scission. However, in the absence of oxygen, polypropylene’s mechanical properties do not deteriorate appreciably (Carlsson and Wiles 1976). Free-radicals are formed in many reactions and are then responsible for the initiation of degradation and cross-linking of polymers. Some of the major free-radicals that have been studied include aliphatic ketones, ethers and peroxides (Rabek 1976). The main mechanisms in the photodegradation of polymers are Norrish Type I and Norrish Type II reactions. Norrish Type I reactions involve free radical production, which lead to further reactions, and random chain scission. There is also cleavage of molecular chains which results in very rapid reduction of molecular weight. In Norrish Type II reactions there are not any free radicals produced, but 13 there is random chain scission, leading to a rapid reduction in molecular weight. Ketone carbonyl is the main product formed in the initial stages by Norrish II photolysis (Scott 1976a). The quantum yield for Norrish type II reactions depends on the polymer’s chain length and whether the ketone carbonyl group is in a side chain or in the main chain of the polymer (Plastics, Environmentally Degradable 1984). Cross-linking is possible in both types of reactions. Degradation may be initiated in some polymers by the absorption of ultraviolet radiation through their normal structure, but frequently it is the presence of structural irregularities or associated impurities that are the primary ultraviolet absorbers (Hawkins 1984a). Degradation is the result of energy that is absorbed by chromophoric groups in polymers. This energy is then available for cleaving bonds. Unsaturated structures (structures containing double bonds) are more susceptible to degradation than saturated structures. Chromophoric groups may be introduced during manufacture, processing, or environmental exposure. Catalyst residues (e.g. titanium, aluminum, and chlorine) and carbonyl groups are common chromophores that may be introduced during the manufacturing of polymers to enhance degradation. Carbonyl groups absorb energy in the 270 to 360 nanometer range, (Hutson and Scott 1974, Johnson 1988). In polyolefin films the percent of carbonyl formation can be used to predict brittleness. 14 Hydroperoxides, peroxides, reactive forms of oxygen (ozone and singlet oxygen), and polynuclear aromatic compounds (PNA) may also be introduced during processing and environmental exposure. Charge transfer complexes (CTC), which are formed between oxygen and polymeric substrates, have been considered as possible sources of photoinitiation for polypropylene (Gugumus 1979, Wiles 1978). Energy transfer reactions are believed to have an important role in the formation of singlet oxygen. This occurs because energy is added to the molecule enabling it to change its molecular configuration (Ranby and Rabek 1976). Van der Waals interactions and quinones are also capable of sensitizing reactions important in polymer degradation mechanisms. All commercially important polymers undergo reactions with oxygen, eventually leading to changes in molecular structure (Guillet 1972, Hawkins 1984a). The mechanism for photo-oxidation begins with the formation of a polymer-chain radical. This is initiated by ultraviolet exposure, mechanical shear, or chemicals such as peroxides, singlet oxygen, or ozone. The radical then forms polymer peroxides and hydroperoxides by reaction with oxygen (Carlsson, et al 1981; Cicchetti 1970; Gabriele, et al 1984; Plastics, Environmentally Degradable 1984). As with photodegradation, intensive photo-oxidation takes place mainly on the surface of the polymer, in a boundary region between a completely degraded upper layer and the unexposed polymer (Rysavy and 15 Tkadleckova 1992). The effects of photo—oxidation are similar to those of photodegradation, for example, loss of mechanical properties and embrittlement. ULTRAVIOLET RADIATION As stated earlier, ultraviolet radiation is responsible for most of the damage to photodegradable plastics. The extent of damage is influenced by contaminants and the activation spectrum for the specific polymer. Energy in the 290-400 nm region consists of only about five percent of the total energy reaching the earth, but it is responsible for most of the damage caused by sunlight (Guillet 1972, Hardy 1983a, Swasey 1980, Tobin and Vigeant 1981). However, these wavelengths do not appreciably penetrate window glass (Johnson 1988). The only requirement involved in the degradation process is that the energy absorbed must be great enough to break the chemical bonds. Therefore, if the energy absorbed is greater than the bond dissociation energy for a specific polymer, degradation will be initiated. Sunlight induced changes in plastics may very well include chemical alterations in side groups (Cooney and Wiles 1973, Hawkins 1984a). The intensity of ultraviolet radiation being absorbed by the material will determine the rate at which chemical bonds are broken. Some variables that will influence the intensity of l6 ultraviolet light include altitude, latitude, seasons of the year, and atmospheric contaminants. Local weather conditions, including smoke, dust, fog, haze, and clouds may affect ultraviolet intensity (Hirt and Searle 1967, Zerlant 1982). Finally, atmospheric contaminants, such as air pollution and oxides of sulfur and nitrogen, may influence the intensity of ultraviolet wavelengths. An activation spectrum represents the direct response of a material to the wavelengths emitted from the source, for a specific degradation measurement (e.g. yellowing, carbonyl formation, cross-linking, or bond scission). The absorption properties of the material are very important in determining the activation spectrum (Searle 1984). An activation spectrum can also be defined as the "wavelength sensitivity" of a polymer may be described as the extent of photodegradation as a function of incident wavelength (Hirt and Searle 1964). Another factor in determining the activation spectrum is the relationship between the bond strength of the material and wavelengths absorbed. The type of degradation being measured (i.e. yellowing, carbonyl formation, crosslinking, or scission) will also influence the activation spectrum of a material (Searle 1984). Activation spectrums can be useful in the determination of appropriate light absorption requirements. This can be especially useful in the selection of proper stabilizers for photodegradable polymers. The relative effectiveness of l7 stabilizers may be estimated based on the match of their spectral characteristics with the activation spectrum. An activation spectrum can also be useful in the selection of accelerated weathering devices and in monitoring actinic radiation. This helps in establishing better correlation among tests as well as predicting lifetimes (Searle 1984). Polypropylene’s activation spectra maxima is approximately 310, and 370 nanometers (Hawkins 1984a, Hsuan and Koerner 1993, Searle 1987). It should also be noted that in no case is there a complete understanding of how photons interact with a polymer. This is due to the complex physics and chemistry involved and because of the fact that polymers are not pure compounds (Wiles 1978). The effects of ultraviolet radiation on polymers were previously discussed in the degradation of polymers section, for example: discoloration/fading (yellowing), weakening of fibers (embrittlement), bond cleavage, charring, crazing, etc. TEST METHODS The fundamental parameters of weathering tests are light, heat and moisture. Materials will respond differently depending on the intensity and combination of these parameters (Crewdson 1993). The major test methods for photodegradation of polypropylene include indoor tests using accelerated conditions and outdoor exposure tests. 18 Tests may be classified as either design or materials tests. Design tests are used to measure the useful life of polymers as they function in an actual device or design. These are the types of tests used to provide information for design engineers. Design tests take all external environmental factors into account as well as all other components that may have an adverse (or beneficial) effect on a polymers stability. Materials tests evaluate only the stability of polymer test samples without consideration of how the polymer samples will perform in a final product (Hawkins 1984b). Accelerated testing is necessary for estimating the useful life of polymers because testing under use conditions is time consuming and natural weathering involves many variables. Accelerated testing has the advantage of much closer control over variables and reduced time of testing (Freedman 1976). Testing is really the only way to determine how stabilizers will improve a polymer’s performance under the damaging effects of ultraviolet light. There are four instruments used to produce artificial sunshine; these include carbon arcs, fluorescent lamps, xenon arcs, and mercury arcs. Carbon arcs give a close approximation to sunlight at short wavelengths (Hirt and Searle 1967). Carbon arcs generate a considerable amount of heat. Therefore, their design may include a baffle that will shield the test 19 samples, or a water spraying device to reduce the effects of this heat. However, carbon arcs have strong emission peaks in the actinic region (violet and ultraviolet parts of the spectrum which are photochemically effective) that are not present in sunlight and may distort results (Hardy 1983b, Hirt and Searle 1967, Searle 1987). These emission peaks in the long wavelength region, of the ultraviolet spectrum, (350-396 nm) will be responsible for most of the degradative effects (e.g. color change and embrittlement) when testing polymers with a carbon arc light source (Searle 1987). Fluorescent lamps are more intense than sunlight in the short wavelength region (below 313 nanometers), but are less intense than sunlight in the long wavelength region (above 313 nanometers). Ultraviolet absorption of clear plastics increases gradually with decreasing wavelengths. As a result, degradation should increase as the short wavelength energy increases. Therefore, fluorescent lamps will have a stronger effect on clear plastics than either sunlight or carbon arcs (Hirt and Searle 1967). The xenon arc’s spectral distribution comes closest to matching natural sunlight in the ultraviolet region (Freedman and Diamond 1976, Hardy 1983b, Hirt and Searle 1967). Xenon arcs are normally preferred over carbon arcs in lightfastness tests. Xenon arcs utilize water for cooling test samples, and filters to reduce the short wavelength emission of the arc. 20 Mercury arcs are comparable to fluorescent lamps in the short wavelength region (below 320 nanometers), but in the long wavelength region they are stronger than fluorescent lamps (Hirt and Searle 1967). Wetting of samples during ultraviolet tests may have two effects. First, wetting can accelerate degradation if the material is sensitive to the synergistic effects of temperature, moisture and sunlight. Second, wetting can cause thermal shock, reducing surface temperatures as much as 25 °C, resulting in physical stresses which can also contribute to accelerating the degradative process. The advantages of wetting include enhanced ability to repeat test, and thermal shock to test samples at peak temperature periods (Searle 1987). The ultraviolet spectrum can be divided into three regions: (i) UV-A region (315 to 400 nanometers), (ii) UV-B region (280 to 315 nanometers), and (iii) UV-C region (below 280 nanometers). Fluorescent lamps are usually categorized depending on the region where most of their output falls.w UV-B lamps include the shortest wavelengths found in sunlight at the earth’s surface. Most of their output is in the UV-B region, but they do have some output in the UV-A and visible regions. UV-A lamps include the longer wavelength spectrum and are especially useful for tests comparing generically different types of polymers. These lamps give enhanced 21 correlation with actual outdoor weathering but they do not emit radiation below the normal solar cutoff of 295 nm. Therefore, they usually do not degrade materials as fast as UV-B lamps. The majority of UV-A lamps’ energy is in the UV-A region, with a small amount in the UV-B and visible regions (A Choice of Lamps for the Q-U-V). The choice of lamps used in lightfastness tests is critical because differences in lamp energy output or wavelength spectrum can cause significant differences in test results. Most weathering tests call for machines to be operated at irradiance levels comparable to average optimum sunlight (Crewdson 1991). But, artificial sunlight can be used to accelerate degradation in two ways; first, the intensity of the wavelengths found in sunlight can be increased; and second, wavelengths of shorter frequencies than those found in sunlight can be used. However, raising the irradiance level and changing the spectral power distribution of the radiation source will cause variation in test results (Crewdson 1993). Correlation of test results has been performed a number of ways. Pearson's method of correlation can be used as a measure of the linear relationship between test samples. Alternatively, "Spearman’s method assigns a rank to each material, based on the amount of degradation, and compares ranks between the test methods under consideration" (Crewdson 1993). 22 After initial polymer degradation studies have been completed using accelerated testing indoors, outdoor testing may be performed to give a more accurate prediction of polymer performance. The purpose of outdoor weathering tests is to determine any one or a combination of the following: to provide statistical data for prediction of the influence of weathering on material properties, as a quality control technique, or to ascertain the weathering characteristics of materials (Zerlant 1982). Outdoor weathering is important because it is estimated that at least 25% of all plastics are exposed to weathering in outdoor environments (Freedman 1976). Outdoor weathering environments should match the conditions of end use, and diagnostic tests should be selected for the most accurate measurement and assessment of the degradation effects which most significantly affect the choice of materials for utilization in a specific environment (Zerlant 1982). Outdoor exposure tests are normally performed in either Florida or Arizona. Samples are exposed to two different sets of conditions at these sites: humidity is high in Florida and low in Arizona. Both of these locations provide high amounts of incident radiant energy from the sun (Hardy 1983b, Hawkins 1984b). Data obtained from outdoor tests includes amount of energy (langleys or ultraviolet sun hours), relative humidity, temperature, and hours of exposure to sunlight. 23 The main disadvantages of outdoor testing are that the time required for initial studies is too long, and the interruption of solar radiation during the night hours makes reaching the failure point in well-stabilized polymers difficult. Ultraviolet radiation is more intense in the summer months than in the winter months. This is due to the fact that there are more daylight hours, latitudes are lower, and ozone concentration is lower, which results in more intense radiation. Even at a constant level of total incident radiation, degradation proceeds faster in the summer than in the winter. Tests that begin in the winter will have about two times the life expectancy as those started in the summer (Zerlant 1982). Variations in exposure conditions may be material dependent. For example, black samples get hotter than white samples and fabrics will remain wetter longer than coatings (South Florida Test Service). There are a lot of uncontrollable variables in outdoor exposure tests, which makes accelerated testing necessary to provide initial degradation results. After polymeric samples have been exposed to harmful rays (real light, fluorescent, xenon, etc.), a method is needed to judge degradation. Methods include: infrared spectrophotoscopy, tensile tests, and colorness tests. Other tests, such as gel permeation chromatography, melt flow index, electron spin resonance, differential scanning 24 calorimetry, thermal gravimetric analysis, and thermal volatization analysis may also be useful. Infrared spectrophotometers are used to monitor chemical changes, such as carbonyl content, ultraviolet absorption, and yellowing (Freedman and Diamond 1976; Allen, et a1 1991; Subowo, et al 1986). Infrared spectrophotoscopy is especially useful in studying hydrocarbon polymers because they do not contain interfering oxygen compounds (Freedman and Diamond 1976). Infrared spectrophotoscopy is commonly used to measure increase of carbonyl content for a polymer in a given region (e.g. the carbonyl region is approximately 1750-1690 cm“). Tensile tests can be performed to determine the tensile properties of a polymeric material. These stretchiness tests and tests to determine elongation at break can be used to determine the effects of sunlight on the polymer’s mechanical properties (Gonzalez, et a1 1989; Hardy 1982, Love 1984, Pouncy 1985). The major property that is evaluated when tensile tests are performed is the force (in pounds = lbf) required to reach a polymers yield point. Colorimeters can be used to determine the yellowness index for a polymer (Searle, et al 1989). Color changes can also be determined by comparison with color standards. Electron Spin Resonance (ESR) spectroscopy may be used to give an indication of stabilizer changes (Bauer, et al 1992; Carlsson, et a1 1978). 25 Gel Permeation Chromatography (GPC) can be used to determine changes in a polymer's molecular weight and molecular weight distribution. Knowledge of a polymer's molecular weight can be useful in determining mechanical properties (e.g. elongation and tensile strength). Molecular weight averages are beneficial because they allow packaging engineers to determine properties such as flex life, stiffness, brittleness, flow properties, extrudability and molding properties. A polymer’s melt flow index can be measured and used to indicate thermal oxidative stability (Amin and Scott 1974, Bremer 1982). Melt flow index values are normally reported in grams/10 minutes. Differential Scanning Calorimetry (DSC) can be used to determine the melting point and heat of fusion for a polymer, which is useful in determining percent crystallinity. Crystallinity can be used to determine a polymer's structural/ stereochemical regularity. Properties affected by crystallinity include: modulus, impact strength, tensile strength, orientability, and brittleness. Thermal gravimetric analysis (TGA), which measures weight loss, may also be used to analyze degradative effects. TGA is conducted in a high vacuum or in an inert atmosphere and is widely used as a test to determine a polymer’s stability to heat (Hawkins 1984b). Thermal volatization analysis (TVA) measures pressure 26 developed by volatile products. A Pirani gauge is used to indicate small pressure changes (Hawkins 1984b). Pyrheliometers can be used to measure the intensity of sunlight in many outdoor locations. The intensity of light is usually reported in either langleys (g-cal/omfi cur "ultraviolet sun hours." Ultraviolet sun hours are measured as the number of hours for which the intensity is greater than a value of 0.823 langleys/min on the samples (Hirt and Searle 1967). When using accelerated tests to evaluate a polymer’s stability, interpretation of results must proceed with caution. The intensity of sunlight expressed in units such as langleys or "ultraviolet sun hours" does not truly measure the actinic radiation. For successful correlations of exposure test data, continuous monitoring and integrating of the activation spectrum is desirable (Hirt and Searle 1967). In the evaluation of test results, it is very important to realize that the results obtained in accelerated tests may be different than the results occurring in the environment in which the plastic will be used. Acceleration of only the primary process by increasing irradiation intensity alone can distort results even if the spectral distribution is maintained constant (Hardy 1982, Hirt and Searle 1967). Accelerated tests should take into account every factor that contributes to degradation under use conditions. The applicable factors 27 should also be present proportional to their existence in the real environment (Hawkins 1984b). Problems associated with accelerated testing are believed to result from changes in light intensity (Io) of photo-oxidation process for different ultraviolet stabilizer mechanisms. For example, the light intensity for a ultraviolet absorber may be L35, whereas the light intensity of a radical scavenger may be Igh° (Carlsson, et al 1979). Other problems include varying ratios of wavelengths emitted from light sources, and the fact that UV irradiation is a surface phenomenon, while classic mechanical tests such as tensile strength and elongation at break are essentially bulk measurements (Gonzalez, et a1 1989). POLYPROPYLENE Pure polypropylene, if saturated, should be transparent to terrestrial sunlight. Therefore, photodegradation must be the result of impurities in the polymer. Hydroperoxide groups which form during the manufacturing process are the main absorbing groups in polypropylene (Hardy 1983b). Aromatic ketones have also been reported to accelerate the photo-oxidation of polypropylene. Other species believed to accelerate the photodegradation of polypropylene include carbonyl groups, transition metals (iron nickel, copper, and chromium), charge transfer complexes, endoperoxides, ozone 28 and singlet oxygen (Gugumus 1979). The major reactions in the photodegradation of polypropylene are surface reactions. Photo-oxidative changes are confined largely on or near the surfaces of the polypropylene film up to the stage of brittleness (Cooney, et al 1973). The depth of the reactions and degradation depends on the structure of the polymer, the wavelength of light, and additives that may be introduced into the polymer. Polypropylene degradation is primarily a result of a free-radical reaction. Initiation occurs by random scission in the main chain. Radicals that are formed undergo transfer reactions most readily at tertiary carbon atoms (Grassie and Leeming 1976). Polypropylene does not show any significant evidence of optical deterioration. Long before the material yellows, it deteriorates physically showing cracks and scratches due to ultraviolet irradiation (Hirt and Searle 1964). When evaluating the degradation of polypropylene, one must be careful because before physical changes are evident, changes in ultraviolet absorption can be detected. Polypropylene degradation can be measured by examining carbonyl content, using infrared spectrophotometry. Changes in physical properties can be evaluated by doing tensile tests, most commonly with an Instron machine. Degradation can also be determined by measurement of UV 29 spectra, phosphorescence, color change, or physical properties such as impact strength (Hardy 1983b). Polypropylene is one of the easiest polymers to make photodegradable because its molecular structure makes it susceptible to oxidative attack. Polypropylene can be made to degrade in days outdoors, while showing negligible physical changes after many months indoors (Cooney, et al 1973). Polypropylene’s crystalline nature leads to complex morphology or microstructure in fabricated articles. Crystallite size, degree of orientation, and density can be influenced by temperature, rate of cooling, and rate of filling the mold. Orientation apparently reduces the loss of ultraviolet stabilizers. Improvement in light resistance due to orientation is not completely understood, but it may be the result of increased transparency, more uniform crystalline order, and reduced oxygen permeability (McTigue and Blumberg 1967). Polypropylene is used in the packaging industry because it has excellent physical properties, chemical resistance, good processability, and low cost. Some of the uses for polypropylene include indoor-outdoor carpeting, stretch tapes, r0pe, twine, bag fabric, chain webbing, and artificial grass (Hardy 1982). The major problem in using polypropylene outdoors is that it is susceptible to photo- oxidative attack. However, the excellent properties can be 30 utilized outdoors by the addition of effective stabilizers. For example, woven polypropylene is stabilized for use in sandbags. STABILIZATION In order to properly stabilize polymers, their mechanisms of photodegradation must be understood at the molecular level. In short, the purpose of stabilization is to allow polymers to be useful for their desired lifetime under adverse conditions. The basic categories of stabilization are preventive and arrestive. A preventive measure results in the production of a more stable polymer. In order to produce a more stable material (internal stabilization), monomers that are higher in purity can be used. Arrestive stabilization can be achieved by the removal, neutralization, or inactivation of potential degradation sources that accumulate in a polymer. The primary method is to introduce reactive species into the polymer (external stabilization). However, stabilizers may also be built-in to the polymer chain (Klein 1983). The major factor in selecting a stabilizer is the initiation mechanism for the degradation of a specific polymer. This can be a problem because synthetic polymers break down by a variety of mechanisms and the reactions frequently involve the presence of moisture, oxygen and/or 31 pollutants (Guillet 1972). The selection of ultraviolet stabilizers should also take into account the activation spectra maxima in order to provide the greatest level of protection. This will allow protection against the most damaging frequencies for the polymer. Some of the desirable stabilizer characteristics include high light stability, high thermal stability, diffusability, resistance to extraction by water, low color, low toxicity, minimal adverse effects on the polymer's properties, and low costs (Hardy 1983b). The early approaches to achieve stabilization can be characterized as using coatings Opaque to harmful radiation. This was not a good approach because of adhesion problems and coating and application costs (Hardy 1982). Today stabilization is achieved, in several different ways, by incorporating additives into the bulk of the polymer. Advances in surface treatment and/or primer coats have solved the adhesion problems with surface coatings, enabling them to adhere to the top coat of polypropylene and provide exceptional protection against damaging ultraviolet rays. For example, polypropylene that was coated with a white pigmented nitrocellulose-acrylic lacquer, showed no evidence of surface damage after a full year of exposure in Florida (McTigue and Blumberg 1967). The general types of photostabilizers can be classified l'l 32 as ultraviolet screeners, ultraviolet absorbers, excited state quenchers, free radical scavengers and/or hydroperoxide decomposers. Ultraviolet light Screeners are opaque additives or pigments that reflect or absorb radiation before it reaches the polymer surface, limiting penetration into the bulk of the polymer material (Hardy 1982). Carbon black is the most common ultraviolet screener. The effectiveness of ultraviolet screeners strongly depends on their dispersion in the polymer matrix (Klein 1983). Some white pigments, such as titanium dioxide, are also used as ultraviolet screeners. Sometimes colored pigments are used, but they are not as powerful as white pigments. However, ultraviolet screeners have been limited in use because of their adverse effect on other additives, contribution of color, or opacity (Hardy 1983a). Ultraviolet light absorbers are stabilizers that function by preventing the light from being absorbed by the photoactive impurities or structural units in the polymer (Hardy 1982). The ultraviolet radiation is absorbed and harmlessly dissipated. 2-hydroxybenzophenones and 2-(2- hydroxyphenyl)-benzotriazoles are the most widely used ultraviolet absorbers. These stabilizers exhibit excellent performance in thick sections. Their efficiency as ultraviolet stabilizers has been attributed to an extremely fast non-radiative decay from the first excited singlet 33 state to the ground state (Gugumus 1979). In the selection of absorbers for photodegradable polymers it is important to note that the effectiveness of the absorber is predictable and should change as a function of the concentration. Experimental results have shown that the effectiveness of the absorber varied as the square root of the change in concentration. For example, to double the life, the absorber concentration should be quadrupled (McTigue and Blumberg 1967). Excited state quenchers function by the abstraction of excited state energy from a polymer molecule through energy transfer (Hardy 1982). These stabilizers deactivate excited chromophores before degradation occurs. Quenchers are effective in thin or thick materials; nickel complexes and benzoates are most common. The effectiveness of nickel complexes can be attributed to quenching carbonyl triplet states or oxygen singlet states (Amin, et al 1974). Free radical scavengers and/or hydroperoxide decomposers function by radical scavenging or by decomposing hydroperoxides. The stabilizers used for this type of stabilization must be stable to ultraviolet light (Hardy 1982). Metal complexes, such as nickel oxime chelates, transition metal dithiocarbamates, and transition metal phosphates are most common. Some of these chelates are more effective as light stabilizers than the 2- hydroxybenzophenones. Peroxide decomposing stabilizers 34 produce a minimal amount of photosensitizers during processing, which makes them effective ultraviolet stabilizers (Scott 1976b). Free radical scavenging is the main step used by phenolic antioxidants in protecting polymers against thermooxidative degradation (Gugumus 1979). Antioxidants can be classified into two main groups which are distinguished according to their mode of action: primary or chain-breaking, and secondary or preventive antioxidants (Klein 1983). Chain breaking antioxidants interfere with the chain propagation steps of photooxidation. Hydrogen donors are the most common chain breaking antioxidants, they function by donating hydrogen atoms to polymer radicals. Preventive antioxidants interfere with the initiation steps of oxidation. Antioxidants can be added to polyolefins to help provide melt stability during processing (Scott 1976b). Hindered amine light stabilizers (HALS) are new antioxidants which have displayed exceptional performance. Many of the HALS are based on 2,2,6,6-tetramethylpiperidine, but they do not exhibit near ultraviolet absorption or excited state quenching (Carlsson, et al 1984). HALS are believed to function similarly to ultraviolet stable antioxidants and are effective in either thick or thin materials. They are oxidized to the appropriate radicals, and function by scavenging free radicals. HALS performance may be improved by the addition of antioxidants, creating a 35 synergistic effect. In most cases, HALS outperform other light stabilizers, such as ultraviolet absorbers and excited state quenchers (Gugumus 1989). However, HALS have been shown to be effective only after a certain level of hydroperoxide concentration has been achieved. In the stabilization of polypropylene, systems may contain one or more UV light stabilizers, an antioxidant (hindered phenol), and a hydroperoxide decomposer (phosphite or thioester) (Hardy 1982). A stabilizer’s performance depends upon the polymer that it is being used in, the polymer’s form, and any other additives that may be present. Combinations of antioxidants with light stabilizers can lead to synergistic or antagonistic effects. Copolymers have also been used to attain synergistic effects and improve processing characteristics (Grassie and Leeming 1976). Some of the problems that occur in the stabilization of polymers are leaching and migration of the stabilizer to the polymer's surface. Ultraviolet screening agents may be lost by evaporation or leached out (Gupta, et al 1981). "The solubility of the stabilizer in the matrix is often less than the minimum effective concentration, leading to stabilizer migration, and exposure to solvents and/or high temperatures in processing or in use can accelerate stabilizer loss." (Tirrell 1981). In the future, stabilizer systems will become more complex in order to maximize 36 polymer lifetimes. Polypropylene is a very useful polymer for the packaging industry. The fact that polypropylene deteriorates very quickly when exposed to ultraviolet light has lead to the development of stabilizers. When stabilizers are added to polypropylene, and other polymers, their desired properties can be maintained as needed in outdoor environments. In the future, better and more efficient stabilizer systems will emerge as more studies are performed on the photodegradation of polymers. Stabilization of polymers will be enhanced because the initiation mechanisms that lead to photodegradation will be better understood. CHAPTER 3 MATERIALS AND TEST METHODS The materials and test methods section of this paper will be divided into four parts: materials, ultraviolet test methods, tensile test, and statistical analysis of data. MATERIALS There were four different woven polypropylene fabrics used in the study. Fabric A, fabric B, and fabric C are currently used by the USDA. The three resins were certified by their manufacturers to have adequate ultraviolet stabilizers to meet the 200 hour carbon arc test requirement. The fourth fabric (fabric D) did not contain any uv stabilizer. The yarns per inch for each fabric was obtained by taking three measures in both the warp and fill directions at different locations along each roll of fabric. Each measure counted five inches of fabric and these were averaged together and divided by five to determine the calculated yarns/inch. The results were as follows: fabric A had 9.8 yarns per inch in the warp direction and 10.6 yarns per inch in the fill direction. Fabric B had 10.8 37 38 yarns per inch in the warp direction and 7 yarns per inch in the fill direction. Fabric C had 9 yarns per inch in both directions. Finally, fabric D had 9.9 yarns per inch in the warp direction and 6.8 yarns per inch in the fill direction. (see Table 1). The fabric weight was determined by cutting six 1 ft2 samples out of each fabric. The samples for each fabric were averaged together to find the average weight per square foot. This weight was then multiplied by nine to obtain the calculated bag weight in oz/yard?. The results were as follows: fabric A weighted 2.73 oz/yd’, fabric B weighted 2.86 oz/yd?, fabric C weighted 2.43 oz/yd?, and fabric D weighted 2.25 oz/yd?. (see Table 1). Fabric thickness measurements were obtained by taking ten measurements (of individual yarns) in both the warp and fill directions at different locations along each roll of fabric. The measurements were determined using a Micrometer Model 549 M, manufactured by Testing Machines, Inc. accuracy of the micrometer was 0.1 mils. Averages of the ten measurements were then calculated to determine the fabric thickness results. The results were as follows: fabric A was 13.99 mils thick in the warp direction and 11.11 mils thick in the fill direction. Fabric B was 8.81 mdls thick in the warp direction and 9.99 mills thick in the fill direction. Fabric C was 7.95 mils thick in the warp 39 Table 1: Fabric weight and yarns per inch Eric ! Measured ; Data Sheet % Measured 4 Data Sheet 7 Fabric J Fabric Yarns/inch Yarns/inch LWefiight 'Wetht (warp x fill) (warp x fill) A 2.73 i 2.6 l 9.8 x10.6 _ 10 x 10 B 2.86 i 2.7 10.8 x 7 5 10.8 x 6.9 C 2A37i 26 j 9x9 : 9x9 D . 2.25 i ———- l 9.9x6.8 ; ———— note: fabric weight = oz/square yard fabric D data sheet was not available Table 2: Fabric thickness results mkness measurements miTs) AW J AF BW BF CW CF DWJ DF 1 13.2 1 1.1 9.3 8.1 7.9 7.7 5.9 7.2 2 14.0 14.6 7.6 7.4 8.1 7.2 5.8 5.5 3 14.3 10.6 8.8 10.1 7.4 10.4 7.7 7.1 4 14.1 11.2 7.4 11.6 7.8 9.1 6.9 5.6 5 14.1 10.5 9.3 9.7 8.0 9.8 6.2 7.0 6 14.2 10.7 9.4 7.6 8.0 11.2 5.9 5.8 7 14.5 9.8 9.2 11.9 7.7 9.7 6.5 5.7 8 13.1 12.4 9.7 10.4 7.2 7.8 6.7 5.4 9 13.8 10.2 8.2 11.4 8.8 8.0 7.4 7.4 10 14.6 10.0 9.2 11.7 8.6 12.0 5.6 5.3 AVG 13.99 1 1.11 8.81 9.99 7.95 9.29 6.46 6.20 STD . 0.50 1.43 0.80 1.75 0.49 1.61 0.71 0.86 40 direction and 9.29 mils thick in the fill direction. Fabric D was 6.46 mils thick in the warp direction and 6.20 mils thick in the fill direction. (see Table 2) ULTRAVIOLET TEST METHODS There were four different sets of tests performed. Samples were prepared for testing, and then tests were performed under two different exposure conditions. First, tests were performed using a continuous uv cycle (no condensation), on all four fabrics (A, B, C, and D). Second, tests were performed using a 8 hour UV (4 hour condensation) cycle, on all four fabrics. Third, replicate tests were performed on fabrics A, B, and C for the continuous uv cycle. Finally, replicate tests were performed on fabrics A, B, and C for the 8 UV (4 hour condensation) cycle. The ultraviolet light was simulated using two different accelerated weathering test machines (ASTM D 5208 1991, ASTM G 53 1988, ASTM D 4329 1984). Tensile tests were performed on all samples to determined their strength (in lbf) after being exposed to uv light. Pr r i Samples were prepared for testing from rolls of woven polypropylene fabric. The samples were cut to be tested in two different directions, warp and fill. In weaving, the 41 warp direction parallel yarns are strung onto a loom first, and the fill yarns are interwoven in the perpendicular direction (thus filling the fabric). To compare to other packaging material terminology, the warp direction is equivalent to the "machine" direction. The three fabrics (A, B, and C) used by the USDA are circular woven, into a tube, which facilitates bag making. In circular woven fabric, the warp yarns are strung the length of a tube and the fill yarns encircle the tube. Fabric D is regular flat woven fabric. A 7%" by 4%" pattern was traced on the fabric with a permanent marker. The pattern was positioned so the 7%" side was in the vertical direction with respect to the fabric coming off the roll for the warp direction. The 7%" side was in the horizontal direction with respect to the fabric coming off the roll for the fill direction. The traced patterns on the fabric were than cut out with scissors. After the samples were out they were labelled with a permanent marker on the inside of the bag material. The inside of the fabric was labelled for fabrics A, B, and C, since the outside was exposed to uv light. While the samples were being prepared for testing it was critical to handle them as little as possible to reduce unravelling and premature damage. Fabric D was very hard to work with because the yarns moved very easily, making it difficult to cut the rectangular pattern. Fabric D was flat 42 woven fabric, the inside of the material, with respect to the fabric coming off the roll, was labelled, and the reverse side was exposed to the uv light. Acgglerated Weathering Tests After the samples were prepared for testing they were placed in the accelerated weathering machines (UVCON and QUV) for testing. .The UVCON (model number UC-327-2) was supplied by Atlas Electric Devices Company in Chicago, Illinois. The dimensions for the UVCON were as follows: 61" (155 cm) * 53" (135 cm) * 20" (51 cm), height * width * depth. The UVCON weighted 285 lbs (129 kg). The UVCON had 26 positions for specimen racks (one position was used for a black panel sensor), resulting in a maximum capacity of 50 samples measuring 3" * 6" (75 * 150 mm). The samples were placed on metal plates (with a solid backing to prevent condensation evaporation), and secured in the specimen holder with snap- in rings. The QUV (model number QUV/SER) was supplied by The Q- Panel Company in Cleveland, Ohio. The dimensions for the QUV were as follows: 53" (135 cm) * 54" (137 cm) * 21" (53 cm), height * Width * depth. The QUV weighted 300 lbs (136 kg). The QUV had 26 positions for specimen racks (two positions were used for uv sensors), resulting in a maximum capacity of 48 samples measuring 3" * 6" (75 * 150 mm). The 43 samples were placed on metal plates (with a solid backing to prevent condensation evaporation), and secured in the specimen holder with snap-in rings. When putting the samples in the machines it was very important to make sure that the correct (outside) side of the fabrics would be exposed to the ultraviolet lights. Test initiation and completion dates and times were calculated and recorded onia calendar. The machines also had timers on them that were used to double check exposure durations. There were two different test conditions used in this study. The duration of testing was different depending on the test conditions used. Condensation occurred because of the temperature change in the test chamber between the ultraviolet cycle and condensation cycle. The temperature in the test chamber was 70 °C in the ultraviolet cycle and 50 °C in the condensation cycle. This condition was meant to simulate a day and night cycle. The first set of tests consisted of a continuous ultraviolet cycle, with no condensation cycle.. This test condition did not have a condensation cycle but their was water in the machines. For this cycle, samples were tested at intervals of 66, 100, 166, 200, 233, 266, and 333 hours. These times represent two-thirds of the 8-hour ultraviolet exposure length times. This was done to compare results of the two conditions based on the equivalent length of 44 ultraviolet exposure (e.g. 8 hours UV for 12 hours is % of 12 hours UV for 12 hours) and to determine if water, and a dark period had any effect on the severity of degradation. The second set of tests consisted of an 8 hour ultraviolet and 4 hour condensation cycle every 12 hours. During the condensation cycle, the uv lamps are not on. For this condition, samples were tested at intervals of 100, 150, 200, 250, 300, 400, and 500 hours. During this test there was one 8 hour delay because the UVCON overheated due to a lack of water for one condensation cycle. The temperature setting for the first set of tests (continuous uv and no condensation) was 70 °C. The second set of tests (8 hour ultraviolet and 4 hour condensation) used a temperature of 70 °C for the ultraviolet cycle, and 50 °C for the condensation cycle. UVA340 fluorescent uv tubes were used as the source of ultraviolet light. Most of the energy emitted by these lights falls in the UV-A region (315-400 nm), with a small amount in the UV-B region (280-315 nm). The QUV was calibrated when the tests began, at 70 °C, with an irradiance level of 0.72. The QUV was also calibrated when the "calibrate" light flashed, showing that it was time to recalibrate the system (this occurred approximately every 400 hours). The calibration was performed using the CR—IO Calibration Radiometer that came with the QUV. This instrument had a calibration connection 45 cable with two jacks. One end was inserted into the calibration instrument and the other end was inserted into the UV sensors in the QUV (there were four different sensors, each sensor monitors two lamps). This calibrated the irradiance level at the desired setting. The fluorescent uv tubes in the UVCON were rotated approximately every 400 hours, as shown in Figure 3 of ASTM G 53, Standard Practice for Operating Light— and Water- Exposure Apparatus (Fluorescent UV-Condensation Type) for Exposure of Nonmetallic Materials. In this rotation procedure, two light tubes are discarded and the remaining six tubes are rotated every 400 to 450 hours. Therefore, tubes are rotated approximately every 400 hours and replaced every 1600 hours. Once a day (approximately every 24 hours), the extreme left hand and extreme right hand samples were rotated into the center. This was done for both the UVCON and the QUV in accordance with the procedure suggested in ASTM G 53, section 9.5.1 for horizontal rotation. Data recorded included the irradiance level and temperature (approximately three times a day), time of sample rotation, and anything unusual that was observed. After the samples had been exposed to test conditions for the desired time interval, they were removed from the QUV and UVCON, and placed in wax paper. Pictures were taken of samples that were determined to be too brittle for 46 tensile tests. The criteria for a sample to be too brittle for testing was deterioration visible to the naked eye. After the continuous uv (no condensation) cycle was completed, the 8 hour ultraviolet (4 hour condensation ) cycle was initiated. Then repeat tests were done for fabric A, fabric B, and fabric C for both ultraviolet conditions (continuous ultraviolet, no condensation, and 8 hour ultraviolet, 4 hour condensation). For the initial tests, two samples were tested for each material (fabrics A,B,C, and D), for each condition. Two samples were also tested for the replicate tests (fabrics A,B, and C). Variability in data may make it difficult to distinguish between tests results. Therefore, replication of testing was necessary (Crewdson 1993). n r n The UVCON had the following advantages over the QUV: the temperature was maintained very well and was easy to set, chart recorder for machine temperature was beneficial, machine had a safety control device "equalizing cycle" that shut off the harmful ultraviolet rays if the test chamber was accidently opened, and the machine warmed up quickly. Disadvantages were as follows: uv tubes must be rotated every 400 to 450 hours, and a specific device (called a "cam") was necessary to set the UVCON for a specific condition. For example, one "cam" was used for the 47 8 hour uv (4 hour condensation cycle) and a different "cam" was used in the continuous uv cycle. These "cams" had smooth sections for the uv cycle and notches for the condensation cycle. The "cams" made one revolution every twenty four hours. The QUV had the following advantages over the UVCON: rotating light tubes was not necessary because the solar eye controlled the irradiance level; sensors were located in the middle of the test chamber, making daily rotation of samples easier; the machine had "tabs" that were placed in or out depending on the desired cycle setting (which allowed the user to modify cycle settings easily, without ordering additional "cams"). Disadvantages were as follows: machine warmed up slowly and temperature settings were difficult, the machine did not have a safety control device to protect the user from accidently opening the test chamber, and the machine did not have a chart recorder to monitor the temperature in the test chamber. TENSILE TESTING Tensile tests were performed to determine the strength of samples that had been exposed to ultraviolet light. The USDA requires 70% strength retention after 200 hours of exposure to a carbon arc. 48 Sggplg Preparation Exposed samples were cut in half in the vertical direction; the new dimensions were 2%" by 7%". Four samples were prepared for each variable being tested. Variables included: fabric (A,B,C, and D), time (Continuous UV Cycle 66, 100, 166, 200, 233, 266,and 333 hours; 8 Hour UV Cycle 100, 150, 200, 250, 300, 400, and 500 hours), direction (warp and fill), and machine (UVCON and QUV). Replicate tests were performed on fabrics ABC. Therefore, for the initial tests, 896 samples were prepared. The second set of tests (replicate tests) required 672 samples. Next, samples were prepared for testing in accordance with ASTM D 5035 Strip test ravel type, any yarns on the samples that were not full length (7%" in the vertical direction) were removed, by unravelling. Ten full yarns were counted from the middle (point that the samples were cut at) to the outside edge, and the rest of the lengthwise yarns were removed. Ten lengthwise yarns, with all crosswoven yarns intact, were determined to be the number of yarns necessary for tensile testing purposes. Samples were then placed back in wax paper and manila envelopes until tensile tests were performed to avoid sample mix-up. Samples that were determined to be too brittle for tensile tests were saved. 49 Tensile Tests Tensile tests were performed with an Instron Machine (Model number 4201). The procedure followed was performed in accordance with ASTM D 5035-90 Strip test ravel type. The Instron Machine was set up with a load cell of 5 kN, air pressure of 90 psi, jaw separation of three inches, and grip separation speed of 12 in/min. The dimensions of the grippers on the Instron machine were 2" by 1%". As the grippers held the samples, the 2" side was parallel to the width of the sample. The grabbers for ravel test are identical, except they have rubber on them. Peak load and extension were recorded. Ten unexposed samples for each fabric and direction were tested as controls. STATISTICAL ANALYSIS OF DATA Averages and standard deviations were calculated for all of the samples. T-tests were performed to determine if the tests are repeatable. Correlation between test methods was determined using linear regression. A multifactor analysis of variance (ANOVA) was also performed. CHAPTER 4 RESULTS As a control, 10 unexposed samples were tested for each fabric, for each direction. It is important to note that there was variation in these tests from 6.5- 13.7% in peak load measurements (see Table 3). Therefore, variation after the uv exposure tests had been completed, was expected. There were four separate tests performed in this study. They were set up as follows: 8 hour ultraviolet (4 hour condensation) cycle for fabrics A, B, C, and D (8 Hour UV - Test 1), 8 hour ultraviolet (4 hour condensation) cycle replicate test for fabrics A, B, and C (8 Hour UV - Test 2), continuous ultraviolet (no condensation) for fabrics A, B, C, and D (Continuous UV - Test 1), and continuous ultraviolet (no condensation) replicate test for fabrics A, B, and C (Continuous UV - Test 2). Four samples were tested for each variable; fabric (A,B,C, and D), time (Continuous UV Cycle = 66, 100, 166, 200, 233, 266,and 333 hours; 8 UV Cycle = 100, 150, 200, 250, 300, 400, and 500 hours), direction (warp and fill), and machine (UVCON and QUV). Replicate tests were performed on fabrics ABC. Therefore, for the initial tests, 896 samples were tested. The second set of tests (replicate 50 51 Table 3: Test Control (Original Fabrics) Control (Unexposed Fabrics) FabnclA l Fabric 8 VVanJ Fm Warp I l Load Ext Load l l l Ext Load Ext l i l 57 FM 4 Load L Ext 10213 (1764 6713 (16 (N157 (1863 98113 (1843 10912 (1762 721%! (1503 1(H.8 (1821 1L48 (18 1031) (1851 691MB (1613 961' (1793 10215 (187 1TI7 (1851 'TL62 (1614 96191 (1848 1071 (195 1181 (1715 761“ (1649 10512 (1644 11(12 0711 881“ (1786 6611 (1695 10412 (1841 991MB (1803 1031 (1754 6915 (1587 761%) (1893 121 (1833 951Ul (1807 6819' (1616 10915 (1797 11231 01N1 1001 (1603 63113 (1483 'fl393 (1717 $1166 (1865 —L oomflmUI-bODN-i‘ 10013 (1776 (”.53 (1608 10012 (1785 92113 1.187 > < (D 104 (1767 ER179 (1597 51126 (18 10512 (1877 STI) S109 (1071 11477 (1063 12102 (1073 $1502 (1127 Fabnc Fabncl D VVan: Fm VVan) Fm Load Ext Load Load Ext Load 921MB (1758 96115 (1825 891MB (1871 871X5 1.038 9819 (1884 'fl174 “L072 6819' (1785 EH.05 (1749 QSJW' (1786 7613 (1803 931K) (1785 85115 (1852 84113 (1899 7211 (1832 ‘fl364 'L24 791W' (1836 1(H.4 (1806 6211 (1857 771Z3 (1659 721' (1836 $1168 (1841 7117' (173 8611) (19 75113 (197 971W' (1961 (£157 ‘L015 851K3 (1667 771M (192 10513 (1866 71138 (1885 98!”' (1934 571“ (1906 10113 (1819 (R198 (1719 7611 (1808 791MB ‘LO48 —L C(DCDVODCfl-hwm-F 1041 (1927 9117' (1832 701“ (1862 59114 (1995 32 o 971fi5 (1855 7712! (1857 (1L93 (1851 753KB (1915 STI) (1329 (1064 1(157 (1112 1(128 (1164 £1883 (1098 r1 (1 It! (1 m m In m 52 tests) required 672 samples. Statistical T-tests were performed comparing the results of the two tests (results of 8 UV - Test 1 vs. 8 UV - Test 2 and continuous UV - Test 1 vs. continuous UV - Test 2) for each variable (time, machine, direction, and fabric) to determine if the results of the replicate tests were similar to the original tests. Correlation between fabrics, machines and test conditions was established using linear regression. Equivalent test times were established for machines and test conditions. A multifactor analysis of variance was then performed on all four test conditions. 8 HOUR UV - TEST 1 In this test, fabrics experienced slightly more degradation in the UVCON than in the QUV. Fabric B and fabric D showed visible signs of degradation (turned white and small holes), in both the warp and fill directions, after 400 hours of exposure in the UVCON, and after 500 hours of exposure in the QUV. Fabric A and fabric C did not show any visible signs of degradation. All four fabrics exhibited a decrease in load strength during tensile tests. However, some of the fabrics showed an increase in load strength at certain time intervals (see Table 4). For example, fabric B showed an increase (of ti 1 L P 1 L 1 \Et E A \L \ \ ~ Table 4: 8 Hour UV, Test 1 - Averages 53 8 Hour UV (4 hour Condensatiofi 1st Test WARP l TFILL ; L . ouv AUVCON iouv i :UVCONi nouns LOAD % RsriLOAo % RETlLOAD 4% RETiLOAD 1% RET A i ! 0 103.98 100.00 103.98 100.00 68.79 100.00 68.79 100.00 100 92.98 89.42 91.88 88.36 66.19 96.22 80.11 116.46 150 91.94 88.42 84.65 81.41 58.71 85.35 58.02 84.34 200 93.97 90.37 73.26 70.46 61.76 89.78 61.72 89.72 250 76.64 73.71 64.72 62.24 53.66 78.01 48.92 71.11 300 78.71 75.70 65.81 63.29 50.51 73.43 46.45 67.52 400 65.43 62.93 63.01 60.60 44.41 64.56 39.51 57.44 500 60.46 58.15 47.62 45.80 34.77 50.55 33.45 48.63 B 0 95.26 100.00 95.26 100.00 105.20 100.00 105.20 100.00 100 82.91 87.04 84.32 88.52 90.66 86.18 90.48 86.01 150 82.33 86.43 90.31 94.80 87.96 83.61 85.45 81.23 200 79.33 83.28 82.46 86.56 77.62 73.78 74.36 70.68 250 73.48 77.14 77.95 81.83 73.52 69.89 45.89 43.62 300 40.83 42.86 64.34 67.54 63.64 60.49 30.29 28.79 400 64.92 68.15 0.00 0.00 18.96 18.02 0.00 0.00 500 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 c 0 97.65 100.00 97.65 100.00 77.12 100.00 77.12 100.00 100 81.99 83.96 90.88 93.07 72.15 93.56 74.20 96.21 150 75.52 77.34 78.20 80.08 68.50 88.82 64.03 83.03 200 76.79 78.64 79.70 81.62 64.84 84.08 62.44 80.96 250 70.71 72.41 77.95 79.83 58.50 75.86 58.01 75.22 300 74.29 76.08 71.82 73.55 59.43 77.06 67.70 87.79 400 69.52 71.19 57.82 59.21 53.50 69.37 57.70 74.82 500 66.21 67.80 47.60 48.75 54.16 70.23 45.81 59.40 0 0 81.93 100.00 81.93 100.00 75.43 100.00 75.43 100.00 100 74.84 91.35 63.52 77.53 64.14 85.03 63.23 83.83 150 74.71 91.19 66.58 81.26 60.83 80.64 60.12 79.70 200 61.99 75.66 53.69 65.53 60.38 80.05 57.55 76.30 250 56.13 68.51 51.38 62.71 51.42 68.17 54.47 72.21 300 50.82 62.03 56.68 69.18 48.48 64.27 44.29 58.72 400 22.90 27.95 0.00 0.00 17.72 23.49 0.00 0.00 500 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 54 approximately 24 lbf) in load strength at 400 hours (compared to 300 hours) in the warp direction, in the QUV. Fabric B and fabric D were too brittle for tensile tests after 400 hours of exposure in the UVCON and 500 hours of exposure in the QUV (the fabrics fell apart while being prepared for the tests). After 500 hours of exposure, fabric C showed the greatest retention of load strength, followed by fabric A, fabric D and fabric B, respectively, for all conditions except 8 UV - Test 1, in the QUV (where fabric B was stronger than fabric D). 8 HOUR UV - TEST 2 Fabrics experienced slightly more degradation in the UVCON, than in the QUV, for the warp direction in this test also. However, results were similar between the two machines for the fill direction. Fabric B turned white and developed small holes after 500 hours of exposure in both machines, in both the warp and fill directions. Fabric A and fabric C did not show any visible signs of degradation. All three fabrics showed a decrease in load strength during tensile tests (note that replicate tests were not performed on fabric D). However, as in the first test, some of the fabrics exhibited an increase in load strength at certain intervals (see Table 5). For example, fabric C had an increase (of approximately 7 lbf) in load strength at 300 55 Table 5: 8 Hour UV, Test 2 — Averages 8 Hour UV (4 hour Eondensation) 2nd Test TWARP ’ A 1 FILL : ouv j UVCON ouv EUVCON : HOURS LOAD % RETiLOAD % BET LOAD g % RET I LOAD 1 % RET A T . ' t 0 103.98 100.00 103.98 100.00 68.79 100.00 68.79 100.00 100 83.54 80.34 100.50 96.65 50.90 73.99 63.901 92.89 150 91 .89 88.37 85.48 82.21 54.38 79.05 64.08 I 93.15 200 82.97 79.79 81 .93 78.79 61 .02 88.70 57.28 83.27 250 78.48 75.48 69.70 67.03 52.80 76.76 49.48 71 .93 300 68.60 65.97 75.69 72.79 50.29 73.1 1 47.15 68.54 400 75.94 73.03 67.63 65.04 44.76 65.07 47.87 69.59 500 63.57 61 .14 52.06 50.07 34.40 50.01 33.44 48.61 B 0 95.26 100.00 95.26 100.00 105.20 100.00 105.20 100.00 100 99.82 104.79 88.69 93.10 102.80 97.72 94.48 89.81 150 82.74 86.86 75.22 78.96 86.70 82.41 85.44 81.22 200 86.12 90.41 82.35 86.45 79.26 75.34 83.73 79.59 250 71 .44 74.99 69.42 72.87 47.01 44.69 46.68 44.37 300 70.94 74.47 74.31 78.01 46.24 43.95 31 .77 30.20 400 58.09 60.98 58.53 61.44 14.16 13.46 13.29 12.63 500 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 C 0 97.65 100.00 97.65 100.00 77.12 100.00 77.12 100.00 100 84.76 86.80 92.05 94.27 70.35 91 .22 67.94 88.10 150 73.59 75.36 80.40 82.33 73.26 94.99 64.52 83.66 200 69.15 70.81 79.99 81 .92 58.59 75.97 67.90 88.04 250 70.76 72.46 92.50 94.73 54.76 71.01 55.1 1 71.46 300 60.86 62.32 78.89 80.79 54.31 70.42 60.33 78.23 400 69.63 71 .31 65.75 67.33 48.23 62.54 55.56 72.04 500 63.90 65.44 53.05 54.33 44.97 58.31 48.55 62.95 56 hours (compared to 250 hours) in the fill direction, in the UVCON. Fabric B was too brittle for tensile tests after 500 hours of exposure in both the QUV and the UVCON during this test. After 500 hours of exposure, both of the machines and sample directions ranked the fabrics the same (C, A, B). CONTINUOUS UV - TEST 1 Fabrics experienced more degradation in the UVCON, than in the QUV, for both the warp and fill directions in this test as well. Fabric D showed visible signs of degradation (white, brittle and holes) at 200 hours of exposure in the UVCON. At 266 hours of exposure, in both the QUV and the UVCON, fabrics B and D showed visible signs of degradation (small holes and white in color). As in the 8 hour UV tests, fabric A and fabric C did not show any visible signs of degradation. All four fabrics showed an overall decrease in load strength during tensile tests, as in the 8 hour UV tests (see Table 6). Certain time intervals showed an unexpected increase in load strength (as found in some 8 hour UV tests). For example, the load strength of fabric C (warp) increased (approximately 13 lbf) at 200 hours (compared to 166 hours), in the UVCON. Fabric D was too brittle for tensile tests in both machines at 266 hours, in the warp direction. In the fill 57 Table 6: Continuous UV, Test 1 — Averages mtinuous UV (No Eondensation) 1st7fit )WARP I I {FILL . !QUV (UVCON, EQUV j UVCON} HOURS 1 LOAD l % RH ! LOAD I % RET LLOAD % RET j LOAD f % RET A ' . 0 103.98 100.00 103.98 100.00 68.79 100.001 68.79100.00 66 1 90.83 87.35 92.97 89.41 67.32 97.86 ‘ 62.95 1 91.51 100 i 90.43 86.97 91.27 87.78 66.28 96.35 63.96 3 92.98 133 75.97 73.06 84.19 80.97 60.13 87.41 58.51 85.06 166 76.84 73.90 77.56 74.59 57.71 83.89 51 .88 75.42 200 85.17 81.91 70.84 68.13 61.98 90.10 48.22 70.10 266 66.41 63.87 53.67 51 .62 48.46 70.45 40.75 59.24 333 53.84 51.78 46.1 1 44.35 38.22 55.56 28.41 41.30 B 0 95.26 100.00 95.26 100.00 105.20 100.00 105.20 100.00 66 87.91 92.28 97.1 1 101.94 99.20 94.30 100.00 95.06 100 91.88 96.45 90.35 94.85 90.61 86.13 87.57 83.24 133 86.62 90.93 86.70 91 .01 73.64 70.00 69.74 66.29 166 81.00 85.03 67.54 70.90 42.87 40.75 32.06 30.48 200 71 .79 75.36 68.86 72.29 25.54 24.28 24.79 23.56 266 48.80 51.23 51.63 54.20 14.76 14.03 14.62 13.90 333 50.78 53.31 0.00 0.00 0.00 0.00 0.00 0.00 C 0 97.65 100.00 97.65 100.00 77.12 100.00 77.12 100.00 66 100.97 103.40 93.30 95.55 71 .51 92.73 83.59 108.39 100 98.53 100.90 70.51 72.21 70.85 91.87 65.33 84.71 133 87.81 89.92 83.67 85.68 65.03 84.32 62.84 81.48 166 63.98 65.52 68.89 70.55 72.25 93.69 59.77 77.50 200 73.52 75.29 81 .59 83.55 70.56 91 .49 53.22 69.01 266 82.20 84.18 65.22 66.79 61.34 79.54 49.36 64.00 333 57.15 58.53 57.61 59.00 54.71 70.94 45.27 58.70 D 0 81 .93 100.00 81 .93 100.00 75.43 100.00 75.43 100.00 66 80.00 97.64 84.67 103.34 72.63 96.29 65.23 86.48 100 73.21 89.36 89125 108.93 70.99 94.1 1 68.35 90.61 133 71.17 86.87 67.30 82.14 60.58 80.31 46.53 61.69 166 71 .08 86.76 46.39 56.62 59.79 79.27 43.83 58.1 1 200 47.91 58.48 33.79 41.24 40.46 53.64 14.82 19.65 266 0.00 0.00 0.00 0.00 37.59 49.83 0.00 0.00 333 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 58 direction, fabric D was too brittle for tensile tests at 266 hours in the UVCON, and 333 hours in the QUV. Fabric B was too brittle for tensile tests in both the warp and fill directions at 333 hours in the UVCON, and too brittle for tensile tests in the fill direction in the QUV at 333 hours. The fabric ranks after 333 hours were as follows: UVCON — Fill (C, A, B, D), UVCON — Warp (C, A, D, B), QUV - Fill (C, A, D ,B), and QUV - Warp (C, B, A, D). CONTINUOUS UV - TEST 2 Fabric degradation was similar for both of the machines, in both directions for this test. Fabric B started to show visible signs of degradation after 266 hours of exposure in both the QUV and the UVCON. Fabric A and fabric C did not show any visible signs of degradation, as in all other tests. However, as with all of the other tests, there were unexpected increases in load strength during certain time intervals (see Table 7), for all three fabrics (note that replicate tests were not performed on fabric D). Fabric B was too brittle for tensile tests for both directions, in both machines, at 333 hours. Retention strength after 333 hours ranked the fabrics similarly in this test. Fabric rank was C, A, B for both machines (QUV and UVCON), and directions (warp and fill). (see Table 8). 59 Table 7: Continuous UV, Test 2 - Averages 'Oontinuous UV (No Oondensation) 2nd Test (WARP FILL : (QUV UVCON QUV , (UVCON; HOURS (LOAD % RET LOAD % RET LOAD (% RET i LOAD j% RET A T i 0 103.98 100.00 103.98 100.00 68.79 100.00 6879110000 66 93.09 89.53 89.64 86.21 ‘ 7364,107051 67.43 98.02 100 86.51 83.20 84.54 81.30 61.62; 89.58E 64.53 93.81 133 81.79 78.66 68.96 66.32 49.611 72.12 60.43j 87.85 166 76.17 73.25 82.52 79.36 55.63 80.87 47.111 68.48 200 73.68 70.86 69.09 66.45 46.1 1 67.03 49.10 71 .38 266 60.70 58.38 75.90 72.99 39.03 56.74 44.46 64.63 333 47.54 45.72 55.93 53.79 31 .33 45.54 24.22 35.21 B 0 95.26 100.00 95.26 100.00 105.20 100.00 105.20 100.00 66 89.37 93.82 93.70 98.36 83.46 79.33 81 .56 77.53 100 91 .76 96.33 79.78 83.75 89.80 85.36 80.88 76.88 133 59.07 62.01 78.47 82.37 80.16 76.20 71 .64 68.10 166 89.58 94.04 68.12 71.51 61.29 58.26 50.14 47.66 200 56.43 59.24 58.03 60.92 44.01 41 .83 47.26 44.92 266 58.16 61 .05 55.32 58.07 25.14 23.90 20.58 19.56 333 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 C 0 97.65 100.00 97.65 100.00 77.12 100.00 77.12 100.00 66 86.84 88.93 94.02 96.28 75.05 97.32 61 .68 79.98 100 84.41 86.44 72.92 74.67 62.33 80.82 67.35 87.33 1 33 69.20 70.87 81 .52 83.48 70.10 90.90 63.58 82.44 166 66.10 67.69 61.45 62.93 61.34 79.54 64.48 83.61 200 79.26 81 .17 76.81 78.66 58.37 75.69 58.10 75.34 266 69.74 71 .42 64.15 65.69 56.66 73.47 46.67 60.52 333 48.07 49.23 58.21 59.61 49.03 63.58 50.28 65.20 60 Table 8: Fabric Bank by Retention fiBEt Worst Condition 1 Direction I Machine 7 1 7 2 3 8 UV - Test 1 Warp j QUV (C A EB .D 8 UV — Test 1 Warp l UVCON C A 10 (B 8 UV - Test 1 Fill QUV C A D B 8 UV — Test 1 Fill UVCON C A D B 8 UV — Test 2 Warp QUV C A 18 NA 8 UV — Test 2 Warp UVCON C -A AB NA 8 UV - Test 2 Fill QUV C A i B (NA 8 UV — Test 2 Fill UVCON C A ‘ B NA Continuous UV—Test1 Warp QUV C B A D Continuous UV—Test1 Warp UVCON C A D 8 Continuous UV-Test1 Fill QUV C A D B Continuous UV-Test1 Fill UVCON C A B D Continuous UV—Test 2 Warp QUV C A 8 NA Continuous UV—Test 2 Warp UVCON C A B NA Continuous UV—Test 2; Fill QUV C A B NA Continuous UV—Test 21 Fill UVCON C A B NA note: 8 UV, after 500 hours of exposure Continuous UV, after 333 hours of exposure 61 RESULTS VS. CURRENT SPECIFICATION The USDA’s current specification for uv degradation resistance due to accelerated weathering, states that a fabric must retain 70% of its original tensile strength after 200 hours of exposure to a carbon arc. The results of the 8 hour UV (4 hour condensation) tests showed that all four fabrics (A, B, C, and D) meet this criteria for both machines (QUV and UVCON) and directions (warp and fill), except one condition (fabric D, warp, UVCON, test 1). (see Table 4 and Table 5). Fabric A and fabric C passed the 200 hour specification for most of the conditions (machine and direction) under the continuous UV tests. Fabric B, warp direction, passed the 200 hour specification in the first continuous UV test. Fabric B, fill direction, and fabric D (warp and fill), failed to pass the 200 hour specification in the first continuous UV test. Fabric B failed to pass the 200 hour specification (for both machines and directions) in the second continuous UV test. (see Table 6 and Table 7). It is important to note that the continuous UV condition was more severe than the 8 hour UV (4 hour condensation) cycle. The results for the continuous UV condition at 133 hours should be equivalent to the results of the 8 hour UV (4 hour condensation) cycle at 200 hours. Therefore, when analyzing the continuous UV results with respect to the 200 hour specification, one should see if 62 fabrics had 70 percent retention at 133 hours. 'At 133 hours, continuous UV, most of the fabrics passed the 70% retention criteria for both machines (QUV and UVCON) and directions (warp and fill). The fabrics and conditions that did not pass specification were as follows: fabric B - fill, UVCON, test 1 (66% retention); fabric D - fill, UVCON (62% retention); fabric A - warp, QUV (66% retention), note: this fabric passed at 166 hours (79% retention); fabric B - warp, QUV (62% retention), note: this fabric passed at 166 hours (94% retention); and fabric B - fill, UVCON (68% retention). T-TESTS One hundred and sixty-eight T-tests were performed comparing the results of the first test, with the results of the second replication test, for all four variables (machine, direction, time, and fabric). This was done to determine the confidence interval for (p,-—1n) and to determine the probability of getting a value as, or more extreme than, the computed t-value. The results of the T-tests showed that only 11 of the 168 conditions had evidence to conclude a statistically significant difference, at the 0.05 level of significance. (see Tables 9-12). Therefore, the results from the two tests were combined for further analysis. 63 Table 9: T—test Results — QUV (8 Hour UV) ‘ OUV — 8 Hour UV (4 hour Condensation) 17Fabric A 1 Fabric B 1 Fabric C Hours lWargTFill LWarp 1Fill (Warp jFill 100 7 0.26 7 0.13 . 0.26 0.29 0.51 V 0.8 150 0.99 0.6 0.97 0.9 0.84 0.21 200 0.23 0.86 0.47 0.86 0.48 0.56 250 0.87 0.83 0.85 0.056 0.99 0.58 300 0.32 0.96 0.03 0.062 0.17 0.23 400 0.1 1 0.95 0.28 0.089 0.99 0.47 500 0.6 0.92 NA NA 0.66 0.18 Table 10: T—test Results — QUV (Continuous UV) QUV — Continuous UV (No Condensation) Fabric A Fabric 8 Fabric C Hours Warp 1 Fill Wag) I Fill Warp (Pill 66 0.7 0.46 0.85 0.26 0.084 0.54 100 0.6 0.32 0.98 0.94 0.016 0.32 133 0.5 0.12 0.1 1 0.65 0.026 0.54 166 0.96 0.76 0.39 0.051 0.084 0.22 200 0.1 0.036 0.31 0.002 0.32 0.068 266 0.52 0.032 0.44 0.097 0.026 0.68 333 0.25 0.32 NA NA 0.31 0.32 note: 1. NA = fabrics were not able to be tested, load of 0 created error message. 2. Fabric D was not replicated. Therefore, T-tests could not be performed. 3. Values are probabilities. 64 Table 11: T—test Results — UVCON (8 Hour UV) ‘ UVCON — 8 Hour UV (4 hour Condensation) Fabric A 1 Fabric B 7 Fabric C Hours ,Warp (Fill (Warp IFill (Warp IFill 100 0.31 Y 0.061 I 0.71 0.72) 0.9) 0.35 150 0.91 0.417 0.2 1 ‘ 0.81 0.95 200 0.35 0.44 0.99 0.3 0.97 0.48 250 0.51 0.92 0.4 0.93 0.006 1 0.57 300 0.16 0.85 0.29 0.71 0.327 0.36 400 0.48 0.21 NA 1 NA 0.36; 0.16 500 0.19 1 | NA i NA 0.53) 0.56 Table 12: T—test Results — UVCON (Continuous UV) UVCON - Continuous UV (No Condensation) Fabric A Fabric 8 Fabric C Hours Warp [Fill Warp 1 Fill ,Warp I Fill 66 0.47 0.53 0.8 0.11 0.921 0.033 100 0.48 0.88 0.25 0.69 0.79 0.76 133 0.23 0.66 0.49 0.88 0.79 0.92 166 0.26 0.38 0.96 0.049 0.37 0.38 200 0.83 0.88 0.28 0.082 0.54 0.46 266 0.007 0.44 0.43 0.27 0.88 0.32 333 0.32 0.22 NA NA 0.92 0.092 note: 1. NA = fabrics were not able to be tested, load of 0 created error message. 2. Fabric D was not replicated. Therefore, T-tests could not be performed. 3. Values are probabilities. 65 COMBINED TESTS The results of the first test and second replication test were combined and the peak loads (lbf) versus time were plotted to determine the best straight line fit for all the fabrics and test conditions (see Figures 1-32). These graphs were than superimposed to determine fabric rank by percent retention. The results of this analysis showed that the fabrics rank as follows: C, A, B, D, with fabric C displaying the best retention and fabric D displaying the worst retention. The fabric ranks are supported by the actual data also, indicating that the linear regression did not distort test results. The fabric rank was also evident in observing the fabrics after tests were completed, tensile tests could be performed on fabric A and fabric C over the entire test duration. On the other hand, tensile tests could not be performed on the later time periods (e.g 400 and 500 hours for the 8 UV condition, and 266 and 333 hours for the continuous UV condition) for fabric B and fabric D. CORRELATION Linear regression was used to determine correlation between fabrics, machines, and test conditions (condensation and no condensation). Equivalent test duration times were then calculated. To determine correlation the following steps were performed: first, the peak loads versus time were 66 plotted to determine a best straight line fit for all of the fabrics and test conditions(see Figures 1-32). Second, the equation of the line from each graph, was used to calculate a time value (X), using 50%, 60%, 70%, 80%, and 90% of the initial load strength for a fabric as Y (see Table 13). Third, the time values (X’s) for each test method were graphed against each other, to produce a best straight line fit (see Figures 33-40). Finally, from the last set of graphs (figures 33-40), equivalent times were calculated for the machines (QUV and UVCON) and test conditions (condensation and no condensation). ggrrglgtign cogffigigg; The strength of a linear relation is measured by where: Sxy=2 (Jr-3?) ( y-37) 5x252 (Jr—7r) 2 Syy=2 (y-7) 2 The value forr2 gives the variability in y that is explained by the linear regression model. The linear model is normally considered to be satisfactory if r2 is 0.8 or greater. The correlation coefficient has a range from -1 to 67 Table 13: Load as a Function of Time (X) _71INITIAL ‘WAR‘P v v 7 LOAD 0.5 0.6 0.7 0.81 0.9 A 103.98 51.99 62.388 72.786 83.1841 93.582 8 95.26 47.63 57.156 66.682 76.208 85.734 c 97.65 48.825 58.59 68.355 78.12 87.885 0 81.93 40.965 49.158 57.351 65.544 73.737 FILL i A 68.79 34.395 41.274 48.153 55.032 61.911 8 105.2 52.6 63.12 73.64 84.16 94.68 c 77.12 38.56 46.272 53.984 61.696 69.408 0 75.43 37.715 45.258 52.801 60.344 67.887 v = LOAD Y=Mx + B x = (Y—B)/ M 8UV — QUV (warp) B M x x x x x A 101.52 -0.0816 606.896 479.488 352.081 224.673 97.2651 8 106.7 —0.1657 356.595 299.088 241.582 184.075 126.568 0 89.534 —0.0594 685.903 521.373 356.843 192.314 27.7839 0 88.647 -0.1558 306.144 253.541 200.937 148.334 95.7303 FILL B M x x x x x A 68.411 —0.0627 542.485 432.779 323.073 213.368 103.662 B 115.57 -0.251 279.693 232.966 186.24 139.513 92.7867 c 76.285 —0.0606 62.268 495.06 367.852 240.643 113.435 0 80.138 —0.142 298.775 245.651 192.528 139.404 86.2807 UVCON WA 8 M x x x x x A 102.16 -0.1057 474.645 376.272 277.9 179.527 81.1542 8 108.5 —0.1853 328.423 277.026 225.629 174.231 122.834 0 99.02 -0.0903 555.863 447.725 339.586 231.448 123.31 0 84.971 —0.1611 273.126 222.275 171.425 120.575 69.7244 FILL B M x x x x x A 72.508 —0.0771 494.114 404.932 315.749 226.567 137.384 B 112.59 -0.2396 250.407 206.495 162.583 118.671 74.7589 0 75.654 -0.0541 685.2 542.744 400.288 257.832 115.376 0 80.007 —0.1513 279.487 229.639 179.791 129.943 80.0952 Table 13 (cont’d) 68 Eontinuous U-V ouiv WARP 1 B M x x - x . x x A l 103131—01514 337.825 269.137: 200.449L131761 63.0731 87 103.67’ —0.2015 278.142 230.862' 183.581) 136.301; 89.0212 0 ' 98.595 —0.1246 399.502 321.119 242.736 1 164.3521 85.9689 0 91.075 —0.2427 206.477 172.718 138.959) 105.2 71.4409 FILlL * l B M x x x l x x A 72.736 —0.1073 357.492 293.352 229.212 165.072 100.932 8 112.7 —0.3433 175.091 144.443 113.795 83.1464 52.4982 c 77.056 —0.071 542.159 433.547 324.935 216.323 107.711 0 82.486 -0.2002 223.665 185.982 148.299 110.616 72.933 UVCON WARP B M x x x x x A 102.29 —0.1521 330.617 262.272 193.927 125.582 57.2368 B 105.98 —0.2318 251.682 210.594 169.505 128.416 87.3275 c 94.893 —0.1154 399.134 314.53 229.925 145.321 60.7174 0 93.485 -0.2883 182.171 153.753 125.335 96.9164 68.4981 FILL B M x x x x x A 72.872 —0.126 305.421 250.818 196.214 141.61 87.0059 B 109.79 -0.3453 165.629 135.162 104.695 74.275 43.7603 0 76.962 -0.0971 395.31 315.923 236.535 157.148 77.7608 0 81.085 —0.2813 154.177 127.362 100.547 73.7327 46.9179 69 1. A value of positive 1 indicates that all values (for x and y) lie exactly on a straight line with a positive slope (perfect positive linear relation). A value of negative 1 indicates that all values (for x and y) lie exactly on a straight line with a negative slope (perfect negative linear correlation) (Johnson and Bhattacharyya 1992). Therefore, if r2 is closer to 1, the strength of the linear relation is greater. ngrigs The four fabrics were analyzed to determine correlation between peak load and length of uv light exposure (see Figures 1-32 and Table 14). In the warp direction, the results were as follows: fabric D had a 0.722 correlation; fabric A had a 0.682 correlation; fabric B had a 0.656 correlation; and fabric C had a 0.556 correlation. In the fill direction, fabric B had a 0.863 correlation; fabric D had a 0.796 correlation; fabric A had a 0.691 correlation; and fabric C had a 0.490 correlation. These results show that in the warp direction, fabric D supports the linear model greatest, followed by fabric A, fabric B, and fabric C. In the fill direction, fabric B supports the linear model greatest, followed by fabric D, fabric A, and fabric C. Results were not greater than 0.800 for most of the individual fabrics (both warp and fill directions), which Table 14: Linear Regression Correlations—Fabrics 70 8 Hour UV (Continuous UV Fabric QUV (UVCON 1 QUV UVCON AVG A-Warpi 0.5861 0.745: 0.715 0.681 1 0.682 A- Fill . 0.6291 0.704 0.638 1 0.793 1 0.691 B—Warp 0.673 0.703 0.573 0.673 1 0.656 B-Fill 0.880 0.897 0.845 0.831 : 0.863 C—Warp 0.462 0.662 0.552 0.548 0.556 C — Fill 0.524 0.498 0.360 0.579 0.490 D—Warp 0.844 0.703 0.630 0.709 0.722 D— Fill 0.856 0.721 0.788 0.819 A 0.796 AVG 1 0.682L 0.7041 0.6381 0.7041 NA Table 15: Linear Regression Correlations - Machines Test Condition 1 Warp 1 Fill UVCON (8UV) vs. OUV (8UV) 0.957 0.972 UVCON (Continuous UV) vs. QUV (Continuous UV) 0.993 0.967 QUV (Continuous UV) vs. QUV (8UV) 0.943 0.936 UVCON (Continuous UV) vs. UVCON (8UV) 0.985 0.993 Average 0.9695 0.967 71 means that correlation using linear regression did not support the model. Variance amongst the fabrics load measurements is the major reason for the low correlation. The reasons for variation among samples will be discussed in Chapter 5. flashines The QUV and the UVCON were plotted against each other for both test conditions, and sample directions. (see Table 15 and Figures 33-36). Correlation between the machines (QUV vs. UVCON) was as follows: 8 hour UV (4 hour condensation), 0.957 in the warp direction, and 0.972 in the fill direction. Continuous UV, 0.993 in the warp direction, and 0.967 in the fill direction. All of these correlation values are very high, representing almost perfect positive correlation, between machines. Therefore, I propose that either machine may be used to achieve similar test results. W Results of the test with condensation (8 UV) were plotted against the test without condensation (continuous UV) for each machine to determine if water would affect strength retention (see Table 15 and Figures 37-40). The length of uv exposure was the variable in this comparison. 72 For the QUV, correlation was 0.943 in the warp direction, and in the fill direction, correlation was 0.936. The UVCON, had correlation of 0.985 in the warp direction and 0.993 in the fill direction. These correlation values are very high, illustrating almost perfect positive correlation, between test conditions. Therefore, I propose that either test condition may be used to achieve similar test results. iv 1 Tim In analyzing the test data, equivalent test times for the QUV and the UVCON were similar, but the degradation was more severe in the UVCON. For example, 150 hours in the QUV, for the 8 hour UV test was equivalent to 150 hours in the UVCON. However, overall the values for the UVCON were lower than the values for the QUV, indicating quicker degradation in the UVCON (see Table 16). In comparing the 8 Hour UV (4 hour condensation) cycle to the continuous uv condition, 100 hours for the 8 hour UV test, should be equivalent to 66 hours in the continuous UV test, based on the length of UV exposure. The results showed that most of the conditions were close to the expected value. For example, at 250 hours in the QUV, warp direction, the equivalent value for the continuous uv condition was 172 hours, which is very close to the expected value of 166 hours (see Table 16). 73 Table 16: Equivalent test times fime (hours) Condition Y—int Slope l 100 150 200' 250 T QUV 8 UV — Warp 38.13 0.749 113 150 188 2251UVCON 8 UV — Fill —15.9 1.049 89 141 1 194 246 % UVCON Cont. UV - Warp — 12.3 1.003 88 1381 188 2381UVCON Cont. UV — Fill 8.631 0.739 82.6 120 156 1931UVCON QUV vs. QUV Time (hours) Condition Y—int Slope 100 150 200 250 8 Hour- UV Warp 40.97 0.523 93.2 119 146 172 Cont —UV Fill 1 -10.3 0.802 69.8 110 150 1904-Cont —UV Expected time 66 100 133 1661 UVCON vs. UVCON Time (hours) Condition Y—int Slope 100 150 200 250 8 Hour- UV Warp 1.486 0.703 71.7 107 142 177 Cont —UV Fill 5.167 0.583 63.5 92.7 122 1514Cont —UV Expected time 66 100 133 1661 note: 1. The expected times are the values for a perfect correlation between the two variables. eg. QUV vs. UVCON (100 hours QUV should equal 100 hours UVCON) (100 hours 8 UV should equal 66 hours Cont. UV) 8 UV vs. Cont. UV Cont. = Continuous *based on length of uv exposure '74 Based on these findings, I propose that either machine (the QUV or the UVCON) may be used for accelerated weathering tests to provide similar results, with equal lengths of exposure in each machine. The results also show that the dark condensation cycle did not have a statistically significant effect on test results. Therefore, either a continuous uv condition or a 8 hour UV (4 hour condensation) cycle, may be used to produce similar results. I propose the use of a continuous uv condition to reduce test time, based on the length of uv exposure. ANOVA The ANOVA table displays the following information: Sum of Squares, degrees of freedom, mean square, F-ratio, and the significance level. The Sum of Squares is the observed value minus the mean, squared. Degrees of freedom are the number of elements whose squares are summed minus the number of linear constraints satisfied by the elements. The mean square is equal to the Sum of Squares divided by the degrees of freedom. The F-ratio is the treatment mean square divided by the error mean square. The observed F-ratio can be compared with the tabulated value for F (given in statistical tables), with the respective degrees of freedom, to determine if there is a significant difference between the effects in question. Statgraphics, version 6.0, was used to compute the 75 ANOVA tables for this analysis. In analyzing the tables, if 0.05 exceeds the significance level given by the table, there is evidence to conclude statistical significance between the elements, at 0.05 level of significance. The ANOVA tables, for the first tests of each condition (8 UV - Test 1 and Continuous UV - Test 1) show that the difference between all of the main effects (fabric, time, machine, and direction) are statistically significant at the 0.05 level of significance (see Tables 17 and 18). Almost all of the interactions between the main effects are statistically significant also. One reason that there is a statistically significant difference between machines for this test is that fabric B and fabric D have zeros at 400 hours for the UVCON, but were able to be tested and have values for the QUV. Separate ANOVA tables were generated to support this fact (see Tables 19-22), when the last two time periods are omitted from the data, there is not a statistically significant difference between the machines (for both conditions in the warp direction and for the 8 hour UV - 4 hour condensation cycle, in the fill direction). The significance level for the warp direction was 0.2110 for the 8 Hour UV (4 hour condensation) cycle, and 0.1858 for the continuous uv condition. (see Table 19 and Table 20). In the fill direction, the significance level was 0.1009 for the 8 Hour UV (4 hour condensation) cycle, and 76 0.0117 for the continuous uv condition. (see Table 21 and Table 22). These results illustrate, that for the first set of tests, the difference between machines is not statistically significant at the 0.05 level of significance for both test conditions in the warp direction and for the 8 Hour UV (4 hour condensation) cycle in the fill direction. However, the difference between machines was statistically significant at the 0.05 level of significance for the continuous uv condition, for the fill direction in the first set of tests. The ANOVA tables, for the second tests (8 UV - Test 2 and Continuous UV - Test 2) show that the difference between fabric, time, and direction are statistically significant at the 0.05 level of significance, but the difference between machines is not statistically significant (see Table 23 and Table 24). CHAPTER 5 SUMMARY AND CONCLUSIONS Photodegradation of polymers is a very complex phenomenon. In order to prevent photodegradation, the reactions which polymers undergo due to ultraviolet light absorption must be understood at the molecular level. The initial steps in the photodegradation of polymers are not totally understood today. Possible initiation mechanisms are believed to involve cross-linking and chain scission reactions, which result in the formation of free-radicals. In this study, the photostabilizer concentrations used were not available, which made it impossible to break down the reactions at the molecular level. Most of the tests resulted in a steady decrease in load strength over time of exposure to the ultraviolet lights. However, there were unexpected increases in load strength observed at certain time intervals, for the tensile tests (see Figures 41 - 56). These increases can possibly be explained by a number of factors. First, cross-linking and photo-induced crystallization may have occurred due to the ultraviolet rays. Second, variation of results may have been due to the time interval between when the samples were removed from the 77 78 accelerated weathering machines and when tensile tests were performed (this was probably a minimal effect, the time between tests was usually less than 50 hours), because once degradation is initiated the reaction may continue whether there is UV light or not. Third, preparing the samples for tensile tests after being exposed in the machines was a destructive process that could have resulted in test variation. This process (cutting samples in half and removing yarns) was not likely to increase strength, but could have decreased strength. Fourth, variation can possibly be explained by the fact that photodegradation is a surface phenomenon and tensile tests are mechanical tests that measure bulk properties (Gonzalez, et al 1989). Fifth, it is important to remember that some variation can be explained by the tensile testing procedure, due to the fact that there was variation in the unexposed fabrics (control group). Finally, increases at certain time intervals may be explained by the fact that there were large standard deviations (up to 20% in some cases) among some of the samples that were tested (see Tables 25-32). The study did show favorable correlation results between the machines (QUV and UVCON) and conditions (condensation and no condensation). The correlation between fabrics was not supportive of the linear regression model in most cases, due mainly to variation between samples tested for each fabric. 79 Correlation between the two machines (QUV and UVCON), and the two different test conditions (condensation and no condensation) supported the linear model, the results were greater than 0.900 for both test conditions and fabric directions. The results of the analysis of variance showed that the difference between all of the elements (machine, direction, fabric, and time) was statistically significant, for the first set of tests. There was not a statistical significance between the machines for the second set of tests. The difference between fabrics, directions, and time are to be expected because the fabrics are different in strength (e.g. fabric A was stronger than fabric D originally), the warp direction was stronger than the fill direction originally (except for fabric B), and a decrease in strength over time is expected due to UV exposure. However, the machines should ideally show identical results. There are differences between the machines that may explain these results, in the first set of tests. First, the QUV was set at an irradiance level of 0.72 (the UVCON did not have an adjustable irradiance level). Second, the QUV had a "solar eye", which made rotation of light tubes unnecessary (the light tubes in the UVCON were rotated every 400-450 hours). Finally, the UVCON warmed up quicker than the QUV (the UV temperature of 70° C was reached in approximately 10-15 minutes in the UVCON and approximately 80 30 minutes in the QUV), after cycle changes (condensation to ultraviolet). This would not have been a factor in the 24 hour UV test, because there was not a cycle change. This does not mean that the UVCON is better than the QUV, or vice versa. Both machines show favorable results in correlation analysis and both machines ranked the fabrics similarly under most exposure conditions (from best to worst C, A, B). I feel that either machine could be used for accelerated weathering tests. However, results must be analyzed with caution, and more testing is needed. RECOMMENDATIONS Further research is needed to provide additional support to these conclusions. I propose the following: 1. Perform a different test, ASTM D 5034 "Breaking Force and Elongation of Textile Fabrics (Grab Test)." This may minimize tensile result variation and would make it possible to immediately perform the tensile tests upon exposure completion. 2. Perform test under different exposure conditions. For example, using UV-B light tubes and different irradiance levels. 3. Perform tests with solid polymers instead of woven material and try different polymers, possibly polyethylene or polystyrene. 4. Use infrared spectrophotometers to monitor 81 chemical changes, such as carbonyl content. 5. Test more samples and critical time intervals. I believe the critical time intervals are between 100 and 300 hours, with continuous uv exposure. Based on the results of this study, I would recommend the USDA uses a specification of 70% retention after 150 hours, with a continuous uv exposure condition, in either the QUV or UVCON. The continuous uv exposure condition is more severe than the 8 hour UV (4 hour condensation) cycle, which decreases test time. However, comparing tests results between the two conditions, based on the length of uv exposure, gave similar results for both machines (QUV and UVCON) and conditions (condensation and no condensation). Therefore, I believe that either machine may be used to produce similar results for uv degradation resistance due to accelerated weathering studies. The results also showed that there was not a significant difference between the test condition with water (8 hour UV, 4 hour condensation cycle) and the test condition without water (continuous uv). Therefore, I propose that studies can be done with a continuous uv condition, reducing testing time. APPENDIX 82 AH ummhv >D m 1 <>Oz< "5H QHQMB .Houum cumsqm some HospHmoH on» do woman can ooHuuunm HHd .poszuxo coon o>mn mosHm> mchmHE 0 0000.0 vmoo.0 0600.0 Hmm0.0 0000.0 momv.0 Hbmm.0 0000.0 0000.0 mwm0.0 0000.0 0000.0 0000.0 0000.0 0000.0 H0>0H .mHm va.m 00¢.m HN¢.¢ bmw.H mmm.m vbw.0 mmN.H mmH.m 0H0.0N NHm.N «mm.bm mmm.ovH 00H.bm 00H.¢mm mmo.vMH bvw mmmem.mm mmm mmmH.emm 0H mmHm.mmm m ¢mHm.NH¢ m m¢mm.mmH mH «www.mom mH OOHm.mm H mmmH.H~H m mmmb.bbm m Hmo>.H¢mH m o¢m~.vmm m HmmH.vmmm mH 5N0.HHHMH H www.mmmm H me.vomwm m mmm.>ommH m mumsqm saw: u p N¢N.mMMHm omm.vmmm me.mmmH mmm.mmma www.mwmm 00m.mm¢m 0Hm.mm 0hr.mmb mmb.mw¢m mHH.mNmm Nmm.NOb m0m.¢bmmv m0.HHHMH mm.mmmm 0N.mmommH mm.Nthm AdDDHmmm Qum< Gum mud de Dm< DU 0m 0m 94 0‘ m< mZOHBUs . mpmoH no“ oucmHum> uo mHm>Hmnd 83 A¢UQHmmm m000.0 oomH.0 NbH0.0 0000.0 H000.0 mmom.0 NOH0.0 0N00.0 0000.0 0H¢v.0 0000.0 0000.0 0000.0 0000.0 0000.0 mmm.N mm¢.H vmv.m mmb.m mmm.m mN0.H w¢m.m mv¢.m mNH.mH Hom.0 mmr.HN «m5.mrm mmm.¢¢ bbm.m>m va.MMH AH umwfiv >D mDOSCfluGOU 1 £5024 "0H OHQMB .uouno mumsqm some HmspHmou onu co pommn mum moHumulm HHd .pmpsHuxm coma m>mn mosHm> mchmHE o N0¢mm.m0H vNNm.mbN 000N.HmH bmmm.vmm Hmv¢.mmm 0H00.mmm HbN0.mmH mmmH.¢mN mmmm.mmm ¢m>0.¢mmH OHNH.mm mmom.b¢mm mwb.H0mmN me.Nmmv mmm.mmNmN HON.¢mmma Hm0.bMva N0¢.mmmv vMb.bom omm.vaH 0m0.meNH mmm.0mmm bN0.mmH bmH.mmbH MHm.mMHN mmm.mmm¢ mmm.mbm mmH.mm¢0¢ wb.H0mmN N0.N0m¢ MN.H0bmmH 00.NomH¢ mZOHEU¢¢mBZH Qum< Gum DU< de um< DU 9m 0m Q¢ 04 md coHuooquun mHm>Hmc< ocHnUMEuU «mmeHuum UHHQMMI¢ mfiumhmm 2H¢Z Hm>mH .mHm oHumuim mmumsvm mo msnm HHH oQ>B 1 «upmoH MOM mocmHHm> mo 84 Ohm: .IH game. >5 m - «>024 "mH 0Hbme .HOHHO whmgm CMUE HMSUfiQflH mnu CO UOGMQ 0H“ mOfiUMHIm HH‘ .vmvnHoxm cmmb w>ms mmsHm> 0chmHE ~m¢ Il[1'[I'll]III.llll|"|""l"|"'|'l""|'0'l"""""'| 8 5" 'l'l" '00'00000 8' '0 0000.0 0000.0 0H00.0 NH00.0 vam.0 v0Hm.0 00b¢.0 0000.0 0000.0 0N00.0 0Hmo.0 0mmm.0 0HHN.0 0000.0 00b0.0 MH0.0 000.0 000.0 ¢vb.H 000.H H00.H H00.0 Nm0.0 000.0 000.0 000.H Nom.H 0bm.H m0F.HN 00m.N HHMH0.0MH 000mm.Hb 00¢Nm.0m 000H0.b00 0NONN.N¢N HHO0H.HOH 00000.00H 00000.MNH Nmm0m.mHH mva0.00 00000.000 00000.00N 0000.00H 0000.0HN H0bm.bmom 0000.0mm QNNQ‘Q‘HCDCDNQ‘CD NQ'Hr-l 000.0000N ¢¢H0.00m 000N.0NN 00N0.m0bH 0H0b.bm0H 0Nb0.0¢¢H 0000.00H 00HN.00¢ Hm¢m.m0v 0N00.00H mmH0.000H mHmH.m0HN 000.00H 000.0HN 0Hm.0HHNH 000.0Hb AdDDHmmm Qumd Gum cud Qmfi 004 GO am 00 ad Ud 04 monBU mo mHm>HMG¢ 85 0063 .AH 06090 >5 msoscHucoo - «>024 "om 0Hnme .HOHHG OHM—00¢ Emma: HMSUflmwh OEU CO Uflflflfl 0H0 GOMUMHIE HH‘ .0003Hox0 c000 o>mn mmaHm> mchmHE mmw ' 'l"---" 111llI'1‘-IIIIII'I|"'Illll-l"||'-'||"""l"""I'-"-l""l-"'-' '5 vaH. Hmm0. mvmm. 0000. ¢0N0. 0000. HHvH. 0000. 0000. «000. 0H00. ONOO. xmmH. H0 a0 H0 n0 . H030 OOOOOOOOOCO C000 '3‘ \D I‘ 0H0. HHN. 000. 000. 000. «00. 00h. 0HN. 0mv. 000. MHN. 00500.00H Hbmm¢.Hmm 0H0vmaom 00000.00 Hbm0m.00 Nvm0m.mHm mmmbv.MH 00000.000 00000.5Hm 00000.m0 00000.0 bNm00.00¢ mmm>.6HvH 0000.000 0000.000m «005.00H 0mm HN¢.H>>mm 0008000000. H4809 00H va.vommm 0400H000 0 >00m.HmmH 0004 4 0000.00H 000 m MMHv.00H . 004 0 >m0>.00> 004 0 ¢>¢H.mmmm 004 H mm>¢.MH 00 v mmvo.m00H 00 v m00m.H>~H 00 m 0H00.0NH 04 0 0000.0 04 0 mmom.000m 04 020H9040092H H mm>.0H¢H umxmuo H 000.mmm mCH£UMEou0 v mmm.0vaH mmEHuonm m mHv.000 UHHQMMun4 0900000 2H4: lull-01.311 l' ' II III" 4|-|"""'II'II'III!|"|I'"""'l'll’llllIll.Ili|""ll'l'-""'||--' 111,19'111"-"|Il'" ""'l|--'|"'l|"'-"l'-"'ll"lIII!""""'Il"-'l"|"" o: :0H30000000024Aoc, 04 «mmEHuov 900000 «mUmOHc 000 mosmHHm> uo mHm>Hmc4 86 Hawk .AH 00090 >5 0 1 4>Oz4 "HN wHQMP .Houum mumsvm :mmE HmschmH ms» :0 00mm0 mum moHumuum HH4 .0mosHoxm cmmn m>mn mmsHm> 0chmHE Nm0 88"- ' '|'5"55|II-'I-'5I'l'l'0‘-l"|"'||'"l"""""'l mmN 0Hm.0000b AQMBUNMMOUV A4HOB 00NOH0.00 00H 0b0.HHNbH A4DDHmmm N000.0 000.0 000m.N0 0 0H0.0Mb 0004 0000.0 000.0 000m.00 0 0M0.H0m 900 000N.0 m0N.H 0MNb.0NH N 000.HON 004 0NN0.0 H00.N 0000.0HN 0 000.000H 004 0000.0 be.N 0H00.00N 0 HH0.000N 0m4 >0MH.0 00N.N . 0000.0HN H 000.0HN 00 MHHm.0 MON.H 0N00.0HH 0 0H0.000 Om 0000.0 NON.N b00N.0HN 0 000.000 00 HON0.0 00H.0 00N0.0H N 000.bm Q4 MH00.0 N00.0 0000.000 N DHH.0HOH 04 0000.0 000.0H 00b0.NO0H 0 000.00bHH m4 mZOH804deZH 0000.0 000.0 HN00.b00 H N00.b00 uQNmufl 000H.0 0Hb.N 0000.00N H 000.00N wnflnumEou0 0000.0 000.00 00bH.m0H0 0 000.N000N 008H00um - 0000.0 HDO.N0 bN00.00H0 N 0Nb.bHNO OflHDMMUH4 0900000 2H4: Hw>mH 0H0 oHumuum mumsvm 2mm: .0 U mmumsvm 00 5:0 coHumHHm> 00 000500 mmxe - 1m om coH0000H600o2400om ma mmsfluoveomqmm momoHu 000 muanum> 00 mHm>Hm:< 87 Hawk .AH ummhv >0 msoscwucou n 45024 "00 wand? .Mouum mumzvm :me Hmsoflmmu may :0 memn mum mofiumn-m Had .UmUSHoxm cmmn m>mn mmsam> 020mm05 0M0 mmm Hmm.0mm00 Acmeommmouv 40000 mmmom.0mH 00H 000.000Hm Adanmmm 0000.0 000.0 Hmmm.moH 0 H00.m¢0 oumd m00H.0 000.H 0000.00H 0 00H.000 cum 0000.0 Hmm.0 0000.00 0 000.0mH 00¢ 0000.0 0H0.m 0m00.000 0 0m0.0mmm omd 0000.0 H00.0 0000.00 0 000.000 um< 0000.0 H00.0 0m00.00 H 000.00 no 0000.0 000.0 m0mm.0vm 0 mmm.000 om 0000.0 000.0 H000.H0 0 000.000 om H000.0 0mm.m 0000.0mm m 0mm.mo0 00 0000.0 mmH.0 mmmm.0H m 000.00 00 0000.0 00m.0H 000m.000~ 0 0mm.¢m00H m< moneu¢mmezH 0000.0 m00.0 MHN0.0 H Hmm.0 umxm a 0HH0.0 000.0 m0mo.m00 H 000.000 mcHsomsu 0 0000.0 mmm.0m 0000.0000 0 000.mmH0m mmsfluu m 0000.0 000.0H 0000.00mH m 000.H0Hm oHunmuou< meummmm 2H0: Hm>m0 0H0 oflumu-m mumsz :mm: .0 U mwumsvm 00 5:0 :Owumflhm> mo mohsom 0 - A0 00 COHuUMMflUUV0Z4A000 00 00®Efluov 000000 0NUMOHU H00 wUGmflHm> NO mflm>amc4 AN ummfiv >0 0 n 4>OZ4 u00 mHQMB .uouuw mumswm came Hmsvflmon may :0 cmmmn mum moHumnum HH4 .0mUDHoxu cmmn m>mn mmsHm> mafimmwe o I'IiI-llI||--'-"I'll"I'I'-'--'|"I-|-"|-I'-"--""""'ll--"l'|I'---""-"' 88 000 0H.m0000H 00090000000 40909 00H000.00 000 000.00000 A400Hm00 0000.0 000.0 H000.00 0H 000.000H 0004 0000.0 000.H 0000.00H 0 000.0HOH 000 0000.0 000.H 00H0.00H 0 000.000 004 0000.0 000.0 0000.H00 NH 000.0000 004 0000 0 000.H 000H.HOH NH 000.00HN 004 0000.0 000.0 0000.0 H 000.0 00 0000.0 000.0 0000.000 0 HH0.0000 00 0000.0 000.0 0000.00 0 000.000 00 0000.0 000.0H 0H00.HO0H 0 000.0000 04 HOH0 0 0H0.0 00H0.HHO 0 000.000 04 0000.0 000.00 0000.0000 0H 000.00000 04 monBU4MMBzH 0000.0 0H0.000 000.00000 H 000.00000 UCNuUUH0000 0000.0 000.0 000.00 H 000.00 6:00:030m500 0000.0 000.HOH 0HN.00HOH 0 000.00000 00GNmEfiu00 0000.0 000.0H 000.000H 0 0H0.H000 fiCNUflHQMMN4 0900000 2H4: Hm>mH 0H0 oflumu-m mumsvm 2mm: .m.0 mmumsvm 00 5:0 coflumHMm> mo mouzom mmumsvm 00 mEDm 000 0000 - mnCNvmoH ~00 mocmfium> 00 mfim>Hmc4 89 Am umohv >0 maoscfiucou - 0>oz¢ "0N mHnma .uouum mumzvm cams Hadonwu an» no Gummn mum mofiumuum HH< .0mcaHoxm cmmn m>mn mmaHm> mchmHE 0 000 00.00000H AomBUmmmouv AdHOB 00000.0HH 000 000.00000 A¢DQHmmm 0000.0 000.H 0000.00H NH 00H.0000 Qumd 0000.0 0HN.H 00HN.00H 0 0H0.000 Gum 0000.0 00H.o 0000.0H 0 000.00 90¢ 0H00.o 000.0 0H0o.000 NH H00.0H00 Dmd 0000.0 00H.H 000o.HOH NH 000.000H Dmd 0000.0 HOH.H 000H.00H H 00H.00H DU 0H00.0 000.0 000H.000 0 000.0000 Om H000.0 H00.H 0HHO.NNH 0 H00.000 Om 0000.0 000.0H 0000.0HOH 0 000.0000 Dd H000.o 000.0 0000.00 0 00H.00H Dd 0000.0 000.0H 0000.0000 NH 000.00000 m4 mZOHBUmH 0am oHumu-m mumsvm :mmz .0 0 mmumsvm 00 E30 COMuMMHm> mo muusom mwhmsvm mo mE:m HHH mm>0 - 000:00m0H MOM mocmHum> uo mfim>Hmcd 90 Table 25: 8 Hour UV, Test 1 — QUV A Warp 1 1 ‘ 2 3 1T 4 1 AVG §TD 100 Hours I T L Load [ 98.95 97.19 82.07 93.7 g 92.98 . 7.59 Ext 0.801 0.62 0.601 0.817 1 0.71 i 0.12 150 Hours T, Load 100.9 86.6 81 .53 98.74 91 .94 9.37 Ext 0.77 0.745 0.726 0.67 0.73 0.04 200 Hours Load 88.56 95.68 98.09 93.53 93.97 4.06 Ext 0.719 0.736 0.736 0.712 0.73 0.01 250 Hours Load 60.43 80.4 78.44 87.29 76.64 1 1 .45 Ext 0.563 0.785 0.582 0.541 0.62 0.1 1 300 Hours Load 73.66 88.78 63.62 88.78 78.71 12.33 Ext 0.608 0.64 0.55 0.581 0.59 0.04 400 Hours Load 57.66 65.23 66.79 72.03 65.43 5.94 Ext 0.49 0.509 0.519 0.47 0.50 0.02 500 Hours Load 63.3 53.53 71 .87 53.15 60.46 8.94 Ext 0.539 0.556 0.454 0.328 0.47 0.10 A Fill 100 Hours Load 58.71 74.17 67.84 64.05 66.19 6.50 Ext 0.844 0.675 0.705 0.605 0.71 0.1 0 150 Hours Load 56.03 58.98 59.97 59.87 58.71 1 .84 Ext 0.621 0.578 0.61 4 0.587 0.60 0.02 200 Hours Load 65.4 53.23 58.87 69.53 61 .76 7.18 Ext 0.639 0.434 0.433 0.756 0.57 0.1 6 250 Hours Load 52.75 59.1 7 47.97 54.76 53.66 4.65 Ext 0.407 0.65 0.395 0.508 0.49 0.12 300 Hours Load 45.26 59.1 9 46.98 50.6 50.51 6.20 Ext 0.534 0.664 0.337 0.385 0.48 0.15 400 Hours Load 56.43 45.61 35.89 39.7 44.41 8.96 Ext 0.509 0.483 0.458 0.407 0.46 0.04 500 Hours Load 31 .52 42.6 30.2 34.74 34.77 5.56 Ext 0.391 0.349 0.52 0.419 0.42 0.07 91 Table 25 (cont'd) TBfWarp 1 1 ' 2 1 3 4 4 T AVE 1 STD 100 Hours E ‘2 . Load 1 78.52 1 114.1 1 61.48 ‘ 77.53 1 82.91 ; 22.21 Ext l 0893‘ 0.724 ‘1 0.712 1 0.8351 0.79 1 0.09 150 Hours T l j 3 Load 87.41 92.99 73.37 75.541 82.33 9.41 Ext 0.657 0.691 0.625 1 0.734 1 0.68 0.05 200 Hours 1 I ' A Load 70.95 84.35 I 75.85] 86.17 . 79.331 7.17 Ext 0.592 0.645 0.824 0.76 0.71 0.1 1 250 Hours Load 73.88 66.5 71 .17 82.36 73.48 6.66 Ext 0.469 0.482 0.719 0.605 0.57 0.12 300 Hours Load 29.99 60.97 45.69 26.68 40.83 1 5.78 Ext 0.323 0.39 0.426 0.38 0.38 0.04 400 Hours Load 62.42 69.1 73.83 54.31 64.92 8.48 Ext 0.587 0.557 0.529 0.487 0.54 0.04 500 Hours Load Too britt for ten ile tests Ext 8 Fill 100 Hours Load 100.8 93.53 85.21 83.09 90.66 8.13 Ext 0.88 0.95 0.794 0.872 0.87 0.06 150 Hours Load 73.8 84.67 94.32 99.04 87.96 11.17 Ext 0.498 0.679 0.837 0.735 0.69 0.14 200 Hours Load 56.97 77.48 88.54 87.49 77.62 1 4.64 Ext 0.61 9 0.899 0.6 0.695 0.70 0.14 250 Hours Load 89.53 49.21 78.32 77.02 73.52 1 7.15 Ext 0.403 0.565 0.333 0.537 0.46 0.1 1 300 Hours Load 71.36 75.65 49.83 57.7 63.64 1 1 .97 Ext 0.613 0.671 0.588 0.568 0.61 0.04 400 Hours Load 14.63 21.83 19.41 19.97 18.96 3.07 Ext 0.379 0.271 0.446 0.44 0.38 0.08 500 Hours Too brittle for tensile tests Table 25 (cont'd) 92 ”E Warp 1 2 3 4 AV STD 100 Hours ' ' * . Load 79.19 74.9 83.25 1 90.63 81.99 1 6.69 Ext 0.598 0.698 0.672 0.506 0.62 i 0.09 150 Hours . i : Load 95.57 I 72.94 72.81 60.75 3 75.52 E 14.54 Ext 0.668 0.61 0.584 0.724 | 0.65 0.06 200 Hours Load 73.18 73.1 74.66 86.2 76.79 6.32 Ext 0.51 0.5 0.587 0.704 0.58 0.09 250 Hours 1 l 1 . Load ' 72.81 74.36 68.08 67.6 70.71 3.38 Ext 0.618 0.544 0.577 0.499 0.56 0.05 300 Hours Load 85.58 59.68 88.1 1 63.8 74.29 1 4.63 Ext 0.577 0.385 0.587 0.56 0.53 0.10 400 Hours Load 76.43 72.05 71 .25 58.36 69.52 7.78 Ext 0.593 0.558 0.555 0.439 0.54 0.07 500 Hours Load 71 .92 72.86 63.52 56.55 66.21 7.69 Ext 0.503 0.525 0.503 0.39 0.48 0.06 C Fill _ 100 Hours Load 79.33 83.89 58.28 67.1 1 72.15 1 1 .65 Ext 0.529 0.586 0.551 0.584 0.56 0.03 150 Hours Load 69.88 69.72 61 .4 72.99 68.50 4.97 Ext 0.461 0.587 0.446 0.583 0.52 0.08 200 Hours Load 42.76 85.34 73.74 57.53 64.84 1 8.62 Ext 0.413 0.663 0.58 0.463 0.53 0.11 250 Hours Load 71.25 53.4 58.25 51.11 58.50 9.00 Ext 0.663 0.635 0.646 0.369 0.58 0.14 300 Hours Load 66.39 62.04 51 .6 57.69 59.43 6.31 Ext 0.689 0.466 0.566 0.393 0.53 0.13 400 Hours Load 38.1 7 50.36 58.98 66.5 53.50 12.16 Ext 0.729 0.524 0.499 0.551 0.58 0.10 500 Hours Load 61.77 58.74 51.22 44.91 54.16 7.60 Ext 0.402 0.453 0.396 0.597 0.46 0.09 Table 25 (cont’d) 93 Tfilvarp 1 1 2 3 4 AVG TD 100 Hours 1 . 1 ; Load 1 65.61 1 70.2 1 74.42 89.13 , 74.84 g 10.18 Ext 7 0.82 0.693 3 0.979 1 0.843 0.83 ‘1 0.12 150 Hours 1 . 1 Load 79.76 80.81 g 69.83 68.43 74.71 6.48 Ext 0.68 0.849 I 0.93 0.689 . 0.79 0.12 200 Hours . ‘ 1 1 3 Load 69.02 47.97 67.89 63.09 61 .99] 9.70 Ext 0.843 0.773 0.859 0.855 0.83 3 0.04 250 Hours Load 66.1 5 47.87 46.55 63.95 56.1 3 10.35 Ext 0.695 0.431 0.557 0.463 0.54 0.12 300 Hours Load 36.1 1 42.17 58.12 66.87 50.82 14.17 Ext 0.554 0.605 0.633 0.579 0.59 0.03 400 Hours Load 31 .22 20.1 1 21.83 18.44 22.90 5.72 Ext 0.48 0.375 0.423 0.305 0.40 0.07 500 Hours Too britt for tensile tests D Fill 100 Hours Load 70.98 55.3 57.88 72.4 64.14 8.80 Ext 0.877 0.746 0.667 0.703 0.75 0.09 150 Hours Load 54.85 58.87 62.87 66.74 60.83 5.12 Ext 0.678 0.639 0.566 0.683 0.64 0.05 200 Hours Load 53.1 5 53.45 65.45 69.45 60.38 8.33 Ext 0.723 0.757 0.623 0.653 0.69 0.06 250 Hours Load 48.67 55.11 47.44 54.47 51.42 , 3.93 Ext 0.554 0.616 0.529 0.417 0.53 0.08 300 Hours Load 50.1 5 46.74 38.68 58.34 48.48 8.1 5 Ext 0.519 0.486 0.846 0.94 0.70 0.23 400 Hours Load 13.44 10.95 20 26.47 17.72 6.97 Ext 0.381 0.27 0.307 0.339 0.32 0.05 500 Hours Too brittle for ten ile tests Table 26: 8 Hour UV, Test 1 — UVCON 94 A Warp 1 2 3 I 4 . AVG STD 100 Hours ‘ T Load 97.56 75.89 107.8 86.28 91 .883 13.817 Ext 0.751 0.552 0.896 0.66 0.7148 1 0.1457 150 Hours . 1 Load 94.58 89.5 81 .07 73.45 1 84.65 9.3164 Ext 0.682 0.71 1 0.758 0.857 0.752 0.0767 200 Hours 1 Load 76.91 69.37 82.44 64.3 I 73.26 8.021 Ext 0.56 0.536 0.573 0.689 0.5895 0.0681 250 Hours Load 51 .54 65.26 70.52 71 .54 64.715 9.2043 Ext 0.597 0.558 0.564 0.656 0.5938 0.0449 300 Hours Load 53.32 66.36 67.41 76.16 65.813 9.416 Ext 0.63 0.474 0.61 8 0.691 0.6033 0.0919 400 Hours Load 51 .6 60.97 77.53 61 .96 63.015 10.744 Ext 0.532 0.373 0.602 0.41 5 0.4805 0.1053 500 Hours Load 45.69 49.1 5 42.76 52.87 47.61 8 4.3684 Ext 0.343 0.365 0.34 0.374 0.3555 0.01 66 A Fill 100 Hours Load 80.24 83.54 81 .13 75.54 80.1 13 3.352 Ext 0.628 0.61 1 0.655 0.652 0.6365 0.0209 150 Hours Load 55.7 52.1 1 66.09 58.17 58.018 5.929 Ext 0.572 0.529 0.591 0.585 0.5693 0.028 200 Hours Load 71.14 54.68 64.54 56.51 61.718 7.6025 Ext 0.551 0.481 0.594 0.513 0.5348 0.0488 250 Hours Load 50.07 50.2 46.44 48.97 48.92 1 .743 Ext 0.389 0.716 0.416 0.379 0.475 0.1614 300 Hours Load 48.3 52.62 47.28 37.58 46.445 6.3471 Ext 0.399 0.418 0.457 0.341 0.4038 0.0483 400 Hours Load 39.57 30.55 53.21 34.71 39.51 9.8491 Ext 0.473 0.31 0.607 0.467 0.4643 0.1215 500 Hours Load 38.04 37.99 24.62 33.1 5 33.45 6.31 77 0.313 0.392 0.315 0.344 0.341 0.0368 95 Table 26 (cont’d) FWarp '1 1 i 2 ; 3 4 AVE 4 §TD 100 Hours 9 7 f Load 93.02 64.547 1011 78.71; 84.318L 16.09 Ext 0.769 0.723 0.82:?j 0.7951 0.77751 0.0425 150 Hours 1 7 Load 94.23 90.15 106} 70.851 90.308 14.609 Ext 0.793 0.669 0.745L 0.5131r 0.681 0.1225 200 Hours l f 1 Load 90.63 95.73 73.45 70.01 82.455 12.636 Ext 0.539 0.728 0.743 0.728 0.6845 0.0973 250 Hours 1 Load 85.23 95.78 57.737 73.07 77.953 16.366 Ext 0.585 0.749 0.545 0.629 0.6271 0.0883 300 Hours 1 Load 64.08 69.32 74.68 49.26 64.335 10.942 0.614 0.508 0.69 0.471 0.5708 0.1 400 Hours Load Too britt for ten ile tests Ext 500 Hours Load Too britt for ten ile tests Ext B Fill 100 Hours Load 72.97 111.5 99.33 78.12 90.48 18.07 Ext 0.87 0.741 0.743 0.946 0.825 0.1007 150 Hours Load 90.82 82.5 97.83 70.63 85.445 11.697 Ext 0.666 0.667 0.751 0.612 0.674 0.0574 200 Hours Loa 66.95 84.72 60.56 85.21 74.36 12.522 Ext 0.571 0.623 0.661 0.644 0.6248 0.0391 250 Hours Load 46.34 56.46 24.94 55.81 45.888 14.711 Ext 0.435 0.369 0.393 0.381 0.3945 0.0287 300 Hours Load 39.36 28.94 30.34 22.5 30.285 6.9468 Ext 0.309 0.231 0.254 0.399 0.2983 0.0747 400 Hours Load Too brittle for tensile tests Ext 500 Hours Too brittle for ten ile tests Table 26 (cont’d) 96 FWarp 1 1 3 4 3 4 1 AV STD 100 HourSl l f ‘ * Load 76: 102.9; 98.85 85.77 90.88 12.322 Ext 0.7181 0.823‘ 0.792} 0.635 0.7421 0.0838 150 Hours ' l 1 Load 73.21 59.79 86.55 93.231 78.195 14.826 Ext 0.495 0.401 0.714 0.6561 0.5665 0.1441 200 Hours 1 E 1 Load 92.05 65.74 78.71 82.311 79.703 10.881 Ext 0.609 0.781 0.603 0.614 0.6518 0.0863 250 Hours Load 78.52 76.46 83.7 73.1 77.945 4.4396 Ext 0.537 0.456 0.521 0.601 0.5288 0.0596 300 Hours Load 57.72 85.4 74.25 69.91 71.82 11.442 Ext 0.376 0.535 0.58 0.588 0.5198 0.0986 400 Hours Load 72.11 55.3 40.94 62.93 57.82 13.186 Ext 0.596 0.5 0.319 0.439 0.4635 0.116 500 Hours Loa 48.4 46.71 56.81 38.47 47.598 7.5192 Ext 0.42 0.396 0.449 0.239 0.376 0.0939 C Fill 100 Hours Load 75.79 75.73 82.04 63.25 74.203 7.879 Ext 0.513 0.589 0.707 0.595 0.601 0.0799 150 Hours Load 79.62 49.02 58.12 69.34 64.025 13.31 Ext 0.622 0.513 0.67 0.797 0.6505 0.1177 200 Hours Load 73.23 71.27 48.91 56.35 62.44 11.755 Ext 0.683 0.499 0.41 0.471 0.5158 0.1175 250 Hours Load 59.6 68.59 53.5 50.34 58.008 8.034 Ext 0.425 0.556 0.588 0.569 0.5345 0.0742 300 Hours Load 71.89 67.68 68.72 62.5 67.698 3.9003 Ext 0.527 0.498 0.451 0.509 0.4963 0.0324 400 Hours Load 59.09 55.28 58.15 58.28 57.7 1.6661 Ext 0.419 0.403 0.463 0.554 0.4598 0.0678 500 Hours Load 46.2 40.59 53.42 43.03 45.81 5.569 Ext 0.404 0.373 0.501 0.571 0.4623 0.0907 97 Table 26 (cont’d) FE Warp 1 1 : 2 1 3 - 4 Ave—1 STD 100 Hours1 1 1 E . Load; 60.241 67.031 45.21: 81.581 63.515; 15.105 Ext 0.619 0.951 0.6341 0.667 0.7178' 0.1568 150 Hours 1 1 Load 49.32 68.99 67.111 80.911 66.5831 13.03 Ext 0.519 0.752 0.6497 0.6431 0.6408} 0.0953 200 Hours 1 I 5 Load 57.26 39.09 52.431 65.971 53.6881 11.229 Ext 0.802 0.656 0.853I 0.867: 0.79451 0.0965 250 Hours 1 Load 43.44 61.45 58.47 42.17 51.383 9.9923 Ext 0.495 0.523 0.762 0.521 0.5753 0.1252 300 Hours Load 64.55 54.31 48.3 59.57 56.683 6.9793 Ext 0.748 0.479 0.522 0.548 0.5743 0.1193 400 Hours Load Too brittle for ten ile tests Ext 500 Hours Load Too brittle for ten ile tests Ext D Fill 100 Hours Load 76.54 64 55.25 57.13 63.23 9.6374 Ext 0.648 0.73 0.707 0.675 0.69 0.036 150 Hours Load 55.87 70.09 52.3 62.2 60.115 7.809 Ext 0.761 0.715 0.561 0.624 0.6653 0.0898 200 Hours Load 65.13 56.03 48.86 60.16 57.545 6.8822 Ext 0.74 0.582 0.482 0.609 0.6033 0.1063 250 Hours Load 70.12 44.27 37.61 65.88 54.47 15.952 Ext 0.675 0.838 0.395 0.622 0.6325 0.1831 300 Hours Load 46.93 31.6 46.28 52.35 44.29 8.8869 Ext 0.619 0.597 0.599 0.439 0.5635 0.0836 400 Hours Load Too brittle for tenslile tests Ext 500 Hours Too brittle for tensile tests Table 27: 8 UV, Test 2 — QUV 98 A Warp 1 1 2 E 3 4 1 AV .. STD 100 Hours 1 i 1 1 Load 83.7T 69.051 82.171 99.221 83.54 12.35 Ext 0.744 0.837 0.726 0.805 1 0.78 1 0.05 150 Hours 3 Load 111.5 83.49 81.53 91.03 91.89 13.70 Ext 0.921 0.779 0.794 0.84 0.83 0.06 200 Hours Load 103 75.22 81.91 71.73 82.97 14.01 Ext 0.721 0.631 0.793 0.835 0.75 0.09 250 Hours Load 80.91 52.78 93.85 86.36 78.48 1 7.93 Ext 0.561 0.34 0.63 0.721 0.56 0.16 300 Hours Load 80.59 66.36 50.6 76.85 68.60 1 3.43 Ext 0.735 0.616 0.387 0.561 0.57 0.14 400 Hours Load 79.76 84.97 64.1 3 74.9 75.94 8.88 Ext 0.512 0.526 0.535 0.459 0.51 0.03 500 Hours Load 68.19 54.04 67.44 64.62 63.57 6.54 Ext 0.42 0.495 0.38 0.386 0.42 0.05 A Fill 100 Hours Load 67.7 35.62 58.2 42.07 50.90 14.69 Ext 0.702 0.573 0.529 0.663 0.62 0.08 150 Hours Load 49.85 73.64 55.68 38.34 54.38 1 4.72 Ext 0.593 0.618 0.603 0.49 0.58 0.06 200 Hours Load 64.19 62.42 57.07 60.4 61 .02 3.05 Ext 0.473 0.54 0.528 0.503 0.51 0.03 250 Hours Load 48 60.64 48.72 53.83 52.80 5.84 Ext 0.465 0.502 0.58 0.434 0.50 0.06 300 Hours Load 45.91 43.89 57.72 53.64 50.29 6.50 Ext 0.436 0.519 0.433 0.456 0.46 0.04 400 Hours Load 38.25 49.74 48.78 42.25 44.76 5.47 Ext 0.391 0.579 0.385 0.329 0.42 0.1 1 500 Hours Load 28.99 34.71 33.5 40.38 34.40 4.69 Ext 0.429 0.298 0.293 0.51 0.38 0.1 1 Table 27 (cont'd) 99 fWarp 1 1 . 2 3 1 4 1 AVG 1 STD 100 Hours 1 1 1 1 T 5 Load 1 92.671 82.2 1 14.3 1 1 10.1 £ 99.82 g 15.02 Ext 1 0.671 0.717 1 0.7691 0.753 1 0.73 ‘ 0.04 150 Hours ' 1 . l l L Load 72.32 1 106.1 78.68 73.85 82.74 1 15.81 Ext 0.803 0.797 0.8 0.756 0.791 0.02 200 Hours 1 1 ' L Load 1 101.1 7 79.33 96.38 67.65 86.12 ' 15.46 Ext 1 0.681 0.663 0.647 0.683 0.67 0.02 250 Hours ' Load 49.05 89.15 63.36 84.19 71 .44 18.64 Ext 0.535 0.661 0.579 0.73 0.63 0.09 300 Hours Load 57.32 78.01 74.5 73.93 70.94 9.26 Ext 0.62 0.613 0.785 0.576 0.65 0.09 400 Hours Load 50.9 57.21 55.7 68.56 58.09 7.48 Ext 0.492 0.429 0.521 0.445 0.47 0.04 500 Hours Load Sample were too brittle fort tensile t ts Ext 8 Fill 100 Hours Load 90.12 126.4 87.52 107.2 102.81 17.99 Ext 0.718 0.965 0.671 0.729 0.77 0.13 150 Hours Load 86.09 88.7 103.8 68.19 86.70 14.60 Ext 0.723 0.56 0.714 0.72 0.68 0.08 200 Hours Load 74.71 72.67 95.44 74.2 79.26 1 0.82 Ext 0.481 0.533 0.658 0.463 0.53 0.09 250 Hours Load 51 .03 43.52 45.18 48.3 47.01 3.33 Ext 0.362 0.491 0.45 0.419 0.43 0.05 300 Hours Load 53.53 46.44 46.85 38.12 46.24 6.31 Ext 0.321 0.272 0.301 0.363 0.31 0.04 400 Hours Load 11.6 14.63 11.62 18.77 14.16 3.39 Ext 0.57 0.169 0.1 15 0.134 0.25 0.22 500 Hours Load Samples were too brittle fofi tensile tests Ext Table 27 (cont’d) 100 E Warp 1 1 2 3 4 AV STD 100 Hours 7; 1 1 Load 1 89.741 86.66 81.37 ’ 81.26 l 84.76 E 4.17 Ext 1 0.711 1 0.693 0.685 0.751 0.71 3 0.03 150 Hours ’ ' V Load 61.74 80.43 84.94 67.25 l 73.59 1 10.90 Ext 0.489 0.548 0.618 0.491 0.54 1 0.06 200 Hours 1 Load 79.06 89.1 50.01 58.42 69.15 1 18.05 Ext 0.619 0.606 0.438 0.3931 0.51 f 0.12 250 Hours 1 1 Load 63.54 65.45 74.25 79.79 70.76 7.62 Ext 0.525 0.44 0.527 0.702 0.55 0.1 1 300 Hours Load 54.01 69.88 62.79 56.74 60.86 7.05 Ext 0.359 0.566 0.373 0.633 0.48 0.14 400 Hours Load 77.85 72.7 65.64 62.31 69.63 6.99 Ext 0.457 0.506 0.556 0.452 0.49 0.05 500 Hours Load 56.64 61.93 65.56 71.46 63.90 6.23 Ext 0.398 0.41 0.406 0.446 0.42 0.02 C Fill 100 Hours Load 71 .25 79.25 64.64 66.25 70.35 6.57 Ext 0.68 0.604 0.617 0.492 0.60 0.08 150 Hours Load 67.68 75.65 77.4 72.3 73.26 4.28 Ext 0.605 0.524 0.617 0.697 0.61 0.07 200 Hours Load 52.56 58.55 62.98 60.27 58.59 4.41 Ext 0.564 0.396 0.617 0.553 0.53 0.10 250 Hours Load 53.83 52.35 45.77 67.09 54.76 8.94 Ext 0.449 0.524 0.392 0.689 0.51 0.1 3 300 Hours Load 52.43 53.66 50.82 60.32 54.31 4.1 7 Ext 0.573 0.453 0.372 0.41 6 0.45 0.09 400 Hours Load 49.99 40.21 49.58 53.1 3 48.23 5.58 Ext 0.48 0.475 0.484 0.427 0.47 0.03 500 Hours Load 40.19 57.29 36.72 45.66 44.97 9.00 Ext 0.28 0.382 0.377 0.39 0.36 0.05 101 Table 28: 8 Hour UV, Test 2 - UVCON A Warp 1 1 2 ' 3 1 4 1 AVG L §TD 100 Hours 1 3 1 ‘ Load 99.06 98.09 101.5 103.41 100.51 2.40 Ext 0.809 0.694 0.81 1 0.7397; 0.76 0.06 150 Hours 1 1 T Load 95.01 90.44 85.69 70.79 85.48 10.51 Ext 0.78 0.699 0.785 0.649 0.73 0.07 200 Hours Load 86.2 61.26 95.1 1 85.13 1 81 .93 14.48 Ext 0.682 0.664 0.785 0.71 ' 0.71 0.05 250 Hours Load 83.19 71.19 66.2 58.23 69.70 10.46 Ext 0.61 1 0.594 0.419 0.459 0.52 0.10 300 Hours Loa 86.47 69.69 73.77 72.83 75.69 7.40 Ext 0.545 0.523 0.583 0.67 0.58 0.06 400 Hours Load 71 .14 69.15 60.67 69.56 67.63 4.72 Ext 0.56 0.582 0.454 0.453 0.51 0.07 500 Hours Load 49.23 48.38 54.23 56.38 52.06 3.87 Ext 0.362 0.323 0.393 0.415 0.37 0.04 A Fill 100 Hours Load 78.9 63.36 58.34 55.01 63.90 10.57 Ext 0.628 0.59 0.493 0.585 0.57 0.06 150 Hours Load 75.25 47.52 64.1 1 69.45 64.08 1 1.94 Ext 0.81 0.69 0.543 0.6 0.66 0.12 200 Hours Load 55.68 50.9 54.87 67.68 57.28 7.24 Ext 0.56 0.509 0.574 0.552 0.55 0.03 250 Hours Load 52.27 61 .21 47.41 37.02 49.48 10.08 Ext 0.609 0.544 0.487 0.531 0.54 0.05 300 Hours Load 49.93 43.17 46.09 49.42 47.15 3.15 Ext 0.63 0.475 0.528 0.441 0.52 0.08 400 Hours Load 50.04 51 .97 44.4 45.07 47.87 3.71 Ext 0.401 0.434 0.447 0.368 0.41 0.04 500 Hours Load 34.52 35.54 30.12 33.58 33.44 2.35 Ext 0.278 0.378 0.28 0.353 0.32 0.05 Table 28 (cont’d) 102 Warp 1 2 1 3 4 AV STD 100 Hours 1 1 1 Load 103.6 97.29 71.17 82.681 88.69 14.60 Ext' 0.762 0.857 1 0.715 0.746 0.77 1 0.06 150 Hours 1 1 . Load 71 .73 1 93.81 59.38 ‘ 75.95 75.22 1 14.25 Ext 0.734 0.7641 0.7161 0.8371 0.761 0.05 200 Hours 1 1 Load 89.61 68.97 89.1 81 .72 82.35 9.62 Ext 0.677 0.65 0.567 0.657 0.64 0.05 250 Hours Load 63.87 69.4 78.39 66.01 69.42 6.40 Ext 0.433 0.61 1 0.603 0.609 0.56 0.09 300 Hours Load 56.62 87.6 75.3 77.7 74.31 12.94 Ext 0.529 0.55 0.531 0.639 0.56 0.05 400 Hours Load 43.41 58.82 71 .49 60.4 58.53 1 1.55 Ext 0.32 0.456 0.417 0.351 0.39 0.06 500 Hours Load Samples were too brittle for tensile t Ext 8 Fill 100 Hours Load 85.42 1 08 95.57 88.94 94.48 9.95 Ext 0.782 0.773 0.981 0.741 0.82 0.1 1 150 Hours Load 79.92 79.65 100.6 81 .6 85.44 10.14 Ext 0.615 0.98 0.838 0.797 0.81 0.15 200 Hours Load 93.56 89.61 70.6 81.15 83.73 10.17 Ext 0.563 0.463 0.57 0.639 0.56 0.07 250 Hours Load 54.82 44.46 54.66 32.78 46.68 1 0.46 0.31 6 0.297 0.337 0.255 0.30 0.03 300 Hours Load 28.51 33.72 32.97 31 .89 31 .77 2.30 Ext 0.16 0.299 0.212 0.267 0.23 0.06 400 Hours Load 15.52 15.89 9.557 12.19 13.29 2.99 Ext 0.776 0.117 0.104 0.098 0.27 0.33 500 Hours Load Samples were too brittle for tensile tests Ext Table 28 (cont’d) 103 Warp 1 1 1 2 3 1 4 AVG STD 100 Hours r 1 4 , Load 99.381 74.85 : 100.3 i 93.66 g 92.05 1 11.84 Ext 0.775 0.691 0.766 1 0.7441 0.741 0.04 150 Hours 1 ' Load 78.68 71 .76 88.89 1 82.25 80.40 7.14 Ext 0.71 0.8 0.517 0.57 0.65 . 0.13 200 Hours 1 1 Load 73.15 71 .49 87.52 87.79 79.99 8.88 Ext 0.625 0.63 0.653 0.717 0.66 0.04 250 Hours Load 94.6 85.93 96.81 92.67 92.50 4.70 Ext 0.769 0.665 0.683 0.578 0.67 0.08 300 Hours Load 80.05 82.39 74.58 78.52 78.89 3.28 Ext 0.615 0.566 0.493 0.594 0.57 0.05 400 Hours Load 76.59 65.83 55.1 9 65.4 65.75 8.74 Ext 0.448 0.432 0.329 0.575 0.45 0.10 500 Hours Load 65.66 38.25 44.13 64.16 53.05 13.92 Ext 0.418 0.276 0.305 0.483 0.37 0.10 C Fill 100 Hours Load 75.76 60.67 58.98 76.35 67.94 9.40 Ext 0.54 0.527 0.594 0.577 0.56 0.03 150 Hours Load 72.72 65.13 60.32 59.92 64.52 5.96 Ext 0.573 0.609 0.537 10.561 0.57 0.03 200 Hours Load 57.53 69.96 76.48 67.62 67.90 7.86 Ext 0.416 0.765 0.64 0.527 0.59 0.15 250 Hours Load 50.31 59.76 58.34 52.03 55.1 1 4.64 Ext 0.638 0.576 0.418 0.576 0.55 0.09 300 Hours Load 58.5 42.68 72.78 67.36 60.33 13.16 Ext 0.499 0.443 0.546 0.513 0.50 0.04 400 Hours Load 53.99 53.93 58.12 56.19 55.56 2.01 Ext 0.399 0.341 0.51 0.358 0.40 0.08 500 Hours Load 38.47 51 .01 52 52.72 48.55 6.76 Ext 0.444 0.51 9 0.476 0.363 0.45 0.07 or! 9 E114» E Na: \ h 104 Table 29: Continuous UV, Test 1 — QUV A Warp 1 2 1 3 J 4 1 AVG : STD 66 Hours 1 1 1 1 Load 95.38 95.6 87.95 1 84.38 1 90.83 1 5.58 Ext 0.638 0.821 0.588 0.75 0.70 1 0.11 100 Hours Load 92.56 89.96 91 .36 87.84 90.43 2.03 Ext 0.82 0.798 0.853 0.804 0.82 0.02 133 Hours 1 1 Load 77.18 84.78 68.67 73.23 75.97 6.83 Ext 0.58 0.836 0.626 0.583 0.66 0.12 166 Hours Load 47.65 83.7 80.89 95.1 1 76.84 20.41 Ext 0.657 0.71 0.81 0.616 0.70 0.08 200 Hours Load 87.46 88.94 75.38 88.91 85.17 6.56 Ext 0.736 0.61 1 0.538 0.632 0.63 0.08 266 Hours Load 72.3 56.05 67.01 70.28 66.41 7.24 0.467 0.527 0.425 0.606 0.51 0.08 333 Hours Load 50.07 65.72 52.81 46.76 53.84 8.30 Ext 0.408 0.403 0.41 0.39 0.40 0.01 A Fill 66 Hours Load 64.54 83.62 62.12 58.98 67.32 1 1.1 1 Ext 0.576 0.593 0.625 0.543 0.58 0.03 100 Hours Load 67.1 1 68.27 65.45 64.27 66.28 1 .77 0.563 0.689 0.573 0.733 0.64 0.08 133 Hours Load 64.48 60.72 56.4 58.9 60.13 3.40 Ext 0.6 0.65 0.789 0.724 0.69 0.08 166 Hours Load 54.68 67.49 55.36 53.32 57.71 6.57 Ext 0.695 0.547 0.553 0.857 0.66 0.1 5 200 Hours Load 64.27 69.1 3 60.38 54.1 5 61 .98 6.33 Ext 0.508 0.608 0.524 0.609 0.56 0.05 266 Hours Load 49.23 43.62 55.1 9 45.8 48.46 5.05 Ext 0.434 0.493 0.446 0.435 0.45 0.03 333 Hours Load 31 .73 32.1 3 35.95 53.05 38.22 10.07 Ext 0.337 0.375 0.607 0.409 0.43 0.12 Table 29 (cont’d) 105 TYWarp 1 1 2 3 4 AVG—' _STD 66 Hours 1 1 1 1 1 Load 95.621 97.02 72.97 86.041 87.91 1 11.09 Ext 0.9531 0.918 0.931 0.841 0.91 i 0.05 100 Hours 1 Load 94.41 100.2 89.53 83.37 91 .88 7.15 Ext 0.995 0.867 0.92 0.857 0.91 . 0.06 133 Hours ' Load 100 69.42 90.36 86.71 86.62 1 12.77 Ext 0.857 0.945 0.671 1 .044 0.88 0.16 166 Hours Load 61.99 79.01 80.48 102.5 81.00 16.61 Ext 0.738 1 .093 0.805 0.799 0.86 0.16 200 Hours Load 69.02 75.36 51.68 91.1 1 71.79 16.31 Ext 0.553 0.677 0.603 0.707 0.64 0.07 266 Hours Load 43.95 56.97 55.95 38.31 48.80 9.15 Ext 0.481 0.667 0.5 0.35 0.50 0.13 333 Hours Load 36.05 58.44 55.44 53.1 8 50.78 1 0.05 Ext 0.835 0.607 0.361 0.453 0.56 0.21 B Fill 66 Hours Load 87.95 1 16.4 1 18.3 74.15 99.20 21 .72 Ext 0.739 0.968 0.944 0.66 0.83 0.15 100 Hours Load 82.1 94.07 85.45 1 00.8 90.61 8.46 Ext 1.136 0.821 1.007 0.846 0.95 0.15 133 Hours Load 83.73 49.05 68.1 3 93.66 73.64 1 9.47 Ext 0.821 0.737 0.374 0.848 0.70 0.22 166 Hours Load 35.19 30.66 53.72 51 .89 42.87 1 1 .65 Ext 0.283 0.496 0.314 0.383 0.37 0.09 200 Hours Load 27.84 23.06 30.6 20.64 25.54 4.51 Ext 0.1 82 0.154 0.233 0.906 0.37 0.36 266 Hours Load 1 1 .25 10.47 19.57 17.74 14.76 4.57 Ext 1 .086 0.681 0.853 0.247 0.72 0.35 333 Hours Load Ext Samples were too brittle for tensile t Table 29 (cont'd) 106 E Warp j 1 2 3 4 AV STD 66 Hours 1 1 . ; Load 106.1 103.5: 101.4 » 92.86: 100.97 1 5.74 Ext 0.805 1 0.8631 0.868 L 0.8724. 0.85 ' 0.03 100 Hours s I T ; ,¢ Load 99.27 101.6 99.33 93.93 1 98.53 ' 3.25 Ext 0.754 0.315 0.995 0.777 g 0.84 0.1 1 133 Hours Load 79.09 89.4 96.59 86.17 87.81 7.27 Ext 0.626 0.65 0.769 0.849 0.72 0.10 166 Hours Load 62.71 78.95 75.09 39.17 63.98 1 7.93 Ext 0.554 0.63 0.559 0.561 0.58 0.04 200 Hours Load 66.58 80.91 81 .58 65.02 73.52 8.94 Ext 0.613 0.726 0.505 0.496 0.59 0.1 1 266 Hours Load 87.65 74.66 81 .53 84.94 82.20 5.61 Ext 0.543 0.529 0.619 0.542 0.56 0.04 333 Hours Load 54.63 74.42 50.12 49.42 57.15 1 1 .74 Ext 0.447 0.557 0.395 0.365 0.44 0.08 C Fill 66 Hours Load 70.25 71 .36 68.83 75.6 71.51 2.92 Ext 0.656 0.941 0.656 0.594 0.71 0.16 100 Hours Load 73.32 62.63 74.47 72.99 70.85 5.52 Ext 0.841 0.688 0.487 0.681 0.67 0.15 133 Hours Loa 58.31 72.67 62.87 66.28 65.03 6.05 Ext 0.689 0.814 0.739 0.786 0.76 0.05 166 Hours Loa 79.14 85.48 55.36 69.02 72.25 1 3.14 Ext 0.832 0.719 0.585 0.713 0.71 0.10 200 Hours Load 66.47 64.59 72.94 78.25 70.56 6.25 Ext 0.596 0.588 0.863 0.567 0.65 0.14 266 Hours Load 45.02 47.62 85.42 67.3 61.34 18.89 Ext 0.409 0.574 0.565 0.54 0.52 0.08 333 Hours Load 48.78 50.39 64.21 55.44 54.71 6.94 Ext 0.515 0.529 0.584 0.459 0.52 0.05 Table 29 (cont'd) 107 TJTNarp . 1 2 g 3 1 4 AVG" _STo 66 Hours 9 . 1 1 1 I Load 87.25 94.71 75.33 ‘ 62.71 1 80.00 14.02 Ext 0.926 0.853 0.844 1.337 1 0.99 1 0.23 100 Hours 1 ' Load 78.71 65.071 60.19 88.863 73.21 3 13.05 Ext 0.678 0.685 1.037 0.849 0.81 1 0.17 133 Hours Load 74.07 81 .53 69.15 I 59.92 71.17 9.06 Ext 0.939 0.687 0.828 0.667 0.78 0.1 3 166 Hours Load 81.1 55.68 86.23 61.32 71.08 14.86 Ext 0.855 0.848 0.858 0.692 0.81 0.08 200 Hours Load 35.87 49.1 54.66 52 47.91 8.34 Ext 0.648 0.843 0.473 0.749 0.68 0.16 266 Hours Load Samples were too brittle for tensile t ts Ext 333 Hours Load Sample were too brittle for tensile tegsts Ext . D Fill 66 Hours Load 71 .6 89.83 74.87 54.2 72.63 14.62 Ext 0.688 0.747 0.67 0.752 0.71 0.04 100 Hours Load 74.71 63.52 74.28 71 .44 70.99 5.19 Ext 0.817 0.6 0.991 0.701 0.78 0.17 133 Hours Load 61 .18 67.14 54.04 59.95 60.58 5.37 Ext 0.637 0.729 0.892 0.643 0.73 0.12 166 Hours Load 63.7 67.14 48.81 59.52 59.79 7.96 Ext 0.704 0.681 0.709 0.926 0.76 0.1 1 200 Hours Load 43.92 36.54 48.43 32.94 40.46 7.01 Ext 0.418 0.415 0.579 0.441 0.46 0.08 266 Hours Load 35.54 47.7 28.1 9 38.93 37.59 8.09 Ext 0.297 0.45 0.322 0.501 0.39 0.10 333 Hours Load Samples were too brittle for tensile t ts 108 Table 30: Continuous UV, Test 1 — UVCON A Warp J 1 ‘ 2 1 3 j 4 , AVG 1 STD 66 Hours ' 1 1 1 Load 95.46 95.78 81 .48 99.17 ' 92.97 7.84 Ext 0.854 1.122 0.745 0.777 0.87 0.17 100 Hours Load 90.79 102.3 78.01 93.99 91 .27 10.08 Ext 0.617 0.706 0.883 0.795 0.75 0.1 1 133 Hours Load 95.44 75.81 86.36 79.14 84.19 8.70 Ext 0.629 0.558 0.924 0.678 0.70 0.16 166 Hours Loa 79.6 76.1 1 74.71 79.81 77.56 2.55 Ext 0.661 0.619 0.646 0.609 0.63 0.02 200 Hours Load 90.58 67.76 63.79 61 .21 70.84 13.44 Ext 0.662 0.547 0.535 0.568 0.58 0.06 266 Hours Load 59.81 46.39 58.28 50.2 53.67 6.43 Ext 0.412 0.422 0.489 0.358 0.42 0.05 333 Hours Load 34.47 51 .38 35.95 62.63 46.1 1 13.41 Ext 0.383 0.31 3 0.249 0.374 0.33 0.06 A Fill 66 Hours Load 62.87 58.5 53.21 77.21 62.95 10.30 Ext 0.581 0.609 0.763 0.686 0.66 0.08 100 Hours Load 64.08 66.66 56.83 68.27 63.96 5.06 Ext 0.61 7 0.589 0.65 0.474 0.58 0.08 133 Hours Load 64.62 63.19 55.49 50.74 58.51 6.55 Ext 0.567 0.567 0.523 0.65 0.58 0.05 166 Hours Load 48.32 57.29 55.41 46.5 51 .88 5.27 Ext 0.61 1 0.465 0.48 0.337 0.47 0.1 1 200 Hours Load 47.79 49.4 42.6 53.1 48.22 4.36 Ext 0.402 0.424 0.357 0.498 0.42 0.06 266 Hours Load 42.28 40.97 45.07 34.66 40.75 4.40 Ext 0.394 0.3 0.421 0.308 0.36 0.06 333 Hours Load 32.43 21 .72 31 .6 27.87 28.41 4.88 Ext 0.293 0.323 0.309 0.252 0.29 0.03 Table 30 (cont’d) 109 E Warp 1 2 3 4 AVG—_"1$To 66 Hours , 1 ; Load 114.6 69.021 102.5 102.31 97.11 19.59 Ext 0.965 1.0421 0.972 0.91 1 0.97 0.05 100 Hours 1 , Load 96.54 81.8 96.21 86.85 1 90.35 i 7.26 0.72 0.729 0.856 0.927 1 0.8L 0.10 133 Hours ' 1 Load 66.07 107.8 92.21 80.72 1 86.70 17.67 Ext 0.691 0.875 0.863 1 .045 0.87 0.14 166 Hours Load 41.96 92.94 60.13 75.14 67.54 21.70 Ext 0.6 0.772 0.965 0.809 0.79 0.1 5 200 Hours Load 84.64 52.05 77.37 61 .37 68.86 14.83 Ext 0.553 0.834 0.591 0.62 0.65 0.13 266 Hours Load 53.64 48.08 56.7 48.1 1 51.63 4.27 Ext 0.62 0.519 0.584 0.477 0.55 0.06 333 Hours Load Samples were too brittle for tensile tests Ext 8 Fill 66 Hours Load 108.1 96.97 91.33 103.6 100.00 7.37 Ext 0.859 0.909 0.722 0.879 0.84 0.08 100 Hours Load 56.21 95.22 83.36 1 15.5 87.57 24.76 Ext 0.61 0.778 0.54 0.846 0.69 0.14 133 Hours Load 49.18 54.25 85.56 89.96 69.74 20.99 Ext 0.687 0.571 0.631 0.659 0.64 0.05 166 Hours Load 39.1 9 26.6 40.94 21 .5 32.06 9.50 Ext 0.281 0.322 0.487 1 .061 0.54 0.36 200 Hours Load 24 31 .44 30.42 13.29 24.79 8.34 Ext 0.21 0.197 0.42 0.182 0.25 0.1 1 266 Hours Load 20.7 1 1 .92 9.262 16.59 14.62 5.06 Ext 0.223 0.321 0.23 0.308 0.27 0.05 333 Hours Load Sample were too brittle for tensile tefts .— fif.\fi F _(L‘Q F Table 30 (cont’d) 110 {Warp 1 2 3 7 4 AVG—T TD 66 Hours : 1 . ‘ Loa 84.7 ’ 98.79 89.96 1 99.76 E 93.30 7.23 Ext 0.637 0.759 0.749 0.624 1 0.69 0.07 100 Hours 1 Load 65.5 80.21 63.71 72.64 70.51 . 7.53 Ext 0.4471 0.5991 0.541 ‘ 0.738 1 0.58 ‘ 0.12 133 Hours ' Load 78.44 90.82 80.21 85.21 83.67 5.56 Ext 0.593 0.707 0.961 0.721 0.75 0.15 166 Hours Load 71.44 58.5 73.91 71.7 68.89 7.01 Ext 0.583 0.449 0.571 0.569 0.54 0.06 200 Hours Load 76.62 89.69 89.85 70.2 81 .59 9.80 Ext 0.526 0.619 0.598 0.454 0.55 0.07 266 Hours Load 56.1 1 61 .66 60.43 82.66 65.22 1 1 .87 Ext 0.495 0.425 0.464 0.52 0.48 0.04 333 Hours Load 54.9 52.1 1 56.05 67.36 57.61 6.71 Ext 0.516 0.347 0.383 0.415 0.42 0.07 C Fill 66 Hours Load 82.44 92.62 77.83 81 .48 83.59 6.34 Ext 0.558 0.846 0.631 0.742 0.69 0.13 100 Hours Load 72.59 62.66 59.84 66.23 65.33 5.50 Ext 0.49 0.534 0.681 0.721 0.61 0.1 1 133 Hours Load 57.74 51.01 65.37 77.23 62.84 1 1 .25 Ext 0.687 0.587 0.671 0.688 0.66 0.05 166 Hours Load 53.53 51.19 64.21 70.15 59.77 8.94 Ext 0.595 0.773 0.54 0.509 0.60 0.12 200 Hours Load 54.39 52.86 60.67 44.94 53.22 6.47 Ext 0.566 0.517 0.427 0.809 0.58 0.16 266 Hours Load 49.42 48.05 45.4 54.55 49.36 3.84 Ext 0.439 0.531 0.659 0.525 0.54 0.09 333 Hours Load 44 40.1 3 47.22 49.72 45.27 4.1 5 Ext 0.403 0.37 0.399 0.375 0.39 0.02 Table 30 (cont’d) 111 'EWarp 1 2 3 4 AVG STD 66 Hours 1 L 1 Load 75.1 11 93.74 101.6 1 66.03 V 64.67 15.75 Ext 0.821 1 0.926 0.889“ 0.9831 0.901 0.07 100 Hours 7 1 1 Load 88.46 89.26 81 .13 98.15 1 89.25 1 6.97 Ext 0.933 0.705 0.627 0.907 I 0.79 0.15 133 Hours = 1 Load 62.47 81 .42 59.49 65.8 67.30 9.76 0.827 0.671 0.731 0.893 0.78 0.10 166 Hours Load 35.97 59.36 23.33 66.9 46.39 20.24 Ext 0.575 0.427 0.531 0.541 0.52 0.06 200 Hours Load 29.1 32.46 38.9 34.68 33.79 4.11 Ext 0.565 0.507 0.509 0.292 0.47 0.12 266 Hours Loa Samples were too brittle for tensile t ts Ext 333 Hours Load Samples were too brittle for tensile t ts Ext D Fill 66 Hours Load 51 .09 73.32 66.93 69.58 65.23 9.78 Ext 0.92 0.642 0.669 0.685 0.73 0.13 100 Hours Load 62.66 88.67 64.16 57.91 68.35 13.81 Ext 0.633 0.731 0.85 0.647 0.72 0.10 133 Hours Load 56.51 38.34 51 .36 39.92 46.53 8.83 Ext 0.649 0.457 0.349 0.573 0.51 0.13 166 Hours Load 31 .76 42.93 56.64 43.97 43.83 10.18 Ext 0.441 0.491 0.473 0.469 0.47 0.02 200 Hours Load 7.302 25.4 1 9.95 6.631 1 4.82 9.34 Ext 0.258 0.461 0.512 0.273 0.38 0.13 266 Hours Load Samples were too brittle for tensile tests Ext 333 Hours Samples were too brittle fon tensile te1sts 112 Table 31: Continuous UV, Test 2 — QUV A Warp 1 f 3 1 4 AVTTTD 66 Hours ' 1 Load 95.95 83.95 87.36 105.1 1 93.09 1 9.47 Ext 0.665 0.746 0.852 0.846 0.78 0.09 100 Hours . Load 84.64 71.95 104 85.45 86.51 13.20 Ext 0.64 0.8 0.804 0.779 0.76 0.08 133 Hours Load 73.05 71 .97 79.54 102.6 81 .79 14.27 Ext 0.542 0.53 0.647 0.82 0.63 0.13 166 Hours Load 77.66 66.63 72.56 87.84 76.1 7 8.99 Ext 0.686 0.611 0.66 0.617 0.64 0.04 200 Hours Load 67.46 69.58 69.96 87.73 73.68 9.43 Ext 0.535 0.505 0.58 0.55 0.54 0.03 266 Hours Load 71 .68 63.41 68.48 39.22 60.70 14.72 Ext 0.503 0.457 0.415 0.347 0.43 0.07 333 Hours Load 45.48 47.81 51 .52 45.34 47.54 2.89 Ext 0.268 0.378 0.359 0.403 0.35 0.06 A Fill 66 Hours Load 68.83 84.38 59.87 81 .48 73.64 1 1.40 Ext 0.508 0.666 0.642 0.732 0.64 0.09 100 Hours Load 59.3 55.7 72.72 58.74 61 .62 7.57 Ext 0.619 0.582 10.681 0.583 0.62 0.05 133 Hours Load 36.94 57.42 55.09 48.99 49.61 9.16 Ext 0.591 0.634 0.526 0.607 0.59 0.05 166 Hours Load 70.31 45.21 50.47 56.54 55.63 1 0.82 Ext 0.543 0.483 0.539 0.406 0.49 0.06 200 Hours Load 43.22 40.62 59.81 40.78 46.1 1 9.21 Ext 0.49 0.465 0.453 0.553 0.49 0.04 266 Hours Load 39.84 36.43 35.6 44.24 39.03 3.93 Ext 0.327 0.267 0.297 0.365 0.31 0.04 333 Hours Load 36.32 31.11 36.72 21.15 31.33 7.25 Ext 0.324 0.278 0.336 0.304 0.31 0.03 Ta r£111mréf~1bndg1g LEEEEL N NolN b “alk K Natlk \ \n/C \ \a\ \ \«(W\ \ \ 113 Table 31 (cont’d) TWarp 1 1 j 2 . 3 4 AVE—T—To 66 Hours 1 1 1 1 1 ; Load 66.19 1 89.341 100.6 1 79.14 1 69.37 1 6.66 Ext 0.7951 0.601 ' 0.7671 0.758 r 0.731 0.09 100 Hours ‘ 1 i 1 1 Load 99.27 100.1 61.1 66.55 ‘ 91.76 1 9.43 Ext 0.986 0.655 0.763 0.715 . 0.78 0.14 133 Hours 1 Load 75.68 44.46 33.32 82.82 59.07 23.92 Ext 0.921 0.857 1.09 0.771 0.91 0.13 166 Hours Load 86.58 99.65 84.1 3 87.97 89.58 6.90 Ext 0.596 0.704 0.761 0.651 0.68 0.07 200 Hours Load 76.86 41 .42 34.66 72.78 56.43 21 .48 Ext 0.495 0.643 0.405 0.601 0.54 0.1 1 266 Hours Load 53.07 64.56 81.02 33.99 58.16 19.78 Ext 0.357 0.461 0.51 1 0.541 0.47 0.08 333 Hours Load Sample were too brittle fon tensile t Ext B Fill 66 Hours Load 69.8 80.54 92.86 90.63 83.46 1 0.57 Ext 0.794 0.776 0.849 0.909 0.83 0.06 100 Hours Load 82.66 1 1 1 71.57 93.96 89.80 16.83 Ext 0.599 0.692 0.698 0.801 0.70 0.08 133 Hours Load 65.26 79.84 68.64 106.9 80.16 1 8.88 Ext 0.465 0.964 0.823 0.73 0.75 0.21 166 Hours Load 55.19 70.09 62.12 57.74 61 .29 6.53 Ext 0.491 0.476 0.404 0.458 0.46 0.04 200 Hours Load 46.36 42.52 44.97 42.2 44.01 2.00 Ext 0.336 0.281 0.291 0.307 0.30 0.02 266 Hours Load 1 8.79 1 9.92 24.62 37.22 25.14 8.44 Ext 0.308 0.145 0.417 0.506 0.34 0.16 333 Hours Load Samples were too brittle for tensile t Ext 114 Table 31 (cont’d) '0 Warp 1 1 g 2 . 3 1 4 AVG STD 66 Hours 1 ‘ 1 1 1 Loa 100.2 74.6 82.391 90.17 1 66.64 1 10.94 Ext 0.695 0.775 0.603 0.657 ' 0.68 1 0.07 100 Hours 1 Load 82.79 77.66 84.54 92.64 84.41 6.22 Ext 0.714 0.757 0.584 0.691 0.69 0.07 133 Hours Load 57.66 79.33 66.17 73.64 69.20 9.39 Ext 0.415 0.564 0.66 0.62 0.56 0.1 1 166 Hours ‘ Load 61 .05 70.66 76.75 55.92 66.10 9.37 Ext 0.363 0.588 0.56 0.451 0.49 0.10 200 Hours Load 74.6 84.89 81 .77 75.76 79.26 4.90 Ext 0.562 0.582 0.585 0.553 0.57 0.02 266 Hours Load 64.16 70.76 66.9 77.15 69.74 5.63 Ext 0.452 0.547 0.409 0.56 0.49 0.07 333 Hours Load 45.05 50.25 35.09 61 .88 48.07 1 1 .15 Ext 0.282 0.333 0.269 0.384 0.32 0.05 C Fill 66 Hours Loa 61 .99 75.65 76.64 85.91 75.05 9.86 Ext 0.571 0.539 0.673 0.801 0.65 0.12 100 Hours Load 60.05 61 .99 79.84 47.44 62.33 13.34 Ext 0.806 0.494 0.635 0.535 0.62 0.14 133 Hours Load 76.78 57.23 59.81 86.58 70.10 14.00 Ext 0.696 0.581 0.651 0.849 0.69 0.1 1 166 Hours 1 Load 54.74 72.64 62.9 55.09 61 .34 8.42 Ext 0.483 0.617 0.614 0.344 0.51 0.13 200 Hours Load 48.99 69.45 58.2 56.83 58.37 8.43 Ext 0.497 0.572 0.413 0.553 0.51 0.07 266 Hours Load 49.58 51 .19 61 .45 64.43 56.66 7.38 Ext 0.517 0.367 0.558 0.644 0.52 0.12 333 Hours Load 54.9 55.01 39.03 47.17 49.03 7.61 0.571 0.422 0.718 0.346 0.51 0.16 115 Table 32: Continuous UV, Test 2 — UVCON A Warp 1 1 2 3 4 . AVE §TD 66 Hours ‘ Load 69.531 90.85 91.62 86.55 i 69.64 ’ 2.23 Ext 0.625 I 0.705 0.909 0.797 1 0.76 * 0.12 100 Hours Load 105.9 77. 56 73.02 81.69 84.54 14.67 Ext 0.826 0.767 0.52 0.73 0.71 1 0.13 133 Hours Load 39.46 79.22 75.3 81 .85 68.96 19.85 Ext 0.67 0.683 0.728 0.842 0.73 0.08 166 Hours Loa 76.83 90.23 76.86 86.15 82.52 6.76 Ext 0.632 0.7 0.604 0.842 0.69 0.1 1 200 Hours Load 65.77 64.91 76.72 68.97 69.09 5.38 Ext 0. 592 0.476 0.658 0.722 0.61 0.11 266 Hours Load 84.75 71 .57 67.33 79.95 75.90 7.89 Ext 0.71 0.487 0.52 0.545 0.57 0.10 333 Hours Load 59.81 50. 44 69. 83 43.62 55.93 11.40 Ext 0.42 0. 477 0. 402 0.465 0.44 0.04 A Fill 66 Hours Load 66.39 70.6 76.24 56.48 67.43 8.34 Ext 0.554 0.589 0.715 0.519 0.59 0.09 100 Hours Load 65.5 59.97 60.89 71.76 64.53 5.39 Ext 0.693 0.525 0.601 0.524 0. 59 0.08 133 Hours Load 64.48 54.01 63.79 59.44 60.43 4. 83 Ext 0.664 0.557 0.511 0.508 0.56 0. 07 166 Hours Load 51.22 46.63 55.03 35. 54 47.11 8. 44 Ext 0.617 0 413 0.5 0.345 0.47 0.12 200 Hours Load 54.82 59.84 38.79 42.95 49.1 0 9.87 Ext 0.498 0.503 0.351 0.48 0.46 0.07 266 Hours Load 35.73 40.75 49.61 51.73 44. 46 7.51 Ext 0.36 0.378 0.394 0.416 0. 39 0.02 333 Hours Load 28.67 20.46 23.97 23.79 24.22 3.38 Ext 0.42 0.289 0.277 0.264 0.31 0.07 1( :3 :6 \ E \ E \ E : 116 Table 32 (cont’d) ‘Bl Warp 1 1 2 1 3 4 AVE ; §TD 66 Hours 1 1 1 1 1 Load 69.61 1 106.71 102.91 95.6 ' 93.76 16.71 Ext 0.8681 0.833 1 0.739: 0.747 0.80 1 0.06 100 Hours ' 7 Y I 1 Load 91.01 76.63 61.32 89.96 1 79.76 1 13.90 Ext 0.73 0.68 0.881 0.679 1 0.74 0.10 133 Hours 1 1 Load 78.58 60.24 88.21 ' 86.851 78.471 12.88 Ext 0.623 0.667 0.661 0.677 V 0.66 0.02 166 Hours Load 67.79 66.23 78.31 60.1 6 68.12 7.55 Ext 0.738 0.493 0.764 0.567 0.64 0.13 200 Hours Load 66.01 44.89 61 .26 59.97 58.03 9.14 Ext 0.56 0.764 0.559 0.482 0.59 0.12 266 Hours Load 50.85 59.17 63.62 47.65 55.32 7.36 Ext 0.519 0.591 0.548 0.497 0.54 0.04 333 Hours Load Sample were too brittle for tensile t Ext B Fill 66 Hours Loa 100.9 70.42 88.94 65.96 81.56 16.29 Ext 0.65 0.677 0.679 0.629 0.66 0.02 100 Hours Load 80.05 102.3 85.53 55.65 80.88 19.30 Ext 0.856 0.917 0.753 0.633 0.79 0.12 133 Hours Load 55.33 71.17 86.12 73.93 71.64 12.66 EXt 0.793 0.615 0.563 0.497 0.62 0.13 166 Hours Load 35.44 50.87 58.04 56.21 50.14 10.26 Ext f 0.316 0.416 0.341 0.497 0.39 0.08 200 Hours Load 31 .49 63.03 61 .8 32.7 47.26 17.52 Ext 0.184 0.421 0.396 0.259 0.32 0.1 1 266 Hours Load 27.46 26.23 9.799 1 8.82 20.58 8.1 4 Ext 0.91 0.665 0.659 0.204 0.61 0.29 333 Hours Load Samples were too brittle for tensile t Ext 117 Table 32 (cont’d) Warp T 1 a 2 3 , 4 AVG—"l 11'0"“ 66 Hours 1 1 I ' Load 100.2 100.7 ' 77.77 97.4 94.02 10.93 Ext 0.776 0.805 0.582 0.6 0.74 1 0.11 100 Hours Load 90.23 53.64 75.54 72.27 72.92 1 5.04 Ext 0.614 0.687 0.888 0.635 0.71 0.13 133 Hours . Load 88.32 78.6 64.05 95.09 81 .52 13.47 Ext 0.806 0.629 0.468 0.551 0.61 0.14 166 Hours Load 58.5 46.93 78.79 61 .58 61 .45 13.17 Ext 0.588 0.452 0.548 0.491 0.52 0.06 200 Hours Load 85.07 60.99 83.25 77.91 76.81 10.97 Ext 0.605 0.632 0.539 0.567 0.59 0.04 266 Hours Load 66.66 62.28 70.98 56.67 64.15 6.12 Ext 0.557 0.427 0.543 0.653 0.55 0.09 333 Hours Load 56.16 47.14 69.74 59.81 58.21 9.35 Ext 0.37 0.482 0.431 0.323 0.40 0.07 C Fill 66 Hours Load 74.25 69.88 53.02 49.56 61 .68 12.21 Ext 0.663 0.548 0.49 0.793 0.62 0.13 100 Hours Load 53.93 71 .89 63.6 79.97 67.35 1 1 .17 Ext 0.474 0.77 0.541 0.81 1 0.65 0.17 133 Hours Load 71 .19 55.09 69.42 58.6 63.58 7.94 Ext 0.582 0.524 0.624 0.459 0.55 0.07 1 166 Hours Load 61.77 63.97 66.6 65.58 64.46 2.11 ' Ext 0.572 0.71 0.441 0.475 0.55 0.12 200 Hours Load 71 .03 59.6 45.8 55.97 58.10 10.41 Ext 0.703 0.625 0.579 0.628 0.63 0.05 266 Hours Load 44.19 47.65 44.48 50.34 46.67 2.91 Ext 0.535 0.476 0.651 0.432 0.52 0.09 333 Hours Load 52.4 51.22 48.97 48.54 50.28 1 .84 Ext 0.521 0.477 0.451 0.397 0.46 0.05 \cuifl WU: 118 Em omnv Em and 1 1Em cm. .4. IEWOMH [Em ”~me .11ch on 41Emoné .1Em can». - ,oEF - 4NNN 4NNN -.-4NNFN. 1- 4NNN 1 4.NF.N..N 1 4NNN 4NNN .-1-.4N.FN.N1 FEE - . Na 84 8 8 N .8 84 8.84 188.4. 14.48”... -28 8. N 15888 - Ne: . - 4NFFFFF .4NFFFFF 4NFFFFF 4MFF. F1F.F. 1 4NFFFFF 4N.F:.FF 1....4NF.,FFFF 14N.F.FF.FF EN 18.». .882 .882 .8 8 8 EN NNNF 1,8 88. 1.881an £88 88813: 1 1 4NFNNFF 4NFNNFF .4.NF.N.N.FF 4NFNNFF - 428m --.--4NFNN1F.F 14NFNNFF 1 4NNN? Wheat Em ooum1Em 8. N . -Em- 8. m ...Em 8. a Emocum Em 8. N Emcowm E188 1. NEF - ...... 4NFFFFF 4NFFFFF 4NFFFFF 4NFFFFF 4NFFFFF1 4NFFF.FF. --4NF.F.FFF 1 -4NFFFFF - FLNNN. .84 Em comm Em cow Em co. m - Em 8m 1 .Em 09w Em 8N .Em 8mm Em 88.19:: 1 4NF4NFF 4NF4NFF .4.NF.4NFF 4NF4NFF 4NF4NFF 4NF4NF F 4NF14NFF 4NF4NFF 1:48: Em comm - Emooa :Em8...m . -Emomd1Emomm 1 Emgnm Em.8..m Emocum -INEF 8:5 8:5 . 4NFF.FFF 1 4NFF4F1F - ..4NF..F.FFF --4NFFFFF 1 4NF.FF.FF -4NFFFFF , New . -NNN EN NNHF . 8o 8F - .8 RF .--FFLFNNUF1EN 8. .F -..E 8F :8 NN. F F88; NE: - 4NFNFN 4NFNFN .4.NNF.N - -4NFNN 1 4NNN ..4N.FNN 4NFNFN - 4NNN 88.: EN 8HF ..EN 8 F 88F 18.4.8: ENS F -. EN 8F . .8 8F 1:6 8F 2:: 4NFNNFF 4NFNNFF 1 4NFNNFF. 44FN1NFF 1 4NNN: ..-4NFNNFF 3.4NFNNF F -4NFNNFF - .FLNFN NNN EN 84 EN 8.4 11.8 N1N4 188.4 .4884 . 1.88.4 .. EN 84 EN 84 NE: - 4NNN 4NNN 4NNN 4NNN 4NNN 4NNN 4NNN - 4NNN ENE: - Em cos Em 8K Em 8K 1.Emoo.~ Em 8K . Emacs Em 8K Em 8K 9:; 4NF4NFF - 4NF4NFF 4NF4NNF 4NF..4NF.F. - -4NF4NFF - .4NF4NFF 4NF4NFF 4N.F.4NFF FLNFN -.8.N EoNN.F ENNQF--ENN0F 1£mmNF ENNNF..ENNNF- ENNN.F ENNQF NE: 4NFNFN 4NFNFN 4NFNN - 4NNN 4NFNFN. . 4N.FN.FN ..4NFNN 1 4NFNN 22:: EN 8. N EN 8N EN oNN 8 SN ..EN NN. N EN 8.. N - -EN 8. N EN 8N NE: 4NNN 4NNN 4NNN . 4NNN 4NNN 4NNN 4NNN 4NNN :NNN 8F 8.48.8 -EFN 8qu EN 88F 1.888 88.9 ENSNF ENSNF EN 8qu NE: 4NF.NN ..... 4NFNN - 4N.FN.FN 1 .4NFN.N - .4..NFN.N . 4NNN - 4NFNFN - 4NNN 52cm EN 8 N EN. EN 8N 8N -- EN NNN EN 8 .N . EN 8 N EN 8. N . EN NNN NE: 4NNN 4NNN 14N.F.NN 4NNN 4NNN - 4NNN 4NNN 4NNN FLNFN 8F 8 8N; ___N 9N; E 8N; E E 9N; 80 go: ,. . .383 1 0.9.8“. . - N 253 1 N, 25$ FmooNo Name. N omoe .>= use: N "mm wanmfi " Ilf\- I axm. kw N W~$1un~c 119 <2 <2 - Ea 8.8 188.8888 lEmoouo .- .Emooé E888 -EQ88 8E: <2 <2 .\ - 858$ l 85%. .-..- 85%. £85.82... 858$ 88$ . 28.2... <2 <2 E888. E8 88 ...IEQ 88 E8 88 E888. E888 ..-.oE.-.r <2 <2 - 8.88 I 8.588 .1 888 -.. 888 -888 -. 885 - 28.8 .8 <2 <2 . . .E88..N. Em 888 148.2888 {V28 88. -- E888 Em8.~ oEF <2 <2 88$ 188$ ----88$ l8<8$ . 88$. 85$ - 28.2.“. <2 <2 : 2.8888 -8.-8.888 _--,.2.8888 1.88888 8888.8 -- ......18888 - 82.2 .‘ <2 <2 8588 . 858.8 -- 8.588 .- 888 -_ 88.8 8588 -. 28.8 -8.. <2 <2 2.88.8... ..-..2885. .5888. -8888. . 2.88.8. 28.8.8. 82.: <2 <2 - .- 888$ 88$ .- 8R$ 188$ 88$ 88$ 282.2... <2 <2- .Eq88 -...E88.8.3Ea88 -E88u8 .Ea8..8 2.88.8 .mE: <2 <2 . 858.8 .- - 8588 -. 888 - 8.88 . 888 885 . 2.888 . 8 <2 <2 - E888 ..---Em88 Em 888 ..Em 828 E8 88 E8 88 .. oEF <2 <2 . 85$ . 85$ 85$ 85$ 885$ 885$ . , 28.2... <2 <2 E8 88 .- ...Em8..8 E8 88 E8 88 E8 88 En 8H8 oEF <2 <2 .8598 - .8598 .8588 V8528 @8528 .8588 5:85 . 6mm <2 <2 - .Ea8...‘ .- :anoé -iEQ 8% ..E8 88.. E8 8;. . E8 86 . .mEF <2 <2 -85.:8 85$ 85$ . .. 85$ 85$ 85$ . 28.2: <2 <2 2.8888 - .888 2.88.8 .. .228 8.8 -228 8.8 .58 8.8 82.: <2 <2 85$ : 85$ . 85$ ..85$ .885$ 885$ 28.8 88 <2 <2 2.28... 2.88.... 5.8.8.. 228.8. 22.28% .5288 82.: <2 <2 885$ 885$ 85$ 885$ 888$ _ 85$ . 28.2... <2 <2 E8 85— Encodp E8888 . .Emoob— E8 86. E8 85. 0E:- <2 ; . <2 888$ 888$ - 88$ . 888$ 888$ 888$ 2.8.8 8. <2 -- .. <2 .Ea88. E888 -E888 .En8.8 E888 E888 mEF <2i . <2 858$ - 858$ 858$ .- 858$ ,. -. 858$ 8585 28.2... <2 - <2- 2.888. 2.88.8 32.288 2.88.8 2.888 288.8 82.: <2 ..<2 85$ --8\8$ 85$ 185$ 885$ ..-8\8$ 28.8 8. ...... . 8.8; --.E 8.82, - : . ...-8- .. 8.82, . . E ...- 8.8.5 .28 8.8: o 258... o 0.588 m 0.58“. < 258... 288882 8888. m 8888 .>: use: 8 .88 98288 .thé pant; . 3.92. ->: m:c::._.:CL ..rm chfih 120 ENN9NF :aN9NF saN9NFpaNN.NF :aN9NF.9aN9NF :aN9NF :aN9NF NE: NNFNNFNF NNFNNFNF NNFNNFNF NNFNNFNF . -.NNFNNFNF NNFNNFNF NNFNNFNF- NNFNNFNF ENE: EQ and ....EQ SN I Em om. N ..-Em om. NI Ea on. N Emomb Eu 8. N -EQ om. N NE: NNFNFFNF . .NNFNFFNF NNFNFFNF - INNFNFFNF NNFNFFNF ...-NNFNFFNF NNFNFFNF ..-NNFNFFNF :NFN NNN EN NNF EN N9F EN N9F EN N9F EN N9F EN INN..F EN N9F . EN N9F NE: NNFNNFNF NNFNNFNF NNFNNFNF I NNFNNFNF -- NNFNNFNF -...NNFNNFNF .NNFNNFNF .NNFNNFNF ENE: - I :NNN-:aN.N ENNN :EN.N caNN :aNN-:aNN EENN NEF NNFNFFNF NNFNFFNF NNFNFFNF ...NNFNFFNF. - NNFNFFN. F - -.NNFNFFNF - NNFNFFINF . --NNFNFFNF F.N..N NNN E N. N . EN N. N IEN N. N - EN NNN. EN FINN ENNN. .NfI . EN N. N EN NNN NE: - NNFNNFNF NNFNNFNF NNFNNFNF IINNFNNIFNF NNFNNFNF -.I.NNFNN.FN.F - I.-NNF.NNF.N..F ‘ --NNFNNFNF ENE: - Ea CNN Ea omIN 39.9 85 IEm om. m Eu 8. N . Ea om. .m -Ea co. m Ea cm. N NE; NNFNFFNF NNFNFFNF «INNFNFFNF IINN.F..N.FF.NF NNFNFFINF INNFNFFN F -NNFNFFNF .NNFNFFNF NNFN - 8N Em on m EN om. m EN omh Em on. m EN om. m . -. ENENHN EN 85 EN 86 NE: FFNFFFFF F.N.FFFFF -I INNFNFF ..l FFNFFFFF .- -FFNFFFFF . , F.NFFFFF FFNFFFFF .. FFNFFFFF ENE: - EN EN EN .N.9N I IENNNNI EN N9 N E... N9 N - EN N9N EN N9N EN N9N NE: NNFNNFNF NNFNNFNF --.NNFNNFNF I NNFNNFNF --.NNFNNFNF NNFNNFNF NNFNNFNF NNFNNFNF F.N.N .NNF ENN9NF :aN9NF FNN9NF FEN9NF IcaN9NF :aN9oF saN9NF ENN9NF 2:: NNFNNFNF NNFNNFNF NNFNNFNF I NNFNNFNF NNFNNFNF NNFNNFNF . NNFNNFNF NNFNNFNF F.NEE EN NN N EN NN. N EN NN. N E .NN. N EN N99 EN INN. N ...,ENNN. .N EN NNFF NE: ‘ - , NNFNNFNF --NNFNNFNF NNFNNFNF . NNFNNFNF -.NNFNNFNF NNFNNFNF - NNFNNFNF NNFNNFNF F.N.N . NNF Em ONFm Em ONHm Em ON. m Em ON. m Em ONM I_.Icm ON. m Em ON.m EN 8% 05:. . - FFNFFFFF .. FFNFFFFF FFNFNFF . FFNFFFFF . FFNFFFFF - -.. FFNFqFF FFNFFFFF FFNFFFFF ENE: ENNN NF --ENNN NF ENNN NF ENNN NF ENNN NF EN-N9.NF , ENNN NF .ENN9NF NE: INNFFNFNF I NNFFNFNF NNFFNFNF .--NNFFNFNF --.NNFFNFNF . NNFFNFNF NNFFNFNF NNFFNFNF ENFN 8F IIEN NNN --NNNN. N -.....EFFNN. N INNNNN - E 8 N .3 N9 N , -38 N E. NE SE II-F.FNFNFF - I -FFNFNFF INNFNIFF NNFNFF - IFFNFNFF - NNFNFF NNFNFF . FFNFNFF is“. ENN9NF-NNN9NFINNNNNF-NNNNNF NNNN.NF :NN9NF :aN9NF :aN9NF NE: INNIFIFNIFNF INWFFNFNF .INmeNIFNF INNFFNFNF :NNFIFNFNF- NNFFNFNF NNFFNFNF NNFFNFNF 56 NN III- II.I|__..F Em? I I -I I=I_m_. NI. I I EINFS. I - _I_I_nIF I. . EMF/FF EN. EN; >50 N50: E w 2.8.... N 25qu < 25M meumc NNNEF F Name .>: NsoscFucou FNN anmN .mm..ms 3.3: m E&. S: m::::.:::; .f .2........ 121 <2 <2 E8 88 En 88m - Eu 8. 8 E8888 Em 88 En 88 8E: <2 <2 8888 8888 8888 888.8 8888 . 8888 88.8.8 <2 <2 E8 88 . E8 88 . E8 8 8 ..E8 8. 8 E8 88 E8 88 8E: <2 <2 888 - . 888 . -- 888 8888 888 888 :88 888 <2 . <2 E8 8; E88. _ E8 8.? - ..E8 8.? E8 8.. Em 8; 8E: <2 <2 8888 8888 .. 8888 -8888 8888 8888 8.58 <2 <2 E888 .E888 .888-8 -.E888 -E8.8.8 .E888 mEF <2 <2 888 : 888 888 . 888 -- 888 888 :88 888 <2 <2 E8 88 E8 88 ,, .E8 8. 8 . E8 88 E8 88 E... 8.8 8E: <2 <2 - 8888 .8888 8888 8888 , .8888 8888 88.8.8 <2 <2 E8 8. 8 .- E8 88 - E8 88 E8 8 8 E8 88 E8 88 8E: <2 <2 . 888 888 888 . 888 888 888 88.8 88 <2 <2 a E8 8. 8 1E8 8.8 - ..EQ 8. 8 E8 8. 8 E8 8K E8 88 mEF <2 <2 8888 . 8888 .- 8888 - 8888 8888 8888 88.8.8 <2. <2 - 1 E888 E888 E888 E888 - E8 88 E8 88 8E: . <2 <2 , . 888 , 8.88 888 . 888 . .888 888 :28 8. <2 - <2 - E888. E888. ...-888.8 E8 88. E888 E8 8.8. 8E: <2: <2 . 8.888 - 8888 - .8888 8888 . 8888 8888 88.8.8 <2 . <2 ; E88: -..E88: --E.8-88 ...E-E8888 $888.8.- E888 8E: , . <2 , <2 8888 - 8.888 - 8.888 -. 888.8. -. 88.88 8888 :28 8. <2 <2 E88... E88... E88... E88... .88.”: E88“: 8E: <2 <2 8888 . 8888 .8888 888.8 888.8 .N .8888 88.8.8 <2.. <2 E8 88 ...E8 8% -...Em8 8 ..Em..8. 8 Em 88 E8 88 8E: <2. <2. 88.8.8 - .8888 - 8888 88.88 - 8888 - 8888 8.8 8. .<2 <2 Ea 8K. .- -EQ 8.8 . E8 8. 8 . E8 8. x. Ea 8K Ea 8K 8E: <2 ! <2. {8888 -- -8888 .\ 8.888 -. . 888.8 - 8888 : 8888 88.8.8 <2- - <2 .- E88. --.E88... 388.. -88.. E88; 88.. 8E: - <2-: - - <2 , .8888 .- -8.-8.8.88 .1388-8 .- 8888 88.888 : .8888 :88 8 2-5M. -- 88>) - ...E .- 883 E 88.3 ...“. . .88; >50 850: ,o 0.588 0.58 m 2.88 < 2588 "88 88288 Ammumo ume. N ummE .>D m=ODCMuEOU "‘- \\\\..\..\1\1\\ 122 Table 37: Test Temperatures (8 UV - lst Test) 8 UV (4 Cond) Rotated QUV UVCON Samples Date Time Yes No temp °C irrad th>°C 1-11 9:00 pm X 70.2 0.72 70.4 1-12 6:35 am X 36.3 NA '28.0 1-12 3:00 pm x 29.9 NA 33.0 1-12 3:40 pm X 50.1 NA 47.6 1-12 4:25 pm X 50.3 NA 50.2 1-12 9:40 pm X 69.9 0 72 70.4 1-13 2:05 am X 48.1 NA 50.5 1-13 6:35 am X 69.7 0 72 70.5 1-13 2:00 pm X 48.0 NA 50.6 1-13 3:50 pm x 49.3 NA 50.4 1-13 9:45 pm X 69.6 0.72 70.4 1-14 6:35 am X 69.9 0.72 70.5 1-14 2:20 pm x 49.2 NA 50.6 1—14 8:40 pm X 70.1 0.72 70.6 1-15 7:00 pm x 69.6 0.72 70.5 1-15 8:45 pm x 69.7 0.72 70.5 1-16 2:05 am X 50.1 NA 50.5 1-16 2:50 pm x 50.5 NA 50.4 1-16 8:50 pm X 70.9 0 72 70.4 1-17 1:30 pm X 49.6 NA 50.4 1-17 9:45 pm X 69.8 0.72 70.5 1-18 6:35 am X 70.0 0.72 70.4 1-18 5:15 pm x "66.1 0.72 70.4 1-18 8:20 pm X 69.5 0.72 70.5 1-19 6:35 am X 69.3 0.72 70.4 1-19 4:00 pm x 49.6 NA 50.1 \\\\\ Table 37 (cont'd) 123 1-19 9:50 pm 69.2 0.72 70.5 1-20 6:35 am X 69.2 0.72 70.5 1-20 2:00 pm x 49.9 NA 50.5 1-20 9:45 pm 69.9 0.72 70.4 1-21 6:35 am X 70.4 0.72 70.5 1-21 4:20 pm x 50.2 NA 50.6 1-21 8:40 pm 70.5 0.72 70.5 1-22 1:05 am X 49.6 NA 49.0 1—22 8:30 pm 70.2 0.72 70.4 1-23 8:00 pm 70.2 0.72 70.5 1-24 2:00 pm x 50.0 NA 50.5 1-24 5:00 pm "62.1 0.72 70.6 1-24 6:30 pm X 69.5 0.72 70.5 1-25 6:35 am X 69.0 0.72 70.5 1-25 9:50 pm 69.7 0.72 70.4 1-26 6:35 am X 69.9 0.72 70.6 1-26 1:20 pm "59.8 NA 70.4 1-26 9:55 pm 69.6 0.72 70.5 1-27 6:35 am X 69.9 0.72 70.5 1-27 6:50 pm 70.1 0.72 70.4 1-28 6:35 am X 70.1 0.72 70.5 1-28 1:20 pm X "62.1 0.72 70.5 1-28 11:00pm 69.7 0.72 70.4 1-29 12:25am X 70.0 0.72 70.3 1-29 9:45 pm 69.3 0.72 70.5 1-30 12:25pm x 69.7 0.72 70.4 1-30 7:05 pm 70.3 0.72 70.5 1-31 1:45 pm x 70.4 0.72 26.0 1-31 9:45-9; 70.2 0.72 50.44 Ta F Flr~ 5 § Table 37 (cont'd) 124 ' it 8 Hour delay Machine was still warming from cycle change 2-1 6:35 am 69.3 0.72 70.4 2-1 2:30 pm X 52.5 NA 70.5 2-1 9:45 70.3 0.72 70.4 2-2 4:35 am 49.1 NA 70.5 2-2 6:00 am X 48.1 NA 47.3 2-2 11:50am X 69.6 0.72 70.5 2-2 4:30 pm X 51.3 NA 50.1 - 9:00 pm 69.7 0.72 70.4 2-3 6:35 am X 47.5 NA 50.3 - 2:00 pm X 70.3 0.72 70.4 2-3 9:45 pm 70.5 0.72 70.5 2-4 6:35 am X 47.7 NA 50.4 - 2:15 pm X 70.3 0.72 70.4 2-4 8:45 pm 70.5 0.72 70.4 — 1:05 am X 70.0 0.72 70.4 2-5 10:40pm 69.5 0.72 70.4 - 10:00am 69.7 0.72 70.5 2-6 11:00am X 69.1 0.72 71.5 - 1:45 pm X 70.2 0.72 70.4 - 1:30 pm 69.1 0.72 70.5 2-7 6:10 pm X 49.6 NA 50.3 - 6:35 am X 49.5 NA 50.4 2-8 1:30Em X 69.1 0.72 70;£__ $=l_»_________--\\\\\\\\-\-\:\4\4\\ 125 Table 38: Test Temperatures (8 UV - 2nd Test) 8 UV(4 Cond) Rotated QUV UVCON 2nd Samples Date Time Yes No temp °C irrad taw>°c 3-30 9:00 pm X 64.5’ 0.72 71.6 3—31 2:05 am X 70.4 0.72 70.8 3-31 6:35 am X 50.2 NA 50.4 3-31 7:45 pm 50.3 NA 50.4 4-1 2:05 am X 69.5 0.72 70.4 4-1 12:40pm X 70.1 0.72 70.4 4-1 8:35 pm 49.8 NA 50.3 4-2 1:05 am X 70.0 0.72 70.4 4-2 8:45 pm 50.3 NA 50.4 4—3 6:30 pm 50.0 NA 57.3" 4-4 3:15 pm 70.4 0.72 83.5? 4-4 9:55 pm x 49.8 NA 48.3 4-5 2:05 am X 70.6 0.72 70.4 4-5 6:35 am X 50.5 NA 50.4 4-5 4:25 pm 69.9 0.72 70.4 4-6 2:05 am X 69.8 0.72 70.4 4-6 6:35 am X 50.1 NA 50.4 4-6 1:30 pm 69.9 0.72 70.5 4-7 2:05 am X 70.4 0.72 70.5 4-7 6:35 am X 50.0 NA 50.4 4-7 6:40 pm 50.0 NA 50.5 4-8 2:05 am X 70.2 0.72 70.4 4-8 6:35 am 49.8 NA 50.0 4—8 12:45pm 69.8 0.72 70.4 4-8 3:15 pm 70.0 0.72 70.4 4—8 8:35 pm 50.1 NA 50.3 Ta Table 38 (cont'd) 126 4-9 1:05 am X 69.8 0.72 70.4 4-9 3:25 69.8 0.72 70.5 4-10 8:00 am 50.3 NA 51.1 4-10 8:45 am X 51.8 NA 49.6 4-11 7:15 am 51.7 NA 50.4 4-12 10:00am 51.5 NA 50.4 4-12 10:45am X 68.7 0.72 71.4 4—13 2:10 am X 69.8 0.72 70.5 4-13 6:35 am X 50.1 NA 48.2 4-13 1:45 pm 70.3 0.72 70.4 4-13 3:30 pm X 70.4 0.72 70.5 4-14 2:05 am X 69.9 0.72 70.5 4-14 6:35 am X 50.1 NA 47.9 4-14 2:00 pm 70.0 0.72 70.4 4-15 2:05 am X 70.1 0.72 70.5 4-15 6:35 am X 49.9 NA 48.4 4-15 12:40pm X 69.9 0.72 70.4 4-15 2:15 pm 70.1 0.72 70.5 4-15 8:35 pm X 51.2 NA 50.4 4-16 1:45 pm 71.0 0.72 70.6 4-16 2:30 pm 69.7 0.72 70.2 4-16 9:50 pm X 50.7 NA 50.4 4-17 2:00 pm 70.9 0.72 70.4 4-17 9:20 pm X 51.0 NA 50.7 4-18 3:00 pm 70.3 0.72 70.5 4-18 4:30 pm X 69.3 0.72 71.6 4-19 2:05 am X 69.6 0.72 70.4 4-19 6:35 am X 51.6 NA 64.8" 4-19 3:05 pm 69.7 0.72 70.5 Table 38 (cont'd) 127 4-20 6:35am 51.2 NA 65.3" 4-20 1:30pm 70.2 0.72 70.4 4-20 6:0flam x 70.1 0.72 70.4 i Still warming up ft Cooling from cycle change TE :1 :1 :1 .4 11 4 4 .-..\ 1\ 1\ 1.\ L\ Q 128 Table 39: Test Temperatures (Continuous UV - lst Test) Continuous UV Rotated QUV UVCON Samples Date Time Yes No temp °C irrad tmu>°c 12-16 9:50 pm x 70.0 0.72 70.2 12-17 2:15 am X 70.2 0.72 70.1 12-17 6:30 am X 70.0 0.72 70.1 12-17 8:45 pm x 70.1 0.72 70.1 12-18 8:35 pm x 70.6 0.72 70.2 12-19 8:35 pm X 70.3 0.72 70.3 12-20 2:50 pm x 70.4 0.72 70.3 12-20 9:25 pm x 70.6 0.72 70.3 12-21 6:35 mm X 69.7 0.72 70.4 12-21 1:25 pm x 70.0 0.72 70.4 12-21 9:35 pm x 70.1 0.72 70.5 12-22 6:35 am X 69.4 0.72 70.4 12-22 9:40 pm X: 69.6 0.72 70.4 12-23 6:35 am X 69.6 0.72 70.5 12-23 4:10 pm X 69.3 0.72 70.3 12-23 8:35 pm X 69.8 0.72 70.4 12-24 1:05 am X 69.8 0.72 70.4 12-24 8:45 pm X: 70.3 0.72 70.4 12-25 5:50 am X 70.6 0.72 70.5 12-25 7:35 am X 70.1 0.72 70.8 12-25 8:25 pm x 72.4 0.72 70.5 12-26 2:25 pm X 71.5 0.72 70.5 12-26 8:45 pm X: 70.8 0.72 70.4 12-28 1:05 am X 70.5 0.72 70.4 12-28 1:35 am X 70.1 0.72 70.4 12-28 3:05 am X .169‘9 0.72 70.6 Table 39 (cont’d) 129 12-28 2:40 pm X 70.4 0.72 70.6 12-28 11:58pm 69.9 0.72 70.4 12-29 12:20pm X 70.6 0.72 70.4 12-29 11:05pm 70.2 0.72 70.5 12-30 12:35pm X 70.3 0.72 70.5 12-30 9:50 pm X 70.2 0.72 70.4 12-31 12:05am 69.4 0.72 70.3 12-31 4:30 pm 70.5 0.72 70.5 1-1-94 7:05 pm 70.2 0.72 70.4 1-2 6:00 pm X 69.9 0.72 70.4 1—2 6:50 pm 69.7 0.72 70.6 1-3 2:00 pm 71.5 0.72 70.4 - 3:35 am 70.3 0.72 70.5 1-4 3:50 am 70.4 0.72 70.5 - 4:20 am X 70.1 0.72 70.6 1-4 5:20 am X 69.7 0.72 70.4 I]. I- u. 130 Table 40: Test Temperatures (Continuous UV - 2nd Test) Continuous UV Rotated QUV UVCON (2nd) Samples Date Time Yes No temp °C irrad tmm>°C 3-16 9:00 pm X 69.6 0.72 69.7 3-17 2:05 am X 70.6 0.72 70.4 3-17 6:35 am X 70.6 0.72 70.4 3-17 6:35 pm x 70.4 0.72 70.4 3-18 6:35 am 69.6 0.72 70.4 3-18 12:40pm X 70.1 0.72 70.4 3-18 2:00 pm X 69.8 0.72 70.3 3-19 1:05 am X 70.0 0.72 70.4 3-19 6:40 pm X 70.4 0.72 70.3 3-20 12:10pm X 70.3 0.72 70.4 3-20 5:00 pm X 70.3 0.72 70.5 3-21 4:00 pm x 69.9 0.72 70.5 3-21 9:55 pm x 70.3 0.72 70.4 3-22 6:35 am X 70.2 0.72 70.3 3-22 5:00 pm X 70.0 0.72 70.4 3-22 9:55 pm X 69.0 0.72 70.3 3-23 6:35 am X 69.6 0.72 70.4 3-23 1:30 pm X 70.0 0.72 70.5 3-23 7:00 pm X 70.3 0.72 70.4 3-23 7:45 pm X 70.5 0.72 70.4 3-24 2:05 am X 70.6 0.72 70.4 3-24 6:35 am X 70.2 0.72 70.5 3-24 4:15 pm X 70.0 0.72 70.4 3-25 2:10 am X 70.6 0.72 70.4 3-25 6:35 mm X 70.7 0.72 70.5 3-25 7:00 am X 69.7 0.72 70.2 Table 40 (cont’d) 131 3-25 4:05 pm 70.4 0.72 70.4 3-25 8:40 pm x 70.8 0.72 70.4 3-26 1:05 am X 69.0 0.72 70.5 3-26 3:15 pm 69.7 0.72 70.4 3-27 1:40 am X 69.8 0.72 70.5 3-27 4:40 pm 69.9 0.72 70.5 3-28 1:00 am X 70.5 0.72 70.5 3-28 1:30 am X 69.7 0.72 70.8 3-28 1:35 pm 71.4 0.72 70.4 3-29 2:05 am X 69.9 0.72 70.4 3-29 6:35 am X 70.6 0.72 70.5 3-29 10:00am 70.1 0.72 70.4 3-29 11:00am 69.6 0.72 70.6 3-29 9:50 pm X 69.7 0.72 70.5 3-30 6:35 am X 70.6 0.72 70.5 3-30 1:35 pm 70.3 0.72 70.5 3-30 7:00 pm X 70.4 0.72 70.4 3-30 8 70.2 0.72 70.5 :00 pm 132 QUV Load vs. Time 8 Hour UV (4 hour Condensation) Fabric A - Warp um y=101.52.-8.1612e-2x 842:0.586 1a) I I I LamAMI 80+ 3 8 6° ‘ ' - . 3 q - n 40 4 m d O ‘ I fl I ' j ' 1 f I ' 0 100 200 300 «400 500 600 ‘flmnflkwmn Fig. 1: QUV, 8 Hour UV - Fabric A (Warp) Load (lb!) 133 QUV Load vs. Time 8 Hour UV (4 hour Condensation) Fabric B - Warp 120 ’ a ‘ y=106.70-0.16565x 942:0.673 1m _\ ‘ ‘ w M a i . 80 .5 ‘ ‘ I . A a ‘ A 60- 4 ‘ 0 . ‘ a 4o .. 20 .. o - l fi I V t V 1 ' l ' I ' —l 0 100 200 300 400 500 600 Humour.) Fig. 2: QUV, 8 Hour uv - Fabric 8 (Warp) Load (lb!) 134 QUV Load vs. Time 8 Hour UV (4 hour Condensation) Fabric C - Warp 120 y = 89.534 - 5.935194! W2 = 0.462 0 MW 40 u q 20 d o *— I ' I I I ' I 1 I I O 100 200 300 400 500 Time (Item) Fig. 3- QUV, 8 Hour UV - Fabric C (Warp) 600 Load (lb!) 135 QUV Load vs. Time 8 Hour UV (4 hour Condensation) Fabric D - Warp 120 " y = 88.647 - 0.15575)! 8‘2 = 0.844 100 x LodDW ' r T I ' I I O 100 200 300 400 500 TII'IIOOIOIIN) Fig. 4: QUV, 8 Hour UV - Fabric D (Warp) Load (lb!) 136 QUV Load vs . Time 8 Hour UV (4 hour Condensation) Fabric A - Fill - y = 68.411 - 627046-21: 842 = 0.629 I Load AF T 1 500 600 j V I 0 v i I I 0 100 300 400 Tlmo (hours) 1 200 Fig. 5: QUV, 8 Hour UV - Fabric A (Fill) Load (lb!) 137 QUV Load vs. Time 8 Hour UV (4 hour Condensation) Fabric 8 - F111 ‘ y=115.57 - 0.22514): m2 = 0.880 a A LuwBF I 2 0 . u 0 100 V I' I 400 500 W I I 200 300 Thudhmm» Fig. 6: QUV. 8 Hour UV - Fabric 8 (Fill) 600 Load 0b" 138 QUV Load vs . Time 8 Hour UV (4 hour Condensation) Fabric C - Fill « y = 76.285 - 6.0825e-2x I842 = 0.524 U LadCF V V o f I I I 0 100 200 300 'flmeflnun) Fig. 7: QUV, 8 Hour UV - Fabric C (Fill) I 400 I 500 600 Load (lb!) 139 QUV Load vs. Time 8 Hour UV (4 hour Condensation) Fabric D - Fill - y=80.138-0.14199x 942:0.858 x manor: V 1 V 0 . I I I I 0 100 200 300 400 500 ‘flmnamuno Fig. 8: QUV, 8 Hour UV - Fabric D (Fill) Load (lb!) 140 UVCON Load vs. Time 8 Hour UV (4 hour Condensation) Fabric A - Warp 120 . y= 102.16 - 0.10570x m2 =0.745 100 I (1::qu 40.1 q 20:- o ' I j I ‘ I I I ' I T 0 100 200 300 400 500 600 ‘flmnflmuno Fig. 9: UVCON, 8 Hour UV - Fabric A (Warp) cs: .23.. Load (lb!) 141 UVCON Load vs. Thme 8 Hour UV (4 hour Condensation) Fabric 3 - Warp um y =108.50 - 0.18534x m2 -.- 0.703 1“) a umdflN ‘ a l O 80- : 4 .l ‘ ‘ ' a 80- O Ii ‘ A ‘0. 4 20- q o . 1 . 1 a t . : a s . _ 0 100 200 300 400 500 600 'flmnflnuuo Fig. 10: UVCON, 8 Hour UV - Fabric B (Warp) Load (lb!) 142 UVCON Load vs. Time 8 Hour UV (4 hour Condensation) Fabric C - Warp ‘ 1 y=99.020-9.0801e—2x 842:0.662 "' 8 o Loadcw V I 500 600 V 1' ‘ o V T v j I I 0 100 200 300 400 Thuwhmmu Fig. 11: UVCON, 8 Hour UV - Fabric C (Warp) Load (lb!) 143 UVCON Load vs. Time 8 Hour UV (4 hour Condensation) Fabric D - Warp 120 y=84.971-0.16112x R"2=0.703 8 WOW V I V I I 300 400 500 V O . I I 0 100 200 ‘flmnflnwn) 600 Fig. 12: UVCON, 8 Hour UV - Fabric D (Warp) Load (lb!) 144 UVCON Load vs. Time 8 Hour UV (4 hour Condensation) Fabric A - Fill " y = 72.508 - 711340-21! H"2 = 0.704 I Load AF ' I ' I 400 500 600 V V 0 . u 0 100 ' I I 200 300 Tlmo (llama) Fig. 13: UVCON. 8 Hour UV - Fabric A (Fill) Load (lb!) 145 UVCON Load vs . Time 8 Hour UV (4 hour Condensation) Fabric 3 - Fill 120 ( :y=112.59-0.23957x masons? 100 4: A A LoadBF b ‘ i w .1 m -1 ‘01 20 .1 1 O ' I ' I ' I 7 I ' I v 0 1 00 200 300 400 500 600 11111001001!) Fig. 14: UVCON, 8 Hour UV - Fabric 3 (Fill) Load (10:) 146 UVCON Load vs. Time 8 Hour UV (4 hour Condensation) Fabric C - Fill 120 y = 75.654 - 5.413662): H02 = 0.498 100 0 WCF w - O o 40 - ° § 20 III 0 - I ' I . I ' I ' I ' 0 100 200 300 400 500 600 'flmoanum) Fig. 15: UVCON. 8 Hour UV - Fabric C (Fill) Load (11:1) 147 UVCON Load vs. Time 8 Hour UV (4 hour Condensation) Fabric D - Fill 120 y a 80.007 - 0.151321: m2 = 0.721 U UndDF 1 0 w I O 100 Fig. 16: UVCON: I 200 I I 300 400 500 600 Thudhmmfl 8 Hour UV - Fabric D (Fill) medA“! 148 QUV Load vs. Time Continuous UV Fabric A - Warp 120 y = 103.13 - 0.15138): 8142 = 0.715 I 100 ' I Lnaqu 20-1 0 fl I 1 I 'fi ' T v i v 0 100 200 300 400 500 600 'flmnflnmn» Fig. 17: QUV, Continuous UV - Fabric A (Warp) ca: 8.34 Load (lb!) 149 QUV Load vs. Time Continuous UV Fabric B - Warp 120* y=103.67-o.20148x 942:0.573 100‘ I 4 2 ' 4 mew ‘ a a 1 ‘ ‘ ’ a 801) a a I a : a 60. a 401 a 20. o ' I ' I ' I Afi I ' l ' 0 100 200 300 400 500 600 ‘flmnflwuno Fig. 18: QUV, Continuous UV - Fabric B (Warp) Load (lb!) 150 QUV Load vs. Time Continuous UV Fabric C - Warp y: 98.595 - 0.12458): W2 = 0.552 UHMJN ' 0 W I 100 r I ' I ' 1 200 300 400 'flmaawun) I 500 600 Fig. 19: QUV, Continuous UV - Fabric C (Warp) Load (lb!) 151 QUV Load vs. Time Continuous UV Fabric D - Warp 120 y = 91.075 - 0.24269x F142 = 0.630 It UmdDW' 0 v I ' I ' .. j ' I ' I ' 0 100 200 300 400 500 600 Thmwhmmn Fig. 20: QUV, Continuous UV - Fabric D (Warp) to: oaoa 152 QUV Load vs. Time Continuous UV Fabric A - Fill 120 1 y:72.736-0.10725x ”2:05:38 100- II undAF E u I o 4 20-1 l 0 v I T I ‘ I ' I f 1 ' ' 0 100 200 300 400 500 800 Thmwhmm» Fig. 21: QUV, Continuous UV - Fabric A (Fill) Load (lb!) 153 QUV Load vs. Time Continuous UV Fabric 8 - Fill 120 . ‘y_=_11270-0.34325x 1342:0845 A LoadBF Y ' 0 . I 0 100 . 1 j 400 500 I ' I 200 300 'flmoflwuno ‘U 600 Fig. 22: QUV, Continuous UV - Fabric B (Fill) Load (lb!) 154 QUV Load vs. Time Continuous UV Fabric C - Fill 120' y = 77.056 - 7.100582: 1342 = 0.360 c Lanna: ' T I I ' I ' I 200 300 400 500 600 V o . . 0 100 linamnun) Fig. 23: QUV. Continuous UV - Fabric C (Fill) to: 0.54 Load (lb!) 155 QUV Load vs. Time Continuous UV Fabric D - Fill um y = 82.486 - 0.200171: R42 = 0.788 100‘ X UndDF 0 ' I ' I ' I “V I v I . 0 100 200 300 400 500 600 Thuwhmm» Fig. 24: QUV, Continuous UV - Fabric D (Fill) Load (lb!) 156 UVCON Load vs. Time Continuous UV Fabric A - Warp 120 . y =102.29 - 0.15214: R42 :- 0.681 -‘ a LauNW' 100 I I a I I 80 d 60 a: 4 I ' I 40 - I I 20 -I 0 ‘ I ' I ' I ' I 1 I ‘ 0 100 200 300 400 500 momma) Fig. 25: UVCON, Continuous UV - Fabric A (Warp) 600 Load (101) 157 UVCON Load vs. Time Continuous UV Fabric 3 - Warp 120* a ‘ y=105.98-0.23184x 842:0.673 a a unnaw a o ' I ' I r I “ I ' I " 0 100 200 300 400 500 600 'nmomnun) Fig. 26: UVCON, Continuous UV - Fabric 8 (Warp) to: noon Load (lb!) 158 UVCON Load vs. Time Continuous UV Fabric C - Warp 120 y = 94.893 - 0.115421: H42 :1: 0.548 0 LoelC'W 20 .1 0 V I V I V I V I V I V 0 100 200 300 400 500 600 Tina (bows) Fig. 27: UVCON, Continuous UV - Fabric C (Warp) Load (lb!) 159 UVCON Load vs. Time Continuous UV Fabric D - Warp 120 y=93.485-0.28830x Fl"2=0.709 X LoadDW T I v i o I I I I I I 0 100 200 300 400 500 'flmnflnmno Fig. 28: UVCON, Continuous UV - Fabric D (Warp) 600 160 UVCON Load vs . Time Continuous UV Fabric A - Fill 120 1 y=72.872-0.12598x 942-0793 1004 I LoadAF S 'o I o ..l o I I I l I I j I I I I 0 100 200 300 400 500 600 manna) Fig. 29: UVCON, Continuous UV - Fabric A (Fill) Load «00 161 UVCON Load vs. Time Continuous UV Fabric B - Fill um A . y=flBJB~Q3fimh we=osm 1oo-. 3 ‘ A UndBF 1 ‘ ‘ ‘ A ‘4 so- a A A a A 60_ a I a A 40- A A . I . A 20- ‘ ‘ a t o ‘l'lIIA'I'l 0 100 200 300 400 500 600 flmeumun) Fig. 30: UVCON, Continuous UV - Fabric B (Fill) Load (lb!) 162 UVCON Load vs. Time Continuous UV Fabric C - Fill 120 y = 76.962 - 9.71440-2X 1342 = 0.579 O UdeF 20 .- 0 V I V I D I V I V I V o 100 200 300 400 500 600 TIIno (hours) Fig. 31: UVCON, Continuous UV — Fabric C (Fill) Load (lb!) 163 UVCON Load vs. Time Continuous UV Fabric D - Fill 120 —— ‘ y=81.085-0.28130x ”2:0.819 100 - X LoadDF I! x 80 m - ‘0 d 20 V I: ' I: O V I V I I“ I I I ' I 0 100 200 300 400 500 Tlma(houra) Fig. 32: UVCON, Continuous UV - Fabric D (Fill) 600 UVCON (8 Hour UV) Warp 164 UVCON vs. QUV 8 Hour UV (4 hour Condensation) Warp ‘ y = 38.130 + 0.74864x 1342 a 0.957 o I I I I I I I T I I I I I I I 0 100 200 300 400 500 600 700 OUV(8l-lourUV) Warp Fig. 33: UVCON vs. QUV, 8 Hour UV - Warp 800 UVCON (8 Hour UV) Flll 165 UVCON vs. QUV 8 Hour UV (4 hour Condensation) Fill y: -15.895+1.0489x Fl"2=0.972 0 V I V I V I V fl f I V I V I V 0 100 200 300 400 500 600 700 800 QUV(8HourUV) Flll Fig. 34: UVCON vs. QUV, 8 Hour UV - Fill UVCON (Conllnuous UV) Warp 166 UVCON vs . QUV Continuous UV Warp y = -12273 +1.0027x 942 = 0.993 100% V fl V 0 r I I 0 100 200 300 400 500 I 600 QUV (Continuous UV) WW 1 I 700 V 800 Fig. 35: UVCON vs. QUV, Continuous UV - Warp UVCON (Conllnuous UV) F!!! 167 UVCON vs . QUV Continuous UV Fill y a: 8.6309 + 0.73933): W2 = 0.967 o I I ' I I I I I I I I I I I I 0 100 200 300 400 500 600 700 800 OUV(GontlnuousUV) Flll Fig. 36: UVCON vs. QUV, Continuous UV - Fill QUV (Conllnuous UV) VVarp 168 QUV vs . QUV Continuous vs. 8 Hour UV Warp y = 40.973 + 0.5226831 842 = 0.943 o I I I I I I I I I I ' I I I fi 0 100 200 300 400 500 600 700 800 ouv (8 Hour UV) “hfl' Fig. 37: QUV (Continuous UV) vs. QUV (8 UV) - Warp QUV (Conllnuous UV) Flll 169 QUV vs. QUV Continuous UV vs . 8 Hour UV Fill y = - 10.327 + 0.80168): 1442 = 0.936 O . I I I I I I I I I I I I I I 0 100 200 300 400 500 600 700 800 OUV(8HourUV) Flll Fig. 38: QUV (Continuous UV) vs. QUV (8 UV) - Fill UVCON (Contlnuous UV) Warp 1'70 UVCON vs . UVCON Continuous vs. 8 Hour UV Warp y =1.4863 + 0.70253)! RAZ = 0.985 0 I I I I I I I I I I I I I I i 0 100 200 300 400 500 600 700 800 UVCON(8l-lourUV) Warp Fig. 39: UVCON (Continuous UV) vs. UVCON (8 UV) - Warp UVCON (Contlnuous UV) Flll 171 UVCON vs. UVCON Continuous UV vs. 8 Hour UV Fill y = 5.1668 + 0.58326x 8‘2 = 0.993 O . O I I I I I I 1— I I I I 100 200 300 400 500 800 UVOON(8HourUV) Fill ‘ I 700 V 800 Fig. 40: UVCON (Continuous UV) vs. UVCON (8 UV) - Fill 8 Hour UV (4 Hour Cond) QUV Warp — Test 1 172 \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\ 9:9 .... 9'. 929.0...0A020202 O AOzonzOAOAOAO. Ac \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\‘k\ 4200 120 100 8 8 3 8 ‘3 uopuozsu % 300 400 500 250 Time (Hours) @ A—Warp % B-Warp % C—Warp g D-Warp 150 100 8 Hour UV - % Retention, QUV - Test 1 (warp) Fig. 41: lllll 173 3.33 H 33-2025 £3333. » - 5 use: a :3 .mE 93510 E ota3lo § oak/1m § 9m>>l< Q . 9.52.3 0E2. 8v can own 8N o2 9: c _ so... I as? 28>: 680 :5: s >3 :5: m cm ow ow ao— c2 uopuolou % 6:00 501 3 >3 50: m QUV Fill - Test 1 8 Hour UV (4 Hour Cond) 1'74 ? : fi§§§§§§§§§§§§§§§fi§§§§§§ g; , ; to».ozozozozozozozozozozoz m 3 § 'AVA‘: ? §§§§§§§§§§§§§§§§§§R§§§S S; ' IIIIIIIIIIIIII§§§§§§ <- ! fififififififififihfifififlfidfififlfib := I (3: SEHFEEKEIHMIEKFEEESIS I S§$§§§§§§§§§$§§§§§§§§R§§§S g; C! §§§§§§§§§§§§§§§§R§§§ «3 E33 fifiéfiéfldfififififlflfifisfififihfififi A A A A A A A A A A 4 E $§§§§§§§§§§§§§Q§R§§§§§X§ =31? flu \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\ '8 5 I )292929292020202.20202920202020202020202.2033 E U C, ‘5 l ‘5’ § § i:- a “r l I J m \\: a E? g < I l 1 J O g g 8 s s 2. ° uopuolag % 8 Hour UV - % Retention. QUV-Test 1 (fill) Fig. 43: 175 Aflasuv H umma-zoo>o .cofiucuuum a - >3 use: a ... .mfim =Euo @ ..Enu \\\\. ..Eum § =Eu< @ €533 08E. 8m :9. can own 8m :3 8. c 1. . 1 ..I.. c ..L cw .. - cw ! 1 8 x 1 3 ii on ---.zlf. 8— cm— . 30,—. I :5 28>: 680 :6: s >3 :5: m uopualou % 1((.(r\ ....(1 V\ x: _ ....(J 0 176 3.8.: m £3.25 £03533 _. - >= .30: m “me .mE 91.3!0 § 935).».— § Ea>>130 680 52.. $ >3 :5: m uopuozo‘d % :CCCL L. .CI V\ >- LJOI m 177 8w 3.3.: m ”$312095 .oognouou a I g use: a "we .3..."— QEBIU § EmBIm g Ew>>I< @ Ame—53V 2:: 2:. com :3 SN cm H 2: N .3 I as? 28>: 680 52.. $ >3 :5: m ON 9. 8 8— GN— uopuaxou % 178 Aaafiuv m unme->oo .eofiuemumm a - >o use: a "hv .mfim =EIU § =Elm § =EI< a $525 25,—. can 2:. 8m cnm 8N ca 8— N 30,—. I En— >30 680 :5: s >2 52.. m cm 9. 8— cm— uopuozou % 179 3.33 N unohIzoug .GOwucmumx « I >5 55: m ”3. .mfim =EIU§ =Elm§ =EI<§ Arno—.5 05:. com 2:. I can an SN c2 9: c a II II I I II cm I- I III ow I I III I I I I S I I I II IIIIII | I II II cm I I I I. 8— cw— N «mop. I En. ZOU>D 680 :5: s >: :6: m uopuowu % SICCC <—‘\ \a—— C.- Continuous UV (No Cond) QUV Warp — Test 1 180 \\\\\\\\ \\\\\\\\\\\\\\\\\\\\\\\ .\\\\\\\\\\\\\\\3.\\\\ I I I 9.9X°:°:°X9X°X°X9.°I’X 9:0: \\\\\\3\\\\\ \\\\\\\\\ quvo I I oAIo AvoAvoAvoAvoA IW\\\\\ \\\\\\\\ \\\\\\\\\\\\\\\\\\ \“ 3:; 120 8 8 S S uopualou % 20» 0 200 266 333 166 Time (Hours) Q A-Warp % B—Warp W C—Warp g D—Warp 133 100 Fig. 49: Continuous UV - % Retention, QUV - Test 1 (warp) Continuous UV (No Cond) UVCON Warp — Test 1 181 LAAAAAAAAAAAA §fifi$§§§§§§§§§§N§N§fi§®§§§$§§ i\\‘\\\\\\\\‘\\\\\\\\\\\\\\‘\\\\\\\‘\\\\\\\\\VZ\\\\ 6.6.6.6.63.6.6.6.6.6.63.636.636.633).6.6.4 r'I-V-I 120 100 uopumau % 200 266 333 166 Time (Hours) w A—Warp w B—Warp % C—Warp @ D—Warp 100 133 66 Fig. 50: Continuous UV - % Retention, UVCON - Test 1 (warp) 182 :Hfiuv H ummn. I ~50 .nofiucwuom w I >5 msoscwucoo "Hm .muh =EID a EmIU § Emlm § =EI< «Mm TEE—t oEE. mmm 3N can 8: m2 2: co _ «mop. I En. >30 680 oz >3 msosczcoo om Ice 8— ON— uopuazau % UVCON Fill - Test 1 Continuous UV (No Cond) 183 ‘ ’Z’X°Z°I°I°I°I°I’I°I°I°I‘ I ’ L m :ozozozoxozozozozozozozozozozozon l I I 'AVIA \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\_ I = t\\\\\\\\\\‘ 2020202020202020202.3203: I Iozoxozozc I I I I !A A A A A A AV V. I \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\V €92.20! $3320202020292020329!02920292924 ‘I I I i I 'AAAAAAAAAAAAA; WWW 39329393939393?39393939393939393939393393939???3?i l T f I I I ' . 120 8 8 uouuotou % 100 :9. M :3. a 8 Q ”E EE‘I‘ g” V 2:. ME 2931.: III \\‘ al If; 8a? O 40 20 0 Fig. 52: Continuous UV : % Retention, UVCON — Test 1 (fill) 184 Amumzv m ummk I >50 .oOHucmumm « I >5 mnonnflucou "mm .mfim e§é§ eSIm§ eSég $53: 25% mmm 03 8m 3. mm. 2: 8 e N 30,—. I 95$ >30 680 oz >2 253528 cu ov cw co— 8— uonumou % 185 UVCON Warp - Test 2 Continuous UV (No Cond) 333 'OIOIOIOIOIOIOIOIOIOIOIOIOIOIOIO I ’A’A’A’A’A’A.A.A.A.A.A.A.A.A.A.A W W 266 AAAAAAAAAAAAAAAAAAAAAA E W AAAAAAAAAAAAAAAAAAAA WW vvv vvvvvvvvvvvvvvvvvvvv! I{02020262020202.202029202 2.20202020202920292ofi 200 166 Time (Hours) E A—Warp Z B—Warp % C-Warp s 133 / | .\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\I m , ¢ 100 ".‘.‘. ....I.'.'. . £0360. I090.0.0?o?o?o?o?o.o.o.0?o?0.o?o?o?o?o? I 100 120 Fig. 54: Continuous UV - I Retention, UVCON - Test'z (warp) UOIIUOIOH % :Lrurkrk (.1: \Z _ (..(..i..+(.(r\ QUV Fill — Test 2 Continuous UV (No Cond) 186 120 W (’3 33 k202¢2020202020202¢2020192‘ I OIOIOIOIOIOIOIOIOIOI>¥>IO>> g A.A.A.A.A AOA.A.A.A.A.A.A.A.A.A.A‘ I = I \§ ‘ ' vvvvvvvvvvvvvvvvvvvv I 20202020202020202026202920202020202¢2é I —— \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\‘\\\\\\\\\\\\\\\\‘ 'V' ...... """"""' >2920202ofofofofofofofofofofofofofofofofofofofofc I _— 66 Time (Hours) w A—Fill % B-Fiil % C—Fill 133 .......'..... ' Iofofofofofofofofofofofofo?ofofofofofofofofi —__ 9M......-......... . ' O. ------ io§§fo§ofo§9¢fofo§féofofifofofififo?ofiféiofifi —— vvvvvvvvvvv 100 '9'9'9'0'9'9'0'9'.'9'9'0'0'9'0'9'0'9'9'9' IoIoIoIoIoI.oIoIoIoIoIoIoIoIoIoIoIoI090909.909...09.909.93.909...a I :\ ° v2.202.202020202020202...$20202.......3.0.0.0...020329... I ' , I I 8 8 8 3 ' «‘3: ° uopuatau %_ \ Fig. 55: Continuous UV - % Retention, QUV - Test 2 (fill) 187 3.33 .3“ m puma - zoo>= .cowunuumm a - >9 uaoscwucoo "mm .mum =EIU § Emlm § =EI< "WW. $535 25,—. c8 8m 3: m2 2: 8 N 39,—. I En— ZOU>D €80 ozv >2 88528 cu 3 co— cm— uouuazau 24, LIST OF REFERENCES LIST OF REFERENCES Allen, N. S., M. Edge, S. Conway, D. A. Doyle, E. M. Howells, K. Kikkawa, M. Minagawa, and T. Sekiguichi. 1991. Synthesis and Thermal and Photo-Oxidative Behavior of Novel 4 -Substituted Alicyclic Amino-2- Hydroxybenzophenone Stabilizers in Polypropylene Films. European Polymer JCurnal. 27:1365-1371. Amin, M.U., and G. Scott. 1974. Photo-Initiated Oxidation of Polyethylene Effect of Photo-Sensitizers. European Polymer JOurnal. 11:1019-1028. Amin, M. U., G. Scott, and L. K. M. Tillekeratne. 1974. Mechanism of the Photo-Initiation Process in Polyethylene. European Polymer JOurnal. 1:85-89. ASTM D 5208-91. Operating Fluorescent Ultraviolet (UV) and Condensation Apparatus for Exposure of Photodegradable Plastics. Annual Book of’ASTM Standards, American Society for Testing and Materials. Philadelphia, PA. ASTM D 5034-90. Breaking Force and Elongation of Textile Fabrics (Grab Test). Annual Book of'ASTM Standards, American Society for Testing and Materials. Philadelphia, PA. ASTM D 5035-90. Breaking Force and Elongation of Textile Fabrics (Strip Force). Annual Book of.ASTM Standards, American Society for Testing and Materials. Philadelphia, PA. ASTM G 53-88. Operating Light—And Water-Exposure Apparatus (Fluorescent UV-Condensation Type) for Exposure of Nonmetallic Materials. Annual Book of.ASTM Standards, American Society for Testing and Materials. Philadelphia, PA. ASTM D 4329-84. Operating Light-And Water-Exposure Apparatus (Fluorescent UV-Condensation Type) for Exposure of Plastics. Annual Book of ASTM Standards, American Society for Testing and Materials. Philadelphia, PA. 188 189 Bauer, D. R., J. L. Gerlock, and D. F. Mielewski. 1992. Photostabilization and Photodegradation in Organic Coatings Containing a Hindered Amine Light Stabilizer. Part VII. HALS Effectiveness in Acrylic Melamine Coatings Having Different Free Radical Formation Rates. Polymer Degradation and Stability; 36:9-15. Bremer, Wayne P. 1982. Photodegradable Polyethylene. Polymer-Plastics Technology and Engineering. 18(2):137- 148. Carlsson, D. J., K. H. Chan, J. P. Tovborg Jensen, D. M. Wiles, and J. Durmis. 1984. "Hindered Amines as Antioxidants in UV Exposed Polymers." In Polymer Additives, pp. 35—47. New York, NY: Plenum Press. Carlsson, D. J., K. H. Chan, and D. M. Wiles 1981. a "Polypropylene Photostabilization by A Tetramethylpiperdine Species." In Photodegradation and Photostabilization of Coatings, pp. 51-63. Washington D. C.: American Cancer Society. Carlsson, D. J., A. Garton, and D. M. Wiles. 1979. "The Photo-Stabilisation of Polyolefins." In Developments in Polymer Stabilisation, pp. 219-259. London: Applied Science Publishing LTD. Carlsson, D. J., D. W. Grattan, T. Suprunchuk, and D. M. Wiles. 1978. The Photodegradation of Polypropylene. IV. UV Stabilizer Decomposition. JOurnal of Applied Polymer Science. 22:2217-2228. Carlsson, D. J., and D. M. Wiles. 1976. Chapter 23, "Effects of UV Light on the Chemical and Mechanical Properties of FiberForming Polymers. In Ultraviolet Light Induced Reactions in Polymers, pp. 321—339. Washington D.C.: American Chemical Society. A Choice of Lamps for the Q-U-V, Bulletin L-816. Literature from The Q-Panel Company; Cleveland, Ohio. Cicchetti, O. 1970. Mechanisms of Oxidative Photodegradation and of UV Stabilization of Polyolefins. Advanced Polymer Science. 7:70-112. Cooney, J.D., G. Colin, and D.M. Wiles. 1973. Sunlight, and the Microbial Susceptibility of Thermoplastics. American Society for Testing and Materials. pp. 17—27. 190 Crewdson, Leslie. 1991. Correlation of Outdoor and Laboratory Accelerated Weathering Tests at Currently Used and Higher Irradiance Levels - Part I. Sun Spots. 21(44). .1993. Correlation of Outdoor and Laboratory Accelerated Weathering Tests at Currently Used and Higher Irradiance Levels - Part II. Sun Spots. 23(46). Freedman, Bernard. 1976. Photodegradable Vinyl Plastics. III. Comparison of Ultraviolet Light and Sunlight Exposure. JOurnal of Applied Polymer Science. 20:921- 929. Freedman, Bernard, and Martin J. Diamond. 1976. Photodegradable Vinyl Plastics. I. Effect of N-Halogen Additives. JOurnal of Applied Polymer Science. 20:463- 472. Gabriele, P. D., J. R. Geib, J. S. Puglisi, and W. J. Reid. 1984. "Photochemical Degradation and Biological Defacement of Polymers - I." In Polymer Additives, pp. 61-70. New York, NY: Plenum Press. Gonzalez, A., J. M. Pastor, and J. A. De Saja. 1989. Monitoring the UV Degradation of PVC Window Frames by Microhardness Analysis. JOurnal of Applied Polymer Science. 38:1879-1882. Grassie, N., and W. B. H. Leeming. 1976. Chapter 25, "Influence of UV Irradiation on the Stability of Polypropylene and Blends of Polypropylene with Polymethyl methacrylate." In Ultraviolet Light Induced Reactions in Polymers, pp.367-390. Washington D.C.: American Chemical Society. Gugumus, F. 1989. Advances in the Stabilization of Polyolefins. Polymer Degradation and Stabilityu 24:289- 301. . 1984. "Advances in U.V. Stabilization of Polyethylene." In Polymer Additives, pp. 17-33. New York: Plenum Press. 1979. Chapter 8, "Developments in the U.V.- Stabilisation of Polymers." In Developments in Polymer Stabilisation, pp. 261-308. London, England: Applied Science Publishers. Guillet, J. E., 1972. Fundamental Processes in the UV Degradation and Stabilization of Polymers. Pure & Applied Chemistry. 30:135-144. 191 Gupta, Amitava, Gary W. Scott, and David Kliger. 1981. "Mechanisms of Photodegradation of Ultraviolet Stabilizers and Stabilized Polymers." In Photodegradation and Photostabilization of Coatings, pp. 27-42. Washington D. C.: American Chemical Society. Hardy, William B. 1983a. Light Stabilization of Polymers. Part I of II. In Atlas Sun Spots. 13(30). . 1983b. Light Stabilization of Polymers. Part II of II. In Atlas Sun Spots. 13(31). 1982. Chapter 8, "Commercial Aspects of Polymer Photostabilization." In Developments in Polymer Photochemistry, pp. 287—346. New Jersey: Applied Science Publishers. Hawkins, W.L. 1984a. Chapter B,"Polymer Degradation." In Polymer Degradation and Stabilization, pp. 3-24. Springer-Verlag. 1984b. Chapter G,"Test Procedures." In Polymer Degradation and Stabilization, pp.98-113. Springer— Verlag. Hirt, Robert. C., and Norma. Z. Searle. 1967. Energy Characteristics of Outdoor and Indoor Exposure Sources and Their Relation to the Weatherability of Plastics. In Applied Polymer Symposia. 4:61-83. . 1964. Wavelength Sensitivity or Activation Spectra of Polymers. In SPE.RETEC (Prepr.). pp. 286-302. Washington, D.C. Hsuan, Yick G., and Robert M. Koerner. 1993. Can Outdoor Degradation be Predicted by Laboratory Acceleration Weathering? Geotechnical Fabrics Report. November. 12- 16. Hutson, G.V., and G. Scott. 1974. The Effect of Processing on the Light Stability of Stabilized and Unstabilized Polyethylene. European Polymer Jburnal. 1:45-49. Johnson, Regina. 1988. An Overview of Degradable Plastics. JOurnal of Plastic Film & Sheeting. 4:155-170. Johnson, Richard A., and Gouri K. Bhattacharyya. 1992. Statistics: Principles and Mathods. NY: John Wiley & Sons, Inc. 192 Klein, Tibor. 1983. Chapter 10,"Stabilization of Polymers." In Polymer Degradation, pp. 173-202. NY: Van Nostran Reinhold. Klemchuk, Peter P. 1989. Chemistry of Plastics Casts a Negative Vote. Mbdern Plastics. 8:48-53. Love, D. L. 1984. How Polyarylates Resist Weathering. Mbdern Plastics. 61(3):60—62. McTigue, F. H., and M. Blumberg. 1967. Factors Affecting Light Resistance of Polypropylene. In Applied Polymer symposia. 4:175-188. Miteff, Steven P. Interview by Dr. Diana Twede, 12 May 1993. Telephone. Plastics, Environmentally Degradable. 1984. Encyclopedia of Chemi cal Technol ogy, Suppl emen t Vol ume (Al cohol Fuel 3 to Toxicology). New York: John Wiley & Sons, Inc. Pouncy, H. W. 1985. How Photostabilizers compare in LLDPE Film Weatherability. Mbdern Plastics. 62(3):68-72. Rabek, J. F. 1976. "Photosensitized Degradation of Polymers." In Ultraviolet Light Induced Reactions in Polymers, pp. 255-271. Washington D. C.: American Chemical Society. Ranby, B., and J. F. Rabek. 1976. "Photooxidative Degradation of Polymers by Singlet Oxygen." In Ultraviolet Light Induced Reactions in Polymers, pp. 391-406. Washington D.C.: American Chemical Society. Rysavy, D., and H. Tkadleckova. 1992. Surface Photooxidation of Filled Polypropylene. Polymer Degradation and Stability; 37:19-23. Scott, Gerald. 1976a. Chapter 24, "Mechanisms of Photodegradation and Stabilization of Polyolefins." In Ultraviolet Light Induced Reactions in Polymers, pp.340-366. Washington D.C.: American Chemical Society. . 1976b. Time Controlled Stabilization of Polyolefins. Journal of Polymer Science: symposium No. 57:357-374. 193 Searle, Norma D. 1987. Printing Inks: Wavelength Sensitivities and Lightfastness Testing. In Atlas Sun Spots. 17(38). 1984. Activation Spectra: The Activation Spectrum and its Significance to Weathering of Polymeric Materials. In Atlas Sun Spots. 14(33). Searle, Norma D., N. L. Maecker, and L. F. E. Crewdson. 1989. Wavelength Sensitivity of Acrylonitrile- Butadiene-Styrene. JOurnal of Polymer Science: Part A: Polymer Chemistry. 27: 1341-1357. Seppala, Jukka, Yu—Yen Linko, and Tao Su. 1991. Photo- and Biodegradation of High Volume Thermoplastics. Acta Polytechnica Scandinavica. 198:1-33. South Florida Test Service. 1991. Test facility brochure. Miami, Florida. Subowo, Wiwik S., M. Barmawi, and Oei Ban-Liang. 1986. Growth of Carbonyl Index in the Degradation of Polypropylene. JOurnal of Polymer Science: Part A: Polymer Chemistry. 24:1351-1362. Swasey, Chester C. 1980. An Updated Guide to UV Stabilization. Plastics Engineering. 36:33-35. Tirrell, David A. 1981. "Preparation of Polymeric Ultraviolet Stabilizers." In Photodegradation and Photostabilization of coatings, pp. 43-49. Washington D. C.: American Chemical Society. Tobin, William, and Fred Vigeant. 1981. Ultraviolet Stabilization Systems. Plastics COmpounding. 4:16-24. U. S. Department of Agriculture. 1954. The Agricultural Trade Development and Assistance Act of 1954. Washington D. C.: Government PrintingOffice. Wiles, D. M. 1978. Photostabilization of Macromolecules by Excited State Quenching. Pure & Applied Chemistry. 50:291-297. Zerlant, G. A. 1982. "Accelerated Weathering and Precision Spectral Ultraviolet Measurements." In Permanence of Organic COatings, ASTM ST? 781, American Society for Testing and Materials, pp. 10-34. CIH GHN STATE UNIV. LIBRHRIES I|III I2IIISIIIIIIIIIIIIIIII|I2I|III|ISIIIIII0 I IIIIII