v . .. ‘ . . . . a _ . . .. . _ . v . . ,1 _ . . . 1... , u . e: Ptrf ‘ , . . _ \ ... _ \ . . . ‘ . o .. , . : . . p . ‘ . s. .1 . . , .., . . . . .. . ,v. . ;, ‘ A v. . V . ~ .. > p ‘ - I u. u n n ‘ u v. s W. . I l . . . r. w‘ 5‘ ~ I a n A o . . ‘ ~ 7 vI . . < . . . . _ Ku.L.n...58 v 4. 9 . u, . 1 .. . . H} n . n r v 4 < .‘ I T. . A . , . I v 0 )x t l . I. i .V Up. I. . . ‘ I A , s . . . . n ‘ ‘ n v . . . v . J. . ~ ,_ . . .. s . . .u . . . ' ‘ . a v .- . . _ . . r . . - . ‘ H ‘ .. ‘ .V .. _ r T . . . . u. .‘ . u . . . n. . . u .. y f . . ¢ - m. I . I . I . .. .. . ‘ f . . _ . ‘ . .. 3 , .. . 7 ~ 4 o > \ ‘3 ‘ I. v . . ; ‘ . - ‘ , _. L . ‘ s w . v n | s - .‘. . . . f x . . . . .n . I ...‘I.. l n l . v : l I t u . p , V I I. . . I .‘ A .. ‘. . ~ L . . . = I l 4 .x ‘ E. V V x . I . - . . .H 9....-. . , ‘ w. - . , I. x . . . . - . . . ‘ ‘o l l.. 1.!" $.10. . \Q W . . . ‘ _ k. '4; .. .v! , A.“ .u .. Avflil n ‘.v in .IL. i \. I w. . -11. r ,K 4". ‘ . I n . > .. . I - . ....$ - . I. . -.., . 4.1110!“ Hxfikhfiéfififig «9 I ‘ ‘ ‘ , ‘ ‘ ‘ w «P ‘f , u gummy A lifllililmIiiliiilifiliflifil'liiWflifllflifl L LlBRHI3|1l293 00652 0435 - Michigan State University This is to certify that the thesis entitled Compression Performance of Corrugated Fiberboard Shipping Containers Having Fabrication Defects: Fixed Versus Floating Platens presented by Mary Margaret Langlois has been accepted towards fulfillment of the requirements for M. S. Packaging degree in 2/ Major profeg 3. Paul Singh v Date March 13, 1989 0.7639 MS U is an Ajfirmati've Action/Equal Opportunity Institution PLACE IN RETURN BOX to remove thle checkout from your record. TO AVOID FINES return on or before date due. mus. DATE DUE DATE DUE ”31 39 199? . d ' EM I 2 199:» 1 f ; = . "git—Fr] MSU le An Affirmdive Action/Equal Opportunity lnetitution COMPRESSION PERFORMANCE OF CORRUGATED FIBERBOARD SHIPPING CONTAINERS HAVING FABRICATION DEFECTS: FIXED VERSUS FLOATING PLATENS BY Mary Margaret Langlois A THESIS Submitted to Michigan State University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE School of Packaging 1989 COMPRESSION PERFORMANCE OF CORRUGATED FIBERBOARD SHIPPING CONTAINERS HAVING FABRICATION DEFECTS: FIXED VERSUS FLOATING PLATENS BY Mary Margaret Langlois The compression strength of corrugated fiberboard containers was studied to determine the effect of using a fixed versus floating platen. . There was a significant difference in the compression strength and deflection values of the containers measured using the fixed and floating platens. The floating platen gave a compression value 3.6% higher than the fixed platen. Three degrees of defect, (1°, 2° and 3°) and a control were incorporated into the boxes during fabrication to determine the effect on compression strength. Two box sizes were used. As the degree of defect was increased, there was a decrease in the compression strength. The deflection values were not significantly affected by the fabrication defects. to my parents , for their encouragement, love, and belief in me. iii ACKNOWLEDGEMENTS I would like to thank my major professor, Dr. Paul Singh, for his guidance, academic support and time. I would also like to thank my committee members, Dr. Gary Burgess, Dr. Diana Twede, and Dr. George Mase for their assistance and support. I wish to express my appreciation to Dr. John Gill , (Department of Animal Science) for his advice on statistical analysis. A special thanks goes to ARVAN Corporation for donating the corrugated board for this research. I would also like to thank Kris Nieman and Pat Brady, friends, for assisting me in fabricating the boxes. Finally, I wish to thank my family and friends for their encouragement and faith throughout this research. iv TABLE OF CONTENTS page LIST OF TABLES .......................................... Vi LIST OF FIGURES ......................................... ix 1.0 INTRODUCTION .................................... 1 2.0 LITERATURE REVIEW ............................... 4 2.1 Compression Strength ....................... 4 2.2 Transport Requirements and Quality Standards .................................. 7 2.3 Corrugated Box Closures .................... 9 2.4 Box Size .................................. 10 3.0 MATERIALS AND METHODS .......................... 11 3.1 Box Specification ......................... 11 3.2 Box Construction .......................... 12 3.3 Test Methods .............................. 15 3.3.1 Moisture Content ................... 15 3.3.2 Static Compression Test ............ 16 4.0 DATA AND RESULTS ............................... 19 4.1 Compression ............................... 21 4.2 Deflection ................................ 31 5.0 CONCLUSIONS .................................... 39 5.1 Recommendations for Future Work ........... 41 6.0 APPENDICES ................................... ..42 A. Compression and Deflection Data ............ 42 B. Data on Statistical Analysis ............... 58 7.0 REFERENCES ..................................... 70 LIST OF TABLES Table Page 1 Average Compression and Deflection Values ......... 20 2 Analysis of Variance for Compression .............. 23 3 Compression T-Test Results of Fixed versus Floating Platen ................................... 24 4 Tuckey's Multiple Range Test of Effect of Degree of Defect on Compression .......................... 25 5 Compression TrTest Results of 2-Way Interaction of Box Size and Defect ............................ 27 6 Factor Anlysis of Compression ..................... 28 7 Analysis of Variance for Deflection ............... 33 8 Tuckey's Multiple Range Test of Effect of Degree of Defect on Deflection ........................... 33 9 Deflection T-Test Results of 2-Way Interaction Between Platen Type and Box Size .................. 34 10 Deflection T-Test Results of 2-Way Interaction Between Box Size and Degree of Defect ............. 34 11 Factor Analysis of Deflection ..................... 36 12 Moisture Content .................................. 36 A-l Compression and Deflection Values for Box A, 0° Defect on the Fixed Platen ........................ 42 A-2 Compression and Deflection Values for Box A, 1° Defect on the Fixed Platen ........................ 43 A-3 Compression and Deflection Values for Box A, 2° Defect on the Fixed Platen ........................ 44 A-4 Compression and Deflection Values for Box A, 3° Defect on the Fixed Platen ........................ 45 A-S Compression and Deflection Values for Box A, 0° Defect on the Floating Platen ..................... 46 A-6 Compression and Deflection values for Box A, 1° Defect on the Floating Platen.. ........... . ........ 47 vi Table Page A-7 Compression and Deflection Values for Box A, 2° Defect on the Floating Platen ..................... 48 A-8 Compression and Deflection Values for Box A, 3° Defect on the Floating Platen ..................... 49 A-9 Compression and Deflection Values for Box B, 0° Defect on the Fixed Platen .............. ..........50 A-lO Compression and Deflection Values for Box B, 1° Defect on the Fixed Platen ....................... 51 A-11 Compression and Deflection Values for Box B, 2° Defect on the Fixed Platen ....................... 52 A-12 Compression and Deflection Values for Box B, 3° Defect on the Fixed Platen ....................... 53 A-13 Compression and Deflection Values for Box B, 0° Defect on the Floating Platen .................... 54 A-14 Compression and Deflection Values for Box B, 1° Defect on the Floating Platen .................... 55 A-15 Compression and Deflection Values for Box B, 2° Defect on the Floating Platen .................... 56 A-16 Compression and Deflection Values for Box B, 3° Defect on the Floating Platen .................... 57 B-l Description of Code Numbers ....................... 58 B-2 Compression 3-Way ANOVA Test Results .............. 59 8-3 Compression T-Test Comparing the Compression Values of the Fixed Versus The Floating Platen....60 B-4 Tuckey's Multiple Range Test Comparing the Compression Values by Degree of Defect ............ 61 B-5 2-Way Interaction Comparing Compression values of Box A to B with the Same Defect and the Same Platen ............................................ 62 B-6 Factor Analysis of Compression .................... 64 B-7 Deflection 3-Way ANOVA Results .................... 65 B—8 Tuckey's Multiple Range Test Comparing the , Compression Values by Degree of Defect ............ 65 vii , Table Page B-9 2-Way Interaction Comparing Deflection Values of Each Platen and Each Box Size .................. 66 B-lO 2-Way Interaction Comparing Deflection Values of Box A to B with the Same Defect and the Same Platen ........................................... 67 8—11 Factor Analysis of Deflection .................... 69 viii LIST OF FIGURES Figure Page 1 Defect Introduction in a RSC during Fabrication...13 2 RSC Blank with 0°, 1°, 2° and 3° Flute Defects....14 3 Floating Platen Compression Test .................. 17 4 Cylinders used to Convert from Floating to Fixed Platen ...................................... l7 5 Compression Tester with Conversion Cylinders in Place .......................................... 18 6 Fixed Platen Compression Test ..................... 18 7 Compression Strength Averages for Box A ........... 29 8 Compression Strength Averages for Box B ........... 30 ix 1.0 INTRODUCTION The compression strength of corrugated containers has been studied at length under varying conditions. Tests have been performed with corrugated containers conditioned to hot and cold temperature extremes as well as high and low relative humidities. All of previous published studies have been performed using a fixed platen compression testing machine. However, the effect of using a floating versus fixed platen to evaluate the performance of corrugated containers has not been studied. In ASTM D642-76 (Compression Test For Shipping Containers), the recommended procedure for testing compression strength states that the top platen may be either fixed or swiveled (floating) for tests where the compressive loads are applied face to face. The standard presumes that both the fixed and floating platens will give the same results. The TAPPI T804 standard for compression testing specifically notes that "floating" platens are not in accordance with the standard. The rational for this decision is that the fixed platen is the most reproducible way of making compression tests (Maltenfort, 1988). In general terms, it may be said that compression testing is used to relate stacking strength of the container (or the container and product) to the physical distribution environment (Peleg 1985). Many people believe that the fixed platen is not an accurate simulation of what compressive forces a container will see. Peleg (1985) states: Most standard compression testing procedures of shipping containers specify fixed platen compression testing machines. Such machines provide a measurement which is less realistic than a floating-type compression testing platen. A floating platen automatically adjusts itself to the nonuniformly yielding containers, rather than measuring the resistance at the strongest points in the stack as it is compressed downwards. The TAPPI fixed platen method does not allow a weak corner or portion of the container to cause failure. From the box user's point of view, if there is a weak spot, the test method should show this, not obscure it. For the boxmaker, on the other hand, the fixed platen method makes it easier to qualify for a specification (Maltenfort, 1988). Although many people agree that the floating platen is a more realistic simulation of the compressive forces on a stack or pallet, few people agree on which platen gives more precise results on a single container. The objectives of this study are as follows: 0 To compare the compression strength and deflection of identical corrugated containers using both the fixed and floating platens. These results will be compared to see if there is a significant difference between the platen types. 0 To compare the compression strength and deflection of corrugated containers ,that have varying degrees of defects incorporated in during fabrication, using both the fixed and floating platens. 0 To determine if a relationship exists between the fixed and floating platen compression testing methods. 0 To determine if a relationship exists between the magnitude of fabrication defect incorporated into the container and the subsequent compression and deflection values obtained using both platens. o to determine the effect of box size on compression and deflection values using both the fixed and floating platens. 2.0 LITERATURE REVIEW Corrugated containers are used to package 90 to 95 % of America's manufactured goods for the consumer (FBA, 1984). The functions of a corrugated shipping container may be summarized as follows: 1) Protection: The corrugated shipping container protects the product from damage and soiling as it moves through the transportation and handling environment from producer to consumer. 2) Storage: It offers a convenient place and a safe method of storing a product until it is sold. 3) Advertising: It can function as an advertising billboard for the users product while the container is in transit, in storage or on display. 4) Economics: It performs above functions at a minimal cost. (Maltenfort, 1970) The standardization of the corrugated shipping container is largely governed by the railroad and motor carrier industry of the United States. The bursting strength, basis weight, transportation requirements, box closure and box size are all considered when designing a corrugated box for a product. 2.1 COMPRESSION STRENGTH The compression strength of a corrugated container is used I to determine how well the container will perform throughout transportation and storage. The higher the compression strength, the higher the stacking height possible. During transportation and storage it is common practice to stack pallet loads to efficiently utilize storage space. In the ASTM standard D 4169-82 (1981), Performance Testing of Shipping Containers and Systems , the ability of a package to withstand the compressive loads that occur during vehicle transport or warehousing can be estimated using a formula that takes into account a combined assurance level factor, the weight of the product and the height of the stack. Peterson and Fox (1980), reported on a theory to demonstrate how boxes fail in compression. The compression failure morphology of the liners was studied, to develop an understanding of what may be done to increase compression strength. Failure is consistently seen in regions of the panel subjected to compressive loads 'as a result of the critical combination of stresses acting there at a much lower level than would be required to cause a box failure due to tension. After a physical examination of linerboard cross sections, that had failed under compressive loads, it was revealed that on occasion the board delaminated as if it were made of many layers and that the bonds between the layers ruptured when loaded. Other samples were seen to have fibers buckle or delaminate and then buckle. It was concluded that interfiber bond strength and fiber stiffness are the most important variables related to linerboard compressive strength. Two basic approaches are possible in constructing a mathematical prediction model of corrugated container stacking strength: (1) One correlates the properties of the material, e.g., paperboard facings and corrugating medium, to the stacking strength of the fabricated container. (2) One views the container as a basic structure, e.g., single degree of freedom system with inherent viscoelastic properties (Peleg 1985). Each of these approaches have been investigated. By far, the most common estimation of compression strength is a well known empirical formula adapted by McKee et a1. (1963). The final simplified version of this formula relates the ultimate compressive strength of a RSC container to the board caliper, container perimeter and edgewise compressive strength of the corrugated paperboard (Peleg 1985). P = 5.87*Pm*(h*Z)1/2 (2-1) where P = maximal top to bottom compressive force Pm= edgewise compressive strength of board h = board caliper z = container perimeter It is important to state that this formula is only valid for corrugated containers of a RSC type at ambient temperatures of 72°F and 50% RH. Kellicut and Landt (1951) investigated the influence of humidity upon static load tests of corrugated containers. They related the compressive strength of moist packages to dry packages by the relationship: P = P0 * 10-3-01x (2-2) where P = compression strength Po= compression strength at 0 moisture content X = moisture content of corrugated material Hanlon (1984), states that for long term storage, it is ideal, to use one-forth of the compressive strength of a corrugated box as a safe load. He also states that a more accurate method would be to calculate the fatigue factor for the length of time the material is expected to remain in storage. It is also important to factor in the affects of humidity and the stacking pattern. 2.2 TRANSPORT REQUIREMENTS AND QUALITY STANDARDS In 1914, when the use of corrugated boxes for shipping began to grow, material standards became necessary. To ensure and control material against the transportation hazards of shipping, the freight carriers established rules, regulations and specifications for corrugated containers (Morris 1978). Various methods for defining the quality of corrugated board were developed. These include Mullen burst test, puncture test, short column crush test and flat crush test. In 1917, rule 41 and rule 222 were established by the railroad and truck industry. As initially adopted, the quality level of the combined board in containers producing satisfactory performance was characterized by the then available test procedures. These procedures were used by papermakers to evaluate the quality of paper based on weight, caliper and mullen strength (Morris 1978). It was basically assumed that if all of the above factors remained constant, the containers would perform satisfactorily. Although these attributes were convenient for use in establishing a grade structure, they were and are indirectly related to corrugated container fabrication efficiency and performance (Morris 1978). This fact has been the center for debates over changing the testing methods for evaluating corrugated container shipping performance by including an edge crush test (ECT). Various researchers like Scott (1988), Morris Jr. (1978) and King(1975) all agree that the currently required shipping performance measures of basis weight, caliper and mullen burst test should be accompanied by a short column edge crush test (ECT) if not entirely replaced by it. Currently the Uniform Freight Classification rule 41 (UFC, 1988) and the National Motor Freight Classification item rule 222 (NMFC, 1988) do not require any compressive strength values. Most companies already require a ECT in their specifications for corrugated containers. In Europe, the ECT is fully accepted as a criterion of corrugated container performance (Jonson,1985). This does not presume that the mullen and puncture tests are not useful as quality standards for corrugated material. The general bursting strength is dependent on the type, proportion, preparation, and amount of fibers present in the sheet and to their formation, internal sizing and to some extent surface treatment (Maltenfort 1979). The puncture test is useful in measuring puncture resistance and board stiffness. All three of the tests described above effect the overall performance of a RSC in the distribution environment. 2.3 CORRUGATED BOX CLOSURES The type of box closure may have a significant effect on the performance of the container. Sheehan (1988) states that when different types of closure materials are to be compared, the physical properties of these materials are significantly different and the performance of the closures on-the-box must be determined for a comparison. A recent study conducted by Sheehan at the 3M Packaging Methods Center evaluated the compression values of empty RSC's 10 sealed with one of two closures: i) a 2 inch wide pressure sensitive tape and ii) beads of hot melt adhesive. From these tests, it was concluded that the compression strength of the corrugated container is affected by'the closure. The taped boxes averaged a higher compression strength (by 6%) than the boxes closed with the hot melt adhesive (Sheehan, 1988). He also observed that the boxes with adhesive closures consistently had slightly higher deformations at failure than taped boxes. 2.4 Box Size The relationship of the dimensions of a container to its compression strength is linear. As the perimeter of the box is increased, the compression strength increases. Maltenfort (1988), states that in the top to bottom compression testing of a container, the depth is only slightly negatively correlated to compression strength. What this says is that by increasing the depth alone, the compression strength of the container will slightly decrease. 11 3.0 MATERIALS AND METHODS The test samples used for this study were constructed of single wall C-flute corrugated board and were of an R.S.C. (regular slotted container) type. Two box sizes were used to determine if there was a relationship between the box size and the effect of the degree of defect on the subsequent compression strength. Fabrication defects of 1°, 2° and 3° were incorporated into the box blank. The 1° defect was thought to be a minor defect that could go unnoticed. The 3° defect was thought to be a more noticeable defect on close sight of the box blank. It was thought that any degree of defect greater than 3° would be immediately noticed and not allowed to continue through further fabrication. 3.1 Box Specification Type = C-flute, double faced corrugated Medium = C-flute Dimensions Box A 10" x 8" x 6" (L x W x D) Box B 12" x 10" x 8" Burst strength - 200 lb. Minimum combined weight of facings = 68 lbs./1000 sq.ft. Board components include two 42 lb./1000 sq.ft. liners, 26 1b./1000 sq. ft. medium and a regular starch adhesive. 12 The boxes were sealed with a paper tape. 3.2 Box Construction The boxes were manually constructed using a creasing and cutting rule. A fabrication defect was introduced into the manufacturing of the box by feeding the corrugated sheet through the creasing and cutting rules at an angle (Figure 1). The box blank was then creased and slotted. The box blank (Figure 2) was then folded and taped at the joint, top and bottom. This technique causes the flutes in the set-up box to be inclined instead of being vertical to the edge. This fabrication defect also causes one corner of the box not to match a perfect square. Four degrees of defects were introduced into the box. 0 0° no defect (control) 0 1° fabrication defect 0 2° fabrication defect 0 3° fabrication defect Two sizes of boxes were tested, A = 10"x8"x6" and B = 12" x 10"x8". For each degree of defect and each box size, 30 replicant boxes were fabricated at the School of Packaging (Package Development Lab). 13 FIGURE 1 Defect Introduction in a RSC During Fabrication q __.____._________._'__.______________,__H__ _____H__ ___ —‘ A GREASE Flute Direction GREASE wooden Block RSC Blank with 1°,2° & 3° Flute Defect 14 'FIGURE 2 Flute Direction b--- a’ RSC Blank (Normal Flute Direction) l RSC Container 15 3.3 TEST METHODS 3.3.1 Moisture Content Method: The ASTM D644-82, Moisture Content of Paper and Paperboard by Ovendrying, (1984) method was followed with the exception that an airtight weighing container was not used to transfer the specimen from the vacuum oven to the balance. The room in which the balance and oven are located is set at standard conditions of 72°F and 50% RH, which is the same conditions the samples were pre-conditioned in. The initial weight was recorded and the specimens were placed in a vacuum oven for 6 hours at 90°F. The oven used was a Vacuum Oven Model No. 5831 manufactured by National Appliance Company. The scale used was an Analytical Balance Model AE160 manufactured by Mettler Company. After 6 hours, the vacuum oven was flushed with nitrogen and the specimens were immediately transferred to a glass desiccator filled with anhydrous Calcium Sulphate and allowed to cool to room temperature for 1 hour. The specimens were then weighed to determine dry weight. The moisture content on a percent dry basis was then determined by using the following formula: Percent Moisture = [(W1 - W2)/W2]* 100 (3-1) where W1 = original weight of moist specimen W2 = weight of specimen after vacuum oven drying 16 3.3.2 Static Compression Test Materials: 240 RSC's conditioned and tested at 72°F and 50%RH. Apparatus: A Lansmont Model 76-5K compression tester with a capacity of 6000 pounds was used to perform the compression tests. The compression tester was used with both the fixed and floating platens. The attached floating platen (Figure 3) was unable to move when the 4 steel cylinders (Figure 4) were in place, thus simulating a fixed platen as shown in Figures 5 and 6. Method: All tests were done in accordance to ASTM D642-84, Compression Test for Shipping Containers (1984). A 50 pound preload was applied to ensure a definite contact between the specimen and the platens. The peak compressive force and corresponding deflection were recorded for each sample tested. A total of 240 boxes were tested as follows: 15 A size, 15 B size at 0° defect (control) 15 A size, 15 B size at 1° defect 15 A size, 15 B size at 2° defect 15 A size, 15 B size at 3° defect total = 120 boxes tested on the fixed platen. 15 A size, 15 B size at 0° defect (control) 15 A size, 15 B size at 1° defect 15 A size, 15 B size at 2° defect 15 A size, 15 B size at 3° defect total = 120 boxes tested on the floating platen. Figure 3 Floating Platen Compression Test Figure 4 Cylinders used to Convert from Floating to Fixed Platen 19 4.0 RESULTS AND DISCUSSION Two hundred and forty corrugated shipping containers were fabricated and tested to determine if there was a significant difference in compression strength and deflection using the fixed versus floating platen. All tests were conducted at 72°F and 50% RH. The average compression and deflection values for each group of boxes are summarized in Table 1. Corrugated board is a highly variable material. The fabrication process of containers from this material further increases the variances. Thus the compression and deflection results collected in this research had a large standard deviation and variance. This variation in data obscures any trends that may be seen by just looking at the raw data. For this reason statistical analysis must be performed on the data to see if there are significant differences occurring. A 3-way between subjects analysis of variance (ANOVAL. test for significance was performed at 90% confidence or better on the compression and deflection results for all tests. The three independent variable were: 0 Platen type (2 types) fixed floating 0 Box size (2 types) A 10"x8"x6" B 12"x10"x8" 20 TABLE leverage Compression and Deflection Values. Compression Platen Box Defect Str.(lbs.) Defl.(in.) FIXED A 0° 695.33 .60 1° 726.47 .66 2° 689.60 .71 3° 686.80 .69 FLOATING A 0° 686.47 .72 1° 677.73 .68 2° 638.13 .76 3° 663.60 .65 FIXED B 0° 774.67 .78 1° 798.00 .85 2° 778.07 .75 3° 649.93 .65 FLOATING B 0° 728.40 .77 1° 782.80 .79 2° 777.67 .67 3° 642.47 .73 21 0 Type of Fabrication defect (4 types) 0° (control) 10 20 30 The dependent variables were compression and deflection. The main purpose of these tests were to determine if there were significant differences in the compression and deflection values obtained from the fixed versus floating platens. The effect of the degree of fabrication defect and the box size on the compression and deflection values were also analyzed. 4.1 Compression Strength The most important test for the performance of a corrugated container is the compression test. A high compression strength allows the container to be stacked to efficiently utilize storage space. An estimation or an actual test of compression strength is used to determine the safe stacking height of the container. External factors such as temperature, relative humidity, time in storage and the stacking pattern will all affect the actual compression strength of a container. Several empirical formulas take into account these external factors. The basis of this study was centered on the test method used to estimate the compression strength. The fundamental objective of the compression test is to reflect the quality of the box being tested under conditions as closely simulating use as possible (Maltenfort, 1988). The ASTM standards state that 22 either the fixed or floating platen may be used when compression testing. This statement suggests that there is not a significant difference in the values obtained by the two methods. The main effects of the ANOVA test show that there are significant differences between the two platen types, the two box types and between the four defect types (Table 2). Since there were not any 2-way or 3—way interactions occurring with the two platen types a simple t-test for significance was conducted. A 2 or 3-way interaction means that the variables act together to affect the subsequent compression strength values. Tuckey's multiple range test was used to test for significant differences in the compression values based on the degree of fabrication defect. Tuckey's test allows pairwise comparisons of means derived from an ANOVA test. The results of the t-test show that there is a significant difference between the fixed and floating platen values (Table 3). The results of the Tuckey's test show that the 1° and 3° boxes were significantly different from all of the other boxes and that the 0° and 2° boxes were significantly different from the 1° and 3° boxes (Table 4). The results of the ANOVA test also predict that there was a 2-way interaction occurring between the box size and the degree of defect (Table 2). Based on these results, t-tests were then eva=¥% . A L. 23 TABLE 2: Analysis of Variance for Compression. Mean Sig. Source of Variation DF Square of F Main Effects 5 96142.311 .000 PLATEN TYPE 1 36927.204 .000 BOX SIZE 1 202478.504 .000 DEFECT TYPE 3 80435.282 .000 2-Way Interactions 7 25480.552 .000 PLATEN, BOX 1 3352.538 .266 PLATEN, DEFECT 3 649.582 .868 BOX, DEFECT 3 57687.526 .000 3-Way Interactions 3 5355.315 .117 PLATEN, BOX, DEFECT 3 5355.315 .117 Explained 15 45009.424 .000 Residual 224 2695.010 MSE sig. sig. sig. not sig. not sig. sig. not sig. 24 TABLE 3: Compression T-Test Results of Fixed Versus Floating Platen. Group# Platen Average 1 FIXED 724.86 2 FLOATING 699.66 X1 ‘ X2 (n1) (n2) (:i_x12 ‘ (25X1)2/n1 ) + (:£322 ‘ (2:32)2/n2 ) (hi +Ik: (D1 + n2 - 2 ) where N = total # subjects = 240 n1= # subjects in group 1 = 120 n2= # subjects in group 2 = 120 df= degrees of freedom (n1 - n2 - 2) = 238 critical t value 1.970 at 95% confidence t = 2.70 -> 1.970 significant 25 TABLE 4: Tuckey's Multiple Range Test of Effect of Degree of Defect on Compression. Compression Combined Avg. Significantly Defect (Original Order) (Ranked Order) Different From 0° 721.22 1° 747.03 0°, 2° + 3° 1° 747.03 0° 721.22 1° + 3° 2° 720.87 2° 720.87 1° + 3° 3° 660.70 3° 660.70 0°, 1° + 2° MSE = 2695.01 Degrees Freedom = 224 60 observations in each mean alpha = .05 26 conducted to identify which interactions were occurring (Table 5). In comparing the compressive values of box A to B, with the same degree of defect and the fixed platen, it was found that the values of the 0°, 1° and 2° boxes were significantly different (Table 5). In comparing the compression values of box A to B, with the same degree of defect and the floating platen, it was found that the values of the 1° and 2° boxes were significantly different. A factorial analysis was performed on the compression averages to see if there was a linear or curvature trend in the data. Since there was not a 3-way interaction occurring, the linear and quadratic equations were broken down only by box size (Table 6). There were both significant linear and curvature trends in the data collected from the B size box. The reason both of these trends were seen is that there were not enough data sets to show which trend was more significant. There was no linear or curvature trend in the data for the A size box (Table 6). The results of this study show that there is a statistically significant difference in the compression values of the fixed and floating platens. The floating platen compression averages, for each degree of defect and box size were generally all less than the fixed platen compression averages (Figure 7 and 8). The floating platen, overall mean of means, gave a compression strength reading 27 TABLE 5: Compression T—Test Results of 2-Way Interaction of Box Size and Degree of Defect. 95% Platen Box Defect TB confidence FIXED A o0 4.18 sig. FIXED B O0 FIXED A l° 3.77 sigo FIXED B 1° ' FIXED A 20 4.67 sig. FIXED B 2° FIXED A 3° 1.94 not sig. FIXED B 3° FLOATING A O° 2.21 not sig. FLOATING B O° FLOATING A 1° 5.54 sig. FLOATING B 1° FLOATIAG A 20 7.36 sig. FLOATING B 2° FLOATING A 3° 1.11 not sig. FLOATING B 3° Fvfivrzm 28 TABLE 6: Factor Analysis of Compression. Platen Box Defect F-Linear F-Quadratic FIXED A 0° FLOATING A 0° FIXED A 1° FLOATING A 1° .304 not .0036 not FIXED A 2° sig. 819. FLOATING A 2° FIXED A 3° FLOATING A 3° FIXED B 0° FLOATING B 0° FIXED B 1° FLOATING B 1° 60.07 sig. 80.97 sig. FIXED B 2° FLOATING B 2° FIXED B 3° FLOATING B 3° -. \‘ e zi-S‘T" m g: * at 95% confidence level. Compression Strength (lbs.) 850 § 29 Figure 7: Compression Strength Averages for BoxA (i 1 0‘) Aflxed platen Ifloating platen p- l i l 0 1 2 3 Degree of Defect :- fl . _ ‘ 30 Figure 8: Compression Strength Averages for Box B (:1: 1 0') § Aflxed platen Ifloating platen a: .. 3 ° 3 08080 lllll 1 I i Compression Strength (lbs.) 8. o l I ' 0| 8 I l l 4 l 450 O 1 2 3 Degree of Defect 31 3.6% lower than the fixed platen. As the degree of defect was increased , from 0° to 3°, for both box sizes and platen types , the general trend in compression values decreased (Table 1). This decreasing trend was expected since the greater the degree of fabrication defect, the more severe is the incline angle at which the flutes are compressed. For optimum performance, the flutes should be perpendicular to the bottom edge of the box. The Tuckey's test on the average compression values showed that in most cases the increased degree of defect significantly changed the compression strength. The largest defect incorporated , the 3° defect, lowered the compression strength by 12%. For the same platen and the same degree of defect it was expected that the larger B box compression values should be greater than the A box values because the perimeter was larger. This was true in all cases except in the 3° defect case and the 0° defect on the floating platen. This significant difference may be explained by the highly variable properties of the material itself and the fabrication process. These results provide supportive evidence for the theory that the fixed and floating platen compression tests give significantly different results. A more realistic compression value that shows fabrication defects is obtained with the floating platen. 4.2 Deflection The deflection of a corrugated container is the other I 32 results of a compression test. As the container is compressed, the box panels bulge or bow out of the way which reduces the depth of the box. This reduction is known as the deflection (Maltenfort, 1988). ' This value is critical when determining the proper head space needed between the product and the corrugated container for optimum strength. If the critical deflection is reached, the product inside the container will become load bearing. The outcome of the compression test is used to estimate this headspace value. The deflection number recorded by the compression tester is only significant to 1/100th of an inch. Although this value meets all packaging requirements, it does not show significant differences among the boxes compared. The results of the ANOVA test suggest that there were 2- way interactions between the platen type and box size and between the box size and the degree of defect (Table 7). A 2-way interaction means that the two variables act together to affect the deflection value obtained. Based on these results, t-tests were then conducted to identify which interactions were occurring (Tables 9 and 10). Tuckey's multiple range test was used to test for significant differences in the deflection values based on the degree of fabrication defect (Table 8). The results of the Tuckey's test show that the 0°, 1° and 2° .M:‘ ‘i J - —-> ’I‘ ML... In A 33 . TABLE 7: Analysis of Variance for Deflection. Mean Sig. Source of Variation DF Square of F Main Effects 5 .080 .000 PLATEN TYPE 1 .007 .286 BOX SIZE 1 .260 .000 DEFECT TYPE 3 .044 .000 2-Way Interactions 7 .056 .000 PLATEN, BOX 1 .058 .002 sig. PLATEN, DEFECT 3 .017 .040 not sig. BOX, DEFECT 3 .094 .000 sig. 3-Way Interactions 3 .054 .000 PLATEN, BOX, DEFECT 3 .054 .000 sig. Explained 15 .063 .000 Residual 224 .00616 MSE TABLE 8: Tuckey's Multiple Range Test of Effect of Degree of Defect on Deflection. Deflection Combined Avg. Significantly Defect (Original Order) (Ramked Order) Different From 0° 0.72 1° 0.75 3° 1° 0.75 0° 0.72 3° 2° 0.72 2° 0.72 3° 3° 0.68 3° 0.68 0°, 1° + 2° MSE = .00616 Degrees Freedom = 224 60 observations in each mean alpha = .05 34 TABLE 9: Deflection T-Test Results of 2—Way Interaction Between Platen Type and Box Size. 95% Platen Box Defect TB confidence FIXED 0°-3° versus 2.66 sig. FLOATING A 0°-3° FIXED B 0°-3° . ”I versus 1.40 not 819. =‘ FLOATING B 0°-3° TABLE 10: Deflection T-Test Results of 2-Way Interaction Between the Box Size and Degree of Defect. 95% Platen Box Defect TB confidence FIXED A O° 6.27 sig. FIXED B O° FIXED A 10 6.62 sig. FIXED B 1° FIXED A 2° 1.39 not sig. FIXED B 2° FIXED A 3° 1.39 not sig. FIXED B 3° FLOATING A O° 1.74 not sig. FLOATING B O° FLOATING A 10 - 3.83 sig. FLOATING B 1° FLOATING A 20 3.14 'sig. FLOATING B 2° FLOATING A 3° 2.79 sig. FLOATING B 3° 35 box values were significantly different from the 3° box and the 3° box values were significantly different from the 0°, 1° and 2° box values (Table 8). The average deflection value for box A using the fixed platen, was determined to be significantly different than the deflection value on the floating platen (table 9). The average deflection value for box B, using the fixed platen, was determined to not be significantly different than the deflection value on the floating platen (Table 9). In comparing the deflection values of box A to B, with the same defect on the fixed platen, it was found that the values of the 0° and 1° boxes were significantly different (Table 10). In comparing the deflection values of box A to B, with the same defect on the floating platen, it was found that the values of the 1°, 2°, and 3° boxes were all significantly different (Table 10). One explanation for the differences in these results is the high variability of the corrugated material. The ANOVA test results also suggest that there is a 3-way interaction occurring between the box type, the platen type and the degree of fabrication defect. What this means is that the three variables contribute together to affect the deflection value obtained. A factorial analysis was performed on the deflection averages to see if there was a linear or curvature trend in the data (Table 11). Since there was a 3-way interaction occurring, the linear and quadratic equations were broken down by box type and platen 36 TABLE 11: Factor Analysis Of Deflection. Platen Box Defect F-Linear F-Quadratic FIXED A 0° FIXED A 10 12.49 sig. FIXED A 2° FIXED A 3° FIXED B 0° FIXED B 1° 29.28 sig. FIXED B 2° FIXED B 3° FLOATING A 0° FLOATING A 1° 2.06 not FLOATING A 20 sig. FLOATING A 3° FLOATING B 0° FLOATING B 10 7.02 sig. FLOATING B 2° FLOATING B 3° 4.0 sig. 18.06 sig. 3.06 sig. 1.0 not 31g. * at 95% confidence level TABLE 12: Moisture Content. Sample # WI (91118.) W2 (91113.) % Moisture 1 10.2731 9.5949 2 10.0652 9.4214 Avg. 7.069% 6.834% = 6.95% r (q! til.” 37 type (Table 11). The calculations showed that there was a significant linear relationship in the fixed and floating platen-size A box and in the fixed platen-size B box. The quadratic equations showed that there was a significant curvature trend in the fixed and floating platen-size A box and in the fixed platen size B box (Table 11). This trend implies that as the degree of defect is increased a decreasing trend is seen in the data. The results of this study also show that there is a significant difference in deflection values for the A size box on the fixed and floating platens. The floating platen results, on the average for box A, gave a reading of 5.5% higher than the fixed platen. The deflection results for the larger B size box were not found to be significantly different on the two platens. This may be explained by suggesting that the deflection of the larger B size box is not affected by using either platen. This may also be explained by the fact that even though the deflection reading is measured to 1/100th of an inch, which meets all packaging requirements, it does not show significant differences among the boxes compared (as described above). Tuckey's test shows that the 0°, 1° and 2° deflection values were all significantly different from the 3° defect, but not significantly different from each other. This shows that , in general, the deflection of the boxes is not greatly affected by incorporating a fabrication defect. Both linear 38 and curvature trends were Observed for both box sizes and platen types. The reason both trends were seen is that there were not enough data sets to determine which trend was actually significant. 39 5.0 CONCLUSIONS The results of this study are: There was a significant difference in the compression strength values of identical corrugated containers using the fixed and floating platens. There was a significant difference in deflection values for the smaller A size box using the two platens. The varying degrees of defect incorporated during fabrication had a significant effect on the compression values of the boxes. The deflection values were not greatly affected by incorporating a defect into the boxes. The fixed platen gave an average compression value 3.4% higher than the floating platen. As the degree of fabrication defect was increased, the compression strength of the containers decreased using both platen methods. The larger (B size) boxes had higher compression strength and deflection values than the smaller (A) boxes. There was no interaction between the box size and the platen type. ”if L’ 40 Based on the results of this study, it can be concluded that the ASTM standard for compression testing Of shipping containers, which states that either a fixed or floating platen may be used, should recommend that the results from the tWO’ tests will be different. This study shows that the fixed platen gives significantly higher results. Maltenfort (1988), states that it is safe to say that what ever the condition of stress application in real life, the one condition which is certain never to occur, except by some freak coincidence, is the one simulated by the TAPPI (fixed platen) version, where the load is applied in such a manner that the weakest portion, if there is one, cannot fail first. From the box makers point of view, using the fixed platen makes it easier for a box to pass specification. The box user, on the other hand, believes that if a box has a weak point, the test should show this, not obscure it. Box users should state in their corrugated container specifications that the floating platen should be used to achieve a realistic compression strength. 41 5.1 RECOMMENDATION FOR FUTURE WORK The major recommendation of this research is that the floating platen compression test be used to estimate the performance of corrugated containers. A similar study is suggested using a larger number of boxes to account for variation in fabricated corrugated as well as additional box sizes. A similar study that looks into other fabrication defects such as nonuniform slotting and misaligned joints would be of interest to the packaging industry. It is also recommended that a similar study be conducted using a wider range in the degree of defect fabricated into the container to determine whether a linear or curvature trend is actually occurring. APPENDIX A 42 COMPRESSION TESTING TABLE A-l: Compression and Deflection Values for Box A 0° Defect on the Fixed Platen. Compression Deflection Platen Box Defect Replication Str.(lbs.) (in.) FIXED A 0° 1 630.00 0.50 2 654.00 0.57 3 750.00 0.69 4 679.00 0.62 5 621.00 0.60 6 706.00 0.38 7 729.00 0.57 8 748.00 0.61 9 695.00 0.62 10 662.00 0.65 11 704.00 0.60 12 677.00 0.62 13 733.00 0.59 14 707.00 0.65 15 735.00 0.68 AVERAGE 695.33 0.60 STD.DEV. 39.52 0.07 VARIANCE 1561.956 0.005 CODES Platen: fixed or floating Box: A = 10"x8"x6" B = 12"x10"x8" Defect: 0° no defect 1. 3o 43 TABLE A-2: Compression and Deflection Values for Box A 0° Defect on the Fixed Platen. Compression Defl. Platen Box Defect Replication Str.(lbs.) (in.) FIXED A 1° 1 718.00 0.59 2 712.00 0.66 3 707.00 0.65 4 801.00 0.67 5 698.00 p 0.72 6 739.00 0.60 7 735.00 0.65 8 700.00 0.64 9 771.00 0.63 10 774.00 0.69 11 689.00 0.60 12 706.00 0.71 13 669.00 0.62 14 754.00 0.71 15 724.00 0.74 AVERAGE 726.47 0.66 STD.DEV. 34.73 0.05 VARIANCE 1205.849 0.002 44 TABLE A-3: Compression and Deflection Values for Box A 2° Defect on the Fixed Platen. Compression Deflection Platen Box Defect Replication Str.(lbs.) (in.) FIXED A 2° 1 712.00 0.74 2 715.00 0.74 3 639.00 0.69 4 716.00 0.77 5 722.00 0.69 6 642.00 0.69 7 654.00 0.69 8 680.00 0.77 9 730.00 0.70 10 683.00 0.65 11 597.00 0.58 12 722.00 0.74 13 729.00 0.71 14 729.00 0.77 15 674.00 0.69 AVERAGE 689.60 0.71 STD.DEV. 39.77 0.05 VARIANCE 1581.840 0.002 45 TABLE A-4: Compression and Deflection Values for Box A 3° Defect on the Fixed Platen. Compression Deflection Platen Box Defect Replication Str.(lbs.) (in.) FIXED A 3° 1 721.00 0.71 2 768.00 0.71 3 713.00 0.66 4 660.00 0.71 5 732.00 0.67 6 653.00 0.67 7 600.00 0.44 8 716.00 0.75 9 703.00 0.70 10 686.00 0.69 11 635.00 0.53 12 703.00 0.74 13 633.00 0.74 14 688.00 0.79 15 691.00 0.77 AVERAGE 686.80 0.69 STD.DEV. 42.32 0.09 VARIANCE 1790.827 0.008 46 TABLE A-5: Compression and Deflection Values for Box A 0° Defect on the Floating Platen. Compression Deflection Platen Box Defect Replication Str.(lbs.) (in.) FLOATING A 0° 1 628.00 0.71 2 621.00 0.76 3 759.00 0.83 4 648.00 0.63 5 713.00 0.70 6 654.00 0.78 7 694.00 0.73 8 642.00 0.60 9 756.00 0.77 10 751.00 0.67 11 769.00 0.79 12 628.00 0.73 13 651.00 0.73 14 698.00 0.68 15 685.00 0.73 AVERAGE 686.47 0.72 STD.DEV. 50.90 0.06 VARIANCE 2590.649 0.003 47 TABLE A-6: Compression and Deflection Values for Box A 1° Defect on the Floating Platen. Compression Deflection Platen Box Defect Replication Str.(lbs.) (in.) FLOATING A 1° 1 606.00 0.56 2 700.00 0.66 3 695.00 0.69 4 707.00 0.58 5 682.00 0.72 6 663.00 0.60 7 686.00 0.76 8 735.00 0.78 9 633.00 0.60 10 685.00 0.72 11 713.00 0.71 12 624.00 0.77 13 698.00 0.68 14 709.00 0.59 15 630.00 0.72 AVERAGE 677.73 0.68 STD.DEV. 36.73 0.07 VARIANCE 1348.729 0.005 48 TABLE A-7: Compression and Deflection Values for Box A 2° Defect on the Floating Platen. Compression Deflection Platen Box Defect Replication Str.(lbs.) (in.) FLOATING A 2° 1 660.00 0.76 2 632.00 0.77 3 535.00 0.68 4 556.00 0.71 5 636.00 0.77 6 592.00 0.72 7 662.00 0.87 8 689.00 0.81 9 709.00 0.82 10 597.00 0.77 11 645.00 0.71 12 619.00 0.75 13 597.00 0.70 14 754.00 0.81 15 689.00 0.74 AVERAGE 638.13 0.76 STD.DEV. 56.58 0.05 VARIANCE 3201.316 0.003 49 TABLE A-8: Compression and Deflection Values for Box A 3° Defect on the Floating Platen. Compression Deflection Platen Box Defect Replication Str.(lbs.) (in.) FLOATING A 3° 1 666.00 0.72 2 694.00 ‘ 0.57 3 674.00 0.63 4 727.00 0.67 5 653.00 0.72 6 639.00 0.57 7 647.00 0.56 8 671.00 0.67 9 704.00 0.77 10 653.00 0.53 11 653.00 0.67 12 618.00 0.61 13 644.00 0.66 14 716.00 0.71 15 595.00 0.67 AVERAGE 663.60 0.65 STD.DEV. 34.52 0.07 VARIANCE 1191.840 0.004 50 TABLE A-9: Compression and Deflection Values for Box B 0° Defect on the Fixed Platen. Compression Deflection Platen Box Defect Replication Str.(lbs.) (in.) FIXED B 0° 1 724.00 0.75 2 700.00 0.73 3 798.00 0.82 4 824.00 0.77 5 832.00 0.85 6 713.00 0.72 7 757.00 0.79 8 665.00 0.71 9 844.00 0.84 10 745.00 0.80 11 788.00 0.75 12 826.00 0.78 13 821.00 0.77 14 776.00 0.73 15 807.00 0.95 AVERAGE 774.67 0.78 STD.DEV. 53.07 0.06 VARIANCE 2816.222 0.004 51 TABLE A-lO: Compression and Deflection Values for Box B 1° Defect on the Fixed Platen. Compression Deflection Platen Box Defect Replication Str.(lbs.) (in.) FIXED B 1° 1 789.00 0.66 2 803.00 0.83 3 754.00 0.85 4 747.00 0.69 5 756.00 0.64 6 724.00 0.74 7 827.00 0.95 8 835.00 0.89 9 788.00 1.01 10 821.00 0.85 11 882.00 0.97 12 797.00 0.83 13 801.00 0.96 14 804.00 0.91 15 842.00 0.94 AVERAGE 798.00 0.85 STD.DEV. 39.80 0.11 VARIANCE 1584.000 0.013 52 TABLE A-ll: Compression and Deflection Values for Box B 2° Defect on the Fixed Platen. Compression Deflection Platen Box Defect Replication Str.(lbs.) (in.) FIXED B 2° 1 677.00 ' 0.61 2 766.00 0.73 3 812.00 0.80 4 660.00 0.75 5 772.00 0.86 6 686.00 0.68 7 847.00 0.74 8 804.00 0.75 9 783.00 0.59 10 803.00 0.69 11 786.00 0.76 12 774.00 0.72 13 777.00 0.86 14 842.00 0.86 15 882.00 0.85 AVERAGE 778.07 0.75 STD.DEV. 60.56 0.08 VARIANCE 3666.996 0.007 53 TABLE A-12: Compression and Deflection Values for Box B 3° Defect on the Fixed Platen. Compression Deflection Platen Box Defect Replication Str.(lbs.) (in.) FIXED B 30 1 647.00 0773* 2 698.00 0.74 3 621.00 0.60 4 695.00 0.62 5 574.00 0.58 6 630.00 0.66 7 615.00 0.62 8 689.00 0.81 9 633.00 0.55 10 613.00 0.57 11 691.00 0.79 12 644.00 0.67 13 739.00 0.66 14 689.00 0.71 15 571.00 0.51 AVERAGE 649.93 0.65 STD.DEV. 47.02 0.09 VARIANCE 2210.596 0.007 54 TABLE A-13: Compression and Deflection Values for Box B 0° Defect on the Floating Platen. Compression Deflection Platen Box Defect Replication Str.(lbs.) (in.) FLOATING B 0° 1 712.00 0.87 2 721.00 0.83 3 700.00 0.88 4 653.00 0.64 5 804.00 0.77 6 659.00 0.69 7 785.00 0.71 8 791.00 0.73 9 713.00 0.73 10 710.00 0.67 11 785.00 0.88 12 806.00 0.81 13 642.00 0.78 14 706.00 0.74 15 739.00 0.79 AVERAGE 728.40 0.77 STD.DEV. 53.13 0.07 VARIANCE 2823.307 0.005 55 TABLE A-14: Compression and Deflection Values for Box B 1° Defect on the Floating Platen. Compression Deflection Platen Box Defect Replication Str.(lbs.) (in.) FLOATING B 1° 1 760.00 0.86 2 812.00 0.89 3 798.00 0.94 4 763.00 0.82 5 771.00 0.71 6 816.00 0.82 7 698.00 0.58 8 863.00 0.85 9 838.00 0.82 10 850.00 0.77 11 744.00 0.77 12 741.00 0.73 13 785.00 0.83 14 788.00 0.74 15 715.00 0.69 AVERAGE 782.80 0.79 STD.DEV. 46.41 0.09 VARIANCE 2153.627 0.008 56 TABLE A-15: Compression and Deflection Values for Box B 2° Defect on the Floating Platen. Compression Deflection Platen Box Defect Replication Str.(lbs.) (in.) FLOATING B 2° 1 721.00 0.65 2 801.00 0.71 3 763.00 0.77 4 805.00 0.73 5 863.00 0.63 6 654.00 0.49 7 798.00 0.72 8 812.00 0.70 9 804.00 0.68 10 821.00 0.66 11 803.00 0.75 12 750.00 0.55 13 795.00 0.76 14 730.00 0.50 15 745.00 0.72 AVERAGE 777.67 0.67 STD.DEV. 49.33 0.09 VARIANCE 2433.556 0.008 57 TABLE A-16: Compression and Deflection Values for Box B 3° Defect on the Floating Platen. Compression Deflection Platen Box Defect Replication Str.(lbs.) (in.) FLOATING B 3° 1 642.00 0.71 2 485.00 0.76 3 481.00 0.73 4 647.00 0.84 5 710.00 0.80 6 692.00 0.74 7 654.00 0.72 8 615.00 0.78 9 612.00 0.72 10 857.00 0.90 11 562.00 0.57 12 642.00 0.63 13 621.00 0.76 14 716.00 0.70 15 701.00 0.61 AVERAGE 642.47 0.73 STD.DEV. 90.00 0.08 VARIANCE 8100.782 0.007 APPENDIX B 58 STATISTICAL ANALYSIS The following code #‘s represent which average compression or deflection value is used in the statistical formulas used. TABLE B-l: Description of Code Numbers. Code # Platen Box Defect l FIXED A 0° 2 FIXED A 1° 3 FIXED A 2° 4 FIXED A 3° 5 FIXED B 0° 6 FIXED B 1° 7 FIXED B 2° 8 FIXED B 3° 9 FLOATING A 0° 10 FLOATING A 1° 11 FLOATING A 2° 12 FLOATING A 3° 13 FLOATING B 0° 14 FLOATING B 1° 15 FLOATING B 2° 16 FLOATING B 3° SYMBOLS USED: P1 = fixed platen P2 = floating platen 3 m n ll mean square error Bl = bOX A B2 = 130)! B Yx = average of 15 replications for that code no. EL = all box defects TABLE B-2: 59 Compression 3-Way ANOVA Test Results. Main Effects PLATEN BOX DEFECT 2-way inter. PLATEN-BOX PLATEN-DEFECT BOX-DEFECT 3-way inter. PLATEN-BOX- DEFECT Explained Residual Total Sum of Mean Sig. Squares DF Square F of F 480711.554 5 96142.311 35.674 .000 36927.204 1 36927.204 13.702 .000 202478.504 1 202478.504 75.131 .000 241305.846 1 80435.282 29.846 .000 178363.862 7 25480.552 9.455 .000 3352.538 1 3352.538 1.244 .266 1948.746 3 649.582 .241 .868 173062.579 3 57687.562 21.405 .000 16065.946 3 5355.315 1.987 .117 16065.946 3 5355.315 1.987 .117 675141.363 15 45009.424 16.701 .000 603682.133 224 2695.010 1278823.496 239 5350.726 60 TABLE B-3: Compression T-Test Comparing the Compression Values of the Fixed Versus the Floating Platen. Group # Platen Compression Avg. 1 FIXED 724.33 2 FLOATING 699.66 X1 - 322 t = LX12 __(§1)2/n1 ) +L§22 -£&)2/na n1 + n2 (in + n2 - 2) (n1 n2) where X1 = any score from group 1 X} = mean of group 1 n1 = # of subjects in group 1 X2 = any score from group 2 X3 = mean of group 2 n2 = # of subjects in group 2 N = total # of subjects 724.86 - 699.66 t: (63594247 - 869832) + (59442797 - 839592) 240 120 I20 (120)(120) (240 - 2) 25.20 t = = 2.70 (543894.59) + (700182.99) (.01666667) 238 critical t value at 95% confidence = 1.970 t = 2.70 >= 1.970 significant 61 TABLE B-4: Tuckey's Multiple Range Test Comparing the Compression Values by Degree of Defect. Compression Combined Avg. Defect (Original Order) (Ranked Order) Significantly Different From 0° 721.22 747.03 0°, 2° + 3° 1° 747.03 721.22 1° + 3° 2° 720.87 720.87 1° + 3° 3° 660.70 660.70 0°, 1° + 2° MSE 2695.01 Degrees Of Freedom = 224 60 observations in each mean at alpha .05 62 TABLE B-5: 2-Way Interaction Comparing Compression Values of Box A to B with the Same Defect and the Same Platen. Compression Platen Box Defect Avg. Ts FIXED A 0° 695.33 FIXED B 0° 774.67 4.18 sig. FIXED A 1° 726.47 FIXED B 1° 798.00 3.77 sig. FIXED A 2° 689.60 FIXED B 2° 778.07 4.67 sig. FIXED A 3° 686.80 FIXED B 3° 649.93 1.94 not sig. FLOATING A 0° 686.47 FLOATING B 0° 728.40 2.21 not sig. FLOATING A 1° 677.73 FLOATING B 1° 782.80 5.54 sig. FLOATING A 2° 638.13 FLOATING B 2° 777.67 7.36 Sig. FLOATING A 3° 663.60 . FLOATING B 3° 642.47 1.11 not 319. The following formula is used: Y1 " Y5 T5 = J2* M33 / 15 Significance: 1% = 3.279 5% = 2.764 sample calculation: 774.67 - 695.33 79.34 = = 4.18 not TB: . J2* 2695.01/15 329.33 sig. 63 Factor Analvsis: Compare all compression test averages for each box type to see if there is a linear and/or curvature trend. The following formulas are used: ELIE], QL = { ‘3[(Y1 + Y97/2] ' [(Yz + Yio)/2] + [(Y3 + Y117/2] + [Y4 + Y12)/Z]} FL = QL2 /[(20)(MSE)/3O] QQ = { [(Yi + Y9)/2] ' [(Yz + Yio)/2] ‘ [(Ys + Y11)/2] + [(Y4 + Y12)/2]} FQ = QQZ/[(4)(MSE)/3O] EL I B2 same equations only with box size B where QL = equation for straight line 00 = equation for curved line FL Factorial equation for straight line FQ = Factorial equation for curved line 6.75 Significance: 1% 5% 3.89 64 TABLE B-6: Factor Analysis of Compression. Compression Platen Box Defect Avg. QL FL FIXED A 0° 695.33 FLOATING A 0° 686.47 FIXED A 1° 726.47 FLOATING A 1° 677.73 -86.33 .304 not FIXED A 2° 689.60 sig- FLOATING A 2° 638.13 FIXED A 3° 686.80 FLOATING A 3° 663.60 FIXED B 0° 774.67 FLOATING B 0° 728.40 FIXED B 1° 798.00 FLOATING B l° 782.80 -266.63 60.07 sig. FIXED B 2° 778.07 FLOATING B 2° 777.67 FIXED B 3° 649.93 FLOATING B 3° 642.47 QQ F0 FIXED A 0° 695.33 FLOATING A 0° 686.47 FIXED A 1° 726.47 FLOATING A 1° 677.73 1.13 .0036 not FIXED A 2° 689.60 519- FLOATING A 2° 638.13 FIXED A 3° 686.80 FLOATING A 3° 663.60 FIXED B 0° 774.67 FLOATING B 0° 728.40 FIXED B 1° 798.00 FLOATING B 1° 782.80 -170.57 80.97 Sig. FIXED B 2° 778.07 FLOATING B 2° 777.67 FIXED B 3° 649.93 FLOATING B 3° 642.47 sample calculation: QL = {-3[(695.33 + 686.47)/2] [(689.60 + 638.13)/2] + 3[(686.80 + 663.60)/2]} -86.33 [(726.47 + 677.73)/2] + (-86.33)2 /[(20)(2695.01)/30] .304 65 TABLE B-7: Deflection 3-Way ANOVA Results. Sum of Mean Sig. Squares DF Square F of F Main Effects .398 5 .080 12.917 .000 PLATEN .007 l .007 1.143 .286 BOX .260 l .260 42.219 .000 DEFECT .131 3 .044 6.074 .000 2-way inter. .391 7 .056 9.061 .000 PLATEN-BOX .058 1 .056 9.462 .002 PLATEN-DEFECT .052 3 .058 2.807 .040 BOX-DEFECT .281 3 .094 15.180 .000 3-way inter. .161 3 .054 8.700 .000 PLATEN-BOX- .161 3 .054 8.700 .000 DEFECT Explained .949 15 .063 10.274 .000 Residual 1.380 224 .00616 Total 2.329 239 .010 TABLE B-8: Tuckey's Multiple Range Test Comparing the Compression Values by Degree of Defect. Compression Combined Avg. Significantly Defect (Original Order) (Ranked Order) Different From 0° 0.72 0.75 3° 1° 0.75 0.72 3° 2° 0.72 0.72 3° 3° 0.68 0.68 0° MSE = .00616 Degrees of Freedom = 224 60 observations in each mean at alpha = .05 66 TABLE B-9: 2-Way Interaction Comparing Deflection Values of Each Platen and Each Box Size. Avg. combined Platen Box Defect Deflection Avg. TB FIXED A 0° .60 FIXED A 1° .66 FIXED A 2° .71 .665 FIXED A 3° .69 2.66 sig. FLOATING A 0° .72 ' FLOATING A 1° .68 FLOATING A 2° .76 .703 FLOATING A 3° .65 FIXED B 0° .78 FIXED B 1° .85 FIXED B 2° .75 .755 FIXED B 3° .65 1.40 not FLOATING B 0° .77 si9~ FLOATING B 1° .79 FLOATING B 2° .67 .74 FLOATING B 3° .73 The formulas used are the same as in the compression analysis of the same type. where MSE = .00616 Significance: 1% = 2.838 5% = 2.258 67 TABLE B-lO: 2—Way Interaction Comparing Deflection Values of Box A to B with the Same Defect and the Same Platen. Deflection Platen Box Defect Avg. TB FIXED A 0° .60 FIXED B 0° .78 .27 sig. FIXED A 1° .66 g FIXED B 1° .85 .62 sig. FIXED A 2° .71 . FIXED B 2° .75 .39 not 819. FIXED A 3° .69 . FIXED B 3° .65 .39 not 819. FLOATING A 0° .72 . FLOATING B 0° .77 .74 not 819. FLOATING A 1° .68 . FLOATING B 1° .79 .83 $19. FLOATING A 2° .76 . FLOATING B 2° .67 .14 $19. FLOATING A 3° .65 . FLOATING B 3° .73 .79 $19. The formulas used are the same as in the compression analysis of this type. where MSE Significance: 3.279 2.764 68 Factor Anlaysis: Compare all deflection averages for each box type and platen type to see if there is a linear and/or curvature trend. (3-way interaction) The following formulas are used: EL I PIBI QL={"3Y1-Y2+Y3+Y4} FL = QLz/[(20)(MSE)/15] QQ = { Y1 — Y2 - Y3 + Y4 } FQ = QQZ/[(4)(MSE)/15] EL I P132 same equations only with box size B EL I P2Bl same equations as EL I P181 only with the floating platen EL I P232 etc. where QL = equation for straight line QQ = equation for curved line FL = Factorial equation for straight line Pa = Factorial equation for curved line Significance: 1% = 6.75 5% = 3.89 69 TABLE B-ll: Factor Analysis Of Deflection. Deflection Platen Defect Avg. QL FL FIXED A 0° .60 FIXED A 1° .66 . FIXED A 2° .71 .32 12.49 Sig. FIXED A 3° .69 FIXED B 0° .78 FIXED B 1° .85 . FIXED B 2° .75 -.49 29.28 819. FIXED B 3° .65 FLOATING A 0° .72 FLOATING A 1° .68 FLOATING A 2° .76 —.13 2.06 not FLOATING A 3° .65 $19. FLOATING B 0° .77 FLOATING B 1° .79 . FLOATING B 2° .67 -.24 7.02 319. FLOATING B 3° .73 QQ FQ FIXED A 0° .60 FIXED A 1° .66 . FIXED A 2° .71 -.08 4.0 819. FIXED A 3° .69 FIXED B 0° .78 FIXED B 1° .85 _ FIXED B 2° .75 -.17 18.06 319- FIXED B 3° .65 FLOATING A 0° .72 FLOATING A 1° .68 _ FLOATING A 2° .76 —.07 3.06 819. FLOATING A 3° .65 FLOATING B 0° .77 FLOATING B 1° .79 FLOATING B 2° .67 .04 1.0 not FLOATING B 3° .73 Sig. sample calculation: QL { -3(.60) - (.66) + (.71) + 3(.69)} = .32 FL (.32)2/[(20)(.00616)/15] = 12.49 L I ST OF REFERENCES 7 . 0 REFERENCES "ASTM D642-83 Compression Test for Shipping Containers", Annual Book of ASTM Standards, 1984. "ASTM D644-82 Test Method for Moisture Content of Paper and Paperboard by Oven Drying", Annual.Book of ASTM Standards, 1984. Carlson, David A. "Getting Top Value from Corrugated Boxes", Package Engineering, September, 1982. FBA , Fiber Box Handbook, Chicago, Illinois, Fiber Box Association, 1984. Fox, T.S. "Shipping Containers and Cartons Shown to Fail Only in Compression When Loaded Internally : Part I", Paperboard Packaging, March 1978. Fox, T.S. , Nelson, R.W. , Watt, J.A. and Whilsitt, W.J. "Shipping Containers and Cartons Shown to Fail Only in Compression When Loaded Internally : Part III", Paperboard Packaging, May 1978. Gill, John L. "Design and Analysis of Experiments: Volume 3 Appendices", Ames, Iowa, The Iowa State University Press, 1978. Hanlon, J.F. "Handbook of Package Engineering : 2nd Edition", New York, McGraw Hill Book Company, 1984. Jonson, G. "Utilizing Liner/Medium Weight in Corrugated Board for Best Box Performance", Boxboard Containers, June 1985. Kellicut, K.O. and Landt, E.F. "Safe Stacking Life of Corrugated Boxes", Fiber Containers, 1951. King, F.W. "Fefco Standard Grades of Board", ICCA Proc., International Technical Conference on Corrugated Cases, May, 1975. Linton, Marigold and Gallo P.S. " The Practical Statistician: Simplified Handbook of Statistics ", Monterey, California, Books/Cole Publishing Company, 1975. Maltenfort, George G. "Corrugated Containers", published in Handbook of Pulp and Paper Technology, New York, van Nostrand Reinhold Company, 1970. Maltenfort, George G. "Mullen Versus Puncture - An Old Controversey Revisited", Paperboard Packaging, June, 1979. 70 Maltenfort, George G. "Testing VI-Methods for Shipping Containers", published in Corrugated Shipping Containers: An Engineering Approach, Plainview, N.Y., Jelmar Publishing Co., Inc., 1988. McKee, R.C. , Gander, J.W. and Wachuta,‘J.R. "Compression Strength Formula for Corrugated Boxes", Paperboard Packaging, August, 1963. Morris, R.M. Jr. "The Status of Rule 41", Paperboard Packaging, August, 1978. Morris, R.M. Jr. and VanLiew, G.P. "Improved Edgewise Compression Test for Linerboard", TAPPI Spring Corrugated Containers/Papermakers Conference (Dallas), April, 1975. National Motor Freight Traffic Association, Inc. "National Motor Freight Classification", Alexandria, Virginia, National Motor Freigt Traffic Association, Inc., 1988. Nordman, L. , Kolhonen, E. , Toroi, M. "Investigation of the Compression Of Corrugated Board", Paperboard Packaging, October, 1978. Peleg, Kalman. "Produce Handling Packaging and . . Distribution" , Westport, Connecticut, AVI Publishing Company , 1985. Peterson, and Fox, T.S. "Workable Theory Proves How Boxes Fail in Compression", Paperboard Packaging, November, 1980. Sheehan, Richard L. "Box and Closure : Partners in Performance" , Journal of Packaging Technology, August, 1988. Scott, R.A. "Toward an International Standard Method for the Edgewise Compression Test of Corrugated Board", Appita 40, November 1987. . Uniform Freight Classification Committee "Uniform Freight Classification 6000B ", Chicago, Illinois, Uniform Freight Classification Committee, 1988. 71 "I71111111111111.1143