H:.u.e.ut..,_|wh....v,,m . 51...: £33 £34 7 H33 ,. M iv why .,

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THESIS

c) ’ ’ ,

This is to certify that the
thesis entitled

EFFECTS OF EXTRUSION BLOW MOLDING INTERNAL
COOLING TECHNOLOGY ON HDPE CONTAINER
PERFORMANCE

presented by
KIRK ALAN VALKO

has been accepted towards fulfillment
of the requirements for the

MS. degree in PACKAGING

 

 

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6/01 cJClRC/Dateouepescpjs

 

EFFECTS OF EXTRUSION BLOW MOLDING INTERNAL COOLING
TECHNOLOGY ON HDPE CONTAINER PERFORMANCE

By
Kirk Alan Valko

A THESIS
Submitted to
Michigan State University
In partial fulfillment of the requirements
For the degree of
MASTER OF SCIENCE
School of Packaging

2004

ABSTRACT

EFFECTS OF EXTRUSION BLOW MOLDING INTERNAL COOLING
TECHNOLOGY ON HDPE CONTAINER PERFORMANCE

By

Kirk Alan Valko
The continuously growing demand for inexpensive, efficient manufacturing
methods drives businesses to develop new technologies which can produce
more products faster with equal or better quality. Companies take different
approaches to increasing production by buying state-of-the-art machinery or
retrofitting older machinery. FastiUSA engineers products for the blow-molding
industry for the improvement of existing machinery through various technologies.
One such product, the Blow Mold Booster, blows the product through the use of
cold air which speeds cooling, therefore reducing cycle times. While some
studies have been conducted to examine the effect that internal cooling has on
the product, the goal of this thesis was to determine its effects on Extrusion Blow
molded HDPE containers. The data shows that the addition of the Fasti internal
cooling device significantly increases package production without significantly

affecting container performance.

Copyright by
Kirk Alan Valko
2004

W

I would like to thank my professors Dr. Harold Hughes and Dr. Laura Bix of the
School of Packaging, and Dr. Dennis Gilliland of the Department of Statistics and

Probability for their support and contributions to this research.

I would like to thank all of my fellow grad students for their support and help in
my studies, especially Napawan Kositruangchai and Krittika Tanprasert for their
help training me on the testing equipment. Thank you, most of all, for your

friendship.

Thank you to my family and friends outside for your support and patience; these

things are often most valuable.

Thank you to the companies and individuals who contributed and donated
supplies for my research:

Donation of Fasti Equipment: Barry Pucillo and Rainier Farrig, FastiUSA Elgin, IL
Donation of Blow Pin Machining: Jim Vassar, Fidelity Tool Addison, IL

Donation of Cutting Ring Machining: Don Maines, Triad Precision Products
Thomasville, NC

Donation of Programming and Labor for Machine Programming: Everyone at

Bekum America Williamston, Ml

TABLE OF CONTENTS

LIST OF TABLES ................................................................................................ vii
LIST OF FIGURES ............................................................................................. viii
KEY TO SYMBOLS AND ABBREVIATIONS ........................................................ x
1 - INTRODUCTION AND LITERATURE REVIEW .............................................. 1
1.1 Need for Development ................................................................................ 1
1.2 Extrusion Blow Molding .............................................................................. 2
1.2.1 Process ............................................................................................... 2

1.3 Fasti System ............................................................................................... 8
1.3.1 Recirculating blow pin ......................................................................... 8
1.3.2 Cooling system .................................................................................. 10
1.3.3 Costs ................................................................................................. 11

1.3.5 Installation ......................................................................................... 12

1.3.4 Efficiency ........................................................................................... 14

1.4 Objective ................................................................................................... 14
1.4.1 Crystallinity ........................................................................................ 14
1.4.2 Wall thickness ................................................................................... 17

1.4.3 Dimensionality ................................................................................... 17

1.5 Hypothesis ................................................................................................ 17
1.6 Statistical Methods .................................................................................... 18

2 — EXPERIMENTAL DESIGN AND TEST METHODS ...................................... 19
2.1 Materials and Setup .................................................................................. 19
2.1.1 Conventional Air Setup ...................................................................... 19
2.1.2 Fasti Cold Air Setup .......................................................................... 20
2.1.3 Controls (Constants) ......................................................................... 22

2.2 Experimental Methods .............................................................................. 23
2.2.1 Sampling ........................................................................................... 23
2.2.2 Conditioning ...................................................................................... 24
2.2.3 Dimensional ....................................................................................... 25
2.2.4 Compression Testing ........................................................................ 28
2.2.5 Differential Scanning Calorimetry ...................................................... 31

3 - DATA AND RESULTS .................................................................................. 35
3.1 Cycle time improvements ......................................................................... 35
3.2 Dimensionality .......................................................................................... 35
3.3 Compression Strength .............................................................................. 39
3.4 Crystallinity ............................................................................................... 40

4 — CONCLUSIONS AND RECOMMENDATIONS ............................................. 44

5 — RECOMMENDATIONS FOR FUTURE RESEARCH .................................... 46
5.1 Utility Needs ............................................................................................. 46
5.2 Redesign of Mold ...................................................................................... 46
5.3 Regrind ..................................................................................................... 47
5.4 Different Containers .................................................................................. 47
5.5 Environmental Stress Cracking ................................................................ 48
5.6 Impact Testing .......................................................................................... 48
5.7 Torque Testing ......................................................................................... 48
5.8 Optical Microscopy ................................................................................... 49
5.9 Permeability Testing ................................................................................. 49
5.10 Resin ...................................................................................................... 49

APPENDIX A ...................................................................................................... 51

APPENDIX B ...................................................................................................... 58

APPENDIX C ...................................................................................................... 60

APPENDIX D ...................................................................................................... 68

APPENDIX E ...................................................................................................... 75

BIBLIOGRAPHY ................................................................................................. 81

vi

LIST OF TABLES

Table 1. Fasti Cost Analysis and Payback Period Estimate (FastiUSA, 2004) 11
Table 2. Effect of Decreased Crystallinity in Polymers (Hernandez et al, 2000) . 15

Table 3. Bekum Blow Molder Conventional Blow Set Points .............................. 20
Table 4. Bekum Blow Molder Cold Air Set Points ............................................... 21
Table 5. Bottle Body Dimension Tolerances (ASTM D 2911-94) ........................ 27
Table 6. DSC Heat/Cool/Heat Setup Method ...................................................... 33
Table 7. Dimensional Test Result Comparison - Conventional vs. Fasti ............ 37
Table 8. t-Score p-Values for Wall Thickness ..................................................... 38
Table 9. Compression Test Results - Conventional vs. Fasti ............................. 40
Table 10. Percent Crystallinity of Virgin HDPE Resin ......................................... 41
Table 11. Percent Crystallinity of Conventional vs. Fasti Containers .................. 42
Table 12. Percent Crystallinity at Points in Heel ................................................. 43
Table 13. Wall Thickness Results - Conventional .............................................. 51
Table 14. Wall Thickness Results — Fasti ........................................................... 52
Table 15. Dimensional Test Results — Conventional ........................................... 53
Table 16. Dimensional Test Results — Fasti ........................................................ 54
Table 17. Compression Test Results - Conventional ......................................... 58
Table 18. Compression Test Results — Fasti ...................................................... 59

vii

LIST OF FIGURES

Figure 1. Current and Projected US Plastic Container Demand (Freedonia

Group, 2002) .............................................................................................. 1
Figure 2. Conventional Extrusion Blow Mold Process ........................................... 4
Figure 3. Conventional Blow Pin ........................................................................... 4
Figure 4. Rotary Extrusion Blow Molder ................................................................ 5
Figure 5. Recirculating Blow Pin ........................................................................... 8
Figure 6.. Fasti Blow Stages ................................................................................ 10
Figure 7. Machine Surround Before .................................................................... 13
Figure 8. Machine Surround After ....................................................................... 13
Figure 9. Sample Tray Layout ............................................................................ 24
Figure 10. Finish Dimensions ............................................................................. 26
Figure 11. Magna-Mike Measurement Locations ...................... . .......................... 27
Figure 12. Container Rotation Callouts ............................................................... 28
Figure 13. Compression Testing Setup ............................................................... 29
Figure 14. Compression Testing Vent Hole ........................................................ 30
Figure 15. Compression Data Example .............................................................. 31
Figure 16. DSC Sample Pan Crimper ................................................................. 33
Figure 17. DSC Readout Example ...................................................................... 34
Figure 18. Conventional Wall Thickness 1 .......................................................... 55
Figure 19. Conventional Wall Thickness 2 .......................................................... 55
Figure 20. Conventional Wall Thickness 3 .......................................................... 56
Figure 21. Fasti Wall Thickness 1 ....................................................................... 56
Figure 22. Fasti Wall Thickness 2 ....................................................................... 57
Figure 23. Fasti Wall Thickness 3 ....................................................................... 57

viii

Figure 24. Assembly Drawing ............................................................................. 68

Figure 25.
Figure 26.
Figure 27.
Figure 28.
Figure 29.
Figure 30.
Figure 31.
Figure 32.
Figure 33.

Detail 01 — Adaptor ............................................................................ 69
Detail 02 - Stern ................................................................................. 70
Detail 03 - Cooling Sleeve ................................................................. 71
Detail 04 - Cutting Ring ...................................................................... 72
Detail 05 - Tip .................................................................................... 73
Detail 06 - Pipe .................................................................................. 74
Main Effects Plot for Factors .............................................................. 79
Normal Probability of Factors ............................................................. 79
Plots of Interactions Between Factors ................................................ 80

KEY TO SYMBOLS AND ABBREVIATIONS

Bv — Bottle Volume (mL)
Be - Weight of Bottle Empty (grams)

Bf — Weight of bottle full of water (grams)

DSC — Differential Scanning Calorimeter

HDPE — High Density Polyethylene
AHf — Heat of fusion of semi-crystalline polymer found using DSC in Jlg

AHf * - Heat of fusion of 100% crystalline sample in Jlg
J - Joules - Energy measurement

9 — grams - Mass measurement

in - inches — Distance measurement

mL — Mililiters — Volume measurement

SCRU - A proprietary unit representing revolutions of the Extruder screw used
by the motor drive on the Bekum Blow Molder

1 — INTRODUCTION AND LITERATURE REVIEW

1.1 Need for Development

Blow molding machines are used for the production of parts in many industries
including packaging and automotive. Packaging, however, is the single largest
user of blow molded thermoplastic containers in the US with approximately 70

percent of market (Rosato et. al., 2004).

The rigid and semi-rigid plastic packaging industry is an economic power that
comprises 21 percent of the $115 billion packaging industry (Ernst and Young,
2002). Plastic containers alone totaled $11.4 billion dollars in 2001. Plastic
bottle demand grows by more than four percent each year and is expected to

reach 11 billion pounds by 2006 as shown in Figure 1.

Figure 1. Current and Projected US Plastic Container Demand (Freedonia

Group, 2002)

U.S. Plastic Container Demand

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

12 11

10 8.8
i
3 8 I Bottles
o. .
'6 6 _ I Pails
2 DTubs and Cups
.3 4 ‘ EOther
ii 2 _

0 2

 

 

1 996 2001 2006

The increasing demand for plastic bottles has forced bottle suppliers to gear up
for the higher outputs required to meet customer demand. The steps taken to
increase output include installing more equipment, retrofitting existing equipment,
or replacing existing machinery with new state-of-the-art equipment. According
to a survey by the Packaging Machinery Manufacturer’s Institute (PMMI), 55.2
percent of respondents reported replacing existing machinery with new models
rated for higher output, while 39 percent reported upgrading their existing
equipment with state-of-the-art retrofit kits (PMMI, 2003). The first quarter of
2003 saw $21.8 million in blow molding machinery sales (SPI, 2003). Total sales
for blow molding machinery in all industries in 2003 are estimated at $505 million

compared to around $350 million for 1999 (Rosato et. al., 2004).

1.2 Extrusion Blow Molding

1.2.1 Process

The extrusion blow molding industry has been on the rise since its first
successful commercially produced item, the “Stopette” deodorant squeeze bottle
by Plax Corporation, in 1945. After this success, nearly every major company
who made rubber machines and injection machines began to develop blow
molders. Material limitations of the time made only small container blow molding
possible (Belcher, 1999). High Density Polyethylene, made available in 1956,
led to the success of low cost, reliable extrusion blow molded manufacturing in

North America and allowed for the production of larger containers (Lee, 1990).

The process of extrusion blow molding was developed from modifications made

to early injection molders as well as glass container machines.

Extrusion blow molding machines use the following process (Figure 2):

0 Plastic pellets of a specific material are fed into the extruder to be melted

o Melted plastic is extruded into a tube called a parison and introduced into
the mold chamber

. An aluminum mold with a cavity in the shape of the desired bottle is
clamped around the parison clamping the bottom shut; the parison is then
cut off at the top

. A blow pin drops into the neck opening of the bottle

0 Plastic is mechanically forced into the “finish” of the bottle by the blow pin
tip forming the threads and mouth of the container

. The blow pin (Figure 3) blows air into the tube, inflating the plastic tube
like a balloon

o The tube is inflated into the walls of the mold cavity

. The mold cavity is water-cooled; when plastic comes in contact with the
mold, the plastic cools and becomes hard

0 The mold opens, the bottle flash is removed, and then the cooled and
formed bottle is dropped onto a conveyor to proceed to a packing or filling

operation

Figure 2. Conventional Extrusion Blow Mold Process

Extrude Clamp Blow

 

Figure 3. Conventional Blow Pin

 

Extrusion blow molding machines are capable of producing multiple containers
simultaneously by using multiple-cavity molds. Many models, including the one
owned by Michigan State University, operate on a continuous rather than

stepwise operating process. During the steps when a bottle is being blown and

cooled, the next parison is already being formed. As soon as one bottle is cooled

and dropped onto the conveyor, the mold shuttles over and picks up the next
parison for molding, greatly reducing cycle times. Other machines use rotary
technology (Figure 4) where a continuously formed parison is wrapped around a
wheel and several operations are performed on the parison as it advances

around the wheel.

Figure 4. Rotary Extrusion Blow Molder

   
 

/EXTRUSION

\ FORMING

The wheel contains multiple molds and bottles are formed in each one. The
wheel contains the air blowing mechanism, which punctures the parison to feed
air inside. Rotary machinery is very expensive, due to the cost of the multiple
molds and blow pins around the machine, but gives very high production rates.
Rotary machines must produce millions of bottles to remain economical (Lee,

1990)

Manufacturers that do not produce extremely high volumes of bottles, but need to
add capacity, are looking for new technologies that will improve the throughput of
traditional blow molding equipment. One of the best areas to reduce cycle times
is in the cooling and blowing stages. Total molding time for a single 2202 bottle
on the current machine is 9.51 seconds; 6 seconds of this is the time required to
inflate the parison into the mold and cool it, forming the bottle. In addition, 0.5
seconds is used to exhaust the air from the bottle before the cooled bottle is
dropped out of the machine. These two processes make up more than two-thirds
of the total cycle time. Reducing the time required for each of these stages

would drastically lower cycle times and increase bottle output.

The blowing stage is required to inflate the bottle and to cool the plastic. The
pressurized air is introduced to the inside of the container to hold the plastic
against the mold cavity. The mold cavity is water-cooled and draws heat out of
the plastic to bring it down to a temperature where it can maintain its shape and
dimensions. The sooner the bottle is brought down to a stable temperature, the
sooner it can be removed from the mold and another bottle can be formed.
There are several ways of reducing bottle cooling time. Traditionally mold-
makers have focused on the radiating effects of different cooling channels in the
mold to reach all parts of the bottle, focusing on the thickest parts of the
container, which require the most cooling. Some companies have taken cooling
a step farther, opting for internal cooling to speed up cool-down times, thereby

reducing blow and exhaust cycle times.

lntemal cooling is the process of cooling the blow-molded part from the inside
out. A standard blow pin inflates the container with room temperature, dry air.
The air is forced into the container, where it remains during the entire blow-cycle
and is allowed to escape during the exhaust cycle. While the air sits in the
inflating container, it remains stagnant and does little to contribute to cooling
since the hot plastic heats it. Water spray, liquid C02, nitrogen, circulated air,
and supercooled air are all methods of internal cooling. Water spray methods
work by spraying an air and water mix into the part. The water helps to cool the
part and is then evaporated into steam. The continuous air stream cycles the
steam out of the part through a pressure release valve. This method requires
that the water mix be introduced after the inside walls of the container are
solidified to prevent the water from affecting the internal surface finish. Finally,
dry air must be blown in to remove any additional water left behind. Air/water
sprays can reduce cycle times by as much as one-third but any residual water
left behind can be undesirable in applications involving moisture sensitive
product or where contamination is an issue (Lee, 1990). Liquid C02 and nitrogen
systems work in similar ways. Internal cooling through cold circulated air is the

basis of the Fasti Blow Mold Booster system.

1.3 Fasti System

1.3.1 Recirculating blow pin

The purpose of the Fasti system is to internally cool the container. The most
important feature of this technique is the continuous removal of hot air while the
system simultaneously introduces cold air into the part. This process of cycling
the air is achieved by using a recirculating blow pin. The blow pin can be easily
engineered for the specific machine and application. The pin consists of a
central exhaust pipe, which pulls hot air out of the bottle and a fitting which sends
cold air into the bottle around the outside of the exhaust pipe (See Figure 5). In
addition, small channels send air around the circumference of the blow pin

externally at the cooling sleeve to cool the mail or top flashing.

Figure 5. Recirculating Blow Pin

 

Blowing of the bottle becomes a three-stage process with the Fasti system

described below and shown in Figure 6.

1. The pre-blow phase uses chilled air through both blow pin channels to

inflate the parison inside the mold as quickly as possible, while the blow

pin is entering the bottle finish. The high-pressure pre-blow process forms
the container, forcing out ambient air between the mold and parison
through the mold vents. The bottle is inflated and comes in contact with

the water-cooled cavity surfaces, which promotes the cooling of the bottle.

. The blowing phase is used to do the actual cooling of the bottle with cold
air. Upon inflation of the bottle in the pre-blow stage, only a small amount
of back-pressure is required to maintain contact with the mold cavity walls.
During this stage, air flow through the center channel of the blow pin is
reversed, allowing hot air to escape while cold air is blown in through the
outer channel. Cold air entering the container forces the cold air out the
center channel. This allows the cold air to circulate instead of trapping the

hot air inside the container as with a conventional process.

. Finally, the venting stage where the air pressure is balanced between the
container and the outside. At this stage, the container will have cooled

sufficiently to maintain its dimensionality.

Figure 6. Fasti Blow Stages

1 2 3

 

The cost of a new recirculating blow pin averages from six hundred to seven
hundred dollars, comparable to that of a traditional pin, but can vary due to size
and complexity. Full Mechanical drawings of the blow pin used in this setup are

available in Appendix B

1.3.2 Cooling system

The air cooling system itself is quite simple. Air is forced into the system and
cooled by cold water. The refrigerated air is then directed into the blow pin for

bottle blowing.

1.3.3 Costs

Total cost of the unit is listed in Table 1 along with an estimate of equipment

payback time based on a three-shift production schedule at 80% efficiency.

Table 1. Fasti Cost Analysis and Payback Period Estimate (FastiUSA, 2004)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Costs

Blow Mold Booster Unit Cost $11,710.00
Blow Valve Blocks $1,490.00
Blow Pin Design Cost $1,100.00
Blow Pin MachinirLcLCost $700.00
Installed lnvestrnent $15,000.00
Values in US$

Conventional Fasti-8MB
Operating Efficiency 80% 80%
Base Machine-Hour Cost $80.00 $80.00
Number of Operators per Machine 1 1
Cost per Man-Hour $20.00 $20.00
Productive Hours per Day 19.2 19.2
Product Weight, Ems 25 25
Cost of Resin per Kilo $1.25 $1.25
Cost of Resin per Part $0.03 $0.03
Energy Consumjtion, KW/h (Included in Base Cost) 7
Energy Cost per KWlh $0.10 $0.10
Additional Energy Cost per Hour $0.00 $0.70
Air Consumption, Nm3/h (Included in Base Cost) 20
Cost of Compressed Air/Nm3/h $0.02 $0.02
Additional Air Cost/h $0.00 $0.39
Total Additional Costs $0.00 $1.09
Manufacturing Cost per Hour $100.00 $101.09
Increase in Production, % 0% 28%
Number of Parts Produced per Hour 379 485
Cost of Resin Consumed per Hour $11.37 $14.55
Total Cost per Part $0.29 $0.24
Savings per Part NIA $0.06
Savings per Day N/A $516.06
PAYBACK PERIOD, DAYS 29.1

 

11

 

1.3.5 Installation

Installation of the equipment required significant modifications to the machine
including fabrication of mounting brackets for both the cooling unit and the
valves. It was necessary to mount the cooling unit at a level higher than the blow
pins and with as short a distance between the blow pin, cooling unit, and valves
as possible. The size of the cooling unit required it to be mounted on top of the
machine surround with a substantial bracket able to support its 90 pound weight.
The final design for the mounting tray consisted of a three-point support with the
main weight of the unit being carried by the machine surround and a third mount
point inside the cabinet on a mounting plate. The mounting tray also needed a
lip to contain the unit to prevent it from vibrating off. The valve units were
mounted to the sheet metal sides of the machine surround using sandwich plates
to stabilize them, this spread out the load further. Photos of the blow mold

machine before and after modification are shown in Figures 7 and 8.

12

Figure 7. Machine Surround Before

 

1.3.4 Efficiency

Fasti USA claims to increase production by reducing air blow cycles by as much
as 35%. The entire forming process for one bottle is 9.51 seconds, with 6
seconds of that being used for blowing of the bottle. If a bottle machine produces
one bottle every 9.51 seconds, that machine will produce 379 bottles in a 1-hour
period. Reducing forming time to 7.42 seconds will allow the machine to produce
485 bottles in 1 hour, a 28% production increase. Production improvements like
this will directly translate into lower costs and higher profits. Savings such as this

could have significant impacts on any industry that uses blow-molding processes.

1 .4 Objective

The question that remains is: what effect do the cooler temperatures and

reduced cycle times have on the physical properties of the finished bottle?

1.4. 1 Crystallinity

Forming temperatures have a direct relationship with the crystallinity and density
of HDPE containers. Polymer crystallinity and density have a direct correlation
with such properties as clarity, permeability, column crush strength, and impact
strength (Hernandez, Selke, and Culter, 2000). The objective is to quantify what
effect lower processing temperatures will have on bottle performance in these
areas. Table 2 shows the effect of decreased crystallinity on various bottle

properties

14

Table 2. Effect of Decreased Crystallinity in Polymers (Hernandez et al,

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

2000)
Crystallinity decreases
Density decreases
Permeability increases
Opacity decreases
Blocking increases
Tensile Stregqth decreases
Compression Strength decreases
Clarity increases
Tear Resistance increases
Impact Stremth increases
Toughness increases
Ductility increases
Ultimate Elongation increases
Heat Sealing Temperature decreases
Heat Sealing Range increases

 

 

As is evident in the table, reduction in crystallinity can have significant effects on
bottle performance. Most notable for those involved in packaging are increased

impact strength, reduced compression strength, and increased permeability.

“During processing, the major difference between amorphous and crystalline
polymers is that amorphous polymers gradually lose their molecular mobility as
the temperature cools, whereas crystallizing polymers (like HDPE) change
suddenly from mobile liquids to crystalline solids at a sharply-defined
melting/freezing point” (Rosato et. al., 2004). For this reason, crystallizing
polymers are more difficult to blow mold because of their narrow workable
temperature range. The rate of crystallization can be controlled by the cooling
process and ultimate crystallinity may be reduced by quenching (Rosato et. al.,

2004).

15

“Crystallization is useful in blow molding because (1) it freezes [the container] in
the stretch orientation and thus gives the oriented structure permanence; and (2)
it improves many end-use properties of particular importance in food packaging,
including rigidity, dimensional stability on reheating, and imperrneability. On the
other hand, crystallinity tends to harm some useful properties such as ultimate
elongation, impact strength, transparency, and environmental stress crack

resistance” (Rosato et. al., 2004).

If we assume that AH , is proportional to the % crystallinity of the test
specimen and if we know the AH f of the test specimen in pure

crystalline form (100% crystallinity), we can compute the %

crystallinity as follows:

 

AH
%Crystallinity = AH f x100%

*

Where:

AH f = heat of fusion of semi-crystalline polymer, Jlg

AH f * = heat of fusion of 100% crystalline sample, Jlg. For PE, this value is

286.2 Jlg (Selke and Xiong, 2003).

The Fasti unit’s internal cooling technology is likely to affect crystallinity of the
finished container due to the quicker cooling and therefore shorter period of time

during which the bottle is at its crystallization temperature.

16

1.4.2 Wall thickness

In addition to impacting crystallinity, the Fasti system may also affect the wall
thickness of the finished containers; reducing the amount of time that the plastic
has to flow out into the mold may affect material distribution. Distribution
changes may be solved using the parison programming to adjust the profile and
maintain uniform wall thickness throughout the bottle and between forming

methods.

1.4.3 Dimensionality

Bottle dimensions may be affected by cold air blowing. It is likely that
dimensional stability will be affected by internal cooling. The quicker cooling and
therefore “freezing" of the container shape will result in less warpage.
Dimensional stability of the container is critical to maintain tolerances for the
filling operations in terms of volume as well as dimensions in the finish area to

allow the closure to work well with the container.

1.5 Hypothesis

An experiment was designed to test the hypothesis:

Ho : The use of internal cooling does not change the physical properties of

extrusion blow molded HDPE bottles; specifically, mean compression strength,

dimensions, and crystallinity do not change.

17

1.6 Statistical Methods

Means for variables measured on conventional and on Fasti bottles were
compared with two sample t-tests. Analyses of residuals showed this to be

reasonable for the comparisons.

Commonly, p-values of less than or equal to 0.05 are regarded as indicative of
(statistical) significance. However, with large sets of multiple comparisons the
level is made more stringent. For example, with the set of four or eight
dimensional comparisons 0.01 is used and with a set of sixty-four thickness

measurement points 0.001 is used.

18

2 - EXPERIMENTAL DESIGN AND TEST METHODS

2.1 Materials and Setup

2. 1. 1 Conventional Air Setup

Setup of the conventional blow settings was accomplished with the help of
Bekum America. The settings are set so that the container is formed in the
shortest amount of time possible that would still allow complete formation of the
container. The cycle time of this setup as shown in Table 3 is 9.51 seconds.
The parison program was designed to create approximately equal wall thickness
throughout the wall and heel of the container. These set points are saved in the

machine as “1602 ROUND THESIS” along with the parison program.

19

Table 3. Bekum Blow Molder Conventional Blow Set Points

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Action fime (sec)
EFend Knife Delay 0.63
Retract Knife Cut Delay 0.63
Mold Close Delay Time 0.00
Carriage Down Delay 0.25
Blowing Delay 0.12
BlowingTime 6.00
Exhaust Time 0.50
Deflash Delay 0.00
Blow pin 1st Step Delay Time 0.14
Blow pin 2nd Step Delay Time 0.10
Container Blowoff Delay 0.00
Container Blowoff Time 0.00
Carriage lip Delay 0.30
Fasti Delay ~~~
Knife Pulse Cut 0.16
Carriage Up First Cycle Delay 2.00
Mold Crack Time 0.25
Mold Crack Hold 0.40
Controlled Support Air Delay 2.00
Controlled Support Air Time 2.00
Machine Cycle Timer 9.51
Etrusion Speed (SCRU) ~48.00
Blow Pressurgpsi) 65.00
Back Pressure (psi) ~~~
Extruder Temperature Set points (deg F) 350.00

 

2. 1.2 Fasti Cold Air Setup

Setup of the Fasti cold air blow settings was accomplished using trial and error.
The settings are set so that the container is formed in the shortest amount of time
possible that would still allow complete formation of the container. The cycle
time of this setup as shown in Table 4 is 7.42 seconds. The parison program
was designed to create approximately equal wall thickness throughout the wall

and heel of the container. Another experiment, shown in Appendix E, attempted

20

to determine the connection between various timer and pressure settings with
container volume or shrinkage. The findings from this study were taken into
consideration when setting up the machine. These set points are saved in the

machine as “1602 ROUND FASTI THESIS” along with the parison program.

Table 4. Bekum Blow Molder Cold Air Set Points

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

_ l Action fime (sec)
Extend Knife Delay 0.63
Retract Knife Cut Delay 0.63
Mold Close Delay Time 0.00
Carriage Down Delay 0.25
Blowing Delay 0.12
Blowing Time 4.50
Exhaust Time 0.35
Deflash Delay 0.00
Blow Pin 1st Step DelayTime 0.14
Blow Pin 2nd Step Delay Time 0.10
Container Blowoff Delay 0.00
Container Blowoff Time 0.00
Carriage Up Delay 0.30
Fasti Delay 0.85
Knife Pulse Cut 0.16
Carriage Up First Cycle Delay 2.00
Mold Crack Time 0.25
Mold Crack Hold 0.40
Controlled Support Air Delay 2.00

. Controlled Support Air Time 2.00
Machine Cycle Timer 7.40
Extrusion Speed (SCRU) ~65.00
Blow Pressure (psi) 85.00
Back Pressure (psi) 18.00
Extruder Temperature Set Points (deg F) 350.00

 

21

2. 1.3 Controls (Constants)

The following pieces of equipment were used in the experiments and setup of the
machine. These items remained constant through all tests.
Plastic Type
0 Union Carbide UNIPOL Polyolefins DMDA-6220 N17 UNIVAL
Mold
. Manufactured by MC Molds, Williamston, Ml
Blow Mold Machine
0 Model H-111S Bekum America, Williamston, MI
Fasti Blow Mold Booster ll (BMB ll)
. FastiUSA, Elgin, IL
Closure
. Rexam Closures and Containers Evansville, IN

0 Cap style: 28 DECO CC2 SPECIAL

. Color: Any
. Material: PLS 10
- Liner: 827

. Description: W01 base/6A4 lid crabsclaw ols

o Orifice: 0.155

22

2.2 Experimental Methods

2. 2. 1 Sampling

Objective:
To obtain consistent samples in a regulated manner in order to facilitate labeling

and tracking of containers.

Methods:

Containers were manufactured by the two different manufacturing methods: Fasti
Cold Air blow and Conventional blow. Short run times were necessary due to
machinery limitations, namely, air supply was inconsistent and only allowed

production of 30 containers before pressures fell below the specified settings.

The manufacturing process was started up. The first five containers retrieved
from the machine were discarded. From then on, each container made was
removed in order and placed inverted (finish down) in a divided, numbered
sample tray. The containers were inverted to give them time to cool and to
prevent the bottom pinch-off from becoming fused to the container. 30 Samples
were made per run. The bottles were laid out in the sample trays as shown in

Figure 9.

23

Figure 9. Sample Tray Layout

 

 

Five minutes after the cycle was complete, the pinch-offs were removed by
twisting them. The containers were then labeled by tray location and placed
right-side-up in a new sample tray. The sample tray was labeled with the date,

run number, and manufacturing method (Fasti or Conventional).

2. 2.2 Conditioning

Objective:

To condition container samples after processing to maintain uniform testing

results.

Methods:

Conditioning was performed in accordance with ASTM D-618-00 Standard
Practice for Conditioning Plastics for Testing. The labeled sample trays were
stored in the room where the bottles were formed and various tests were being

performed and allowed to sit for a minimum of 40 hours before being tested.

24

Average temperature, checked by thermometer, of this room was 24.2 degrees

Celsius.

2. 2.3 Dimensional

Objective:

To determine the overall dimensions of a container and determine variance

among samples.

Equipment:
Scherr-Tumico Industries Model 20-3500 Optical Comparator (0.0001”)
Mitutoyo Model CD—6”BS Digital Caliper (0.0005”)
Mettler PM2000 Scale (0019)
Magna—mike (0.0001 ")

Methods:

Container samples were measured according to ASTM D 2911-94 Standard

Specification for Dimensions and Tolerances for Plastic Bottles.

Finish: Finish dimensions were measured using the optical comparator. Typical
tolerances for a finish of this size have a range of around 0.020 inches. T
indicates diameter of the finish at the tips of the threads. E indicates diameter of
the finish at the base of the threads. H indicates the dimension from the top of
the bottle to the transfer bead. l indicates the inside diameter of the finish area.

A diagram of the different dimensions is shown in Figure 10.

25

Figure 10. Finish Dimensions

 

L

 

 

ll :1

 

 

Tl

 

Volume: Containers were weighed empty, and then filled with water conditioned
according to ASTM C2911-94 and weighed again. Container volume was

calculated as follows:
BV(mL) = (Bf — Be)/ 0.997

Bottle overflow Capacity Tolerance with a volume between 384 and 531 mL is

:I:11mL.

Body Dimensions: Width is an average of the measurements at the parting line
and then rotated 90 degrees. The width is measured using calipers 3” from the

bottom of the container.

26

Table 5. Bottle Body Dimension Tolerances (ASTM D 2911-94)

 

Body Wall thickness: Wall thickness was measured using the magna—mike with
measurements taken at 0.25” increments up the container wall, as shown in
Figure 11, as well as measurements in the heel. These measurements were
taken at the parting line by the bottom detent at 12:00 as shown in Figure 12 and
then repeated every 90 degrees around the container for a total of 64

measurements.

Figure 11. Magna-Mike Measurement Locations

 

27

Figure 12. Container Rotation Callouts

Parting Line

 

 

2.2.4 Compression Testing

Objective:
Column crush tests provide information about the crushing properties of blown
thermoplastic containers. Column crush properties include the crushing yield
load, deflection at crushing yield load, crushing load at failure, and apparent

crushing stiffness.

Equipment:
Lansmont Corporation Squeezer Compression Tester (0.1 lbs, 0.001 in)

Mettler AE 160 Scale (0.00019)

Methods:

Crush testing was performed in accordance with ASTM D 2659-95 Standard Test

Method for Column Crush Properties of Blown Thermoplastic Containers (ASTM

28

D 2659, 1995). Twenty samples from each manufacturing method were tested
as shown in Figure 13 to determine crushing yield load, deflection at crushing
yield load, crushing load at failure, and apparent crushing stiffness. A modified
closure was applied to the container. The closure had a vent hole which allowed
air to escape during testing as shown in Figure 14. The crown of the closure
prevented the hole from sealing and causing pressure to build in the container

which could affect compression strength.

Figure 13. Compression Testing Setup

-’

 

29

Figure 14. Compression Testing Vent Hole

 

The data from the compression tester was exported to an Excel file for analysis.
The crushing yield load, deflection at crushing yield load, and apparent crushing

stiffness were extrapolated from the data as follows:

Crushing Yield Load - Point on the crush load/deflection curve at which an
increase in deflection occurs without an increase in crush load expressed in lbs.

to three significant figures (Figure 15).

Deflection at Crushing Yield Load - Reduction in height (x-axis of Figure 15) of
the sample at the crushing yield load expressed in inches to three significant

figures.

Apparent Crushing Stiffness — Calculated by selecting a point on the straight line
segment of the crush load/deflection curve as shown in Figure 15 and dividing
force at this point by the corresponding deflection expressed in pounds per inch

to three significant figures.

30

Figure 15. Compression Data Example

CONSTANT RATE TEST DATA: FORCE vs DEFORMATION

 

 

Crushing z . i . z 3
Yield Load .

 
      
 

 

 

 

...-.-.........l-.....-........i.......-. ..2-..',............._. ..................................

 

Force (Lbs.)
8

o I I I t
. . . .
. . . . . ,
‘ 1 i - I ' i ;
q-.-...~...-...." ................................ .. .. ...................................................................... (
. . . . , . .
I I I . l . .
t I a I . -
u 1 l . - 1 ~ -
t b 0 y . - I
. . . . . .
v s . . , _ .
Segment | > ' ‘
‘. ' r I
I ~ . t
T 1 . . . .
2,..-,--- 1-, .... ,,.......... .....W... ..
t a

 

 

 

 

 

 

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 0.5
Deformation (ln.)

2. 2.5 Differential Scanning Calorimetry

Objective:
To determine the melting point and percent crystallinity of

HDPE samples by differential scanning calorimetry.

Materials:

TA Instruments DSC Q 100 Differential Scanning Calorimeter
Mettler AE160 scale (0.00019)

31

Methods:

Handle all samples with tweezers, cut a 9-10 milligram sample from the
container, weighing sample in the bottom aluminum pan. Record sample weight
then apply top pan and crimp sample closed as shown in Figure 16. Place
sample in DSC centered on thermocouple. Using the settings shown in Table 6,

run the experiment.

32

Figure 16. DSC Sample Pan Crimper

 

Table 6. DSC Heat/CoolIl-leat Setup Method

 

Integrate the curve shown by the analysis program shown in Figure 17 with the
curve starting at 60°C and ending at 150°C. Calculate percent crystallinity from
the result using 286.2 Jlg as the baseline for 100% crystalline HDPE (Selke and

Xiong, 2003).

33

Figure 17. DSC Readout Example

 

 

 

 

§
,
~§
i
9 a
33.
o g: 8
to a .— ,
00 v ..
.- q’ -8
N (0 '-
‘— N
-§
-8
_- '-8
L/ -0
v
F
8

 

 

10

(61M) MOB 199H

34

Temperature (°C)

W

3.1 Cycle time improvements

The improvement of cycle time was indeed significant, accomplishing a 22%
decrease from 9.51 seconds per cycle to 7.42 seconds per cycle. Containers
manufactured using the two methods were complete and correctly formed and

similar in appearance.

3.2 Dimensionality

Comparison of container dimensions between Fasti and conventional
manufacturing methods reveal several differences and are shown in Table 7. P—
values shown in bold show statistical significance. The most striking difference
between the containers is an overall shrinkage of the Fasti containers. While
shrinkage after the forming process is common, this effect appeared to be
magnified by the Fasti system. While the Fasti containers shrank more than the
conventional bottles, the shrinkage was consistent across containers as
displayed by the low standard deviation found among samples. Shrinkage does
not entirely account for the reduced volume of the Fasti containers. This is
explained by the increased part weight. More resin in the container walls makes

the volume inside the container smaller.

Warpage after the forming process is also a common occurrence. Warpage of
the body area of the Fasti containers was significantly lessened with the Fasti

process as can seen in the “Body Diameter Difference” category of Table 7. This

35

category is a calculation of the differences in diameter of the container across the
parting line versus turned 90 degrees from the parting line. The decreased
warpage is best attributed to the uniformity of the wall thickness at the measuring
point. The container diameter was measured 3 inches from the bottom of the
container at point 8 of the wall thickness measurements. Review of the wall
thickness found in Appendix A proves that decrease of warpage is not related to
varying wall thickness around the container. The likely reason for reduced
warpage of the container is the internal cooling. Container thickness at the
diameter measuring point is relatively thin and would receive the most cooling.
This proves that the Fasti unit will actually "freeze" the container in place with

more thorough cooling.

36

 

 

 

 

 

 

 

 

- Conventional vs. Fasti

 

I‘ISOI'I

 

 

 

 

 

 

 

I Test Result Compa

 

 

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Table 7. D

 

 

 

 

 

 

 

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37

The Fasti containers had a more consistent wall thickness throughout the
container while conventional containers had thinner walls near the top as shown
by the wall thickness data in Appendix A. The most statistically significant points
(those with p-values less than 0.001) are shown in bold in Table 7. These values
coincide with the thinnest spots on the conventional containers. This can be
explained by the extrusion speed. The Fasti containers used a higher extrusion
rate in order to prepare the parison faster. The slower extrusion rate of the
conventional process allowed the parison to stretch under its own weight and
therefore thin out near the top. This issue could be easily resolved by altering
the parison profile or possibly by lowering the melt temperature in the

conventional process.

Table 8. t-Score p-Values for Wall Thickness

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

t-score p-values (3 df)
Point 12:00 3:00 6:00 9:00
1 0.197 0.083 0.052 0.606
2 0.664 0.861 0.016 0.243
3 0.005 0.097 0.094 1.000
4 0.022 0.372 0.397 0.170
5 0.228 0.559 0.217 0.205
6 0.397 0.155 0.023 0.941
7 0.332 0.047 0.052 0.403
8 0.078 0.029 0.038 0.200
9 0.011 0.016 0.008 0.095
10 0.002 0.013 0.001 0.049
1 1 0.000 0.018 0.000 0.049
12 0.001 0.026 0.002 0.086
13 0.002 0.015 0.003 0.163
14 0.042 0.010 0.003 0.045
15 0.058 0.135 0.830 0.028
16 0.042 0.022 0.008 0.025

 

 

 

 

38

 

3.3 Compression Strength

Compression strength tests performed on the finished containers revealed very
little difference between processes. In both cases, failure was seen in the heel
area resulting in buckling of the bottle walls. Table 9 shows a comparison of the
compression test results for conventional versus Fasti containers. The p-values
in the table are less than 0.01 in each category showing that the data is
statistically significant. The statistical significance however, does not speak of
the practical significance of the effect the Fasti system has on the container. The
higher crushing yield load of the Fasti container is likely attributed to the slightly
higher average thickness of the container at the crush failure point displayed in

the data in Appendix A.

Table 8 shows significant data difference in the apparent crushing stiffness of the
containers to theorize that the Fasti containers may have a lower percent
crystallinity and therefore lower stiffness as expressed in Table 9. This theory
was tested in Section 3.4. All compression strength data is displayed in

Appendix B.

39

E s

E 5

o .d

_l a

1:

—. a 54

2 a f:

A v C a

3 8 “E ‘”

.- o a g

4: ..r a .-

.9 1: o f,

2’ I ~ 2

r: >- g u

o g ,0 '5

.§ '5 3 2

O a, 0 N

a a '= a

m g 8 5

Conventional
Xbar 25.8795 72.225 0.29855 409.124
s 0.26863 3.20836 0.00635 14.9418
7 Fasfi
Xbar I 28.2515 76.115 0.27105 371.583
s | 0.0981 1.60173 0.00876 15.0963
Statistics
ang-ang -2.372 -3.89 0.0275 37.5409
SE 0.06395 0.80184 0.00242 4.74952
t 37.0927 4.85131 11.3675 7.90416
p-value 1E-22 4.2E-05 2.7E-13 1 .5E-09
3.4 Crystallinity

Crystallinity of the container is determined by processing conditions. The

average crystallinity of the virgin HDPE resin pellets, as displayed in Table 10, is

76.32%.

Table 9. Compression Test Results — Conventional vs. Fasti

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

40

Table 10. Percent Crystallinity of Virgin HDPE Resin

 

 

 

 

 

Jlg %Cry
Pellet 1 220.8 77.15%
Pellet 2 213.8 74.70%
Pellet 3 220.7 77.11%
_A_v_g 218.4 76.32%

 

 

 

 

 

Initial crystallinity tests involved removing a sample from three points on the
bottle: in the heel, in the body 3 inches above the bottom, and in the shoulder.
These samples were taken without regard to their orientation on the container as
far as container rotation. This may explain the large variance percent crystallinity
between container samples shown in Table 11. For example, the shoulder
sample from conventional bottle 28 from sample tray as shown in Figure 9 was
taken at the 12:00 position while conventional bottle 29 was taken from 5:00.
Wall thickness data in Figures 18, 19, and 20 in Appendix A show significant wall
thickness differences from point to point around the container at the shoulder

(thickness measurement 16).

41

Table 11. Percent Crystallinity of Conventional vs. Fasti Containers

 

 

 

 

 

 

 

 

 

 

 

 

 

Body I Shoulder Heel
Conventional
Bottle 28 218.7 219.1 231.6
Bottle 29 219.2 234.4 226.5
Bottle 30 220 228.8 223.5
Avg 219.3 227.4333 227.2
%-Crystallinity 76.62% 79.47% 79.39%
Fasfi
Bottle 28 230.8 233.2 220.3
Bottle 29 234.8 227.9 209.8
Bottle 30 230.9 228.9 215.5
Avg 232.1667 230 215.2
%-Crystallinity 81.12% 80.36% 75.19%

 

 

 

 

 

 

More thorough and controlled testing was done on a single sample container for
each conventional and Fasti container at the heel. A sample was taken at each
of the four points of rotation as shown in Figure 12 after the container was
measured for thickness. The thickness measurement at the sample area
corresponds to measurement point 2 of the data shown in Figure 20 and Figure
23 in Appendix A. Table 12 shows the thickness at each measuring point and its
corresponding percent crystallinity. This data shows that there is no significant

correlation between wall thickness and percent crystallinity in the heel area.

42

Table 12. Percent Crystallinity at Points in Heel

 

 

 

 

 

 

 

 

 

 

 

 

12:00 I 3:00 6:00 ] 9:00
Conventional
Thickness (in.) I 0.0261] 0.0175 0.0256] 0.0192
fig I 220.5] 222.8 226.8] 234.5
%-Crystal|inity I 77.04%] 77.85% 79.25%] 81.94%
Fasfi
Thickness (in.) I 0.0223] 0.0180 0.0289 0.0177
£9 I 225.8] 225.7 231 236.7
%-Crystallinity [78.90%] 78.86% 80.71% 82.70%

 

 

 

 

Of further interest is the difference in crystallinity between conventional and Fasti
containers. The data in Table 12 shows no significant difference in percent

crystallinity between manufacturing methods.

43

4 - CONCLUSIONS AND RECOMMENDATIONS
The addition of Fasti internal cooling technology to the Bekum blow molder
significantly increased production rates of the machine. Production increases as
high as 22% were seen between conventional and Fasti molding methods
despite limitations with our equipment including insufficient air-supply. An
increased air supply would likely drastically lower the blow air temperature
released from the Fasti unit. Decreased blow temperatures would result in more

thorough cooling and more stable container properties.

Dimensional analysis of containers proves that reduced warpage is a positive
effect of internal cooling. The proof is found in the more consistent container
diameter of Fasti containers, which is not associated with wall thickness. The
thorough cooling and therefore setting of the body walls with low blow air
temperatures reduced warpage after being released from the mold. Further
proof of this could come from continued research upon implementation of a more
reliable air supply. Fasti container formation resulted in a higher overall
container weight which caused a reduction in volume. Without container and
closure drawings it is difficult to determine if the container finish dimensions fell
within desired tolerances but a low standard deviation among samples of the

same manufacturing method displayed consistency and low standard deviation.

Compression tested containers showed very little difference in performance that

could be directly attributed to changes in crystallinity, container dimensions, or

44

wall thickness. Compression strength could be improved for certain applications

by increasing wall thickness in the heel area.

Study of the containers by Differential Scanning Calorimetry at various container
locations reveals that the percent crystallinity of the container is independent of
container wall thickness. Furthermore, the percent crystallinity did not appear to

be dramatically affected by blow temperature.

It should be noted that the tests were run on containers produced through short
run times. Increasing the reliability of the air supply and therefore lengthening

run cycles would produce greater sample sizes and allow more thorough testing.

In summary, the Fasti internal cooling technology greatly increased output
without making considerable changes to container performance. Any
shortcoming found with the system can easily be programmed out with a
combination of changes in processing temperatures, air flow, and parison
programming. The positive effects of the Fasti system including reduced cycle
times and reduced warpage would likely be magnified with the use of more air

volume resulting in lower temperatures.

45

5 - RECOMMENDATIONS FOR FUTURE RESEARCH

5.1 Utility Needs

In order to properly use the Fasti internal cooling equipment, it is necessary to
have a more reliable air supply. The current setup allows only around 5 minutes
of continuous operation of the machine with sustained air pressure. Air pressure
was monitored throughout the forming process with the use of an added-on
gauge at the wall. If pressures dropped below what was required for the
machine, forming was stopped. It is likely that the longer the machine is left to
run, the process will become more stable. Higher air volumes used for producing

the containers will also allow faster and more complete cooling.

Many solutions are feasible for this problem, the most reliable being an upgrade
for the air compressor unit to one capable of a higher volume output (cubic feet
per minute). Another possibility would be the addition of a large surge tank near
the machine itself. This would allow longer runs, though not necessarily more

volume.

5.2 Redesign of Mold

The mold that was supplied with the machine uses a finish which is very
outdated. The threads used are a custom thread design available only from
Rexam Closures. Various attempts to acquire sample caps, finish drawings,
production tolerances, turned up little information. A very small number of caps

were acquired for studies but the hinged lid is not acceptable for many

46

performance tests. It would be desirable to redesign the finish area of the mold.
This section is removable and could be replaced with a more standard thread for

which closures are more readily available.

In addition, the use of the Fasti system would produce better quality bottles with
less shrinkage in the finish area if the water channels allowed better cooling.
Redesigning the mold for the new finish would allow the opportunity to redesign

these cooling channels.

5.3 Regrind

The School of Packaging has a granulator which could be used for regrinding
containers. Studies could then be conducted regarding the changes in
processing temperatures and conditions with the use of the regrind material.
Furthermore, studies could be done using various mixes of regrind and virgin

material and their effects on container performance.

5.4 Different Containers

The use of the Fasti machine on a 16 fluid ounce container from this mold does
not compare to the benefits realized from a larger container with thicker walls.
According to Fasti, a common application for the Fasti unit is for the production of
blow molded gas tanks. These containers have very thick coextruded walls
requiring long blow times to cool the tank and set the plastic. Factors like

shrinkage may be magnified in the larger part. Investigating the effect of

47

container size and volume on cooling time and container shrinkage is

recommended.

5.5 Environmental Stress Cracking

Another important test which could be run on these containers is an
environmental stress cracking test. Comparisons could be made between the
two manufacturing methods following the test procedures outlined in ASTM
D2561-95, Environmental Stress-Crack Resistance of Blow-Molded Polyethylene

Containers.

5.6 Impact Testing

Impact testing of HDPE containers is difficult through standard testing methods
including ASTM D 2463-95 Drop Impact Resistance of Blow-Molded
Thermoplastic Containers. The problem lies in the incredibly high inherent
strength of the materials. Preliminary testing failed to produce any impact failure
at all. Possible solutions to this problem could include freezing of the containers

before testing to increase brittleness.

5.7 Torque Testing

The different manufacturing methods could potentially produce different results in
closure torque testing. Application and removal torque could be tested for each

of the containers.

48

5.8 Optical Microscopy

Optical microscopy is another method for analyzing the physical composition of a

container including crystallinity by observing crystalline regions.

5.9 Permeability Testing

Permeability could be conducted on different containers produced by the

machine.

5.10 Resin

Various resins could be tested in this machine with the current setup. The
current extruder screw is capable of running polyethylene including HDPE and
LDPE as well as polyethylene blends. Further information could be obtained
from Bekum America regarding the compatibility of this screw for other materials
as well as possibly acquiring a new screw capable of a wider array of material

compatibility.

49

APPENDICES

50

APPENDIX A

Dimensional Results

Table 13. Wall Thickness Results - Conventional

 

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888—838— 888— 888—882 .888

888— 888— 888

88.2 -8.o_ 888— 2

 

888— m-o.o_ 888— 888— 888— 8-88

888— 888— 888

8~o.o_ 888— 888— 3

 

888— 883 888— 888— 888. 888

8887882 888. 8~o.or8-o.o_ 888— 2

 

$~o.o_ 288— 88.“: 888— :88 888

-~o.o_ 888— 888

888— 888— 888— 3

 

 

:88— 8F~o.o_ 8-o.o_ 888— 88.2 888

8-o.o_ 888— :88

888— 882 888— :

 

8~o.o_ -~o.o_ :88— 882 888— 888

888— 888888

882 882 888— 8

 

888— 888— 8~88W8~AE 8~o.o_ 888

888— 8~o.o_ -~88

888— 8~o.o_ £88— a

 

vnmod

888— 888— 888— 888— 888

888— 28.8888

homod— {Nod— mmNod— m

 

vowed

888— 888— 888— 88g 888

888— 888— 888. 888— 8~o.o_ 288— ~

 

 

035.0

88.2 888— 888— 888— 888

888— 888— 288T888— 888 888— g

 

 

mmmod

288— 88.2 3.88— t88_ B88

888— :88— 888.8_ 388— :88 888— ....

 

 

88.2 888888— 388— 882 888

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888— 853 83% 888— 888— 888— 882 388— 888— 888— 88.3 ~838— ~

 

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29qu

 

can»

 

88 _ 88 _8”~._ 88

 

88 _ 88 _8”~r_ 88 _ 88 88 _

 

 

 

 

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N canon >=oO _

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51

Table 14. Wall Thickness Results - Fasti

 

:82 888— 888_ 888— 88.2 888fi882 888— 888T888_ 888— 3.88— 8

 

 

 

 

 

 

888 888_ 888_ 888_ -88 2888— 882 888— 888_ 888_ 888_ 288— 8
3.88 888— 8887888— 888 88.2 2.88 88.8888— 888_ {8.8— 888— 3
888 888— 888_ 888_ 888. 888_ 888 888_ 888— 888fl888— 888_ 2
888 888_ 88.2 888_ 888 888_ E88 888— 888_ E88b888fi888_ 8
888 888—8888— :.88_ 88.8 88.8—88.2 888_ 888W~8£ E88— 888? :

 

 

88.2 888_ -88_ k88_ 888.

8888— 88.9888— 888_ 888_ 888— 288_ 8

 

888_ 2.88_ 888— 888_ 888

888— 888— 88£388_ 8.88— 888_ 888—

 

88.3 888_ 888— 888_ 888

888_ 888— 888_ 888— 888— 888— 888—

 

88.2 888_ 888— 888_ 288888.“; 88.2 888— 288 88.2 888F888—

 

 

momod

888_ 888_ 888—288— 888— 888

 

888— 888_ 888

888% 3.88—

 

—

 

homo?

 

8.88— 288_ 28% -88_ 8888— 38.2 888— 8~88_ 888_

888— 3.88—

 

ommod

888— 8881888— :88_ 88.%S88_ 888— 288_ 288— -88_ 888—

 

 

2.88_ 382 388— 888— 88.2 388— 888W~88_ 88.2 8887889888fl

 

88.2 888— 888_ 8887888

888— 888— 888. 888— 888— 888_ 52°F

 

:82 8887882 8882 882 888— 88.2 :88_ 888— 888_ 88.2 888—

 

FNM‘IDCDNQOD

 

oafir

 

can”

 

comm

 

88 _8"~P_ 88 — 88

 

88 _8"~._ 88 _

88 88 758

 

 

 

 

_. 0.300 tau“.

_ ~ 288 .88“.

_ - some 8.8 _

 

52

I Test Results - Conventional

Imenslona

Table 15. D

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

00.00 00.000 00.00V 0000.0 000V.0 0000.0 0V00.0 00V0.0 0000.0 0000.0 030.0 0V00.0 «000.0 00
00.00 00.000 00.00V 0000.0 000V.0 0000.0 0000.0 00V0.F 0000.0 0000.0 0V00.0 0000.0 0000.0 0r
00.00 00.000 0V.00V 0000.0 000V.0 0000.0 0000.0 00V0.F 0000.0 0V00.0 0000.0 0000.0 0V00.0 00
00.00 00.000 00.00V 0V00.0 000V.0 0V00.0 00000 FOV0.F 0000.0 0000.0 030.0 VV00.0 0000.0 0..
00.00 00.000 00.00V 0000.0 000V.0 0000.0 0000.0 003... 0000.0 0000.0 0000.0 0000.0 0000.0 0..
00.00 00.000 00.00V 0000.0 000V.0 0000.0 0000.0 003... 0000.0 0000.0 8000.0 0000.0 0000.0 00
00.00 00.000 00.00V 0V00.0 000V.0 0000.0 0000.0 0030 0000.0 V0000 0000.0 0000.0 0V00.0 VF
00.00 00.000 00.00V 0V00.0 000V.0 0000.0 0000.0 0VVO.F 0V00.0 V0000 0000.0 0000.0 300.0 0..
00.00 00.000 00.00V 0000.0 000V.0 0VV0.0 0000.0 00V0€ 0V00.0 0V00.0 0000.0 0V00.0 V0000 Ne
00.00 00.000 00.00V 0000.0 0V_.V.0 00V0.0 0000.0 00V0.r 0000.0 0000.0 0000.0 0000.0 0000.0 ..w
00.00 00.000 00.00V 0000.0 000V.0 00V0.0 0000.0 V0004 0000.0 0000.0 0000.0 0000.0 0V00.0 0w
00.00 00.000 00.00V 0000.0 000V.0 0VVo.0 0V00.0 0VVoé 0000.0 0000.0 030.0 0000.0 0000.0 0_
08.00 V0.0..0 00.00V 0000.0 000V.0 0000.0 0000.0 00V0.F 0000.0 0000.0 0000.0 0000.0 0000.0 0—
V0.00 00.000 00.00V 0000.0 000V.0 00V0.0 0V00.0 00V0.F 0000.0 V0000 005.0 0000.0 0000.0 0_
00.00 00.000 00.00V 0000.0 000V.0 0000.0 0000.0 00V0.F 0000.0 0V00.0 V0000 0V00.0 0000.0 0_
00.00 00000 00.00V 0000.0 000V.0 0000.0 0000.0 00V0.r 0000.0 0000.0 0000.0 0000.0 3.000 0—
00.00 0V000 V0.00V 0V00.0 000V.0 0000.0 V0000 00V0€ 0000.0 0000.0 0V00.0 0V00.0 0000.0 V
00.00 0V000 V0.00V 0V00.0 000V.0 0000.0 0000.0 00V0.r 0000.0 0000.0 V0000 VV00.0 0000.0 0
00.00 V0.00 00.00V 0000.0 000V.0 0V00.0 0000.0 00V0.F 0000.0 0000.0 0000.0 0000.0 0000.0 0
V0.00 0_..0_.0 00.00V 0V00.0 000V.0 0000.0 0000.0 00V0.F 0000.0 0000.0 0000.0 0000.0 0000.0 r
_N:OB:0>:OU
o ) . 9 )

m I 0 MM m M . m u . ..

www.mmMmmm 0.88.88

B B B DP D." D D T E..." E E E H

 

53

Table 16. Dimensional Test Results - Fasti

 

00.00

00.000

00.00V

0000.0

0000.0

83.2880

0000. _.

88.2 88.2 88.2 88.2 88.2 8

 

00.00

00.000

00.00V

0V00.0

0000.0

88.2 880

0000. _.

88.2 88.2 88.2 :82 88.2 8

 

V0.00

_.0.000

00.00V

0000.0

0V00.0

S8.%88.~

0.00...

88.2 88.2 9 880882 88.2 8

 

V0.00

00.000

0V.00V

0VOV.0

0000.0

85.2 880

0000. _.

88.2 882 8880882 888— t

 

00.00

00.000

00.00V

0000.0

000V.0

88.2 880

0VVo.—.

882 3.3.2 882 88.2 88.2 8

 

00.00

00.000

00.00V

0000.0

0000.0

85%83

0000. F

88.2 23.2 882 E82 282 2

 

00.00

00.000

00.00V

0000.0

0000.0

88.2 880

00V0._.

88.2 83.87862 88.2 :82 3

 

00.00

00.000

00.00V

0000.0

0000.0

88.2 880

V000. F

:82 :32 858—882 88.2 2

 

00.00

00.000

V0.00V

0000.0

0000.0

28.2 880

00V0. _.

88.2 88.2 888888.8— 882 a.

 

00.00

00.000

00. _.0V

0000.0

0000.0

88.2 88.x.

00V0.?

88.2 :82 88.2 88.2 888— 3

 

00.00

00.000

00.00V

0000.0

0.00.0

88.2 880

V000.?

88.2 88.2 88.2 88.2 88.2 8

 

00.00

0V.000

V0.00V

0000.0

0000.0

88.2 880

0VVo._.

88.2 83.2 888

88888.2

 

00.00

V0.000

00.00V

0000.0

0000.0

88.2 880

00V0...

 

88.2 888

85.2 88.2 28.2

 

P000

0V.000

00.00V

000V.0

0000.0

83%080

0000. P

 

888— E82 2.82 88.8882

 

00.00

0V.000

00.00V

0000.0

0000.0

838.2 880

.000...

88.2 83.2 86.2 888

88.2

 

 

V0.00

00.000

F0._.0V

0V00.0

0000.0

28.2 88.0.

0000. _.

88.2 23.2 88.8— 88.0

88.2

 

0.00

90.000

V0.00V

0000.0

0000.0

0V00.0

 

0000.0

0wV0._.

 

28.2 28.2 88.2 88.2 88.2

 

00.00

V0.000

0V. 00V

0000.0

0000.0

0000.0

0000.0

00V0...

88.2 83.2 88$ 88.0— 88.2

 

00.000

00. _.0V

0000.0

0000.0

88.02880

0000. F

88.2 88.2 88.2 88.2 28.2

 

3.00

 

0_..000

 

0V. 00V

 

0000.0

 

0000.0

 

28.2 88.~

 

00V0. _.

88.2 83.2 83.2 88.2 88.2

 

was".

 

 

BE (9)

 

BF (9)

 

3v (mL)

 

Diam
(PIL)

 

Diam (90°
from PIL)

 

Diam Diff.

 

Diam Avg

 

E (90°
from PIL)
E (PIL)
E Diff.
E Av .

 

 

 

 

 

 

Figure 18. Conventional Wall Thickness 1

     

S16
S13
S10

87 Point

 

55

Figure 20. Conventional Wall Thickness 3

  
 
  
 

Thickness 0.0300

S16
0 513
0.0200 7
Point
8
2' § § E
Figure 21. Fasti Wall Thickness 1
Thickness 00300 S16
813
Point

56

Figure 22. Fasti Wall Thickness 2

   

0. 0600

    

0.0500

 
 
 
 
 

0.0400

  

Thickness 0.0300 S16
313
0.0200 '_
Point

i
i
E
E
i
i
O
§§s§§

 

57

Comgression Test Results

APPENDIX B

Table 17. Compression Test Results - Conventional

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

3 2
g ..
a 3
A v
u
a g i
’1 - .. c
e Z; -' E.
v o a
A U .5 c 3 (I)
z? 3 f. 3 § 2'
F -' E E *- :E
g 2 o .9 w 0
0 ea 8 C a
3 F " .. ° 0
C I: in : ..
0 2 .2 I: o =
E E E 0 g 2
a 'o a
i a 3 =5 2
Conventional
1 26.50 77.5 0.299 50.1 0.116 431.90
2 26.56 76.9 0.299 50.5 0.120 420.83]
3 25.93 70.4 0.304 50.7 0.129 393.02]
4 26.09 71.6 0.295 50.1 0.120 417.50]
5 25.81 67.9 0.295 50.1 0.129 388.37]
6 25.89 68.1 0.295 50.9 0.129 394.57]
7 25.72 68.3 0.304 49.8 0.129 386E
8 25.85 71.0 0.303 50.4 0.129 390.70]
9 25.80 69.6 0.291 50.5 0.124 407.26]
25.88 72.7 0.316 50.9 0.129 394.57]
25.39 70.3 0.295 50.8 0.129 393.80]
25.96 69.6 0.291 51.1 0.124 412.101
25.64 68.0 0.291 49.9 0.124 402.42
26.03 75.4 0.303 50.5 0.120 420.83
25.76 73.8 0.295 50.3 0.120 419.17
25.75 74.3 0.291 50.3 0.120 419.17
25.73 74.1 0.299 50.0 0.120 416.67
25.84 77.5 0.307 51.1 0.120 425.83
25.65 74.5 0.299 49.9 0.120 415.83
25_.§_1_ 73.0 0.299 50.1 0.116 431.90]
fiber 25.8795 72.2 0.2986 50.4 0.123 409.1243]
Is 0.2686 3.2 0.0064 0.4 0.005 14.9418]

 

 

 

 

 

 

 

58

Table 18. Compression Test Results - Fasti

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

3 2

E Z

A V

- E 2 §

13' z; '3 é

a. V 5 ° 2 a”)

:3" E 5 5 9 2’

= _. a 2 g z

% 2 u .9 ‘” 9

z 5 ’6 2 5 8

r: a g (D g E.

E 5 5 2

“a E 35 3 35 a

Q

Fasti

1 28.41 74.7 0.274 60.6 0.170 356.4706
2 28.15 74.2 0.265 59.6 0.166 359.0361
3 28.3 76.7 0.253 60.1 0.149 403.3557
4 28.21 76.6 0.278 61.0 0.166 367.4699
5 28.37 77.9 0.286 60.4 0.162 372.8395
6 28.19 76.5 0.270 60.2 0.149 404.0268
7 28.36 77.1 0.278 59.7 0.157 380.2548
8 28.16 76.5 0.278 60.0 0.157 382.1656
9 28.32 76.3 0.274 60.4 0.161 375.1553
10 28.14 76.0 0.265 60.3 0.162 372.2222
11 28.32 76.3 0.274 60.2 0.157 383.4395
12 28.18 74.6 0.261 62.6 0.178 351.6854
13 28.33 75.6 0.261 60.5 0.166 364.4578
14 28.19 74.9 0.282 59.9 0.166 360.8434
15 28.33 79.6 0.257 62.9 0.178 353.3708
16 28.14 73.8 0.270 60.9 0.174 350
17 28.23 74.8 0.278 60.8 0.161 377.6398
18 28.38 79.4 0.278 61.3 0.161 380.7453
18 28.25 76.6 0.265 60.6 0.166 365.0602
20 28.07 74.2 0.274 59.8 0.161 371.4286
[i‘bar 28.2515 E1" 0.271 60.590 0.163 371.5834
[s 0.098102 1.6 0.009 0.862 0.008 15.09633

 

 

 

 

 

 

 

 

59

APPENDIX C

BEKUM
H-111S

Extrusion Blow Molding Machine

Operations Manual

Contact Dr. Harold Hughes for assistance

This Machine Was Supplied By:

Bekum America
1140 w. Grand River
Williamston, Michigan 48895
(517) 655-4331

60

Bekum Blow Molder Operating Instructions

Service Personnel: John, Lee, Jose (517) 655-4331

These instructions were develomd by School pf Packaging mrsonnelI not

1)

taken from the Bekum Manual

Safety

This machine operates with components in excess of 350 degrees
Fahrenheit and can cause severe burns. While advanced safety
mechanisms prevent pinching accidents, they do not protect you from hot
surfaces, hot plastic, and the sharp cutting knife. Please be careful and stay
out of the Yellow cabinet while the machine is on or still hot. Plastic parts

remain hot even after coming out of the mold.

If extra extrusion or bottles become wrapped around machine components
please do your best to carefully remove them before they set to prevent

malfunctions and messes.

Startup

Retrieve key from electrical cabinet (Large Tan Doors)
a) Unlock Padlock

b) Use Screwdriver to turn catch above door handle
c) Retrieve Key and place in look on front panel

d) Close doors and replace lock

61

i) Note: Electrical power handles must be aligned to “OFF” position to
close doors
2) Turn on Both Power Handles marked “230V“ and “460V”
a) Controller Display will activate and display
i) Model Number
ii) Serial Number
iii) Controller Number
3) Turn on Water Supply on wall marked “Bekum Water"
a) Turn knob Counter-Clockwise to turn on
b) Turn on both yellow water valves inside yellow cabinet to the right of blow
pin
i) Yellow levers will be parallel to pipes when on
c) You will see and hear water running through the system and into the drain
near the wall
4) Use Yellow arrows to move cursor to security code (green box will flash)
a) Type in security code
i) Level 1 — Default: code 1, press [Enter](yellow button)
ii) Level 2 — code 5566, press [Enter]
iii) Level 3 - code 5455, press [Enter]
5) Press button under Blue box Labeled [Main Menu]
a) Displays general information about machine status

6) Press [Temp 1-11 Monitor]

62

a) “SP1”(set point one) temperatures are the required operating
temperatures
7) Pull Red “Emergency Stop” knob out to “On” position
8) Press “Control Power" White button (will light up)
9) Start Hydraulics
a) Red Handle on reservoir (near rear of machine on wall-side) must be
horizontal to start pump.
b) Press Black [HYDR MOTOR ON] Button on control panel

c) You will hear hydraulic pump start up

***CRITICAL: It takes at least 1.5 hours to heat up the machine regardless of
temperature readings. This time is required for heat to soak through plastic in

extruder, which will have solidified in the barrel.

If ou attem tto o erate the machine before this soak-down time on WILL
break the extruder screw causin a lot of dama e! PLEASE be atient.***

10)Watch Temperature monitors to see that all temperatures are up to their
setpoints
a) It takes 1.5 hours for plastic and machine components to heat up
b) It takes around 45 minutes (With the Hydraulic motor running!) to heat up
the hydraulic oil
c) The Flashing Strobe light on top of the machine will stop flashing once the

machine is up to temperature

63

i) The strobe will not indicate if the plastic in the screw is melted

11)Keep resin hopper full to avoid running out of resin. The hopper must be

1)

manually filled. Do not allow debris to enter the hopper, metal shavings will
be sorted out but paper and other items will go through extruder and either

burn or end up in a bottle.

Omration

Manual Operation
a) Note: Security code must be set above 1
b) Turn Key Switch to “MAN” (Manual)
c) Remove the leather cover from the cut knife
d) Turn on Hydraulic Pump
i) Set Red Lever near rear of machine to vertical
e) Press Black [Manual Mode] Key
f) Press key for the function you want to control ([Knife], [Blow Pin],
[Carriage], or [Mold])
i) Key will light green
9) Control the function with the yellow Pendant
h) To change functions
i) Press the key for the function you want to control
(1) Key will light green
ii) Press the key for the function you were previously using

(1) Green light on key will turn off

64

2)

0

Only one function may be used at a time

Automatic Operation (Bottle Making)

a)
b)
C)

d)

9)

h)

l)

k)
I)

Turn Key Switch to “MAN”

Remove the leather cover from the cut knife

Press Black [Manual Mode] Key

Turn on Hydraulic Pump

i) Set Red Lever near rear of machine to vertical

Press [Extruder Start] Key

Press [FWD] on Baldor Motor drive

i) This will start the extruder turning

ii) You will hear some popping or cracking as air escapes, this is ok
Press Yellow key with Up arrow [A] to increase extruder speed to about
“48.00 SCRU”

Trim off extrusion with manual mode knife (cut from right to left) as
extruder comes up to speed

Turn Key Switch to “Auto”

Press Black [Auto Mode] Key

Yellow [Move To Basic] Key will flash, press it

Black [Cycle Start] Key will flash, Press it

m) Bottles will be made

11)
0)

P)

Press red [Cycle Stop] key to stop system
Press Red [STOP] key on Baldor drive to stop extruder

Trim excess extrusion with manual mode knife (cut from right to left)

65

Operating Notes

1) If you must enter the yellow cabinet, pull the door flrrnly and quickly to avoid
shutting off the hydraulic pump and having to reset Red handle to horizontal,
etc.

2) Opening any doors during operation will initiate safety shut-downs. I.E. Pulling
open the yellow cabinet doors during operation will stop all motion in cabinet
and leave you with a mess of melted plastic

3) Formed bottles are HOT and should not be handled immediately after

forming, especially the top and bottom flashing.

m

1) Turn off both Water Supply valves inside yellow cabinet (levers perpendicular
to feed lines

2) Return leather cover to cut knife

3) Turn off water supply knob on wall behind machine

4) Turn off hydraulic motor [HYDR. MOTOR OFF]

5) Return Red Hydraulic Pump lever to Horizontal

6) Press Red “Emergency Stop” Button

7) Turn Key to “OFF”

8) Turn off both Power Handles marked “230V” and “460V”

9) Return key to electrical cabinet (Large Tan Doors)

a) Unlock Padlock

66

b) Use Screwdriver to turn catch above door handle
c) Return Key
d) Close doors and replace lock
i) Note: Electrical power handles must be aligned to “OFF” position to

close doors

67

APPENDIX D

Blow Pin Drawings

Figure 24. Assembly Drawing

 

 

 

0 894.15

03——

04.___

05——

 

 

[11.590]

 

 

06

 

 

RECIRCULATING BLOW-PIN
W

 

 

 

 

 

 

 

 

 

 

__>
rq-—

I 1 r r

DRAWN BY:
KIRK VALKO

 

68

 

Figure 25. Detail 01 - Adaptor

 

Retaining Ring DIN472-15

 

 

 

7/8' - 14

610.5 [0.414]

915 [0.591]
015710.02 [0.619141]! 1

*
‘—

 

 

 

 

34 [1.34OJ-C-
1.5 [0.059]
1/4 NPT

H--—--

—
u_-—-——-d

 

 

 

2.6 [0.102]

 

P
7|

 

‘7
__J

 

‘-——-— 72 [2.837] ———¢-

“-—— 73 [2.876]
‘— 47 [1.852] —-~

‘— 45 [1.773] fil

*- 35 [1.379] 4"-

V

 

 

 

 

—- 30 [1.182]

 

L—o-Lnao x 1.5

20 [0.768]

MATERIAL: STAINLESS STEEL

 

W

 

 

I I necrmmrue BLOW-PIN
I 'r

 

 

 

 

 

 

 

I I l I

DRAWN BY:
KIRK VALKO

 

69

 

Figure 26. Detail 02 - Stem

 

[0.867]

     
   
    
  

021

15 [0.591]
17 [0.670]

    

[0.473]

  

626.4 [1.040]

  

9 [0902]
19812 M

28.5 [1.123]
30 [1.182.]
27 [LW]

19.05 [07513 8259
(0.667]

MATERIAL: STAINLESS STEEL

 

KIRK VALKO

 

 

 

 

I] necmxma BLOW-PIN DRAWN av:
WINE
I I

 

 

 

 

 

 

J 1 l I

 

70

 

Figure 27. Detail 03 - Cooling Sleeve

 

“364 ”'04” —--~ 1629.4 [1.1581-t—

    

 

 

--’-‘ *4 [0.158]

 

 

 

0.5)(45' [0.020]—--‘—
*—40 [1.5761—9"

 

 

 

MATERIAL: STAINLESS STEEL

 

 

 

 

 

 

 

 

 

 

 

 

H Fecncumme BLOW-PIN I DRAWN av:
W 1 KIRK VAlJ<O
I I P T I

 

71

 

Figure 28. Detail 04 - Cutting Ring

 

0.26 [0.010]

Lg].

 
  

 

EDGE

 

l l
l-——-l—¢as.78 [1.016]

—- +4.75 [0.187]

019.05 [0.7511
Section A-A

 

MATERIAL: TDDL STEEL
HARDENED HRC 58+2

 

WWN BY:
KIRK VALKO

 

 

 

I I RECIRCULATING BLOVV-PIN
W
I I

-“l

 

 

 

 

 

 

 

I I l

 

72

 

Figure 29. Detail 05 - Tip

 

  
   
  

    
  

 

   

 

 

 

 

 

 

 

 

 

 

 

 

01 [0.552] M18311
'6
8 n
9; 8 .4
m Efi 9.05 [0.751]
N a 7:;
918.8 [0.741] ‘ f; . [0.861]
814 £05521 1 a 1:, g
'n 3 v1 5’
Q
R s.
D
N
Anen-Hex
101m wrench
/ r
1’40)
1.3 I?)
‘9 $3521.
.0-
MATERIAL: STAINLESS STEEL
I I RECIRCIAATING BLOW-PIN DRAWN BY:
I I W I Kan VALKO
I I F I I

 

 

 

 

 

 

 

73

 

Figure 30. Detail 06 - Pipe

 

FLARE
TUBING
BEFORE

WELDING

 

 

 

   
   
  
 

 

 

 

 

 

 

 

 

/
/ 1-1
... n /fif K B
a) \D / <-
93 .4 S 2'
' m d u
8 3 ... V
6 8 3: mg
m 8 o 60. I 0.1
—= * 014.88 [0.586]
, ‘61234 [0.486]
g ] I \D-Rlng 12x1.5r1n
5 118.77 [0.346]
"- l
a I
—-l ~l-——¢e.71 [0.3431
—-- +877 [0.3033

FLANGE MATERIAL! STAINLESS STEEL
TUBING: MICRDGRDUP F1-344x20 VD SL

 

KIRK VALKO

 

 

 

 

I I I

 

 

 

 

 

I I RECIRCULATING BLOVIV-PIN WWN BY:
W
I
, 1,

 

 

74

 

APPENDIX E

Fasti Setug Exggriment

Effect of Timings and Air Pressure on an Extrusion Blow Molding Process

A 2‘5;1 Factorial Experiment

Introduction

Optimizing an extrusion blow molding machine is a complicated and in depth
process which involves many variables, all of which contribute to the final quality
of the produced part. In packaging it is important to take into consideration the
size of the produced part as it directly affects the capacity of the containers.
Containers are often filled with product using level filling, where a machine
detects the depth of the product in the container. This is the quickest method for
filling and gives the customer the most satisfaction seeing that each container is
filled to the same amount. However, a more accurate approach is to fill a
container by volume, making it much easier for the producer to meet legislation
requiring a product be filled within certain tolerances of the stated capacity. In
order to maintain container volume and account for shrinkage of the container
after leaving the mold, we must develop a machine setup which minimizes

shrinkage and maintains consistency between containers.

75

Experimentation

The experiment involves 5 two-level factors in a 23" factorial design.

The Factors are as follows:

A: Fasti Delay — The amount of time the bottle is given to inflate in the mold
before cooling operation starts.

B: Back Pressure - The amount of internal pressure maintained in the bottle
during the cooling process

C: Blow Time — The amount of time the air is blow into the bottle to maintain
contact with the mold and cool from the air

D: Exhaust Time — The amount of time that the bottle is given to sit in the mold to
finish setting without pressurization

E: Air Pressure — The amount of air pressure being blown into the container for

cooling

Response Variable: Container volume measured by weighing the empty bottle,

filling the bottle with water, weighing it full and then calculating the volume in mL.

Each of the 16 experiments was run with 3 repetitions giving a total of 48 data

points. Each run was done in random order with the appropriate machine

settings adjusted for the new run.

76

Data Analysis

Figures 31, 32, and 33 are effects plots for the experimental data. The estimated
effects are in line with expectations. Blow Time (C) and Air Pressure (E) are the
variables which have the most effect on bottle shrinkage. As blow time
increases, bottle volume increases. This is due to the extended amount of time
the plastic has to cool and therefore set to counteract shrinkage. As blow
pressure increases, bottle volume also increases. This is due to the increased
air flow created by the higher pressures. The more air that passes through the
bottle, the faster the container will cool therefore setting the bottle shape and

counteracting shrinkage.

It is also seen that Factors A, B, and D have small main effects on the bottle
quality. The estimates of main effects and the interactions CD and CE discussed
below suggest that Factors C and E should be set at their high values with
Factors A, B and D set at their low values for the optimal setup (to maximize
volume). With Fasti delay and Exhaust time set low, we are able to shave nearly
1 second off of the total cycle time. Also the lower back pressure allows more

transfer of air inside the container allowing faster cooling.

The significance of the CD and CE interactions is unknown. These are small
effects compared to the main effects of C. I believe that blow time may cause
instability on the air pressure in the container. By rights exhaust time should

have little effect on the bottle properties especially since the time is so short.

77

These interactions are likely magnified by the intensity of the effect that blow time

has on container volume.

78

Figure 31. Main Effects Plot for Factors

93’" 58°39 2° 95° 999556 98°38 9°

 

 

Results

__________ /
.///

 

 

 

 

 

 

 

 

Fasti Back Blow Exhaust Air
Delay Pressure Time Time Pressure

Figure 32. Normal Probability of Factors

 

 

 

 

 

. C
. E
9
8
U)
'6
5
0
Z
5 1'0
Standardized Effect

79

Figure 33. Plots of Interactions Between Factors

 

A B C D g
Fasti Delay /,«' ..
-1.5 g:_,__._.—-o """ I /’ 3.13:4 ~ 5""
o0.85

 

Back Pressure

-20 x’ M” "’T
l’

 

 

 

 

o 15
Bloleme “an“ ._ ..... .
Exhaust Time ..
-0.5 Vet—’5’:
. 0.35
Air Pressure
- 75
° 85

 

 

 

 

 

80

 

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81

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82

 

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