THERMOFORMING High Density Polyethylene sheet using Temperature-CONTROLLED ALUMINUM TOOLING - PowerPoint PPT Presentation

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THERMOFORMING High Density Polyethylene sheet using Temperature-CONTROLLED ALUMINUM TOOLING

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Prove that HDPE can be a relevant material to use in thermoforming, instead of just amorphous materials. Get project results by spring break, ... – PowerPoint PPT presentation

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Title: THERMOFORMING High Density Polyethylene sheet using Temperature-CONTROLLED ALUMINUM TOOLING


1
THERMOFORMING High Density Polyethylene sheet
using Temperature-CONTROLLED ALUMINUM TOOLING
  • Brett Braker
  • MET496
  • April 28th, 2011

2
Individual Performance Objectives
  • Show the importance of temperature-controlled
    molding in thermoforming.
  • Prove that HDPE can be a relevant material to use
    in thermoforming, instead of just amorphous
    materials.
  • Get project results by spring break, one week
  • Create a lab for future curriculum

3
Purpose
  • Almost all of thermoforming industry uses
    amorphous materials
  • Use molds that are not temperature-controlled
  • Material options Better quality parts

4
Material
  • 50 High Density Polyethylene sheets
  • 22.5 (MD) x 40 (TD) x 0.125
  • Levant finish on top, smooth bottom
  • 285-385F forming temp, 330F optimum
  • 170F ejection
  • Density 0.0345 lb/in3 (0.955 g/cc)
  • 66.3 Shore D hardness
  • Ultimate Tensile Strength 3,800 psi
  • Tensile Yield Stress 3,829 psi
  • Deflection temp with 66 psi 166.5F

5
Grid Layout
  • Original Idea
  • Penn College Printing Department
  • Pat Bundra
  • Screen Printing

6
Non Temperature-Controlled Mold
  • Renshape 472 Medium Density Polyurethane Board
    (REN)
  • Wooden base, machined Polyurethane core
  • Exact same dimensions as aluminum mold
  • 15.25 x 33.125 x 4.2

7
Renshape Cycle
  • Bottom platen
  • Material Build-up
  • Stretching
  • Material Properties

8
Renshape Cycle
9
Renshape Cycle
  • Top platen
  • Machine settings

10
Renshape Cycle
  • Perfect cycle
  • Rails too close
  • Mold too deep
  • Ovens too hot

11
Production-Style Run
  • 10 parts
  • Continuous cycle
  • Measurements
  • Temperatures
  • Aluminum Jig
  • Thicknesses
  • 2 minutes after forming
  • 24 hours after forming

12
Temperature Measurements
  • Mold
  • Front
  • Top
  • Back
  • Sheet temp before and after forming
  • Room temperature
  • Humidity
  • All taken with infrared gun

13
Aluminum Jig Measurements
  • 15.875 x 33.500
  • Corner 3-4
  • Height
  • 5.562
  • 5.562 x h
  • Jig thickness
  • Aluminum blocks
  • Meter stick height
  • Dial calipers

14
Thickness Measurements
  • Drill with hole saw attachment
  • 1-inch holes
  • Left, Right, Front, Back, and Top of part
  • 2 minutes Left side
  • 24 hours Right side
  • Discs
  • Dial calipers

15
Measurement Formulas
  • After jig measurements
  • Match corresponding points (1-8, 6-3, 5-9, etc.)
  • Take combination of both and subtract from jig
    dimension
  • Y1 15.875 (0.1025 0.4865)
  • Y1 15.2860
  • Points show warpage
  • Y1 shows shrinkage

16
Renshape Mold Production
  • I.R. eye 370F
  • Heating 120 seconds
  • Cooling 180 seconds

17
Renshape Production Results
18
Renshape Production Results
19
Renshape Production Results
20
Renshape Production Results
21
Aluminum Mold Production
  • I.R. eye 370F
  • Changed to 360F before Sheet 5
  • Cooling time 100 seconds
  • Changed to 120 seconds before Sheet 4
  • Changed to 150 seconds before Sheet 5
  • Changed to 130 seconds before Sheet 7
  • Changed to 120 seconds before Sheet 8
  • Changed to 110 seconds before Sheet 9
  • Circulator temp 200F

22
Aluminum Mold Production Results
23
Aluminum Mold Production Results
24
Aluminum Mold Production Results
25
Aluminum Mold Production Results
26
Renshape vs. Aluminum
27
Renshape vs. Aluminum
28
Renshape vs. Aluminum
29
Renshape vs. Aluminum
30
Renshape vs. Aluminum
31
Renshape vs. Aluminum
32
Design Of Experiment
33
Design Of Experiment
34
Renshape Tensile Testing
35
Aluminum Tensile Testing
36
Renshape vs. Aluminum
37
Conclusion
  • Temperature-controlled aluminum tooling shows
    much more consistency with HDPE than Renshape
    does.
  • Much less warpage, shrinkage, and higher
    dimensional stability as a result
  • HDPE needs a temperature-controlled mold to be
    deemed relevant in the thermoforming industry.

38
Individual Performance Objectives
  • Show the importance of temperature-controlled
    molding in thermoforming.
  • Prove that HDPE can be a relevant material to use
    in thermoforming, instead of just amorphous
    materials.
  • Get project results by spring break, one week
  • Create a lab for future curriculum

39
References
  • Defosse, Matthew. "Thermoforming." Modern
    Plastics Worldwide World Encyclopedia 2006. Los
    Angeles, CA Canon Communications, 2006. 106.
    Print.
  • Harper, Charles A. Handbook of Plastic Processes.
    Hoboken, NJ Wiley-Interscience, 2006. Print.
  • Illig, Adolf, and Peter Schwarzmann. Thermoforming
    A Practical Guide. Munich Hanser, 2001. Print.
  • Peacock, Andrew J. Handbook of Polyethylene
    Structures, Properties, and Applications. New
    York Marcel Dekker, 2000. Print.
  • "Sheet/Thermoforming Grade HDPE." www.matweb.com.
    Material Property Data. Web. lthttp//www.matweb.co
    m/search/DataSheet.aspx?MatGUIDc35a0a3e740e424fad
    260a5da2c2b50ackck1gt.

40
Acknowledgements
  • John Bartolomucci, Pennsylvania College of
    Technology
  • Patrick Bundra, Pennsylvania College of
    Technology
  •  
  • Todd Chrismer, McClarin Plastics
  •  
  • Todd Kennedy, McClarin Plastics
  •  
  • Roger Kipp, McClarin Plastics
  •  
  • Aaron Lapinski, Pennsylvania College of
    Technology
  •  
  • Gary McQuay, Plastics Manufacturing Center

41
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