Thermoforming Mold Comparison: Temperature vs. Non -Temperature Controlled Molds

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Thermoforming Mold Comparison Temperature vs.
Non -Temperature Controlled Molds

• Aaron Lapinski

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Purpose

• To prove to Industry that using a temperature
  controlled mold helps improve cycle consistency
  and part dimensions

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Goals

• To determine how a temperature controlled
  aluminum mold and non-temperature controlled Ren
  Shape mold of the same dimensions will affect
  shrinkage of a thermoformed ABS part.
• To gain experience on the set up and operation of
  the industrial scale MAAC thermoformer
• To develop a thermoforming lab experiment on the
  MAAC thermoformer for student education in
  Pennsylvania College of Technologys BPS program.
• To demonstrate to the thermoforming industry that
  a temperature controlled mold is essential for
  maintaining consistency in the finished product.

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Equipment

• MAAC Thermoformer
• REN Mold
• Aluminum temperature controlled mold
• Circulator
• Sterlco VISION 4410-C
• 250F max temp

  Hardness Density Density Tensile Compressive Compressive Modulus Flexural Flexural Glass Coefficient Color
  g/cc lbs/ft.3 Strength Strength Elasticity (psi) Strength Modulus Trans. Thermal Color
        psi psi   psi psi Temp (F) Expansion Color
                    (in/in/F) Color
Ren Shape 472 81 0.88 55 7,000 10,900 460,000 9,540 416,000 248 25.8 x 10-6 Lt. Gray
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Material

• Spartech ABS
• Amorphous Terpolymer
• .125 x 40 (W) x 22.5 (L) inches
• Premium Grade
• Natural
• Polished Finish

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Optimum Settings

• Sheet temperature 285-400of
• 340oF
• Circulator settings 175-215oF
• 200oF
• De-molding temperature
• 180-190oF

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Procedure

• Dry ABS
• 180F
• 24 hours
• Hang the Mold
• Placement
• Center
• Form parts
• Collect Dimensions
• Perform Mechanical Testing

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Operating the MAAC

• Turn on Main Power
• Turn on Air
• Turn on Vacuum
• Turn on Fume Hood
• Enter MAAC software PC62
• Log in
• Load or Build Program
• Choose set up
• Turn on Vacuum Pumps and Oven
• Index Clamps into Oven on Diagnostics screen

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Operating the MAAC Continued

• Remove preheated clamps from oven
• Open clamps
• Place sheet
• Start cycle

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Trials

• Ren Shape Mold Production Trial
• Aluminum Mold Production Trial
• DOE

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REN Mold Process settings

• Timers
• Ovens
• Encoders
• I.R. Eye
• MAACFlex

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Aluminum Mold Process Settings

• 380F
• 55 Second Forming Time

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Thermal Conductivity

• Aluminum Mold
• 144.447 Btu (IT) foot/hour/square foot/F
• Ren Shape or Polyurethane
• 0.011556 Btu (IT) foot/hour/square foot/F.

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Temperatures

• Humidity
• Room Temperature
• Mold Temperatures
• Front
• Back
• Top
• Clamp Temperature
• Sheet Temperature
• De-molding
• Molding

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Measurements
Jig Dimensions Jig Dimensions
Y Direction (MD) 15.875
X Direction (TD) 33.500
B 8(Y1) 7(Y2) 7(Y2) 6(Y3)

9 (X2) 5 (X2)
10 (X1) 4 (X1)

F 1(Y1) 2(Y2) 2(Y2) 3(Y3)
Mold Dimensions Mold Dimensions
Y Direction (MD) 15.25
X Direction (TD) 31.125
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REN Part Width vs. Aluminum Part Width
Mold Dimensions Mold Dimensions
Y Direction (MD) 15.25
X Direction (TD) 31.125
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REN Part Length vs. Aluminum Part Length
Mold Dimensions Mold Dimensions
Y Direction (MD) 15.25
X Direction (TD) 31.125
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Thickness
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REN Mold
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Aluminum Mold Temperature
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DOE
  High Low
Cooling Time 100 40
Circulator Temp 205 170
I.R. Eye Temp 400 340
Run Cooling Time Circulator Temp I.R. Eye Temp
1 - - -
2 - -
3 - -
4 -
5 - -
6 -
7 -
8
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Testing Equipment
23
Testing Results
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Defects

• Holes
• Stuck to mold

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Project Cost
cost/hr () of hours Number of sheets cost per sheet
Material Cost n/a n/a 75 40.00 3,000.00
Mentor 50 20 n/a n/a 1,000.00
Consultant 50 10 n/a n/a 500.00
Labor 18 100 n/a n/a 1,800.00
Thermoformer cost 100 85 n/a n/a 8,500.00
Testing Equipment 100 15 n/a n/a 1,500.00
REN Mold Cost n/a n/a n/a n/a 3,800.00
Aluminum Mold Cost n/a n/a n/a n/a 7,500.00
Total cost Total cost 27,600.00
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Benefits

• More Predictable dimensions
• Higher mechanical properties
• Shorter cycle times
• Forming time from 100 to 55 seconds

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Cost Savings
  Ren Shape Aluminum
Heating Time (seconds) 120 120
Forming Time (seconds) 100 55
Ejection Time (seconds) 2 2
Remove and load next part 30 30
Total (seconds) 252 207
Time saving (seconds)/Part 45 45
Time saving (seconds) /24 hour day 1080 1080
Extra Parts/day 4.3 4.3
Extra Parts/ 5 day week 21.4 21.4
Extra Parts/20 day month 85.7 85.7
Extra Parts/50 week year 1071.4 1071.4
Cost () / Sheet 40.00 40.00
Extra Production / Year () 42,857.14 42,857.14
REN Mold Cost 3,800.00 3,800.00
Aluminum Mold Cost 7,500.00 7,500.00
Total Profit 39,157.14 39,157.14
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Obstacles

• Lack of Knowledge
• Measurement Device
• Drying
• Grids
• Mold Position
• Circulator
• Machine access

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Individual Performance Objectives

• To determine how a temperature controlled
  aluminum mold and non-temperature controlled Ren
  Shape mold of the same dimensions will affect
  shrinkage of a thermoformed ABS part.
• To gain experience on the set up and operation of
  the industrial scale MAAC thermoformer
• To develop a thermoforming lab experiment on the
  MAAC thermoformer for student education in
  Pennsylvania College of Technologys BPS program.
• To demonstrate to the thermoforming industry that
  a temperature controlled mold is essential for
  maintaining consistency in the finished product.

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Acknowledgements

• Mr. Roger Kipp
• Mr. John Bartolomucci
• Mr. Gary McQuay
• Mr. Howard Troup
• Mr. Todd Kennedy
• Mr. Todd Crismer
• Mr. Brett Braker
• Mr. Chris Denmon
• McClarin Plastics Inc.
• Spartech Plastics
• Tooling Technology
• KYDEX LLC.

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References

•  
• "Acrylonitrile, Butadiene and Styrene (ABS) -
  FormTight Plastic Thermoforming." Custom
  Packaging - Clamshells, Food Packaging, Blister
  Packaging - FormTight Plastic Thermoforming. Web.
  27 Oct. 2010. lthttp//www.formtightinc.com/materia
  ls/ABS/default.htmlgt.
•  
• "Acrylonitrile Butadiene Styrene." Wikipedia, the
  Free Encyclopedia. Web. 27 Oct. 2010.
  lthttp//en.wikipedia.org/wiki/Acrylonitrile_butadi
  ene_styrenegt.
•  
• "Acrylonitrile-butadiene-styrene Copolymer (ABS)
  (chemical Compound) -- Britannica Online
  Encyclopedia." Encyclopedia - Britannica Online
  Encyclopedia. Web. 27 Oct. 2010.
  lthttp//www.britannica.com/EBchecked/topic/4259/ac
  rylonitrile-butadiene-styrene-copolymergt.
•  
• "ASTM D638 - 10 Standard Test Method for Tensile
  Properties of Plastics." ASTM International -
  Standards Worldwide. Web. 24 Apr. 2011.
  lthttp//www.astm.org/Standards/D638.htmgt.

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Questions?