1. Technoform – For Rapid, Repeatable
Thermoformability Analyses
Dr. Amit Dharia
Transmit Technology Group, LLC, TX
www.transmit-technology.com

2. Outline
® Properties –Thermoforming Process
relationship
® Current test methods
® Description of Technoform
® Application and data interpretation
® Products – Basic, Standard, Advanced
® Conclusion

3. Thermoforming Process
® Extruding sheet stock
® Heating sheet above Tg
® Stretching heated sheet in rubbery state
® Cooling
® Trimming
® Finishing

4. Structure - Properties -
Thermoformability
® Rate of change of strength with the
change in strain rate at forming
temperature
® % Crystallinity – Breadth of rubbery
Plateau
® Molecular weight, Molecular weight
distribution, molecular architecture
(branching, crosslinking) – MFR, Melt
Elasticity

5. Other parameters
® Density - % filler, type of fillers, degassing
® Geometry – Thickness, area, multi-layered
structures, adhesion between layers
® Residual stresses between and within in
extruded layer sheet stock
® Thermal diffusivity (Cp, K. Rho)
® Extrusion quality ( gels, unmelts,
thickness variation, grain patterns)
® Color (IR absorption)

6. Current tests
® Low shear melt viscosity (MFR, RMS)
® Melt Tension (Draw Force –Melt
tension, Break Velocity -extension)
® Sag Test (sag distance, sag time)
® Hot Creep Test
® DMA (Relaxation time)

7. Major disadvantages of current
methods
® Most tests are conducted in melt or near melt
phase
® Test Specimens does not reflect actual test
geometry (shape, size, clamping mode)
® Tests does not account for orientation, thermal
stresses, thickness variations
® Isothermal environment, does not account for
transient nature of heating/ cooling
® Effects of secondary process parameters can not
be evaluated
® Results cannot be directly used.

8. What processors want to know?
® Will this material thermoform?
® Will this new material process the same?
® Will this lot process the same as the last one?
® Why this lot does not process the same?
® How much time is needed to heat the sheet?
® How fast material will heat?
® What is the right forming temperature range?
® Will melt adhesion between layers survive
heating and stretching step?
® Will material discolor, fed or degrade during
heating?

9. What processors want to
know? -II
® What is the maximum draw down?
® How fast part can be made?
® What is the MD and TD shrinkage?
® Will material tear at the corners and ribs?
® How much regrind can I use?
® Will grains retain shape and depth?
® Does extruded sheet have gels or
unmelts?

10. What Industry Needs?
® A standard test method which reflects all unit
steps – heating, 3D stretching, forming, and
cooling
® A test equipment which can be precisely
controlled, is rapid, easy to use, provides
repeatable and quantitative information, using the
lease amount of material.
® Easy to use “Thermoformability Index” standard
for comparing, contrasting effects of selected
process/ material variables

11. TECHNOFORM TM
Patent PendingTTG
TECHNOFORM

12. Schematics of Technoform
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13. Typical Data input
® Mode of operation – Plug Assisted, Vacuum
® The heating element distance from the sheet
surface
® The heating element temperature
® The sheet temperature
® Heat Soak time at given temperature
® Plug velocity (2 to 200 mm/second)
® Plug Delay Time
® Plug Temperature
® Part Cooling time

14. Typical user Input Screen
Sag Distance
Thinning
Strain
hardening
Forming Depth mm
Thermoformability Index=
slope

15. Typical Data Output
® Heating rate (Delta C/ time) = f (thickness)
® Sag distance
® Forming force (Stress) vs. forming
distance (strain)
® Forming Force vs. time
® Yield force
® Forming force vs. actual temperature
® Shrinkage (manual measurements)

16. Effect of Heating time
Force vs. Depth (180 C, Isothermal)
4" dia hemi-spherical plug, 20 ipm
(effect of pre-heat time)
0
10
20
30
40
50
0 20 40 60
Depth, mm
Force,lbs
10 min
15 min

17. Plug Material and Shapes
® Truncated cone with flat end (2.5” Top
D, 0.75 “ Bottom D, 4” Height)
® Truncated cone with Rounded End (2.5”
Top D, 1” D bottom, 4” Height)
® Hemisphere of 3.5” Diameter
® All tools made of Foam Epoxy

18. Effect of Plug Temperature
35 Mil Black HIPS, 130 C,40 mm/s
- No control -
0
2
4
6
8
10
12
0 50 100 150
Draw Depth, mm
Force,Lbf
Series1
Series2
Series3

19. Effect of controlling Plug Temperature
HIPS, 40 mm/second with T control
HIPS @130 C, 40 mm/second
Plug cooled for five minutes
0
2
4
6
8
10
12
0 20 40 60 80 100 120
Depth, mm
Force,Lbf
#1
#2
#3
#4

20. Effect of Plug Geometry
Force vs. Depth 180 C, 40 mm/s
Hemi-Spherical Plug with 4 " Diameter
0
5
10
15
20
25
30
35
0 10 20 30 40 50
Depth mm
Force,lbsf
1
2

21. Effect of plug material
HIPS, 170 C, 40 mm/second, 35 mil
0
1
2
3
4
5
6
0 20 40 60 80 100 120
Depth (mm)
Force(lb)
WF WFT Bix

22. Effect of forming Speed on HDPE @ 150 C
Effect of Forming Speed on HDPE
0
2
4
6
8
10
0 50 100 150
Distance (mm)
Fromingforce(N)
20 mm/sec
30 mm.sec
50 mm/sec

23. Heating rates for various plastic materials
(Heater at 600 C, 3” from upper, 2” from lower)
30
80
130
180
230
0 20 40 60 80
t (seconds)
T(c)
PP
HDPE
HIPS
PVC
ABS
Acetal
PMMA
Nylon

24. Effect of Crystallinity
0
5
10
15
20
25
30
50 70 90 110 130
Forming distance, mm
Force(N)HDPE PP HIPS PETG ABS PMMA PVC

25. Comparison of various PE
LDPE, LLDPE, MDPE @ 60 mm/s
0
5
10
15
20
25
30
35
0 20 40 60 80
Depth, mm
Force,lbf
LDPE120
LLDPE120
MDPE120

26. Effect of Forming Temperature
0
2
4
6
8
10
12
14
125 145 165 185
Temperature (C)
Force(N)
ABS
PP
HDPE
HIPS
PETG
PMMA
ACETAL

27. Force100 = f (T, V, material)
® F(ABS) =9.2348 -0.0547 T (R2 =99%)
® F(PMMA)=7.1587 -0.0341 T(R2=98%)
® F(PETG)=10.096 -0.0601 T (R2=92%)
® F(HIPS)=9.6782 - 0.0503T(R2=93%)
® F(HDPE)=5.2771 -0.0266 T (R2=86%)

28. Effect of Thickness
PC/ABS, 40 mm/sec, 200 C
0
1
2
3
4
5
6
7
8
9
0 20 40 60 80 100
Depth (mm)
Froce(lbf)
95 150 250

29. Lot to lot variation in TPO
170 C, 40 mm/second, 190 mil
0
1
2
3
4
5
6
7
8
9
10
0 10 20 30 40 50 60 70
Depth (mm)
Froce(lbf)
1-1 1-2 1-3

30. Effect of Color
Co PP, 160 C, 40 mm/second, 35 mil
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0 20 40 60 80 100 120
Depth (mm)
Force(lb)
0
2
4
6
8
10
12
blue red Metallic

31. Effect of thickness on the Heating Rate
0
50
100
150
200
250
0 500 1000
time (sec)
Surface
Temperature(C)
100 mil 150 mil 250 mil

32. Effect of % Regrind on formability TPO
20% regrind / Five Successive Extrusions
0
1
2
3
4
5
6
40 60 80 100 120
Forming Distance, mm
FormingForce,Lbf
1st
2nd
3rd
4th
5th

33. Effect of % Regrind in FR-ABS
0
2
4
6
8
10
12
14
0 20 40 60 80 100
Depth (mm)
Froce(lbf)
50% RG 100% RG

34. Comparison of filled vs. HMS-TPO
0
10
20
30
40
50
0 20 40 60 80 100
Distance (mm)
Force(N)
40HMSTPO 20HMSTPO
40 FTPO 20FTPO

35. Effect of adding HMSPP in PP
0
1
2
3
4
5
6
7
40 60 80 100 120 140
Form ing Dist ance, mm
FormingForce,Lbf
10%H MSPP 20%HMS PP 30% HMSPP
0
1
2
3
4
5
6
7
40 60 80 100 120 140
Form ing Dist ance, mm
FormingForce,Lbf
10%H MSPP 20%HMS PP 30% HMSPP
0
1
2
3
4
5
6
7
40 60 80 100 120 140
Forming Distance, mm
FormingForce,Lbf 10%HMSPP 20%HMSPP 30%HMSPP

36. Formability of HMSPP/PP Blends
0
2
4
6
8
10
12
10 20 30
%HMSPP
thickness(High/Low)

37. Comparison of Test Methods
Relaxation Time (s) Vs. Force @ 75 mm depth
R2
= 0.9968
0
2
4
6
8
10
12
0 2 4 6 8
Relaxation Time (sec)
FormignFroce(75mm)
PP, 165 C
HDPE,140C
HIPS,160 C

38. Processing window for E-3500
170 C, 40 mm/s, 190 mil
0
10
20
30
0 20 40 60 80 100
Depth (mm)
Force(lbf)
170 180 190 170TPO

39. Technoform Features
Basic Standard Advanced
Fixed heaters, 120 V Manual Adjustment Automated
Adjustment = F
(thickness, material)
Fixed Watt Fixed Watts Close loop
Chamber at Ambient Chamber T control Chamber T control
Speeds 0-120 mm/s 0-200 mm/second 0-200 mm/second
Plug T @ ambient Plug T @ ambient Plug T Controlled
Plug mode only Plug and Vacuum Plug and Vacuum
No Vacuum mode No Vacuum vs. depth Vacuum vs. Depth
record
Basic software Basic Software Advanced features

40. Conclusions
® Technoform is a simple to operate test
equipment is which closely reflects all unit
steps of the typical thermoforming
process and generates quantitative and
repeatable information in short time.
® The test data can be used in raw form to
compare or contrast various materials,
process parameters or can be further
modeled as a design or predictive tool.