Heating injection thermoset molds in a uniform manner to achieve near isothermal mold face conditions is a critical requirement for dimensionally sensitive engineered products. This presentation will highlight a case study that will address a technologically advanced heating system which provides near isothermal mold face conditions in conjunction with rapid thermal energy throughput. This system offers faster overall molding cycles,more consistent product performance outcomes, simplified maintenance and reduced downtime.

1. Acrolab
Energy Transfer Systems
for
Thermoset Injection Molds
Joe Ouellette
Chief Technology Officer
Acrolab Ltd.
Advanced Thermal Engineering Research & Development
Products and Services
1/31/2011 © Acrolab 2011
1

2. Overview
Heating injection thermoset molds in a uniform manner
to achieve near isothermal mold face conditions is a
critical requirement for dimensionally sensitive
engineered products.
This presentation will highlight a case study that will
address a technologically advanced heating system
which provides near isothermal mold face conditions in
conjunction with rapid thermal energy throughput. This
system offers faster overall molding cycles, more
consistent product performance outcomes, simplified
maintenance and reduced down time.
1/31/2011 © Acrolab 2011
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3. Case Study #1: Headlight Housing
 Automotive headlight
reflector housings present
a particular challenge in
injection thermoset mold
processing.
 The following presentation
will specifically deal with
these types of molds.
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4. Thermoset headlight reflector bodies/ headlight assembly
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5. Acrolab - Advanced heating system methodology
The heating system consists of a matrix of heatpipes
embedded in the mold inserts incorporating the working faces
of the mold. The mass energy input for the mold is provided
through a series of distributed watt density cartridge heaters
located remote from the mold face.
These heaters interact with the heatpipe matrix to provide a
uniform thermal energy transfer to the mold face.
Thermocouples mounted proximate to the mold face control
power to the heaters. A unique heated mold component
provides heat to the sprue cone to decrease the cure time of
the sprue.
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6. Acrolab – Advanced energy transfer system
Integrally Heated Heaters
Sprue Spreader Pin
Thermocouples
Heatpipes
Sprue Spreader
extension
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7. System Components
Distributed watt density cartridge heaters
Type J adjustable bayonet thermocouples
Integrally heated Sprue Spreader c/w thermocouple
Isoball® heat pipes
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8. Component Features and Benefits
Distributed Watt Density Cartridge Heaters
Cartridge heaters are of a swaged construction to permit the most
efficient transfer of heat to the O.D. of the heater
The pitch of the winding within the element is increased at each end to
provide a linear thermal output over the length of the heater.
Uniform Temperature
Temp
Length
Cartridge Heater
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9. Component Features and Benefits
Standard Heater
Linear pitched winding with the standard cartridge results
in a nonlinear heat output with 50% of the energy of the heater
being generated in the center 33% of the heater length.
Temp DT
Length
Cartridge Heater
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10. Component Features and Benefits
Distributed Watt Density
Distributed wattage
pitched windings
Cartridge Heaters
Normal pitch
windings
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11. Component Features and Benefits
Type J adjustable bayonet thermocouples
Adjustable thermocouples (TCs) are installed in proximity to
the mold face.
TCs are installed in pairs to provide an on board
replacement in the event of TC failure.
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12. Component Features and Benefits
Type J adjustable bayonet thermocouples
Spring Loaded
Type J
Ungrounded Thermocouple
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13. Component Features and Benefits – Isosprue™ Spreader
Integrally heated Sprue Spreader and onboard
thermocouple
Using a proprietary process, the Heated Sprue Spreader Pin is
constructed as a swaged distributed wattage heater integrally heated and
controlled with its own on board replaceable TC.
The heated sprue pin now actively cures the sprue while directing the
resin to the runners and gates.
Typically the resin sprue is the thickest cross section and takes the longest
time to cure.
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14. Component Features and Benefits – Isosprue™ Spreader
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15. Component Features and Benefits – The Isoball™
Ball Radiused Heatpipes
Heatpipes are super thermal conductors which
transfer energy at rates in excess of 10,000
time the speed of metals.
Heatpipes are isothermal devices that do not
require electrical power.
Ball radiused heatpipes are designed to be
installed in holes with matching ball radii. The
radii prevent stress cracks from forming.
A matrix of heatpipes draw energy from a
remote bank of heating elements and uniformly
transfer that energy to the mold face.
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16. Component Features and Benefits – The Isoball™
Heatpipe Function Schematic
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17. Heating System Methodology
 The next graph shows the time to steady state and the
magnitude of that thermal steady state for one inch diameter
by six inch long bars of various materials as well as an
Isoball™ heatpipe of the same geometry.
 All bars were uninsulated and oriented vertically on a
temperature controlled hot plate maintained at 350º F.
Thermal bridging compound of the type used in installing the
heating system was used to bridge the gap between the hot
plate and the end of the bars.
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18. Isoball™ heatpipe vs. various metal bars of common geometries
Thermal Transients to Steady State
230
220
210
200
190
180
170
Temp. (deg. F)
Temp° F
160
150
140
Isobar-Top
130
120 Copper rod-Top
110
Steel rod-Top
100
90 Alu. Rod-Top
80
70
0 5 10 15 20 25 30 35 40 45 50 55 60 65
Time (minute )
Time
[min]
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19. Heating System Methodology
 Historically each of
these materials have, at
one time or another,
been installed in
hardened inserts to
promote rapid heat
transfer.
 The heatpipe achieved
the highest level of
thermal steady state after
the shortest interval.
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20. Heating System Methodology
 Of particular note, all of the metal bars with the exception of
the heatpipe demonstrated a significant delta T from end to
end both during the transient to steady state and at steady
state.
 The heatpipe remained Isothermal during both the transient
and at steady state.
 The difference between the steady state temperature of the
heatpipe and the temperature of the hot plate is due to losses
to the atmosphere.
1/31/2011 © Acrolab 2011
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21. System Design
Core and Cavity
Left and Right hand – “theoretical headlamp reflector mold”
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22. Heating System Methodology
 Every heating system is custom engineered to insure the
matrix of heatpipes is optimally developed to provide heat
energy uniformly to the mold working faces based on the
geometry of the part being molded.
 A remotely located heater bank is situated either within the
mold inserts, within the holder block or within the holder block
backing plate.
 In all instances these heaters are positioned to thermally
integrate with the heatpipe array so that all the energy
generated is redistributed at high speed by the heatpipes.
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23. Heating System Methodology
 When design considerations require that the heaters are not
integral with the inserts, heatpipes are designed with lengths
to bridge the thermal break which occurs at the mating
surfaces of the inserts. Heatpipe lengths extend to permit
close proximity with the remote heaters.
 Heatpipes incorporate a spherical radiused end to mate with
a spherical radius at the bottom of all installation holes. This
assures no stress cracking and places the thermodynamic
action for the heatpipe closest to the mold face.
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24. Heating System Methodology
 When heaters are installed within the inserts, their length is
defined by the insert. Spacers are installed at either end of
through holes that line up with the insert heater holes. These
spacers position the heater within the insert.
 In all cases, heaters are installed in through-holes to permit
extraction via push rods if necessary.
 All heaters are wired to local terminal blocks mounted in the wire
channel. The wiring harness is attached to these terminal blocks
and resides permanently in the mold.
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25. Heating System Methodology
 Thermocouples are mounted through the back plate of the
tool and are wired to local terminal blocks. All control zones
have both an active thermocouple and a spare, both wired to
the wire harness.
 The terminations for the thermocouples can be found in the
terminal box for each half of the mold.
 If a thermocouple fails, its spare can be connected to the
control system by jumpering to the spare terminals.
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26. Example:
Heatpipe Matrix
in a
cavity insert
[prior to insertion]
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27. System Design
Core insert Isoball™ heatpipe array
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28. System Design
Cavity insert Isoball™ heatpipe array
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29. Heating System Methodology
 The isoball™ heatpipe matrix is custom engineered to
assure that the whole insert is dynamically responsive to
temperature changes and reactive to thermal throughput
demands.
 The next slide shows an acceptable and unacceptable
array configuration.
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30. System Design
Detailed view: Heatpipe Matrix
ARRAY DESIGN FOR Ø5/8
3.875
1.875 1.875
3xØ 3xØ
1.875 1.624
3.875 2.6xØ
3xØ
1.875
1.875 3xØ
3xØ
2.652
2.652 6.8xØ
6.8xØ
Additional Cooling Required
Non reactive heated areas
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31. System Design
Type J adjustable
Ball radiused thermocouples
heatpipes
Electrical
Distributed wattage Terminal Boxes
cartridge heaters
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32. System Design – 4 configurations
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33. System Design
Heatpipes remain within the inserts to integrate with heaters also within
the inserts.
Guard heaters
in the holder block
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34. System Design
Heatpipes within the inserts. Heaters located in the holder block
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35. System Design
Heatpipes extending from the inserts through the holder block to
integrate with heaters in the holder block.
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36. System Design
Heatpipes extending from the inserts through the holder block to
integrate with heaters in the holder block clamp plates
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37. Isosprue ™Spreader System Design
sprue bushing Sprue Spreader
installed to core out
the sprue cone
and cure the cone
independently
Sprue spreader extension
cut to size and made
from a core sleeve section
Local terminal block
for the Sprue Spreader
and thermocouple
1/31/2011 © Acrolab 2011
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38. Isosprue spreader animation
Isosprue spreader animation is located on this disk in a separate AVI file.
1/31/2011 © Acrolab 2011
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39. System Assembly
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40. System Assembly
The system is electrically installed using locally mounted
terminal blocks located in wiring troughs adjacent to the exits of
the heaters and thermocouples.
Each thermocouple and heaters are independently wired to its
individual terminal block. A wiring harness is permanently set into
the wiring trough to bring the connections to the main terminal
box for the core and cavity.
Multipinreceptacles mounted on the box ends provide interface
with a multizone control system.
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41. System Assembly
Termination
box showing
the wiring
harness,
terminal strips
and multipin
receptacles
1/31/2011 © Acrolab 2011
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42. System Assembly
Heating System
Multipin
Receptacle
Multipin receptacles are
used for both power and
thermocouple connections
on both the cavity and core
halves of the mold.
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43. System Schematic Methodology
 The covers of the main termination boxes on the
mold are placarded with both physical location
schematics of the heater and thermocouple exit
points.
 An electrical schematic of the heater wiring and
thermocouple wiring scheme from the terminal
strips to the multipin receptacles on the box
ends is also mounted.
1/31/2011 © Acrolab 2011
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44. WF
HTR#7, Ø5/8 x 15.75", 1500W HTR#1, Ø5/8 x 15.75", 1500W
HTR#8, Ø5/8 x 15.75", 1500W HTR#2, Ø5/8 x 15.75", 1500W
TC#3A TC#3S TC#1S TC#1A
ZONE#1
HTR#9, Ø5/8 x 15.75", 1500W HTR#3, Ø5/8 x 15.75", 1500W
ZONE#3
HTR#10, Ø5/8 x 13.00", 1500W HTR#4, Ø5/8 x 13.00", 1500W
1/31/2011 © Acrolab 2011
TC#4A TC#4S TC#2S TC#2A
HTR#11, Ø5/8 x 15.75", 1500W HTR#5, Ø5/8 x 15.75", 1500W
ZONE#2
ZONE#4
HTR#12, Ø5/8 x 15.75", 1500W HTR#6, Ø5/8 x 15.75", 1500W
HTR#24, Ø5/8 x 15.75", 1500W HTR#18, Ø5/8 x 15.75", 1500W
ZONE#8
HTR#23, Ø5/8 x 15.75", 1500W HTR#17, Ø5/8 x 15.75", 1500W
ZONE#6
TC#8A TC#8S TC#6S TC#6A
DCX 09DS H/L REFL
HTR#22, Ø5/8 x 13.00", 1500W HTR#16, Ø5/8 x 13.00", 1500W
HTR#21, Ø5/8 x 15.75", 1500W HTR#15, Ø5/8 x 15.75", 1500W
CAVITY HALF (STATIONARY)
TC#7A TC#7S TC#5S TC#5A
ZONE#7
HTR#20, Ø5/8 x 15.75", 1500W HTR#14, Ø5/8 x 15.75", 1500W
ZONE#5
HTR#19, Ø5/8 x 15.75", 1500W HTR#13, Ø5/8 x 15.75", 1500W
System Schematic Methodology
HTR#31, Ø5/8 x 15.75", 2000W HTR#25, Ø5/8 x 15.75", 2000W
TC#11S TC#11A TC#9A TC#9S
HTR#32, Ø5/8 x 15.75", 2000W HTR#26, Ø5/8 x 15.75", 2000W
HTR#33, Ø5/8 x 11.00", 2000W HTR#27, Ø5/8 x 11.00", 2000W
ZONE#9
ZONE#11
TC#12A TC#10A
TC#12S TC#10S
HTR#34, Ø5/8 x 15.75", 2000W HTR#28, Ø5/8 x 15.75", 2000W
HTR#35, Ø5/8 x 15.75", 2000W HTR#29, Ø5/8 x 15.75", 2000W
ZONE#10
ZONE#12
HTR#36, Ø5/8 x 11.00", 2000W HTR#30, Ø5/8 x 11.00", 2000W
HTR#48, Ø5/8 x 11.00", 2000W HTR#42, Ø5/8 x 11.00", 2000W
HTR#47, Ø5/8 x 15.75", 2000W HTR#41, Ø5/8 x 15.75", 2000W
ZONE#16
HTR#46, Ø5/8 x 15.75", 2000W HTR#40, Ø5/8 x 15.75", 2000W
ZONE#14
TC#16S TC#14S
DCX 09DS H/L REFL
TC#16A TC#14A
HTR#45, Ø5/8 x 11.00", 2000W HTR#39, Ø5/8 x 11.00", 2000W
CORE HALF (MOVEABLE)
ZONE#15
HTR#44, Ø5/8 x 15.75", 2000W HTR#38, Ø5/8 x 15.75", 2000W
TC#15S TC#15A TC#13A TC#13S
ZONE#13
HTR#43, Ø5/8 x 15.75", 2000W HTR#37, Ø5/8 x 15.75", 2000W
WF
Location schematics for heaters & thermocouples grouped by zone
44

45. System Schematic
Electrical schematics showing wiring connections for heaters and
thermocouples grouped by zone
POWER
CAVITY HALF (STATIONARY) MULTI-PIN
CONNECTOR
1 1A
THERMOCOUPLE ZONE 1 ZONE 2 ZONE 3 ZONE 4 ZONE 5 ZONE 6 ZONE 7 ZONE 8 2 1B
MULTI-PIN 3 1C
CONNECTOR 4 2A
1A 1B 1C 2A 2B 2C 3A 3B 3C 4A 4B 4C 5A 5B 5C 6A 6B 6C 7A 7B 7C 8A 8B 8C 5 2B
1 WHITE IR +
1 6 2C
TERMINAL NUMBER
9 RED CO -
2 WHITE IR + 7 3A
10 RED CO - 2 Ø5/8 x 15.75" Ø5/8 x 13.00" Ø5/8 x 15.75" Ø5/8 x 13.00" Ø5/8 x 15.75" Ø5/8 x 13.00" Ø5/8 x 15.75" Ø5/8 x 13.00" 8 3B
PIN NUMBER
1 4 7 10 13 16 19 22
1500W,230V 1500W,230V 1500W,230V 1500W,230V 1500W,230V 1500W,230V 1500W,230V 1500W,230V 9 3C
PIN NUMBER
3 WHITE IR +
3
ZONE NUMBER
11 RED CO - Ø5/8 x 15.75" Ø5/8 x 15.75" Ø5/8 x 15.75" Ø5/8 x 15.75" Ø5/8 x 15.75" Ø5/8 x 15.75" Ø5/8 x 15.75" Ø5/8 x 15.75" 10 4A
2 5 8 11 14 17 20 23
11 4B
4 WHITE IR +
4
1500W,230V 1500W,230V 1500W,230V 1500W,230V 1500W,230V 1500W,230V 1500W,230V 1500W,230V
12 RED CO - 12 4C
Ø5/8 x 15.75" Ø5/8 x 15.75" Ø5/8 x 15.75" Ø5/8 x 15.75" Ø5/8 x 15.75" Ø5/8 x 15.75" Ø5/8 x 15.75" Ø5/8 x 15.75"
5 WHITE IR + 3 6 9 12 15 18 21 24 13 5A
13 RED CO - 5 1500W,230V 1500W,230V 1500W,230V 1500W,230V 1500W,230V 1500W,230V 1500W,230V 1500W,230V
14 5B
6 WHITE IR + 15 5C
6
DCX 09DS H/L REFL
14 RED CO - 16 6A
7 WHITE IR + 17 6B
15 RED CO - 7 18 6C
8 WHITE IR + 19 7A
16 RED CO - 8 20 7B
ZONE 1 ZONE 1 ZONE 2 ZONE 2 ZONE 3 ZONE 3 ZONE 4 ZONE 4 ZONE 5 ZONE 5 ZONE 6 ZONE 6 ZONE 7 ZONE 7 ZONE 8 ZONE 8 21 7C
(ACTIVE) (SPARE) (ACTIVE) (SPARE) (ACTIVE) (SPARE) (ACTIVE) (SPARE) (ACTIVE) (SPARE) (ACTIVE) (SPARE) (ACTIVE) (SPARE) (ACTIVE) (SPARE) 22 8A
23 8B
IR CO IR CO IR CO IR CO IR CO IR CO IR CO IR CO IR CO IR CO IR CO IR CO IR CO IR CO IR CO IR CO 8C
24
1 9 2 10 3 11 4 12 5 13 6 14 7 15 8 16
CAVITY HALF (STATIONARY)
ZONE 1 ZONE 2 ZONE 3 ZONE 4 ZONE 5 ZONE 6 ZONE 7 ZONE 8
WATTS WATTS WATTS WATTS WATTS WATTS WATTS WATTS TOTAL
RE RE RE RE RE RE RE RE (WATTS)
AB
1500 1500 1500 1500 1500 1500 1500 1500
23.5 23.5 23.5 23.5 23.5 23.5 23.5 23.5
12000
AC
1500 1500 1500 1500 1500 1500 1500 1500
23.5 23.5 23.5 23.5 23.5 23.5 23.5 23.5
12000
BC
1500 1500 1500 1500 1500 1500 1500 1500
23.5 23.5 23.5 23.5 23.5 23.5 23.5 23.5
12000
TOTAL 11.4 11.4 11.4 11.4 11.4 11.4 11.4 11.4
AMPS
DCX 09DS H/L REFL
TOTAL WATTAGE FOR STATIONARY HALF = 36,000W
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46. Case Study # 2: Breaker Housing
Subject to confidentiality, specific mold designs, system layouts or detailed molding parameters
will not be presented. The photos above are only a general representation.
1/31/2011 © Acrolab 2011
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47. Case Study # 2: Breaker Housing
 Square D Corporation molds commercial, industrial and
residential switch gear and electrical breakers.
 A six cavity residential breaker housing mold was built
for operation in a 200T Bucher injection thermoset molding
machine.
 The material being molded was a polyester BMC.
Injection thermoset was chosen over a manually loaded
vertical press in order to reduce scrap and increase
production and part uniformity.
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48. Case Study # 2: Breaker Housing
 This complex mold incorporated slide actions and
was constructed using mold face inserts.
 These inserts presented intrinsic thermal gaps at their
contact surfaces. The mold was electrically heated by
positioning cartridge heaters in locations that were as
close as possible to the contact surfaces of the inserts.
 When heated, the mold indicated temperature
variations from random point to point on the working
faces from 300º F to 350º F, a 50º F delta T. The
resultant cycle time for the mold was unacceptable. The
mold part exhibited heat stress and blistering.
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49. Case Study # 2: Breaker Housing
The mold was modified to accept a matrix of
over 150 heatpipes in various diameters to
bridge the inserts with the heater array.
The mold was machined to accept the retrofit by
the mold maker, Artag Plastics Corp of Chicago.
The heatpipe matrix and associated components
were installed.
The mold was then installed in the same press
and operated using the same parameters loaded
into the PLC as in the first instance.
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50. Case Study # 2: Breaker Housing
Major improvements were noted immediately.
1) The mold face delta T random point to point dropped
from 50º F to 10º F.
2) The cure time was reduced by 13 seconds.
3) The overall cycle time was reduced by 22 – 23%.
4) The surface appearance of the housings were
improved and now met Square D standards.
As a result of the uniform temperature and rapid energy
throughput provided by the heating system, Square D was
able to reduce the process temperature by over 40º F with
a corresponding reduction in energy costs.
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51. Thank You
Advanced Heatpipe Energy Transfer Systems
for
Thermoset Injection Molds
Joe Ouellette
Chief Technology Officer
Acrolab Ltd.
Advanced Thermal Engineering Research & Development
Products and Services
1/31/2011 © Acrolab 2011
51