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PLASTICS ENGINEERING COMPANY |
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3518 LAKESHORE |
Compression Molding Guidelines
for PLENCO Granular Polyester
Molding Compound
|
Parameter |
Suggested
Press Settings |
|
Mold Temperatures |
163° - 182°C (325° - 360°F) |
|
Preheated Material Temperature |
93° - 100°C (200° - 212°F) |
|
Mold Close Time |
3 - 6 Seconds |
|
Clamp Tonnage |
27.6 - 41.4 MPa
(2 - 3 Tons/in2) Of Projected Part Area |
Additional Technical Information
·
Preform preheat or
cold powder compression molding of PLENCO granular polyester materials is not
recommended because the material is difficult to preform
and has a limited amount of material flow during the molding process. As a result, the outline of unplasticized pellets can be seen in the finished
part. For these reasons, we suggest that
if this material is to be compression molded, then a screw preplasticizer
should be used to preheat it.
·
A clean, highly polished, chrome plated mold is recommended.
Use a mold release such as Carnauba Wax, being careful to coat the entire
surface. After several shots wipe off
the excessive mold release using a clean, soft cloth.
|
Common
Molding Problems |
Potential
Solutions |
|
Blistering |
Increase mold temperature Increase
material temperature Increase
cure time |
|
Gas Burns |
Slow mold close time Check for
blocked vent(s) Lower
material temperature |
|
Short Parts |
Increase preform weight Lower mold
temperature Lower
material temperature |
|
Sticking Parts |
Increase
mold temperature Increase
cure time |
The listed parameters
are suggested for use as a guide when setting up a compression molding machine
for molding