Plastics Engineering Company

PLASTICS ENGINEERING COMPANY
SHEBOYGAN, WISCONSIN 53082-0758 U.S.A.


 

3518 LAKESHORE ROAD
POST OFFICE
BOX 758
PHONE
920-458-2121
FAX
920-458-1923

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 Plenco Thermoset materials. These parameters are for your evaluation and may or may not be compatible for all mold designs, press configurations, and material rheology.  Please feel free to call Plenco and a Plenco Technical Service Representative will be happy to assist you.                                                        Revised 4-30-03