Thermoset molding

  

As opposed to thermoplastic resins, thermoset material has special characteristics basically due to its chemical cross-linkage during processing.

Major properties and applications:

  • resistant to high temperatures
  • excellent chemical resistance
  • very good mechanical strength
  • good creeping behaviour
  • applications in the electrical/electronics industry, household and automotive industries
  • major thermoset materials are phenlic resins (PF), unsaturated polyester resins (UP), melamine resins (MF), melamine-phenolic resins (MP), urea resins (UF) and epoxy resins (EP)

 

The major difference in processing thermoset and thermoplastic resins is the processing temperature. Thermoset melt is heated to approx. 70° C - 100° C and subsequently injected into an up to 150° C - 190° C heated mold.

Aside from standard injection molding, Battenfeld offers two other processes for thermoset molding:

  • Injection compression molding: injection into a slightly open mold which is subsequently closed completely
  • Core compression: injection into a fully closed mold with embossing through one or more mold cores

 

For thermoset processing a special injection unit is utilized.

Main characteristics:

  • relatively short screw with low or without compression
  • no non-return valve
  • liquid-cooled barrel
  • machines with special options, e.g. mold heating control zones, embossing and venting programs
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