Structural Foam Molding Process

Structural Foam Molding is a process where the addition of a blowing agent and modification of process parameters creates a sandwich construction that has a solid skin on the outer layers and a foam core in center.

In the structural foam molding process a blowing agent creates a cellular structure while a rigid skin forms. The wall thickness ranges from 0.080" to 0.500" with typical thickness between 0.230" and 0.250".

Design Benefits Compared to Solid Injection:

  • • Reduced part weight (up to 15%)
  • • Larger parts… lower pressure
  • • Thick sections (up to 0.500”)
  • • Sink mark reduction
  • • Lower cost tooling

Performance Benefits Compared to Solid Injection:

• Increased stiffness to weight ratio
• Reduced part stress
• Better heat insulation
• Improved acoustical characteristics
• Improved electrical insulation characteristics

Materials Used in Structural Foam

Most any thermoplastic material can be used in a structural foam application including:
• Polycarbonate
• Polyphenylene Oxide - PPO (Noryl)
• Polybutylene terephthalate - PBT (Valox)
• Acrylonitrile Butadiene Styrene – ABS

sturctural foam product

Design Features & Considerations

• Lower internal stress than injection molding
• Thick ribs and bosses are possible
• Brass inserts can be used for threaded bosses
• Solid look and feel with a reduced weight and cost
• Product is almost always painted
• Slower cycle time than standard injection molding

Gas Counter Pressure

Gas counter pressure is a process within structural foam molding whereby the mold is pressurized prior to injection offering these benefits:
• Allows the product to have the benefits of structural foam without paint
• In mold texture possible
• High gloss possible
• Makes very flat, dimensionally stable parts

Call us today at 603.569.5100 for assistance on your molding and finishing requirements.