1. Heat resistance
  2. Electrical properties


  1. Warpage
  2. Process limitations
  3. Proper drying prior to molding


Polyethylene terephthalate (PET) is a thermoplastic polyester engineering resin. When used as an injection molding compound, it must be reinforced with glass and/or minerals.

When PET is compounded with reinforcements, its strength, rigidity and heat resistance properties are dramatically enhanced. PET resins are also noted for their excellent melt flow characteristics, close molding tolerances and high productivity from multicavity molds.

Because its mechanical and electrical properties are so broad, PET is often used to replace metals in motor housings, switches, sensors and other electrical applications.