Polyethylene terephthalate or PET, which is polymerized using a high purity antimony trioxide catalyst, is a very common resin used in the manufacture of beverage bottles. However, to be used in other applications, PET needs to be reinforced to increase strength, stiffness and heat-resistant properties. Engineering-grade PET has all of these characteristics.

Engineering-grade PET resin is typically reinforced with glass fibers, glass flakes, minerals or micas. One very common formulation is a 30% glass-reinforced PET. These upgraded PET resins have superior strength and stiffness as well as excellent dimensional stability. In addition they have better chemical and heat resistance than their unreinforced counterparts and have good electrical properties.

These enhanced properties make engineering-grade PET appropriate for a variety of industries including the automotive industry, electronics, appliances and furniture. Basically, engineered PET resins can be used in any application that needs and very sturdy plastic that will be under a lot of stress.