Thermoplastics are polymeric solids which can be repeatedly melted, shaped or formed, and then cooled back to a solid. Processes such as extrusion, injection molding, and thermoforming are utilized to produce thermoplastic articles for a variety of applications ranging from food packaging to automotive body panels to biomedical devices.
There is a broad selection of thermoplastic materials available for use. They vary in terms of cost and performance. Thermoplastics can be categorized by cost as:
Commodity thermoplastics : include materials such as polyethylenes, polypropylenes, polystyrenes, and polyvinylchloride (PVC).
Engineering thermoplastics : include polyamides (PA, nylons), polyesters (PBT, PET), polyacetal, and polycarbonate. This category includes thermoplastic elastomers (TPE), thermoplastic materials that that have mechanical properties similar to thermoset rubbers. TPEs include block copolymers such as thermoplastic polyurethanes (TPU), thermoplastic polyamides (PEBA), styrene block copolymers (SBC), thermoplastic polyolefins (TPO), and polymer blends such as thermoplastic vulcanizates (TPV).
High performance thermoplastics :include polysulfones (PSU), polyetheretherketones (PEEK), and polyetherimides (PEI).
Commodity thermoplastics are lowest cost, engineering thermoplastics are moderate cost, high performance thermoplastic materials are the highest cost category. Generally speaking, there is a trade-off between cost and performance attributes such as strength and temperature resistance.