Small amounts of other thermoplastic polymers such as, for example, thermoplastic rubbers, certain polyurethanes, talc-filled polypropylene, acrylonitrile/butadiene/styrene terpolymers (ABS resins), and chlorinated polyethylene, are sometimes processed by calendering methods.
"polyester polymers such as, for example, poly (ethylene terephthalate), abbreviated herein as``pet"", or poly (1,4-butylene terephthalate), abbreviated herein as``pbt"", are difficult to calender successfully."