Polyester is a synthetic polymer made of purified terephthalic acid(PTA) or dimethyl ester dimethyl terephthalate(DMT) and ethylene glycol. It doesn’t have high resistance to heat, so it is usually used at the very end of the progress, where the profile is cooler.
You may know Polyester as a clothing fiber, but it is widely used in aluminum extrusion. For aluminum extrusion, Polyester usually can withstand temperatures up to 300℉/150℃.
How Polyester Felt Belts Are Made