In the production of pet plastic packaging belt, if the use of recycled material, single screw 3 Segment-5 segment machine, drying temperature of about 180 ℃, bake 6-8 hours, processing temperature 250 ℃-260 ℃. Pet is water-sensitive plastic, long-time heating drying on the material itself is easy to degrade, single-screw extruder friction heat is also prone to degradation, so in the process, to adjust the temperature according to the actual situation, the material is brittle because of the production process of molecular chain broken (degradation) serious, low molecular weight, viscosity is not enough, will result in the product is more brittle, scrap rate is too high. This should shorten the drying time to about 4-6 hours or so, add chain extender, prevent degradation, increase the molecular weight of the chain, improve the characteristic viscosity.