Process for recycling immiscibles in PET film

摘要

Described are methods for recycling biaxially oriented thermoplastic crystallizable films, such as polyester terephthalate (PET) films, that have been coated with various polymers or waxes that are immiscible in the primary molten thermoplastic. The resultant processed recycle can be used to make new biaxially oriented thermoplastic films while avoiding process instability and optical defects in the finished film associated with immiscible polymeric and/or wax coatings.

主权项

1. A method for recycling a coated thermoplastic film coated with 0.1 wt %-20 wt % polymers or waxes that are immiscible in the molten thermoplastic comprising:
densifying a ground coated thermoplastic film using a blade centrifuge, wherein a bulk density of the ground coated thermoplastic film is less than 1 lb/ft3; feeding the densified coated thermoplastic film into a multi-screw secondary extruder with vacuum to form a molten polymer; filtering the molten polymer to produce a recycled resin; and producing a biaxially oriented thermoplastic film from the recycled resin, wherein the film does not contain surface or embedded optical defects larger than 100 microns.