Methods for preparing a polyester film an compositions thereof

Abstract

This disclosure provides methods of preparing heat-shrinkable polyester films, wherein the heat-shrinkable polyester films are made of compositions which include recycled material. Such methods include a method for manufacturing a heat-shrinkable polyester film comprising: (a) heating a mixture comprising terephthalic acid (TPA) or dimethyl terephthalate (DMT), ethylene glycol (EG), a modifier component, and optionally, recycled material to undergo esterification to provide an esterified product; (b) heating the esterified product in the presence of a catalyst, heat stabilizer, and optionally, recycled material to undergo polymerization and to provide a polyester product; (c) granulating the polyester product to provide a polyester resin composition; (d) extruding the polyester resin composition to provide a sheet, wherein the extruding occurs at a temperature of about 180° C. to about 280° C.; and (e) subjecting the sheet to a film formation process to provide the heat-shrinkable polyester film, wherein the recycled material is added at step (a), step (b), or both steps (a) and (b).

Dependencies are inferred from the claim text.