Thermal treatment of polyester to make partly crystalline material, e.g. for film production, involves passing extruded strands through a surface-roughening device before cold granulation so as to reduce surface contact

摘要

A method for the thermal treatment of polyesters to achieve partial crystallisation by converting the strands of polyester melt (obtained by melt condensation and extrusion through a perforated die plate) into granulated strand with a cold chopper, involves passing the strands through one or more surface roughness-producing devices after leaving the die plate and before entering the granulator.