Method of imparting heat sealability to the biaxially oriented polyester film, biaxially oriented polyester to impart heat-sealing film and package using the same

摘要

PROBLEM TO BE SOLVED: To provide a method of imparting heat sealability to a polyester film efficiently and safely.SOLUTION: In a predetermined area of a film composed of a single layer of biaxially oriented polyester, or a laminate comprising a layer of biaxially oriented polyester on its surface, the biaxially oriented polyester layer is continuously irradiated with a laser beam while scanning it, so that the surface of the biaxially oriented polyester layer in the predetermined area gets heat sealability.