Methods for lowering melt viscosity and improving heat-sealability of polyester and for manufacturing a heat-sealed container or package

摘要

The invention relates to methods for lowering the melt viscosity and thereby improving heat-sealability of a polyester. The invention also relates to a method for manufacturing a heat-sealed container or package from fibrous- based, polyester-coated packaging material, and a method for heat-sealing polyester. The solution according to the invention is subjecting polyester to electron beam (EB) radiation. The lowered melt viscosity allows a lower heat- sealing temperature, and permits sealing of polyester to an uncoated fibrous surface. The preferred polyester for the invention is polylactide, as such or as blended with another polyester.