Direct heating method, for forming a weld between polymer films and a tubular polymer insert, uses radial flow of air to cool the weld over the entire length

摘要

The welded joint is cooled over it's entire length using air flowing in the radial direction. Forming a leakproof joint between a tubular polymer insert and two polymer film sheets comprises: (a) holding the insert firmly in a pre-determined position; (b) introducing the films to opposite sides of the insert; (c) joining the films and insert together in a tension-free state so that the films are shaped around the insert periphery; (d) heating regions of the films to form a continuous leakproof joint between the films and insert; and (e) removing the insert-film assembly. Prior to step (e), the joint is cooled using air flowing in the radial direction so the welded joint is cooled over its entire length. An Independent claim is also included for the apparatus used to carry out this method.