VERFAHREN ZUR PLANIERUNG VON WARMSIEGELMASSEN AUF MIT PROFILSCHLUSSSTREIFENKUNSTSTOFFOLIEVERPACKUNGSB UTELN

摘要

In the manufacture of plastic articles such as thermoplastic film zipper bags and the like heat sealing the film to the zipper produces a seal line that shrinks, resulting in unsightly appearance. An apparatus and method are disclosed for restoring the shrunk seal line to its original length by corrugating and stretching it between mating teeth. A method is also disclosed for restretching the seal without corrugation.