APPARATUS FOR SEALING FILM WEBS OF A THERMOPLASTIC SYNTHETIC MATERIAL

摘要

1222-1 APPARATUS FOR SEALING FILM WEBS OF A THERMOPLASTIC SYNTHETIC MATERIAL An apparatus is described for welding a thermoplastic film web, typically in the manufacture of plastic bags. When the apparatus is stopped, overheating of the plastic web is avoided by retracting the welding bars away from the film web thus creating an air cushion between the hot surfaces and the thermoplastic film web. If desired, the air cushion can be augmented with an air flow.