Continuously lap welding thermoplastic films - using intermediate film squeezed at edge to form bead with main film

摘要

In the parent patent thermoplastic films or sheets are continuously lap-welded together by heating and pressing, with a third material in a hot soft state inserted between the areas concerned. In the patent of addition the third material is squeezed out from the lap area at least at one end. Pref. the overlapping regions to be welded are also heated prior to welding.