seen and device for framstellning by one of several different materials composite foremal

摘要

Joint strip is formed between the juxtaposed marginal zones, of a blank of flexible sheet matls. eg. paper, cardboard, plastics, or metal esp. for a container by gripping the marginal zones between the gripping surfaces of two mould sections, one surface having a flow channel for the injectable synthetic matl. forming the joint strip and (b) injecting this matl. through the flow channel to join the marginal zones. The flow channel is shaped to form a preferred flow path for the injected matl. over at least one marginal zone, the matl. flowing along the joint in a zone removed, from the edges of the blank, and holding this marginal zone against the other shaping surface. Precise control of the flow path of injected matl. is possible. Good joint strips are obtd. without soiling the external surface of the finished prod.