Patent ID: 6077377
Filing Date: 2000-06-20
Classification: B29C,B29K,B29L,B31C

Abstract:
Method for the manufacture of the shell of gas-tight, composite material cans, having from the outside to the inside at least one paper or cardboard layer, a metallic barrier layer and a polymer layer, facing the filling material and covering said barrier layer, in that a continuous web of the composite material is wrapped round on a longitudinal edge to a double layer marginal strip, the continuous web on a marginal strip is heated along the opposite longitudinal edge, accompanied by the melting of the polymer layer, and subsequently wound helically onto a mandrel for forming a laminated tube, the heated marginal strip running up in overlapping manner onto the outside polymer layer of the double layer marginal strip of a web portion placed on the mandrel and joined thereto by welding together the polymer layers and subsequently at least one further paper or cardboard layer is placed in overlapping manner on the outside and marginally bonded, wherein the marginal strip is heated from the paper or cardboard layer side thereof subsequently forming the outside of the core by means of halogen light linearly focussed parallel to the longitudinal edge adjacent thereto for melting the polymer layer on the opposite, inner side of the composite material of said marginal strip.