Method for welding flat plastic sheets one over the other

摘要

The present invention relates to a method for welding plastic sheets lying flat one on top of the other, in which the said sheets are brought into contact with a heated cutting edge and the said sheets are welded with a parting seam. Welding is carried out using two-layer or multilayer laminated sheets of different schematic compositions, of which one laminated sheet has an opaque coloured or uncoloured layer on which a transparent sealing layer based on a propylene/ethylene copolymer or a propylene/ethylene alloy is arranged. The sealing layer of the opaque laminated sheet is welded directly to a sealing layer of a transparent laminated sheet. The invention furthermore relates to plastic bags, pockets or envelopes which are correspondingly welded with a parting seam.