| 摘要 |
Production method for the manufacturing of very thin gas barrier layers of thermoplastic polyethylene vinylalcohol (EVOH), whereby an extruded layer of EVOH or a coextruded EVOH based film with 2 layers or more (7) is fused to a substrate layer (8) by means of an extrusion coater/laminator characterized in that the molten polymer flows as a thick film from the extrusion head (1) and is, in the distance from the extruder head to the nip, stretched to the very thin thickness of 8 to 150 gsm, preferably of 30 to 80 gsm and is subsequently fused either onto two substrates (8,15) (lamination) on both sides of the polymer base, or onto one substrate (8) (coating) on one side of the polymer base by a pressure roller (9) backed by another roller (10), supported by a guidance roller (12), onto one side of the molten polymer layer whereby a cooling counter roller (11) exerts counter pressure on the opposite side of the polymer layer and cools and hardens the molten film, and after which the finished product leaves the production process at a line speed of 40 to 800 m/min, and more preferably at a line speed of 100 to 300 m/min supported by another guidance roller (13). |
