PROCEDURE FOR THE MANUFACTURE OF A FOAMED PLASTIC PRODUCT

摘要

Procedure for the manufacture of a foamed plastic product, in which procedure a filmlike plastic product (1) is perfoamed e.g. by using foaming agents added into the manufacturing process, in such a way that lamellar discontinuities (2), e.g. prefoamed bubbles, are created in the product (1). The product (1) is pressurized with a desired gas, such as nitrogen or air, under positive pressure, causing the gas to diffuse into the product. The product (1) is then inflated by sujecting it to a heat treatment under reduced pressure during which the product is heated at a temperature below its melting point.