A METHOD OF PRODUCING MICROCELLULAR FOAMS AND MICROCELLULAR FOAMS OF SEMI-CRYSTALLINE POLYMERIC MATERIALS

摘要

A process for producing a microcellular foam from a semicrystalline polymeric material. The material is heated to its high melting point and is then saturated with a uniform concentration of a gas. The pressure is then lowered to cause bubble nucleation and growth in the material. The material is then cooled to prevent it foams further. Bubbles with a diameter of the order of 5 microns are produced, their density being approximately 1010 bubbles / cm3.