Method for microcellular polymer extrusion

摘要

The present invention relates to a method which comprises the steps of continuously extruding microcellular polymeric material having cells of essentially uniform size of less than about 50 microns average size from a single-phase solution of polymeric material and blowing agent contained in extrusion apparatus (30) including a nucleating pathway (66), the blowing agent present in the solution in an amount less than about 80 percent saturation concentration as determined at the lowest pressure in the system after the point of blowing agent injection (54) prior to the nucleating pathway (66). IMAGE