MELTING RESIN AND INJECTING BLOWING AGENT THROUGH MULTIPLE PORTS

摘要

Extrusion apparatus and method for making a cellular resin product are characterized by a conduit that extends into the extruder whereby a blowing agent is injected therethrough into the resin through a plurality of ports provided in the conduit in order to disperse the blowing agent more uniformly through the resin before it is extruded through a die into a zone of lower pressure whereupon the blowing agent expands to form numerous cells within the resin structure.