A process and apparatus for producing polyurethane foam, comprising bringing together under pressure one or more foam components and a gaseous CO.sub.2 auxiliary blowing agent and discharging the combination through a permeable discharge head in the form of plural individual wire meshes sintered together...http://www.google.de/patents/US6326413?utm_source=gb-gplus-sharePatent US6326413 - Process and apparatus for producing plastics and polymeric foam
