摘要 |
Foam thermoplastic materials are generated in the form of foamed thermoplastic extrudates by utilizing blowing agents. As blowing agents harmless ingredients are utiltzed to make the manufacturing process more ecologically sound. Gases such as air are controllable injected into an extrusion system upstream of the extruding die. The extruder system has various access points at which controlled amounts of blowing agents can be added to the molten thermoplastic mass. |