PROCESS AND APPARATUS FOR PRODUCING EXTRUDED THERMOPLASTIC FOAM BODIES

摘要

Extruded thermoplastic foam bodies are produced by continuously extruding a foamable thermoplastic resin into a first zone (10) at subatmospheric pressure to form a continuous foamed extrudate (50). The first zone (10) has a liquid removal means (14) and a seal means (16) for passing the foamed extrudate (50) into a second zone (20). The second zone (20) is a liquid reservoir with the liquid open to the atmosphere and present in such volume to completely submerge the seal means (16). The continuous foamed extrudate (50) is then passed from the liquid reservoir (20) to the atmosphere. The liquid removed from the first zone (10) may be recirculated back to the liquid reservoir (20).