Efficient degassing extruder cascade - has separate drives for two extruders, passes melt from first to degassing chamber in second, and regulates first screw by pressure in second

摘要

An extruder cascade consists of two successive but separately driven extruders with a vacuum degassing chamber between; this chamber is in the inlet area adjacent to the drive in the second extruder and is passed through by the flight on the screw of the second extruder, the degassing outlet being at the drive end of the second extruder. The plasticated material (plastic material is particular) is fed into the degassing chamber through a slotted die or a series of perforations in part or the whole of the circumference of the bore of the barrel. ADVANTAGE - The design feeds the plasticated/fused melt into the degassing chamber in such a way that it is degassed rapidly and effectively (in contrast wth existing designs where the material is compacted and has little surface area when it reaches the degassing chamber)