Extruder combination for gas free extrudate - has first single screw extruder, twin screw extruder and second single screw extruder or gear pump

摘要

Plant comprises initial single screw extruder followed by second, twin screw extruder. The first machine underfeeds the second extruder which has initial zone forming vacuum chamber and screws with the same rotational direction. Further single screw extruder or alternatively gear pump is positioned downstream from the second extruder and has controlled speed to give constant pressure. USE/ADVANTAGE - The extruder arrangement produces thermoplastic extrudate for use in spinning of microfibres where gas-free material is essential to avoid breakageI