Compounding extruder with outflow rate control by gear pump - by viscosity control independent of throughput rate

摘要

Extrusion compounding machine comprises a combination of screw extruder and a volumetric pump where the latter is mounted downstream from the extruder on a frame in which the thrust stress is monitored by a strain gauge. Pref. the pump is a gear pump. The thrust may be determined by a strain gauge transducer mounted either coaxially with the extruder (on a radial discharge die head) or on a frame in parallel with a coaxial outlet die. Pref. the screw operates with a flight/barrel clearance of 0.3-5 mm. The throughput is controlled by the output rate of the pump while the melt viscosity can be controlled independently by adjusting the speed of the extruder screw.