AN EXTRUDER AND A METHOD OF EXTRUDER OPERATION

摘要

A method of extruder operation is described; the extruder comprising a housing having at least two cylindrical housing bores, each housing bore having an axis disposed parallel to the other axis and the first and second axes separated by a distance“a”; at least a first screw shaft and a second screw shaft being disposed in the first and second housing bores; the first and second screw shaft with a first and second screw respectively; the first and second screw each having an extruder diameter D and a screw root diameter d; the first and second screw shaft each having a volumetric ratio of at least 1.4 wherein the volumetric ratio is defined by the extruder diameter D divided by the screw root diameter d; at least two inlet hoppers in the vicinity of the housing bores and opening into said housing bore with at least one of the inlet hopper having a side inlet into the housing bore; the method comprising: feeding material to be processed through the at least two inlet hoppers into the housing bores; conveying the material through the extruder length from the inlet hoppers to the extruder outlet; driving each of said first and second screw shafts at a speed of at least 1000 rpm and at a torque density of at least 8.5 Nm/cm3; the torque density being the shaft torque at each first and second shaft divided by the third power of the distance‘a’of the first and second axes.