EFFECT OF KNEADING BLOCK TIP CLEARANCE ON PERFORMANCE OF CO-ROTATING TWIN-SCREW EXTRUDERS

摘要

Over the years the design of the co-rotating intermeshing twin-screw extruder has evolved to meet the processor's never ending need for improved performance and processing efficiency. The most significant change in recent years has been the introduction of the high speed high torque machines. These high speed extruders, while producing increased throughput and reduced average residence time, also generate significantly higher shear rates and exit melt temperatures. This paper examined the effect of kneading block tip clearance on machine performance as a function of screw speed and specific rate. Machine performance will be defined in terms of power consumption, extrudate melt temperature, residence time distribution, melt index, and mix quality.