Compounding Tasks and Requirements

The properties of polymers need constant refinement in order to meet the constantly increasing demands on plastic parts. Since the development of new polymers is steadily decreasing [1], deliberate modification of the properties of a base polymer by means of additives and/or blending with other polymers is becoming increasingly important. Herein lies the primary task of compounding. 

According to an AMI study [2], 6,000,000 tons of compounds and 750,000 tons of masterbatches were consumed in Western Europe in 2003. The Western European compound and masterbatch market is shown in Fig. 4.1. 

compounding is predominantly carried out with co-rotating twin screw extruders with constantly increasing available drive powers, torques, and screw speeds. 

In particular, increasing throughput means increasing the screw speed, which in turn leads to 

This increases the risk of loss of product quality due to a decrease in the molar mass, thermal inhomogeneities and melting problems. The extruder and screw concepts need to be constantly optimized and adapted to avoid quality loss. 

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