The multiple processing and use of regrind material of plastics are widely used in the plastics processing industry. The subsequent changes in material characteristics, certainly in the viscosity of the polymer melt, have been analyzed and are well known. However, to quantify the changing viscosity, a general modeling approach is necessary using a low quantity of lab measurements. For the example of a polyamide 6, rheological measurements have been performed and a general modeling approach for the viscosity based on the Carreau model has been developed. The verification of the modeling was successfully proven by comparing additional viscosity measurements with model prediction results.
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