Proposal of an empirical viscosity model for quality control in the polymer extrusion process

An empirical model to evaluate the viscosities of thermoplastic polymers in the extrusion process for quality control is proposed in this article. The viscosity is calculated from the screw rotation speed, melt temperature, geometric dimensions of the extruder and material constants, which were experimentally determined. Polypropylene (PP) was used in this study to test the effectiveness of the model. Comparing the calculated results, it was found that the viscosities obtained with the present model are in agreement with those obtained by using an in-line rheometer. The result shows that the proposed method can be applied to control the polymer extrusion process without imbedding an in-line rheometer, which influences the output of the product.

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