Rheodynamical analysis of flow defects in capillary extrusion of polymers

Investigatordoc. Petr Filip, CSc.
External Co-InvestigatoIng. Jiří Bartoš (Fakulta technol. VUT, Zlín)
Duration1993 - 1995

Subject of Research:  Extrusion of polymer materials is often accompanied with the defects ranging from the less apparent surface ones to the significant cross-sectional irregularities. These defects are determined by unstable behaviour of polymer that is extruded throughout the systém reservoir-capillary. Their origin substantially limits production rate of extruded materials.

Research Goal:  - a detailed analysis of causes of origin, existence and conditions of duration of oscillatory flow regime in the capillary of an extruder; - derivation of a rheodynamical model that describes behaviour of a systém reservoir-polymer-capillary on the basis of multifactor analysis (i.e. simultaneous consideration of geometry of the systém, method of loading, material and adhesive characteristics of polymer, hysteresis of flow curves, influence of pressure and temperature); - experimental verification of the obtained results.