Melting of Polymer Blends in Co-rotating Twin Screw Extruders

Abstract

Abstract Part II of the publication describes a model for calculating the melting of polymer blends which has been implemented in the SIGMA simulation software for the design of co-rotating twin screw extruders. The model is based on the findings discussed in Part I and makes it possible to calculate the temperature progression in the solids conveying section and during the subsequent melting process for binary incompatible polymer combinations. The two material components are observed in parallel during the melting process, and the respective degrees of melting over the length of the screw are calculated. The properties of the melt phase, which forms from both components, are calculated with mixing rules implemented in the program. The calculations supply the melting profiles for both components, thereby permitting a comprehensive analysis of the melting of binary polymer combinations. The results additionally form the basis of a calculation to estimate the morphology development of polymer blends in the melting section of the extruder. Part III of the report looks into a means of investigating the melting of binary polymer combinations, and the results of experimental investigations into polypropylene/polyamide blends are discussed. The simulation calculations are compared with the results of experimental studies in order to verify the model presented in this part of the publication.