Features of the Flow of Amorphous Polymer During the Extrusion of Sheet Materials on Production Lines

Abstract

Особенности течения аморфного полимера при экструзии листовых материалов на производственных линиях 81 even with a possible orientation of macromolecules. A mechanism for the interaction of macromolecules of different molecular weights (MWs) has been proposed, which explains this behavior of amorphous polymers. The reason for this is steric "hindrances" arising during the flow of macromolecules. Despite the smaller size of the ABS plastic macromolecules than polyethylene, the side substituents of acrylonitrile, butadiene and, especially, styrene, included in its composition, are much bulkier and heavier than the hydrogen included in the polyethylene. As a result typical for polyethylene conformation of a flat zigzag is transformed into a spiral conformation for ABS plastic, with the mutual packing of side substituents, for example, phenyl groups, etc., inside the spiral. It is difficult for macromolecules of various MWs to escape from such a coil of spirals, even when flowing in a melt. The steric difficulties that arise in ABS plastic, as well as other similar amorphous polymers, due to such a structure, do not allow mac-romolecules to be separated by mass during the melt flow in the collector channel of the flat-slot die of an industrial extruder. The uniformity of the molecular mass distribution of amorphous polymers ensures the uniformity of the properties of the material over the width of the sheet.