Rheological Study of Some Melts of High‐Density Polyethylene Intensively Charged with Surface Treated CaCO3. III. Study of the “Melt Fracture”

Abstract

This article is part of a more extended series of studies devoted to charged polyolefin; it discusses the influence of some increased ratios of the modification and compatibilization agent of CaCO3 with high‐density polyethylene on the composite's melt fracture. In the extrusion of polymer melts, there is a critical value of shear rate (or shear stress) at which the extrudate's surface becomes rough. During polymer melt containing charging materials processing as foils and films, on its output off the extrusion head, the foil's surface becomes rough and covered with microcraters. A viscoelastic fluid during flowing with shearing becomes instable at a critical value of S R. At the same time, it may be demonstrated that melt's elastic properties are first responsible for the behavior during flowing through narrow slits.