Blown Film of m-LLDPE Using a Novel Eccentric Rotor Extruder

Abstract

Metallocene linear low-density polyethylene (m-LLDPE) has superior physical and mechanical properties. While, the film blowing processability of m-LLDPE was very poor when processed under shear flow. To overcome this drawback, a novel device based on elongational flow was self-developed to process m-LLDPE. In order to investigate the effect of elongational flow on the processability improvement of m-LLDPE, five types PE were studied in this paper. All kinds of PE were prepared using this novel device and traditional single-screw extruder with molecular weight and its distribution, mechanical properties and WAXD characterization. Gel Pemeation Chromotographer (GPC) data shows that molecular weight of each resin prepared using this novel eccentric rotor extruder (ERE) is higher than that processed by traditional single screw extruder (SSE). Mechanical properties showed that tensile properties of all kinds of films blowing from ERE is better than the one from SSE. However, tear properties of m-LLDPE films made from ERE differ from LDPE or LLDPE. And had a relative low value than the one made from SSE. In addition, Wide-angle X-ray Diffraction (WAXD) results indicate that films blowing from ERE exist a partially ordered component in addition to the usual crystalline and amorphous components which can’t be achieved from SSE.