Extrusion Coating Performances of iPP/LDPE Blends

Abstract

The performance of iPP/LDPE blends in an extrusion coating process was investigated in the terms of coating width and draw-down ability. It is well known that iPP alone is not proper because of lower draw-down ability with severe draw resonance in elongational flow. To obtain higher draw-clown ability, iPP was blended with LDPE. Additionally, iPPs having different molecular weight distribution (MWD) were used in this study to find out the effect of MWD of iPP on neck-in an( draw-down ability. It was observed that iPP/LDPE blend with narrower MWD exhibits narrower coating width and higher draw-down ability. Neck-in and draw-down ability were correlated with shear and elongational properties obtained by several rheological measurements. From this study, the major rheological parameters affecting extrusion performance in iPP/LDPE blends could be assessed. (C) 2008 Wiley Periodicals, Inc. J Appl Polym Sci 111: 3121-3127, 2009