RESIN AND MOLECULAR WEIGHT DISTRIBUTION EFFECTS ONEXTRUSION COATING OF POLYPROPYLENE

摘要

Key polymer parameters for optimum extrusion coating of polypropylene (PP) have been investigated. The effect ofPP resin type and molecular weight distribution (MWD) on extrusion coating performance has been determined.Results will aide the resin selection process for extrusion coating. PP homopolymer, ethylene random and impactcopolymers, each with relatively narrow and broad MWD, were extrusion coated onto PP woven fabric substrateusing commercial scale equipment. The effects of resin type and molecular weight distribution on adhesion tosubstrate, neck-in, edge weaving and surging were investigated. A highly cracked impact copolymer of narrowMWD emerged as the preferred resin in this study. This resin technology allows the processor to avoid the practiceof mixing PP homopolymer with other resins (e.g. LDPE) for extrusion coating.