EFFECTS OF MOLECULAR STRUCTURE ON THE RHEOLOGY AND PROCESSABILITY OF HIGH DENSITY POLYETHYLENE BLOW MOLDING RESINS

摘要

The influence of molecular structure on the rheology and processability of HDPE blow molding resins is studied. Experiments were conducted using capillary and ex-tensional rheometers, a melt indexer and a blow molder unit. Twenty four resins were analyzed in terms of their shear flow and extensional properties, extrudate swell characteristics, and melt strength. The studied samples were produced using a variety of manufacturing technologies and had varying molecular weight characteristics. From the results, the influence of molecular structure on the rheological properties was determined. Furthermore, to assess resin processability, pillow mold (blow molding) experiments were performed. The implications of rheology on processability (parison sag and weight swell) are also discussed.