A Novel Processing Aid for Greater Flexibility in Blown Film Extrusion

The high melt viscosity of linear low density polyethylene (LLDPE) presents several problems, particularly melt fracture, when this resin is processed on blown film equipment which has been designed for use with high pressure, low density polyethylene (LDPE) resin. With the help of processing aids, the same equipment may be used to process LLDPE, LDPE and resin blends to produce blown films. Data is presented to show that the use of one of these processing aids, UCARSIL PA-1, results in blown film through narrow gap dies with improved properties while throughput rates are maintained without excessive pressures in the extrusion pro cess.