The Effect of Extrusion Processing Conditions and Polyisobutylene Concentration on the Properties of Polyethylene for Stretch and Cling Film Applications

A range of LLDPE films with polyisobutylene (PIB) content from 2-8% was manufactured using a Killion blown film extrusion system and a cast film extrusion system. The films were aged at 25, 35 and 45 C for up to 28 days, to enable tack (cling) development. The results show that tack, in both blown and cast films, improved significantly with ageing at increased storage temperatures and at higher film blow up ratios. DSC analysis showed only a slight decrease in film crystallinity with increasing PIB concentration. The film tensile modulus, elongation and tear properties in both MD and TD were not significantly affected by an increase in PIB concentration.