Durability of Polyethylene Films

Abstract

This work deals with the weather-resistance of low-density polyethylene films. The performance under controlled laboratory conditions, of well-characterized polymer grades and various combinations of stabilizers was studied. The high molecular weight and narrowly-distributed grades seemed to have a better performance. While the unstabilized films were found to fail after a relatively short period, the synergistic combinations of UV absorbers, quenchers and anti-oxidants showed a marked increase in film duration. For the protected films, increasing film thickness improved performance. The increase of crystallinity upon ageing with the resulting decrease in oxygen permeability are highlighted. The role of oxygen diffusion into the film is significant both in thermal and in photo-oxidation.