Effects of Processing Aids on the Hot-Tack Properties of LLDPE Blown Films, 1998 Polymers, Laminations & Coatings Conference Proceedings

Fluorine-based processing aids are an effective means for improving the surface quality of polymer extrudates, especially in LLDPE film applications. By reducing the shear induced stresses which can cause melt fracture and die-lip build-up, processing aids have also allowed many film processors to increase the output of their equipment. Although their effects on extrusion processes are generally viewed as positive, the effects of processing aids on downstream film properties have been a historical concern. Many studies have been conducted which indicate that most commercially available processing aids have little or no effect on surface related film properties such as print adhesion and heat-seal integrity. In terms of heat-seal, these studies have focused primarily on the effects of fully quenched seals. In high-speed filling operations, such as vertical form and fill loading, the film processor must often rely on the hot-tack strength of the film to bear the weight of the load until the seal has fully quenched. In this study, three different fluorine-based processing aids were evaluated in a monolayer LLDPE film application over a range of concentrations. The hot-tack performance of these films was not adversely affected by the processing aids.