Adhesion Problems with Coextruded Multilayer Films.

This article deals with the adhesion between the different layers of polyethylene/polyamide composite film. If these layers are to be connected with a bonding agent, this will raise the question about the minimum thickness of layer required. An inter-layer adhesion sufficient for some applications can be obtained by using polymer combinations as bonding agents. It is in this way that adhesion can be controlled within certain limits and bonding costs be reduced. The report discusses the coextrusion in a common extrusion die, using several extruders. Adhesion mechanisms, influences on adhesion strength; relationship between surface tension and inter-layer adhesion; consequences for establishing this adhesion; normal methods of establishing adhesion, ionomer based bonding agents. Polymer combinations as bonding agents; ionomer/polyethylene compound; polyethylene/polyamide compounds; polyethylene/polyamide/ionomer compounds. Potential applications for bonding agent compositions.