Coextrusion Coating for Multi-Layer Films
topic
Coextrusion coating systems use multiple extruders feeding different polymer melts into a multi-manifold die that combines them into a layered structure before exiting the die as a single multi-layer film applied to the substrate in one pass, enabling production of composite coatings with different polymer compositions in each layer such as PE tie layer plus EVOH barrier layer plus PE sealant layer for food packaging barrier laminates.
Role
Enables multi-layer functional coating structures in a single pass through the simultaneous extrusion of multiple polymer layers that combine their individual properties in the final composite, with coextrusion being the economically optimal route for producing multi-layer barrier coatings where sequential single-layer extrusion would require multiple coating passes with intermediate cooling and reheating that increases production cost and the risk of inter-layer adhesion problems.