English
In order to extend the shelf life of food, medicine and other substances, many packaging materials for food and medicine now use multi-layer co extruded composite films. Currently, there are two-layer, three-layer, five layer, seven layer, nine layer, and even eleven layer composite packaging materials. Multi layer co extruded film is a thin film formed by simultaneously extruding multiple plastic materials into multiple channels from a single die, which can leverage the advantages of different materials.
Multi layer co extruded composite films are mainly composed of polyolefin combinations. Currently, the most commonly used structures include polyethylene/polyethylene, polyethylene/vinyl acetate copolymer/polypropylene, LDPE/adhesive layer/EVOH/adhesive layer/LDPE, LDPE/adhesive layer/EVOH/EVOH/adhesive layer/LDPE. The thickness of each layer can be adjusted through extrusion technology. By adjusting the thickness of the barrier layer and the combination of various barrier materials, films with different barrier properties can be flexibly designed. The heat sealing layer material can also be flexibly replaced and adjusted to meet the needs of different packaging. This multi-layer and multifunctional co extrusion composite is the mainstream direction for the development of packaging film materials in the future.
