Co-extruded film is used in pure milk bags, express bags, and metal protective films. It is characterized by good tensile properties and good surface brightness.https://www.wenxipacking.com/functional-film/food-packaging-film/environmentally-friendly-co-extruded.html
In the processing of film, a raw material is extruded onto another film that has been made, or the films of different varieties that have been made are bonded to each other to form a multi-layer film. This product is called a composite film. Most of the composite film materials are plastic, but paper, metal foil (usually aluminum) or fabric can also be used. The basic requirement of co-extruded film manufacturers is to have excellent adhesion between layers to ensure the overall mechanical properties of the package.
In addition, composite films are mostly used for food packaging, and adhesives are used in the processing of co-extruded film manufacturers, and the selection of solvents and bonding processes must meet the corresponding hygienic standards. The co-extruded film has most of the characteristics of the composite film, but there is one difference, that is, all layers of the co-extruded film are extruded at the same time, so there will be no other non-plastic materials such as aluminum foil and paper. The combination of product materials is relatively small, and the scope of application is also small. However, because the winter bonding layer and the layer are bonded by hot melt without adhesive, the hygienic safety of the co-extruded film for food packaging is relatively reliable.
Functional co-extruded films can be used to replace some structural co-extruded film manufacturers. For example, the composite film with PA/PE in the middle layer can be replaced by PA/PE co-extruded film; the composite film with high insulation structure can be replaced by EVOH-containing co-extruded film Instead, especially for products with high insulation requirements such as fruit juice, ketchup, jelly, etc., functional co-extruded film is used for packaging, which can effectively prevent product discoloration and odor.