Co-extruded film: It has most characteristics of composite film, but there is one difference, that is, all layers of co-extruded film are extruded together at the same time, and the layers are bonded by hot melt without adhesive.
Composite films can be layered under certain conditions, but co-extruded films can't, so there will be different shapes between them under the action of tensile tension; In addition, because the materials of co-extruded film are bonded together by hot melt, spherical bubbles will be generated when forced extrusion, while spherical bubbles will not be generated when composite film is forced extrusion because it is bonded by adhesive.
Use performance differences:
1. Composite membranes are widely used. If you want to use aluminum foil packaging and paper plastic packaging, you can only choose composite film. The composite film can basically realize the functionalization and personalization of packaging, and meet the quality assurance, processing performance, transportation and storage conditions of packaging contents.
2. Co-extrusion film is generally used for pure milk bags, express bags and metal protective films. Black and white film of coextruded film, used to make express bags or milk bags. Because the courier bag is easy to break due to hard objects or various factors, it is not suitable to use ordinary PE film, so co-extrusion film is used at this time; When used as a milk bag, it should also meet the food standards and non-fragile standards.