共挤膜与复合膜有什么区别

在薄膜的加工中将一种原料挤出到已制成的zhi另一种薄膜上或将已制成的不同种类的薄膜相互黏合到一起而成为多层薄膜，这种产品称为复合膜。复合膜的材料大多数为塑料，但也可用纸、金属箔(通常为铝)或织物等。复合膜的基本要求就是层与层之间要有良好的黏接性以保证包装的整体力学性能。此外，复合膜多用于食品包装，在复合膜的加工中要使用黏合剂，其溶剂的选择和黏接工艺等都要满足相应的卫生标准要求。

共挤膜具有复合膜的大部分特征，但有一点区别，即共挤膜的所有层都是在同一时间一齐挤出成型的，因此不会有铝箔、纸等其他非塑料材料。其产品材料的组合形式相对较少，适用范围也较小，但由于结合层与层之间是靠热熔结合而无需黏合剂，因此对食品包装共挤膜的卫生安全性要相对可靠。

In the process of film, a kind of raw material is extruded onto another kind of film, or different kinds of films are bonded to each other to form a multilayer film. This kind of product is called 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 composite film is good adhesion between layers to ensure the overall mechanical properties of packaging. In addition, the composite film is mostly used for food packaging, and adhesives should be used in the processing of the composite film. The selection of solvents and bonding process should meet the requirements of the corresponding health standards.

Co-extruded has most of the characteristics of Laminated film, but there is one difference, that is, all layers of Co-extruded are extruded at the same time, so there will be no aluminum foil, paper and other non plastic materials. The combination form of product materials is relatively small, and the scope of application is also small, but because the bonding layers are combined by hot melting without adhesive, the health and safety of coextrusion film for food packaging should be relatively reliable.