What is cast film

Cast film is a non-stretched, non-oriented casting hot fusible film flat-extruded film produced by melt casting and quenching. There are two methods of single layer salivation and multi-layer co-extrusion salivation. Compared with blown film, it is characterized by fast production speed, high output, and outstandingly good transparency, gloss, and thickness uniformity of the film.Application Take the widely used self-polypropylene cast film CPP as an example.

CPP is a non-stretched, non-oriented flat-extruded film produced by melt casting and quenching. Compared with blown film, it is chrized by fast production speed, high output, and good film transparency, gloss and uniform thickness. At the same time, because it is a flat-extruded film, the subsequent processes such as printing and compounding are extremely convenient, so it is widely used in the packaging of textiles, flowers, food, and daily necessities.

There are two methods of CPP production: single-layer casting and multi-layer co-extrusion casting. The single-layer film mainly requires the material to have low temperature heat sealing performance and good flexibility. Multi-layer co-extruded cast film can be generally divided into three layers: heat seal layer, support layer and corona layer. The degree of material selection is wider than that of single layer film.

The materials that meet the requirements of each layer can be selected separately to give the film different Functions and uses. Among them, the heat sealing layer needs to be heat-sealed, which requires a low melting point of the material, good hot melt, wide heat sealing temperature, and easy sealing; the support layer supports the film and increases the stiffness of the film; The corona layer should be printed or metallized, requiring moderate surface tension and strict restrictions on the addition of additives.