Casting film，which is a non - stretching, non - directional flat extruded film produced by melt salivation quenching. Compared with the general blowing method, it is characterized by fast production speed, high yield, film thickness uniformity and transparency, luster and so on are very good. It can be divided into monolayer salivation and multilayer co-extrusion salivation in two ways. The main requirements of monolayer film material low temperature heat sealing performance and good flexibility. Multilayer coextruded film can be generally divided into three layers: heat sealing layer, support layer and corona layer.
The production process is that the raw material is plasticized and melted by the extruder, the melt is extruded through a T-shaped slit die head, the casting piece is cooled by the quenching roller, and the film is formed. This method is fast in production, the quenching roller is generally chromium plated on the surface, high finish steel roller, and the film transparency is high, the thickness is uniform, the longitudinal and transverse properties of the film are consistent.
High finish steel roller, and film transparency, uniform thickness, film longitudinal and transverse performance consistent.
Support layer: play a supporting role on the film, increase the stiffness of the film, at the same time to reduce costs, first of all to have good rigidity, followed by good optical performance, the overall performance of the film is basically reflected by the support layer, the amount of the total amount of film about 70%.
Corona Layer: For printing or metallization, proper surface tension is required.