PA film has the advantages of high strength, good continuity, high temperature resistance and cold resistance, etc. It can be used in the range of -50~180¡æ to replace high-temperature cooking materials and frozen packaging materials; it also has good oxygen barrier properties Characteristic, it is a barrier material.
The main types of PA used to produce films are: PA6, PA12, PA66, etc., packaging meat products and sausages, requiring an oxygen permeability of 20 to 80 cm3/m2¡¤24h, PA6 is the ideal packaging material.
¡ñExtruder: Generally use ¦µ90¡«150mm single screw extruder, L/D is 28¡«35, the geometric compression ratio of screw is 3.4¡«4, and mixing type screw is used.
¡ñDie head: branch-pipe type heads are mostly used, and the length of the die lip shaping section is slightly longer than that of CPP.
¡ñCooling device: The cooling device of PA film is different from that of CPP, and it needs to be cooled in two steps. The casting roll is an oil-cooled roll with hot oil passing through the roll, and the surface temperature of the roll is 90-100¡ãC. Then it was cooled with a water cooling roll, and the film was cooled to room temperature. If the CPP rapid cooling method is used, the PA film will be severely wrinkled, and a product with good flatness cannot be obtained.
¡ñOther equipment: Other equipment is basically the same as CPP.