What are the processing conditions for matting film?

In order to obtain a uniform rough surface, that is, a matte surface, the thickness of the matte surface must be guaranteed. The minimum allowable thickness value is closely related to the die structure, the uniformity of the thickness distribution of the melt flow section in the die, and the smooth compounding of the multi-layer material flow state. The level determines the uniformity of the thickness distribution of the matting material. 

In order to ensure that the matte layer completely covers the BOPP surface, the thickness of the matte surface layer is recommended as follows:

1. When the total film thickness is greater than 15 μm, the surface layer thickness is generally 2.3 ~ 2.6 μm; when the total film thickness is 12 ~ 15 μm, the surface layer thickness is ≥ 2 μm.

2. The matte surface of the single-sided matte film should be placed on the air knife surface instead of the chilling roller surface. The temperature of the cooling roller and water tank can be appropriately higher, such as around 30°C.

3. The extrusion filter uses 80 to 100 molybdenum, and the extrusion temperature is slightly higher than that of general homopolymer PP by 5 to 15°C. For example, the feeding section is 210℃ and other sections are 245℃.

4. The longitudinal stretching ratio is about 4.8:1, and the longitudinal stretching temperature is similar to that of the random copolymer as the surface layer, such as the stretching zone 125℃±