Reasons, countermeasures and effects of BOPP film slitting quality —

Color circle
The color circle is caused by a certain degree of contamination inside or outside the film, which causes the quality of the color circle on the end face of the film roll after slitting and winding. Membrane surface pollution sources come from two aspects. One is the film-forming process. The color circles generated in the front part of the film, such as raw materials, feeding systems, extrusion systems, and die flow channels, generally cause pollution to the inside of the film (core layer). Some color-circle products can clearly observe a large amount of fish-eye impurities in the film. The color circles generated in the film-forming stage and the slitting process mainly cause pollution to the outside (surface) of the film, but whether it is internal or external pollution, It is impossible to remove the impurities from the contaminated film and restore the original appearance. The product with serious color circle has low transparency, the film color is different from the normal product, and it can not be used at all. It can only be reduced to other external treatments, while the products with slight color circles are It has little effect on the transparency of the product and does not affect the use effect of the single film. However, due to the inconspicuous appearance of the color circle product, the “selling phase” is poor, which has a great influence on the image of the German brand. It is not suitable for direct delivery. Secondary processing. If the color circle is caused by external dust pollution factors, the dust will be adsorbed on the surface of the film, resulting in poor quality of heat sealing and poor laser compression.