PE protection film, if it appears white spots after the coating, then, in specific reasons, is for the presence of glue particles, or the baking temperature is uneven, in addition, it is possible, it is a problem for the cloth head, so one by one, to find out the real reason to effectively solve. Moreover, this problem is a product quality issue, which should be paid attention to.
1, different batch of printing ink to add particle size inspection target, strict control, especially full bottom ink type and granularity distribution outside the standard size of the selection; select the excellent stable supplier.
2. Select the special adhesive for the electronic protective film. The special adhesive for electronic protective film has lower surface tension, and the spreading effect on the surface of the glue layer is better than that of the universal adhesive. Choosing glue glue will be very easy to control the leveling of the glue, and have a better coating condition. From the perspective of adhesive coating, the possibility of white spots can be eliminated by using electronic glue.
3, the viscosity of the liquid and the line number of the wire has a certain matching connection, beyond the matching range of the coating of the General Assembly damage adhesive coating situation, the "white spot" is more important.
4, select the coating method of electronic protective film. The general selection of coating technology is the printing film (ink surface) coating. Here, the special coating method is selected to avoid the doubt of the inhomogeneous immersion of the ink layer and avoid the problem of the inhomogeneous penetration of the ethyl ester to the ink layer. At the same time, the coated adhesive can plentiful and evenly cover the surface of the glue layer, so that it can be perfectly eliminated. White spot. However, this technology has its great limitations. First, it is limited to the combination of VMPET, and the influence of other electronic protective films on the oven is stretched by tension; secondly, it will sacrifice the exfoliation strength.
5, soft packaging companies must adhere to the regular cleaning guidelines for coating rollers, and grasp the correct cleaning methods for coating rollers. Pay attention to two points when producing full white or shallow background printing film. First of all, before the production, scraper, coating roller, flattening roller and so on are completely cleaned.
6, it should be completely dry of the adhesive. Because the barrier property of aluminum plating is better, if the composite membrane is not completely dry, then the residual solvent should be released quickly after entering the curing chamber, and it is bound to form bubbles under the barrier of electronic protective film. It even shows that there is no white spot on the machine, and the white spots appear after ripening.