How to reduce the impact of protective film white spots on products
Aug 10, 2022
1. The adhesive should be dry
Due to the good barrier properties of aluminum plating, if the composite film is not dried in the bonding, then after the composite film enters the curing chamber, a large amount of residual solvent must be quickly released, and bubbles are bound to form under the barrier of the electronic protective film. There may even be no white spots when the machine is turned off, but white spots appear after curing.
2. The viscosity of the glue and the number of wire rolls
The viscosity of the glue liquid has a matching relationship with the number of lines of the mesh roll. If it exceeds the matching range too much, the coating state of the glue will be damaged, causing the generation of "white spots" to be more concerned.
3. Use electronic protective film adhesive
The surface tension of the electronic protective film composite adhesive is lower, and the coating and spreading effect on the surface of the glue layer is obviously better than that of the general-purpose adhesive. Using glue will make it very easy to control the leveling of the glue, and have an ideal coating state. From the point of view of the coating state of the adhesive, the use of electronic glue can remove the possibility of white spots.
4. Use electronic protective film coating method
The commonly used coating process is the printing film (ink surface) coating. The coating method is used here to avoid the problem of uneven penetration of ethyl ester to the ink layer, and at the same time, the coated adhesive can fully and evenly cover the adhesive layer. surface so that white spots can be removed very well.
However, this process has its great limitations, which are limited to the compounding of VMPET, while other electronic protective films will be stretched and deformed under the action of tension under the influence of heat in the oven; secondly, the peel strength will be sacrificed.
5. Correct coating roller cleaning method
Flexible packaging enterprises adhere to the regular cleaning system of the coating roller and master the correct cleaning method of the coating roller. When producing full white background or light background printing film, two points should be paid attention to. Clean the scraper, coating roller, flattening roller, etc. before production.
