The ink consists of pigments, binders, solvents and additives
(1) Pigments: The hiding power is not strong and the leveling performance is poor. The printed film has spots on the light. After lamination (especially duplicative aluminum film), there are obvious spots. This phenomenon is mostly caused by the hiding power of pigments.
(2) Binder: Because the binder is used to connect the film and ink. The bad adhesive force of the connecting material will make the adhesion between the ink and the outer film unsound. After the compounding, the ink will be completely transferred to the inner film. This phenomenon may also be due to poor corona treatment of the outer film. caused.
(3) Solvents: The ideal solvent should have good fast-drying properties. If there is too much residual solvent, it will cause odor and surface quality problems of the composite film.
(4) Auxiliaries: Some auxiliaries also affect the compounding; for example, the anti-blocking agent is mainly composed of heavy oil and white kerosene; it prevents post-adhesion after printing; it can quickly penetrate the ink surface. Due to the anti-sticking properties of the anti-sticking agent, the adhesion to the laminating adhesive is a contradiction. So the amount of anti-sticking agent is very important.
For this issue, we believe that it should be explained in detail.
After compounding, there is a good adhesion of ink in places where there is no ink, but not in places where there is no ink; after curing, there is no problem in bonding where there is ink, and there is almost no adhesion in places without ink. There are two reasons for this.
The first one is because there are too many anti-sticking agents. After the printing, it penetrates into the surface of the ink. After the composite roller press, due to the good permeability of the ink, it quickly penetrates into the surrounding adhesive film. With time, the anti-adhesive agent It is distributed in a place where there is little glue on the periphery of the ink, so that the adhesiveness of the place where there is no ink drops.
The second reason is because of the film additives. Film additives include plasticizers, lubricants, and antioxidants. Excessive amounts of these additives can also affect the composite adhesion. Some film-mulching plants see this kind of situation, generally considered to be the cause of glue, encountered similar situations, should be carefully observed, careful analysis of the reasons, to find the crux of the problem lies.