Film covering is one of the common surface finishing processes for sticker label printing, which helps to improve the abrasion resistance, water resistance, dirt resistance, chemical corrosion resistance and other properties of labels. Although laminating can effectively improve the grade of labels, but in the process of laminating, there are often some small bubbles, and it is impossible to completely avoid. We can ignore the bubbles that meet the quality standards of self-adhesive labels, but for larger bubbles, we need to find and treat them in time. So, what are the reasons for the bubbles after film laminating?
1. The quality of film
Some film materials do not pass the factory quality, so these films have bubbles itself. In the case of such defective raw materials, they can only be inspected frequently in the production process, found in time and replaced when necessary.
2. Uneven material surface
The uneven surface of the material here refers to the adhesive material covered with film. As we know, film materials are used to cover the surface of printed self-adhesive materials. If the surface of self-adhesive materials is not smooth, it may lead to film-covered bubbles. There are many reasons for the uneven surface of the adhesive material, such as the defects of the material itself, poor printing, etc., may lead to the uneven surface of the adhesive material.
Faced with this problem, we can observe carefully to see whether the bubbles have regularity, and check whether the surface of the adhesive material is smooth at different light angles. If there is an uneven place, look at the position of the bubble and whether the uneven place of the adhesive material can be matched. If the due, then it should be the surface of the adhesive material is not smooth caused by the film bubble. At this time, we analyze the reasons for the uneven surface of the adhesive material, such as whether there are foreign bodies on the paper pressing roller of the equipment to press the material into pits, whether the raw material itself has defects, etc. Finally, according to the reasons found to develop a plan, think of a way to solve the problem completely.
3. Aging of roller surface
The aging roller can’t press the film material and the printing material together well. And it is easy to form bubbles. In this case, we can check whether the pressure roll has the aging phenomenon mentioned above, if so, the replacement of the pressure roll can solve the problem.
