In the process of designing and developing new products, craftsmen often use a special hot stamping process to highlight the topic of the product. In the course of this process, hot stamping foils are often pulled back by printing inks, which not only seriously damages the design effect but also is very disadvantageous to the printing equipment. Because the hot-stamped foil powder that is pulled back quickly accumulates on the blanket, the image dots will be lost if it is light, and the partial image will not be printed when it is heavy.
Not only that, the hot stamping foil powder will reach the ink roller by transferring, accelerating the wear of the ink roller, and causing damage to the printing equipment. From the above analysis, we can see that if you want to use the first hot post-printing process, you must put an end to the problem of the hot stamping foil being pulled back during the printing process. Solving the problem of the hot stamping foil being pulled back can start from the following two aspects.
1. Hot Stamping Quality Control Hot stamping quality is a prerequisite for ensuring that the subsequent printing production runs normally. First, according to the different surface properties of paper, choose the right hot stamp foil. The electro-foiled aluminum foil after stamping generally has a great contrast with the background, and there is no need to worry about the effect of hot stamping. The key is to ensure that the hot stamping foil is firmly attached to the surface of the paper.
To achieve this goal, in addition to the hard work of selecting stamping foils, it is necessary to strictly regulate the operating procedures of the staff. In addition to the requirement of machine personnel to control the hot stamping temperature, the hot stamping pressure and the hot stamping speed, it is more important to regularly test the adhesion of the hot stamping layer. Because in the hot stamping process, the adhesion between the hot stamping layer and the paper may change as the number of hot stamping increases.
Adhesion test using glue test method specifically: the tape was glued to the hot stamping layer, quickly pulled off the tape. In general, if the hot stamping layer cannot be pulled off, the problem of ink reversal hot stamping foil does not occur during printing. If the hot stamping layer is pulled off by the tape, it indicates that the hot stamping layer is not firmly attached and the pressure correction process needs to be performed again. When the school pressure reaches a certain number of times, the stamping quality tends to be stable.
2. Control of the printing process Generally, the viscosity of the offset ink is relatively high, and the pulling force on the surface of the paper is large during the printing process. This contradiction can be alleviated by appropriately reducing the viscosity of the ink. In addition, in the case of normal printing, the printing pressure is as small as possible.