Hot stamping process hot stamping foil ink reverse pull, how to solve?

In the process of implementation of this process, the hot stamping foil is often pulled down by the printing ink, which not only seriously destroys the design effect, but also is very detrimental to the printing equipment. Because pull down the hot stamping foil powder will soon pile up on the blanket, light cause image dot loss, heavy cause local image printing.

Not only that, hot stamping foil powder will reach the ink roller through transfer, accelerate the wear of the ink roller, causing damage to the printing equipment.

From the above analysis, it can be seen that if we want to use the process of stamping first and then printing, we must eliminate the problem of hot stamping foil being pulled back in the printing process, and solve the problem of hot stamping foil being pulled back can be started from the following two aspects.

1. Control of hot stamping quality

Hot stamping quality is the premise to ensure the normal follow-up printing production. First of all, according to the different surface properties of the paper, choose the appropriate hot stamping foil. Hot stamping after the electrochemical aluminum foil will generally have a great contrast with the background, the hot stamping brightness effect do not worry about, the key is to ensure that hot stamping foil firmly attached to the surface of the paper.

To achieve this goal, in addition to the hot stamping foil selection efforts, but also strictly standardize the operating procedures of machine personnel. In addition to requiring machine personnel to control the hot stamping temperature, pressure and speed of hot stamping, it is more important to regularly test the adhesion of hot stamping layer. Because in the hot stamping process, the adhesion between the hot stamping layer and paper may change with the increase in the number of hot stamping.

Adhesion test using adhesive test method: tape to hot stamping layer, quickly pull off the tape. Generally speaking, if the hot stamping layer can not be pulled off, printing ink will not reverse hot stamping foil problems. 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 needs to be adjusted again. When the pressure reaches a certain number of times, hot stamping quality will tend to a stable state.

2. Control of printing process

Generally offset printing ink viscosity is relatively high, in the printing process of the paper surface tension is larger. This contradiction can be alleviated by reducing ink viscosity appropriately. In addition, under the condition of ensuring normal printing, the less printing pressure, the better.