How to deal with the phenomenon of reverse pull in the automatic stamping machine?

The automatic stamping machine plays an important role in the advertising, graphic and printing industries. When using the automatic hot stamping, pay attention to the correct operation method to prevent damage to the machine and effectively reduce the damage of the automatic hot stamping.
How to deal with the phenomenon of reverse pull of the automatic hot stamping machine? The following is an introduction to us by the Great Wall Machinery manufacturer:
Reverse pull is also a common hot stamping problem. The so-called reverse pull means that after hot stamping, the anodized aluminum foil layer is not firmly attached to the bottom color ink layer of the printed matter or the surface of the white paper, but part or all of the bottom color ink layer is pulled away by the anodized aluminum. In the actual production, it is not easy to distinguish between reverse pulling and hot stamping. If it is judged that the hot stamping cannot be applied or the hot stamping is not strong, the purpose of increasing the hot stamping temperature and pressure, or even replacing the anodized aluminum with stronger adhesion, will encourage the growth and make the anti-pulling problem more serious. Therefore, it is necessary to firstly distinguish between reverse drawing and hot stamping. The simple way to distinguish is: observe the anodized aluminum base film layer after hot stamping, if there are traces of the background ink on it, it can be concluded that it is reverse pulling.

The reasons for the reverse pull failure: one is that the silver layer of the background color of the printed matter is not dry; the other is that white ink is used too much as a weakening agent on the light-colored ink layer.
Hot stamping anodized aluminum is different from the general multi-color printing. It has a peeling force during the hot stamping process. This peeling force is much larger than the separation force that occurs during ink printing. After the ink on the printed matter is transferred to the paper surface, as long as it is sufficiently dry, it can have a strong adhesion on the paper surface. Before the rejection layer is not completely dry, the peeling force of the anodized aluminum hot stamping separation is much greater than the solidification of the ink layer. If force is applied, the base color layer will be pulled away by the anodized aluminum. Therefore, the hot stamping process of anodized aluminum requires that the oil layer on the surface of the printed matter must be fully dry to ensure that it is well fixed on the paper surface.

In operation, it is often felt that the dark ink layer of the printed matter is easier to be hot stamped than the light ink layer. This is because the light ink is mostly made of white ink to weaken the distribution. Because the pigment particles of the strontium ink are thicker, the binding force between them and the linking material is difficult. Very poor, the bonding material of the ink after printing is easy to be absorbed by the paper surface, and the pigment is easy to float on the surface and become pulverized. On paper, the pulverized layer will be taken away by the anodized aluminum.

Automatic stamping machine
The fundamental measures to prevent anti-pulling problems: First, to grasp the interval between the printing of the printed matter and the hot stamping of anodized aluminum, which requires the control of the addition of drying oil during printing, and the printed matter that needs to be hot stamped. The amount should be appropriately added to the printed matter that does not need hot stamping (for example, the amount of red drying oil can be controlled at about 0.5%), but it should not be passed away to prevent the crystallization and emulsification of the ink layer, which will also bring trouble to hot stamping; Second, it is forbidden to use the ink alone as a weakening agent during printing. Because the weakening effect of white ink is good, it is impossible not to use it completely.
When the hot stamping has a reverse pull problem, if it is caused by the dry ink layer of the product, the solution is to place the product in a ventilated and dry place, and appropriately delay the hot stamping time. If it is caused by the chalking of the inner layer of the background color or the excessive addition of white ink, you can use No. 991 bright light remover and 3% white drying oil to overprint it again and then perform hot stamping.