Problems to be Noted When Hot Stamping on Composite Paper Surfaces

In recent years, with the continuous improvement of people's requirements for the packaging of goods, hot stamping as a means commonly used in packaging and finishing processing has achieved rapid development, and its process technology has been increasingly perfected, and new application forms continue to emerge. However, due to many factors in the actual application, there are still some more difficult problems.

Hot stamping on the surface of composite paper Hot stamping on the surface of white paperboard is relatively easy. Most hot stamping foils can obtain a good hot stamping effect on the surface, and the hot stamping foil does not require much. Most operators only need to perform simple pad pressure and temperature adjustment on the hot stamping plate to solve all kinds of problems in hot stamping. However, the hot stamping of the composite paper puts higher requirements on the performance of the hot stamping foil. It is imperative to correctly understand and deal with the relationship between the composite paper and the hot stamp foil.

1. Surface tension of composite paper
There are many kinds of composite papers. At present, there are mainly PET film papers, aluminum foil papers, aluminum spray papers, and transfer papers. The surface tension of these composite materials is different, which directly affects the hot stamping effect and the normal operation of the hot stamping process. Therefore, the problem of hot stamping on such papers cannot be solved by simple adjustment of process parameters. From the analysis of the characteristics of composite paper and the performance of hot stamping foil, the surface tension of composite paper stamping can be solved by the following methods.

(1) External assistance method A hot stamp foil is selected based on the surface properties of the paper. It is mainly through the technical force of hot stamping foil manufacturers to solve the hot stamping problem. Under normal circumstances, hot stamping foil manufacturers will solve the hot stamping problem by adjusting the adhesive layer of the hot stamping foil according to the properties of the surface of the composite paper.

(2) Active attack method Surface treatment of the composite paper, changing its surface tension to meet the requirements of hot stamping foil. One of the methods is to coat the surface of the paper with a thin layer of colorless varnish, using an integral or partial coating method depending on the circumstances.

(3) Coordinating with each other When the above two methods are used alone or when the problem of hot stamping cannot be solved, the external assistance method can be combined with the active attack method to solve the hot stamping problem.

2. Types of Composite Papers There are various kinds of composite papers and their physical properties are different. In solving the problem of hot stamping of such papers, it is also necessary to pay attention to the different requirements of various composite materials on the properties of hot stamping materials. According to different papers, different hot stamping foils are used. The appropriate temperature range of the hot stamping foil adhesive layer is also selected according to the type of composite material, and hot stamping is performed under the best condition. For example, when printing on PET film, the temperature is lower than that on aluminum foil.