Comparison of Hot Stamping and Cold Stamping Technology (Part 2)

(1) Cold stamping graphics often require secondary processing of the film or glazing, which increases the stamping cost and process complexity.

(2) Coated high-viscosity adhesives have poor leveling and are not smooth, which causes diffuse reflection on the surface of cold stamping foils, which affects the color and gloss of hot stamping graphics, thereby reducing the aesthetics of the product.

J.Michael Rivera, deputy general manager of sales for AMAGIC Hologrphics, said that although the cold stamping process cannot achieve the high precision and high definition of the hot stamping process, the cold stamping technology can bring many advantages to the flexographic printer, among which, Including: less initial equipment investment, lower platemaking cost, faster hot stamping, online completion on the press, materials that are not suitable for hot stamping processes (eg film without base, PET and plastic bags, etc.) ) Hot stamping and so on.

Cold foil stamping technology can achieve the best hot stamping effect on film and non-absorbent paper materials. On the contrary, when cold stamping on porous materials with high permeability, the effect is not ideal. However, Mr. Rivera pointed out that some of AMAGIC's customers have performed hot stamping on Raflatac Raflasilk's matte PSA material, and the feedback results are also quite good. In addition, some customers can obtain better cold stamping results by applying primers and gluing on matt paper materials.

Cold stamping technology has become a strong competitor of hot stamping technology, and cold stamping technology is expanding from narrow flexographic printing to other printing processes, such as wide flexographic printing, embossing, web offset and single printing. Sheet offset printing and so on. For example, on Drupa 2004, Roland 700 sheet-fed offset press equipped with Manroland's new Prindor InLine cold stamping device was exhibited.

Cold stamping technology has provided new opportunities for printing companies. Its greatest advantage is less investment, or even no investment at all. Another outstanding advantage is the high cost performance, which is also the biggest selling point of cold stamping technology. As some industry insiders have said: “For customers, the cost-effectiveness of cold stamping technology is higher, which can help customers increase the added value of the products and is very cost-effective.” In addition, since cold stamping technology does not require the production of expensive hot stamping, So it is very suitable for short-lived, low-quality labeling and proofing production. However, compared with the hot stamping technology, the cold stamping technology still has certain defects in quality and needs to be further improved. Therefore, the cold stamping technology is not suitable for the processing of high quality packaging and label products.

Here, I would also like to mention here that although gold and silver ink printing can also produce metallic gloss decorative effects similar to those of hot stamping, and gold and silver ink printing technology has made great progress in recent years, it still cannot be achieved. Hot stamping or cold stamping technology brought about by the kind of strong visual impact.

2 cold stamping process conditions

In general, cold stamping can usually be applied to a job printed on a UV flexographic printing press. The equipment and materials required for the cold stamping process are as follows.

(1) Standard flexographic printing or embossing unit.

(2) Photopolymer plates and anilox rollers, and there must be enough spare anilox rollers to choose from.

(3) The embossing roller with a hardness of HS90 must be able to be easily installed in the printing unit, and it must be ensured that sufficient pressure is provided to ensure that the hot stamping is carried out smoothly.

(4) Hot stamping foil unwinding device and rewinding device. Care should be taken to adjust the winding tension when cleaning waste to avoid wrinkling or delamination of the stamping material.

(5) Hot stamping foil.

(6) UV adhesives.

(7) UV curing system. The UV curing system must be as close as possible to the imprinting device in order to cure the UV adhesive in time after printing and stamping. In addition, the UV curing system must have a power of at least 300 W. The UV lamp and the reflector must be kept clean and free of UV varnish and dust impurities, so as not to affect the UV adhesive curing effect.

(8) Stripping device. The peeling device is installed at the back end of the UV curing system. In addition to peeling the waste foil, the device can also prevent the delamination phenomenon of the hot stamping foil before the UV curing, and can also reduce the wrinkle, skew and other defects of the printing material.

In addition, in order to obtain high-quality hot stamping products and high profit margins, skilled operators are also required to be able to handle and solve various problems occurring in the production process, especially those related to UV systems.

Conclusion

In actual production, in the end choose hot stamping technology or cold stamping technology? The answer is: It should be based on specific circumstances. Using hot stamping technology can achieve the best hot stamping quality and hot stamping effect, but the cost is higher. Although the quality of the cold stamping is not bad, it is inferior to the hot stamping but at a lower cost. No matter which kind of hot stamping technology you use, you should pay attention to these two kinds of hot stamping technologies because the price of hot stamping is constantly being adjusted downwards, and the quality of cold stamping is also constantly improving. Both kinds of stamping technologies are in constant condition. Progress and development.

When a printing company decides whether to invest in cold stamping technology, it must combine the actual situation of the company to understand the situation of the company's printing press, because the use of cold stamping process means that a printing unit is to be replaced by cold stamping units, but also need to add The stripping device may affect the normal printing of the job if the number of color groups of the printer is not enough.

In addition, it is also necessary to determine whether the job is suitable for the cold stamping process. A careful study of the graphic texts to determine whether it can achieve the desired effect after cold stamping. Printing companies can work together with UV adhesive suppliers to test cold stampings to provide customers with more choices and improve their ability to serve customers. On the basis of existing customers, it can also enhance the company's own competitiveness and create the potential for consumer demand for its products.

Source: "Printing Technology"