Talking about the Process and Precautions of the Stamping and Stamping Process

The essence of hot stamping is heat transfer, which is the process of transferring the electrochemical aluminum to the surface of the substrate by the action of temperature and pressure. The perfect hot stamping effect depends on temperature, pressure and hot stamping time. The constant of the three parameters is the continuous printing and the guarantee of quality. The process of hot stamping is: the electroless aluminum is heated by the hot stamping plate, the peeling layer is melted, and then the adhesive layer is bonded to the substrate, the colored layer is separated from the base layer of the polyester sheet, and the aluminized layer and the colored layer are left on the substrate.

Type and basic characteristics of hot stamping process

The type of hot stamping process is mainly divided into lithographic hot stamping, engraving hot stamping + bump, hot stamping + embossing. The surface of the hot stamping process is flat, and the plate is mainly made of zinc plate or red copper plate, and the thickness is generally 2mm. The surface of the hot stamping + bumping hot stamping pattern is three-dimensional, and the main plate is copper plate and resin. The thickness of the plate is generally 7mm; the surface of the hot stamping + embossed substrate has obvious grain, and the plate is generally made of copper plate, and the thickness is generally 2mm or 7mm.

After hot printing , a large area of ​​anodized aluminum is usually printed on a spot color ink or an unprinted paper surface, and then a UV ink is printed on the aluminum alloy. It has high requirements for printing materials, printing inks, printing equipment and printing personnel.

Production process and process control of hot stamping products

According to the actual requirements of the sample and production work orders, the production requirements are understood according to the corresponding samples and production work orders, and the corresponding plates and auxiliary materials (including anodized aluminum, hot stamping plates, film and other auxiliary materials) are determined according to the sample. The key monitoring items are as follows.

1. Set: Set hot stamping or specific inspection tools, such as film.

2. Hot stamping effect: pattern integrity, edge uniformity, surface gloss.

3. The surface of the printed matter is printed with indentation, scratches, nozzles, ink-printed edges, ink-printed edges, gold, and anodized aluminum.

Problems that are prone to hot stamping

During the hot stamping process, pay attention to the choice of the type of anodized aluminum and the matching between hot stamping speed, temperature, pressure and other factors. In the case of fixed hardware such as equipment, correct mastering of hot stamping is the most important means to improve the quality of hot stamping.

1. Hot stamping is not possible or hot stamping is not true: this is related to the surface characteristics of the print, the nature of the electrochemical aluminum, hot stamping temperature and pressure. 1 The surface of the printed matter is too dusty or the surface contains additives such as detacking agent and brightening paste, which will hinder the adsorption of the electrochemical aluminum and the paper. Solution: Surface de-powder treatment or solution in the printing process. 2 improper use of electrochemical aluminum directly affects the hot stamping fastness. According to the size of the hot stamping area and the characteristics of the hot stamping material, what type of electrochemical aluminum should be selected. The domestically produced anodized aluminum is mainly Guangzhou Leibao and Wuhan Huagong Technology; the imported electrochemical aluminum is mainly the German Kurz series and the Taiwan Guangqun series; 3 the correct matching of the hot stamping equipment and the matching between the hot pressing time and the hot stamping temperature, the influence The sharpness of the hot stamping and the sharpness of the graphic outline. Due to the different materials and hot stamping materials, the hot pressing time and hot stamping temperature are not the same. For example, the high-speed circular pressing machine is fast, the embossing line is in contact, and the hot stamping temperature is higher than the round flat or flat flat. Under normal circumstances, the round stamping temperature is 190 ~ 220 ° C, the round flat is about 130 ~ 150 ° C, the flat pressure is about 100 ~ 120 ° C. Of course, the hot pressing time, hot stamping temperature and production efficiency are also largely restricted by the transfer performance of the electrochemical aluminum.

2. Reverse pulling: refers to the removal of printing ink or printing varnish after the hot stamping. The main reason is that the ink on the surface of the printed product is not dried or the UV treatment on the surface of the printed product is improperly processed, resulting in the ink surface of the printed product and the UV oil combined with the surface of the paper. Solution: After the printed products are dried, they are hot stamped. In addition, anodized aluminum with low separation force and excellent thermal transferability can be selected.

3. Paste plate and hot stamping aluminum after discoloration: Paste plate is mainly caused by poorly produced hot stamping plate, slack of electrified aluminum installation or incorrect aluminum foil. After the hot stamping, the discoloration of the anodized aluminum is mainly caused by the excessive hot stamping temperature. In addition, the wrinkling of the anodized aluminum is also likely to cause discoloration and discoloration of the hot stamping, which can be solved by appropriately lowering the temperature. For the round flattening machine type, a fan can be installed at the foil feeding position to keep the foil fluttering up, avoiding the scorching of the electroplated aluminum before the hot stamping.

4. The process arrangement is not proper, destroying the gloss of the surface of the electrochemical aluminum, the contour of the graphic is faint: the hot stamping of the film processing is required, people often worry that the gold foil is easy to be rubbed and the hot stamping is applied again, which is easy to cause: 1 film especially It is the matt film that will destroy the surface gloss of the electrochemical aluminum. It is not suitable to use water-soluble glue film. Otherwise, the surface of the electrochemical aluminum will be black, and it will easily cause the gold powder to stick to the edge of the image to cause fading. 2 After hot stamping, it is sunken due to pressure, and the glue is not easy to penetrate the surface of the electrochemical aluminum. It is easy to cause the separation of OPP and paper in the hot stamping area and affect the product quality. The correct process is to cover the film and then hot stamp, choose the electrochemical aluminum that matches OPP.