ã€China Aluminum Industry Network】 1. Hot stamping is the primary factor in guaranteeing the quality of stamping. At present, the production of hot stamping version mainly adopts the photo etching technology and the electronic engraving technology. The materials are often used for copper plate or zinc plate. Copper plate material is delicate, surface finish, heat transfer effect is better than zinc plate, the use of high-quality copper plate can increase the bronzing graphic gloss and outline definition. The traditional photographic corrosion technology makes the bronzing plate process simple and low cost, mainly used for text, thick lines, general images; for the finer, uneven thickness of the text and other bronzing plates need to use the second rotten or the use of electric carving technology. Electric carving production bronzing version can express rich and delicate level changes, greatly expanding the packaging performance, the process is conducive to environmental protection, but the electric carving equipment investment is relatively large, the depth of the current sculpture is not ideal enough, easy to cause hot stamping "glue". Holographic anti-counterfeit stamping production technology requirements are relatively high. Previously, they were mainly produced in Taiwan or abroad. The plate making cycle was long and only used for the packaging of fixed and large-volume products. At present, there are several units that can be produced in Shanxi Yuncheng, Beijing and Shanghai. Second, bronzing equipment "workers want to do something good, we must first sharpen its device" The selection of bronzing equipment is a key factor in determining the quality of bronzing. Sheet-foil hot stamping machine has flat pressing, round flat pressing and round pressing. There are three types of flat pressing machines at present. The main ones are: Shanghai Yahua Printing Machinery Co., Ltd. TYM series die cutting hot stamping Dual-use machine, TYMl020 automatic bronzing die-cutting machine of Tangshan Yuyin Group Company, MK series automatic bronzing die-cutting machine of Tianjin Ever Machinery Industry Co., Ltd., with high bronzing speed of 5000 hours. The German Stoll FOLLJETFBRl04 hot stamping machine is represented by a round press circle. Using the design concept of an offset press, the high hot stamping speed can reach 10,000 hours. Currently, it is an internationally high-speed single sheet hot stamping device. Round press, round press, and flat press Three stamping methods have their advantages and disadvantages: Round press, round press The hot press is a line pressure, the total pressure is small, and it can be easily completed with a relatively small pressure. A large area of ​​gilding in the field, smooth movement, and high round-ring production efficiency, especially suitable for large quantities of live stamping, but due to the difficulty of copper circular surface processing, higher production costs, heating roller is also more difficult than the plane heating. Flat press operation is flexible and convenient, and it is more suitable for short version products. Compared with imported bronzing equipment, domestic bronzing equipment has obvious advantages in terms of performance and price. The price of domestic machines is only equivalent to the price of similar products in the foreign countries, but the accuracy, stability and function of imported machines are obviously better than that of domestic ones. Machines are also more durable than domestic ones and are more suitable for the processing of fixed high-end packaging products. Therefore, the product type and lot size are the key factors that determine the selection of bronzing equipment. Whether or not BOBST and other high-end stamping die cutting equipment have become the preferred conditions for customers in the industry. Third, the bronzing suitability The so-called gilding suitability refers to the choice of model and the bronzing speed, temperature, pressure and other factors. In the case of fixed hardware such as equipment, proper control of bronzing suitability is an important means of improving the quality of bronzing. The following analysis of some of the quality issues reflected in the actual operation, in order to scientifically grasp the bronzing nature. 1. This is not related to hot stamping or hot stamping. This is related to various factors such as the surface characteristics of the printed part, the nature of the electrochemical aluminum, the hot stamping temperature and pressure. Too much dust on the surface of the print or the surface contains additives such as release agents, bright sizing, which will hinder the adsorption of aluminum and paper. The solution: surface dusting or solution in the printing process. Improper use of anodized aluminum directly affects the fastness of hot stamping. According to the size of the bronzing area, the characteristics of the stamped material should be considered in consideration of what type of galvanized aluminum is selected. Domestic aluminum products are mainly peacock brand series produced by Shanghai Shenyong Hot Stamping Materials Co., Ltd. The imported galvanized aluminum is mainly the PM and LK series from Germany Kurtz, the A, K and H series from Japan, and the KO series from South Korea. According to our practice and testing, the matching of the galvanized aluminum can mainly refer to the following classifications: The bronzing type of electro-aluminum on common products has type 88-1, PM type of KURZ; printed materials such as cigarette packets, cosmetics, etc. (including gold and silver) ) The gold-clad anodized aluminum is type 88-2; cigarettes, cosmetic packaging and other fine handwriting stamping of electro-aluminum are 88-3, 88-4, PM288, etc.; suitable for OPP or PET laminated paper and UV ink The paperboard, glossy paper and other products stamped with electro-aluminum are 88-4 type, K series, LK series, and SP series. The correct match between the hot stamping equipment and the hot stamping time and the hot stamping temperature does not affect the hot stamping fastness and sharpness of the graphic outline. Due to the different equipment and hot stamping materials, the hot pressing time and hot stamping temperature are not the same. For example, a high-speed circular press has a fast speed and the embossing line contacts. The hot stamping temperature is higher than that of a round press or a flat press. Under normal circumstances, the round stamping hot stamping temperature is between 190°C and 220°C, the rounding pressure is approximately between 130°C and 150°C, and the flattening is approximately between 100°C and 120°C. Of course, hot pressing time, hot stamping temperature and production efficiency are also largely constrained by the transferability of the electro-aluminum. 2. Anti-pulling and pulling means that after the hot stamping, the electro-aluminum will pull off the printing ink or the varnishes on the printings. The main reason is that the ink on the surface of the printed product is not dry or the post-processing of UV on the surface of the printed product is improperly processed, resulting in the combination of the ink on the surface of the printed product, the UV oil, and the surface of the paper. Solution: After the prints are dried and then hot gold. In addition, it is possible to use anodized aluminum with low electro-aluminum separation and excellent heat transfer. 3. Paste-printing and hot stamping of electro-aluminum discoloration pastes are mainly caused by poor bronzing production, looseness in the installation of galvanized aluminum, or improper foiling in galvanized aluminum. After the stamping, the discoloration of the electro-aluminum is mainly due to the high stamping temperature. In addition, the wrinkling of the aluminum foil is also likely to cause discoloration due to uneven color stamping, which can be solved by appropriately lowering the temperature. For the round-flattening machine, fans can be installed at the foil feeding place to keep the foils from floating, avoiding the aluminum foil touching the hot stamping and scorching before the stamping. 4. The improper arrangement of the process destroys the luster of the surface of the electro-aluminum, and the outline of the graphic is confusing. In the bronzing process that requires lamination, people often worry that the gold foil will be easily wiped off and hot stamped and then laminated. This can easily lead to: 1 The film (especially the matt film) will destroy the luster of the surface of the electrodeposited aluminum. It is not appropriate to use water-soluble glue to cover the film. Otherwise, the surface of the electrodeposited aluminum will be blackened, and the powder will easily stick to the edges of the picture and cause the phenomenon of hair crazing. 2 After the bronzing, the dent is caused by the pressure, and the glue is not easy to penetrate the surface of the galvanized aluminum, which can easily cause separation of the OPP from the bronzing office and affect the product quality. The correct process is to apply foil and then hot stamping, choose the matching of aluminum and OPP. In short, there are many factors affecting the quality of bronzing. Making high-quality bronzing plates and correctly grasping bronzing suitability are the key to improving the quality of bronzing. The bronzing process utilizes the principle of hot-press transfer to transfer the aluminum layer in the galvanized aluminum to the surface of the substrate to form a special metal effect. Since the main material used for the bronzing is the galvanized aluminum foil, the bronzing is also called galvanized aluminum hot stamping. Electrochemical aluminum foil is usually composed of multiple layers of material, the substrate is often PE, followed by the separation coating, color coating, metal coating (aluminum) and glue coating. In the printing industry, electronic foils are commonly used for hot stamping on paper, which is called bronzing. Hot stamping is a collective term for a process. Bronzing does not mean that gold is hot? There are many kinds of gold foil paper materials, including gold, silver, laser gold, laser silver, black, red, green and so on.