The gold sweep technology is widely used in the packaging of cigarettes, wine, medicines, cosmetics and high-end foods, as well as the printing of greeting cards, invitations, calendars and other products, which can make great progress in the added value of goods. In the 1990s, China's gold-sweeping technology has achieved certain development. Some areas with advanced packaging and printing (such as Guangdong) have also introduced several gold-sweeping machines, which are mainly used for the production of cigarette packets and drug packets. With the progress of packaging requirements in China, the gold-sweeping technology will have greater development. The processing of imitation gold effect is one of the effective measures for the advancement of commodity packaging. At present, there are mainly gold ink printing, matte printing, gilding and sweep gold. Each method has its own characteristics. The following mainly talks about sweeping gold technology. 1 What is sweeping technology The so-called gold sweeping is the process of realizing the metallic luster effect by attaching a special metal powder to a specified part of a commodity package or a label print through a special process. This technology gives a realistic metal texture and good gloss, while the pattern is fine and the overlay is correct. 2 The application of sweep gold technology The gold sweep technology is widely used in the packaging of cigarettes, wine, medicines, cosmetics and high-end foods, as well as the printing of greeting cards, invitations, calendars and other products, which can make great progress in the added value of goods. In the 1990s, China's gold-sweeping technology has achieved certain development. Some areas with advanced packaging and printing (such as Guangdong) have also introduced several gold-sweeping machines, which are mainly used for the production of cigarette packets and drug packets. With the progress of packaging requirements in China, the gold-sweeping technology will have greater development. 3 sweep gold process principle The process of sweeping gold is very simple. You need to place sweeps of gold on a monochrome or 2-color offset press. Use a special PS board to print a layer of viscous glue on the part where you need to sweep the gold. Then the print sheet goes through the paper feed device and enters the sweeper. Machine, sweeping the powder and polishing, gilt, etc. can be completed. At present, the German-made Jazz brand automatic gold-sweeping machine is mainly composed of five departments: paper-feeding mechanism, coating mechanism, polishing mechanism, cleaning mechanism, and delivery mechanism. The prints can be processed from thin paper to cardboard, from four to full sheets, and the speed can reach 8000 sheets/hour. The gold sweeper usually needs a flat sheet single (double) offset press (to remove the delivery device) to connect with the sweeper. Firstly, the special PS version of the sweeper machine is well installed and adjusted on the offset printing press. The printed version of the PS version is printed with a thin and average primer on the printed matter, and then the print is passed through the gold sweeper. The paper transfer device is sent to the suction rubber conveyor belt of the sweeper, and the gold powder is averaged by the coating mechanism and applied to the surface of the print sheet. When the side of the applicator roll, on which the gold powder is adsorbed, goes to the top of the sheet, the department switches from inhalation to blowing and distributes the powder evenly over the entire surface of the sheet. The four polishers of the polishing mechanism are rubbed and polished with the gold powder on the print sheet so that the gold powder printed on the printed sheet is tightly adhered to the primer. At the same time, the gold sweeper also uses four special gilt-metal strips, which perform opposite reciprocal movements between each other to improve the metallic luster and adhesive fastness. The latter two have powerful suction tubes to remove excess gold powder. The high-vacuum adsorption multi-path sweeping system of the cleaning organization plus the front suction pipe can quickly clear the excess gold powder on the printed sheets. These extra gold powders can be used in a round manner without causing environmental pollution or spreading. Finally, the paper collection agency completes the collection and collection of food. Of course, if the printing plant has multi-color printing presses and UV drying devices, on-line sweeps can be performed. That is, the prints are printed on the first few colors of the printing press before being fully dried by the UV drying device on the last color set. The primer is printed and then transferred to the gold sweeper via the connecting device. 4 The characteristics of sweep gold technology The gold-sweeping technology and several other gold-imitation effect processing techniques have advantages in many aspects. Of course, there are also deficiencies. 1) Compared with printed gold At present, gold can be offset, gravure, flexo, and screen printing, especially offset and gravure, both of which are faster. Offset ink layer is thin, metallic luster is not very good; gravure ink layer is thick, gloss is better than offset printing, but metal texture is not strong enough when printing on a large area, easily deformed when printing small characters and small lines, and the quality is not well controlled. 2) Compared with bronzing Hot stamping as a traditional imitation gold processing technology, metal luster and metal texture are very strong, is an indispensable processing technology for some high-end packaging, in this regard it is better than the gold scan. Although the quality of the gilding effect is good, but most of it needs to be affixed to the family and the genus. Persimmon ç° ç° åˆ‚ 刂 刂 å–½               æ’¸îƒè –å—îž æ’¸îƒè –å—îž æ’¸îƒè –å—îž æ’¸îƒè –å—îž æ’¸îƒè –å—îž æ’¸îƒè –å—îž æ’¸îƒè –å—îž æ’¸îƒè –å—îž æ’¸îƒè –å—îž æ’¸îƒè –å—îž æ’¸îƒè –å—îž æ’¸îƒè –å—îž æ’¸îƒè –å—îž æ’¸îƒè –å—îž 3) Compared with matte printing Although the matte printing has good metal texture and luster, but the production efficiency is low, the discarded packaging is not easy to recycle, which is not conducive to environmental protection. 4) The strengths of sweeping technology The technology of sweeping gold is simple, speedy, and low in cost. It can achieve good results regardless of the thickness of the image and the size of the area. After sweeping gold, the product has a better metal sand grain and light diffuse reflection effect, and the metal texture is more real, giving people a visually significant three-dimensional feeling, different from gold printing and bronzing. The color of the sweeper is rich and colorful. In addition to the most commonly used gold, there are silver, bronze, green, graphite, tan, lemon yellow, peacock blue, and the widely used imitation diamond powder that has recently been used in Europe and North America. And laser gold powder. These gold powders have different particle sizes and can show a variety of unique effects.  Anti-counterfeiting effect: Because the gold imitation effect obtained by sweeping gold is different from that of printing gold, bronzing and frosted printing, it is unique, difficult to imitate, and has a certain anti-counterfeiting function. 5) The disadvantages of sweeping money Although sweeping gold technology has a very significant advantage, it is not perfect. The most important feature of sweeping gold is the formation of imitation gold effects in specific areas. However, it is difficult to achieve the best metallic luster and texture in a single gold sweeping process. It is not as good as gold foiling in some respects. In the case of prints that require a large area of ​​imitation gold, it is not as good as printing gold, and it has no advantage in effect. Therefore, gold sweeping is only a mid-range gold-imitation effect processing technology. It has certain limitations, which restricts its rapid development to some extent. The requirements of the sweeper on the environment are very high. The temperature should be controlled at 22 to 25°C and the humidity should be controlled at 50 to 55%. Otherwise, quality problems will easily arise. The common faults in sweeping gold are dirt and powder. The main causes are as follows: (1) The humidity of the gold sweeping workshop is too high or the moisture content of the paper is too high, which can cause the gilt-gold ribbon to get wet and dirty; 2 the imprinting of the printed matter is not dried out, resulting in the adhesion of gold powder to the parts that do not need to sweep gold; 3 The viscosity of the primer at the site where the gold is to be scanned is insufficient or the glue is insufficient to cause powder fall-off. 5 Conclusion From the analysis above, we can see that the gold-sweeping technology still has some disadvantages, but its advantages are still very long and short-term, especially in terms of security, metal texture and advertising effects. At the same time, the cost of sweeps is relatively low, and printers can obtain higher profits. Although there are few manufacturers currently using sweepers in the country, following the continuous maturation of gold powder processing technology and gold sweeping technology, as well as the perfect combination of gold sweeping and bronzing and silk screen printing, will be in the packaging and printing industry in China, especially in the tobacco industry. The unique function of the bag, wine bag, high-grade medicine and food packaging.