Gold sweeping technology for new process commodity

2022-08-14
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New post press technology: Gold scanning technology of commodity packaging

release date: Source: Wenhong machinery editor in charge: China Packaging browsing times: 1162 copyright and disclaimer

core tip: with the development of packaging and printing market, packaging technology is also becoming more mature and diversified. In order to pursue the grade of commodity packaging and improve the added value of commodities, a new process of imitating ◆ pellethane TPU - the best substitute for PVC in medical equipment manufacturing - Gold sweeping technology was born

[China Packaging News] with the development of the packaging and printing market, the packaging technology is becoming more and more mature and diversified. In order to pursue the grade of commodity packaging and improve the added value of commodities, a new process of gold scanning technology using gold imitation effect on commodity packaging was born

I. what is gold sweeping technology?

Gold sweeping is a special post press processing process in fine printing. It is to attach special metal powder to the designated part of commodity packaging or label printing, so as to realize the gold imitation effect of golden light flashing. This technology can get realistic metal texture and better gloss, at the same time, the pattern is fine and the overprint is accurate. The metal sand feeling and light diffuse reflection effect of the products after gold sweeping are better, and the metal texture is more real, giving people a visually obvious three-dimensional feeling, which is different from gold printing and bronzing

II. Gold sweeping process

the process of gold sweeping is actually very simple. Put the print sheets that need gold sweeping on the monochrome or two-color offset press, and apply a layer of adhesive with a special PS plate on the parts that need gold sweeping, and then the print sheets enter the gold sweeping machine through the paper feeding device, sweep gold powder, polish, wipe gold, etc

the gold sweeping process is completed by the gold sweeping machine, which is mainly composed of five parts: paper feeding mechanism, coating mechanism, polishing mechanism, cleaning mechanism and paper receiving mechanism. The process flow is as follows: when scanning gold, a single sheet single (double) color offset press (removing the paper receiving device) is generally required to connect with the scanning machine. Using the color separation negatives of the printing products, a PS version dedicated to the gold scanning machine is made and installed on the offset press. The registration work can be completed by adjusting the rules of the offset press. Use PS plate to print a thin and uniform primer (commonly known as gold sweeping primer) on the part of the print that needs gold powder

the printed matter printed with primer is sent to the rubber conveyor belt with suction channel in the gold sweeping part through the paper conveyor of the gold sweeping machine. The coating device composed of gold powder filler, applicator with ink bucket roller and coating roller with different fixtures can be started. The coating roller rotates, and when the side of the coating roller adsorbing the gold powder turns to the top of the paper, this part changes from suction to blowing, and the gold powder is evenly sprayed on the surface of the paper. Four special polishers rub and polish the gold powder on the paper, and stick the gold powder with the primer printed on the paper to the paper

the gold sweeper adopts four special gold wiping tapes, which turn opposite to each other to improve the metal luster and bonding fastness. The latter two with strong suction pipes, coupled with the high vacuum adsorption multi-channel cleaning and circulation system of the cleaning mechanism, can clean up the excess gold powder on the printing sheet cleanly and quickly. These excess gold powder can be recycled, which will not cause environmental pollution and waste. Finally, the paper receiving mechanism completes the paper receiving and finishing work

if the printing factory has a multi-color printing machine and UV drying device, online gold scanning can be carried out, that is, the printed sheets are printed on the first few color groups of the multi-color printing machine and fully dried by the UV device, then the sticky primer is printed on the last color group, and then enter the gold scanning machine through the connecting device for gold scanning. In the above cases, when it is not necessary to sweep the gold, the gold sweeping equipment can be separated from the printing machine within a few minutes, so that the printing machine can carry out ordinary printing again

III. characteristics of gold sweeping process

gold sweeping has its unique advantages compared with other gold imitation processing processes in fine printing. As a widely used process, gold printing and bronzing have many advantages, but also some disadvantages. For example, at present, offset printing, gravure printing, flexo printing and silk screen printing can be used for printing gold, especially offset printing and gravure printing, both of which are relatively fast. Offset ink layer is thin, and the metallic luster is not very good; Although the gravure ink layer is thicker and the gloss is better than offset printing, the metal texture is not strong enough when printing large areas, and the deformation is relatively serious when printing small characters and thin lines; As a traditional process, bronzing has a strong sense of metal, but it has high energy consumption, relatively low efficiency, and some difficulties in registration. The quality of small graphics and large areas of bronzing is not easy to control

although frosted printing has good metal texture and luster, its production efficiency is low, and the waste packaging is not easy to recycle, which is not conducive to environmental protection. The gold sweeping technology has the advantages of simple operation process, high production speed (up to 7500 pieces/hour), and low cost. Good results can be obtained regardless of the size of the image and text and the size of the area. Gold powder also has a variety of colors, such as gold, silver, reddish gold, copper, green, stone, but its versatility is poor. Ink, Tan, lemon yellow, malachite blue, etc., can be described as everything, and has different particle sizes, which can show a rich color

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