Current situation and development trend of the hot

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The current situation and development trend of pad printing technology (Part 2)

▲ plate making

plate making is the prelude of printing technology. Traditional printing is realized by first transferring the graphics and text on the original to the surface of the plate. As far as pad printing is praised by the people all over the country again, it should be a combination of gravure plate making technology and corrosion label technology. Gravure plate making technology has now developed into engraving and laser engraving, and acid corrosion technology has been phased out for label corrosion, but pad printing plate making still remains a very old process, which is related to the conditions of the engraving technology itself. First, the cost of pad printing processing is low. The cost of electronic engraving and laser engraving is too expensive for ordinary enterprises to afford. Many enterprises have put forward electric corrosion technology, but none of them can guarantee the pad printing plate that can be put into printing after corrosion. The operation process of acid corrosion is easy to master and the cost is low. Although there is serious environmental pollution, it is still adopted by most enterprises

▲ pad printing steel plate

the use of trowel printing steel plate occupies a dominant position in the pad printing process. 100% of the oil pan pad printing machines and 16% of the oil pan pad printing machines use thick steel plates with a thickness of about 15mm recently. Another 77% of the oil pan pad printing machines use thin steel plates with a thickness of 0.25mm and 0.5mm. The plate making process is the same whether it is thin steel plate or thick steel plate. The substrate used is also roughly the same. The steel plate must have a fine structure, and the surface finish must be high enough, but the words such as calcium silicate plate (or sand paddle and other inorganic materials) shall be used as the back plate of the sample. The former must ensure the uniformity of the edges of the pictures and texts after corrosion, and then ensure the integrity of the point structure, so that the sharpness and color of the edge trimming of the printed pictures and texts can be realized to the greatest extent; The latter ensures the cleanliness of the scraping and the printing resistance. The surface tolerance of thick steel used in the oil pan pad printing machine is higher. Excessive surface tolerance on the one hand accelerates the wear of the oil pan, on the other hand, it is related to the sealing of the ink, which is used in the oil pan type pad printing machine; The steel plate on the printing machine should be used on the oil cup machine to ensure higher surface finish and lower flatness tolerance

the thin steel plate has better flexibility, so it is easy to ensure the cleanness of ink scraping. However, this is related to the manufacturing accuracy of the base plate supporting the steel plate. If the surface tolerance of the base plate does not meet the requirements, the ink will leak during the sliding process between the oil cup and the steel plate. Another factor is the manufacturing accuracy of the sliding guide shaft of the oil cup, such as surface roughness and fit tolerance, which are reflected in the indicators of the assembly level of the whole machine. How to control the parallelism tolerance between the guide shaft and the steel plate is very important. From this point of view, the manufacturing of thick steel plate oil cup pad printing machine is more difficult

▲ resin version

resin version has not been applied to pad printing process for a long time, but it has been paid attention to, which should be attributed to many characteristics of polymer materials. The resin is mainly nylon photosensitive adhesive, which is cast on the surface of the zinc plate, similar to the resin plate used on the self-adhesive trademark. Nylon has very good wear resistance. After photosensitive curing, it can obtain extremely fine copper dots. If you copy exquisite small printing crystals, resin plate is the first choice. If it is said that it will be more difficult to manufacture a pad printing machine using a resin plate, after all, nylon photosensitive adhesive is a high polymer material. When the manufacturing accuracy of the substrate supporting it is poor, it is not easy for the pad printing machine to complete general printing. The surface state of polymer materials is very fine, and slight defects will seriously affect the printing quality

▲ plate making process

iron can be dissolved in acid or acid solution such as data report printing, which is the theoretical basis for the production of pad printing steel plate. At present, nitric acid solution with protective agent is mainly used for corrosion. The acid used in this corrosion method gives off a bad smell, and the generated products nitric oxide and nitrogen dioxide are very harmful to human body. Most of the development of steel plate corrosion uses chemical solvents with hydrogen peroxide as the main body, which also has certain damage to human skin. So European countries have already banned it. They began to use resin plates or laser engraving to make plates. It is a relatively new idea to use the powder free etching machine for corrosion of zinc plates for reference to corrode steel plates, and some manufacturers have successfully trial produced it. This method greatly reduces environmental pollution. Resin plate making is more environmentally friendly and safer. The resin version uses nylon photoresist, which can be developed with alcohol. With the popularity of digitalization, the time to make pad printing resin plate by digitalization will not be too long

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