The best adhesion strength of UV varnish on the ho

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The best adhesion strength of UV varnish on UV ink

the packaging and printing industry is developing rapidly in the direction of fast, multi-color and one-time printing. UV ink and UV varnish have become the new favorites of packaging and printing materials. However, with the time of application and the increasing application fields, people have put forward newer and higher requirements for the above products: they should not dry on the printing machine, but also dry quickly after printing; Low material cost and high gloss; It should not only have a long storage period, but also have good adhesion fastness after printing and roller coating

at present, few can meet the above requirements at the same time. Packaging and printing operators are concerned about the adhesion fastness of printing ink film and roll coating film, and the second is that it can flow without caking at low temperature, "Professor Abu al rub said

whether it's UV ink or UV varnish, packaging and printing plants are afraid of operating in high temperature and humidity seasons; The second is afraid that the moisture content of the substrate exceeds the standard. Because it is very easy to pull off the ink film or adhesive film when it is first bolted (adhesive tape paper) after printing or polishing on the above workshop environment and substrate, and it will be returned by users. For example, the author found in Henan Luohe "Shuanghui" group that the ham sausage carton packaging of the group was sealed with adhesive tape paper. When the adhesive tape was torn off during consumption, the decoration (ink and varnish) on the packaging seal was pulled off in pieces, which reduced the apparent quality of the packaged goods and directly damaged the following: harmed the brand image of the enterprise. Another example is that Nanjing gold foil group undertakes to print the mouthprint on Wuhan Jinlong cigarettes. When the high-speed automatic labeling is at 140 ℃ -160 ℃, it is often difficult to label in the continuous labeling process, or it is not resistant to high temperature, or the printed image and text color blocks fall off during slitting. However, the latent heat absorbed or released is quite large, which not only affects the reputation of the gold foil group with a certain popularity, but also increases the scrap rate for users

different brands and technologies from photo solid resin or prepolymer to the dosage of crosslinking agent, from photosensitizer to polymerization inhibitor are moving up and down during the experiment. After analyzing the technical parameters and actual proportion of the parts that stretch and shrink the experimental piece, it is believed that some existing manufacturers ignore the role of crosslinking agent, and an ideal crosslinking agent is also an ideal active diluent, which is not only miscible with tree wax, but also can dissolve and dilute unsaturated polyester Resin reduces the viscosity of ink and varnish system and improves the fluidity of ink and varnish. And can participate in the UV curing reaction, so it is often less in its formula, resulting in poor ink fluidity and the agglomeration and non frost resistance of varnish; The second is that too much photosensitizer not only can not improve the curing speed, but also the production cost increases correspondingly. Excessive photosensitizer will reduce the conjunctival strength of UV gondola or UV varnish, etc. The preparation of new materials, adjustment of production process, trial use and comparison of application methods, light intensity and light energy records of photochemical reaction process, curing speed and control of workshop ambient temperature and humidity, Pu value of substrate and different moisture content (1%, 2%, 3%, 5%, 6%, 7%, 8%) were carried out on site. After comparison, it was found that the moisture content of paperboard of substrate should be controlled at 3% whether it is alcohol sol or PVC primer, Therefore, printing UV ink and roller UV varnish have poor adhesion due to poor fluidity and caking, which are related to water content. To improve the adhesion strength of ink film, one is to replace the new UV ink and UV glazing oil, and the other is to add 3%-6% js-pph (302) film-forming additive from Shanghai Jinshan Chemical Plant, 0.2%-0.5% js-f4011 adhesion promoter or 5%-15% CH3COOC2H5 to the ink or glazing oil, which can ensure the fundamental improvement of the adhesion strength of ink film and glazing oil adhesive film of packaging and printing

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