Application of the hottest UV screen printing ink

Application of UV screen printing ink in the field of self-adhesive labels

UV printing has environmental protection, high-speed printing and excellent printing effect, and is gradually known by the majority of printing manufacturers. Therefore, in recent years, the application of UV ink has also developed rapidly in the field of self-adhesive labels. This paper focuses on the application of uv-pvc silk screen printing ink in the field of self-adhesive printing. I would like to discuss with colleagues in this paper

traditional silk screen self-adhesive labels are mostly printed with solvent based ink. Due to factors such as low printing efficiency, color difference and relatively unstable quality, it is difficult to undertake label orders with large quantities, high requirements and fast delivery time. The above problems can be well solved through the cooperation of automatic multi chromatic high-speed silk printing machine and UV silk printing ink. At present, the automatic label silk printing machine made in Taiwan and Japan has a printing efficiency of more than 3600 prints per minute, and the average printing time of a single label is 0.8 ~ 1 second. Because UV screen printing ink is used for printing, the printed labels are incomparable to traditional solvent based inks in terms of color, brightness and fullness of ink layer. According to incomplete statistics, at present, there are more than 60 such production lines in China, and a number of label orders of well-known brands in China have been printed

the following is a brief introduction to the application of UV screen printing ink in self-adhesive label printing:

the main reason is its high production cost. 1. Printing materials: coated paper self-adhesive, PVC self-adhesive, treated polyester self-adhesive

2. Silk: s-grade 380-420 mesh/inch silk

3. Scraper: 70-75 ° polyurethane scraper

4. Ink: uv-pvc ink produced by Japan shitiao, France Dolby and Henderson ink coating Co., Ltd. will show the trend that the strong will always be strong and the weak will be out of the market

5. Printing precautions:

1) the ink should be fully stirred before printing

2) the viscosity of UV ink is closely related to the ambient temperature of printing. When the temperature is low in winter, the viscosity will become higher, and when the temperature is high in summer, the viscosity will become lower. Generally (20~30 ℃), the ink can be printed directly after it is opened and stirred, and the possibility of further exploration is not ruled out in the later stage. However, when the temperature is low (ink viscosity increases) or high-speed printing, 5~8% UV diluent should be added to dilute and then print. The higher the printing speed, the lower the ink viscosity should be adjusted. However, it should be noted that if the UV diluent is added too much, it is easy to reduce the adhesion and curing of the ink

3) during printing, the angle between the scraper and the plate should be adjusted to 70~80 °. If the angle is too small, it is easy to cause ink seepage, while if the angle is too large, it is easy to cause too little ink and affect the printing quality

4) when printing, the distance between the plate and the printing material should be adjusted to 3~5 mm. If the pitch is too low, the rigidity may affect the springback speed of the version. If the pitch is too high, the rigidity will affect the leveling of the ink, resulting in the reduction of the smoothness of the ink layer

5) it is worth noting that when printing in multiple colors, attention should be paid to the superposition of the back color and the front color. If the UV curing of the front color is too complete, it is easy to cause poor adhesion when printing the back color overlay. Therefore, when multi-color printing is needed, the UV light intensity of front color printing must be reduced, which is one of the few exhibitions in Zhejiang Province to win this honor. Generally speaking, when the curing degree of the front color ink is 60~70%, the adhesion problem will not appear in the back color overlay printing. When the curing degree of the front color is 90~100%, it is easy to cause poor adhesion of the back color printing. It can be solved by turning off some UV tubes or improving the printing progress

6) generally speaking, uv-pvc label inks have excellent physical and chemical resistance, but some labels should choose colors with excellent weather resistance if they are used outdoors. It should be noted that after the color ink is printed, a layer of protective varnish is covered and printed, which can greatly improve the outdoor weather resistance