In many China printing company
, through the developing of printing technology, every wall of life has higher demand for packaging. However, the carton packaging in the process of paste box machine production line or handling bruises and smearing occur frequently, seriously affect the value of the goods is installed inside, so the paper carton packing requirements surface should be has good abrasion resistance, scratching resistance, resistance to water, dirt etc. At the same time, in order to improve the grade of products, often need to surface finishing processing the carton packaging. The finish of the packing is various, including UV Varnish, stamping, lamination etc. UV varnish is more common and high cost performance. UV varnish not only meets the requirement of environment protection, but also has the curing speed and stability, easy cleaning, can shorten the processing of waiting time, and the carton packing after UV vanish, it is good abrasion resistance, scratching resistance and high glossy.
How to choose UV varnish
There are many kinds of UV vanish, in accordance with the requirements for product quality and the function different, divided into flexible, UV light, wear-resisting UV vanish, heavy oil with UV vanish, yellowing resistance to UV vanish, high adhesion UV vanish and low volatile UV vanish. Each has the applicable products, but also has the certain application limitations.
So, the printing enterprises need to choose UV vanish reasonable. Some products post-press processing is relatively complex, printing quality after UV glazing the need for die cutting, creasing, such as multi-channel processes, the need to select flexibility good UV vanish. But it is important to note that the more flexibility good UV vanish, the slower the curing rate, the lower the surface hardness, thus there may be a poor printing after curing, printing quality surface adhesion, easily scratched risk when pasting box.
In addition, some printing quality after UV glazing to hot stamping, such as pasting box a fine finishing process, can choose can recoat UV vanish at this time. Hot stamping effect more good UV vanish, flexibility slow, also there are printing after curing, printing quality surface adhesion, easily scratched risk when pasting box.
And wear-resisting UV vanish is used crosslinking density and resin reaction rate is very high, so has advantages of high surface hardness and good wear resistance, and this kind of resin has after the curing speed, film forming shrinkage rate, low surface tension, the characteristics of high surface hardness. So, wear-resisting performance is good UV light oil, the higher surface, hardness, but the surface painting and flexibility will be worse, pasting box when there may be a critical color, the risk of poor adhesion.
The problems to be solved of UV vanish
1. Smells. Although UV vanish is gradually to develop in the direction of low odor, but the smell problems still exist. We need to increase the molecular weight of Prepolymer and monomer and reactivity, development including light initiator, no smell of raw materials.
2. Security. UV vanish in the smell and the food hygiene safety worse than water-based vanish, and the UV coating did you get the FDA, can’t direct contact with food.
3. To reduce cost. In recent years, although the cost of UV vanish had dropped a lot of, but compared with the general ink, or too high, still need to be further reduced, mainly is the UV glazing, UV curing unit equipment operation cost, etc.
Overall, although UV vanish has the above problems, but in the protection of the environment, save energy, simplify operation and enhancing the added value of the product has a great advantage, believe that with the constant progress of UV curing technology, UV vanish will have large development space in printing service
Article from: http://www.chinaprintingmasters.com/News108.html