Talking about six problems and solving method of UV ink printing 

UV offset printing in the surface texture, protection, wear resistance and production efficiency, etc. with traditional offset printing can not match advantage, especially for plastic sheet, gold and silver cardboard, non absorbent material printing. These advantages make the printing enterprise application of UV offset printing technology talent shows itself from the competition. But UV printing process is more complex, how to package printing enterprises handle existing problems in the process of UV printing? To use the UV offset printing packaging printing enterprises should be how to prepare? 

To solve the problem of UV offset 

To make the UV offset to play a better role, the main problems to be solved are as follows. 

1 design plate 

Design of UV printing production must be decided according to the work order output format, such as the membrane surface is swept or reverse sweep, output line number, the angle of the wire. Some special printing demands more high, such as 3D printing resolution to be high, the angle of the wire must be matched with the substrate material, avoid moire; transparent plastic sheets and aluminized paper often need to print white ink, should pay attention to the effect of expansion of printed materials, pre by modifying the film to achieve the best quality. 

2 adhesion 

Because of the poor permeability of plastic sheets or gold and silver cardboard printing, ink adsorption force is very weak, so even with the use of UV printing ink, ink adhesion is poor, printing quality is not high. Can be solved by surface treatment of materials. 

3 ink emulsification 

UV ink ink balance tolerance is very narrow, ink emulsification, dirty version is easy to cause the printing effect, printing quality. 

Solution: reduce the speed of printing, the printing speed is controlled in 5000 ~ 8000 India / hour. 

4 degree of cure 

In order to improve the printing color saturation, UV printing on plastic sheet substrate surface, printing pressure, ink layer thick, dot is serious, which makes the ink curing is not easy. In order to ensure the quality of printing, the printing pressure does not make a big adjustment. Solution is first moderately reduced the printing speed, the UV lamp exposure time should be appropriately extended, so that the ink completely cured; followed by adjusting the distance between the UV lamp and substrate, increase the intensity of UV light irradiation, so that the ink curing. 200 ~ UV wavelength range is effective in curing 400nm, printing workshop in some light source wavelength is within this range, will cause the ink surface light curing, so attention should be paid to the influence of environmental light on UV ink. 

5 color arrangement 

UV offset printing color sequence arrangement problem is more complicated. Due to limitations of the principle of inking, printing ink layer thinner, when the need to compare thick layer of ink, printing difficult to achieve expected to replicate the effect. Such as four-color overprint, usually use the printing color sequence black, cyan, magenta, yellow, because black filled almost all space, green, magenta, yellow describes force lower, total amount of ink is not enough, it will cause color is not full. 

Solution: change the color sequence, first printing ink with a smaller amount of color. Finally, the large amount of ink black, so that you can let inking reached highest, more full of color. 

6 printing sets 

UV offset printing using UV lamp irradiation for ink curing, the curing of the main problems is to substrate thermal expansion, which leads to misregister. This is in contradiction with the UV ink curing, because the ink curing requires UV lamp irradiation time is a little longer, and the printed set of guidelines requires UV lamp illumination time is shorter. 

Solution: after the end of the same color finish UV curing, this time even if the substrate expansion, by placing a period of time to reduce the temperature, but also to minimize the deformation of the substrate. Under special circumstances, the intermediate color group can also open UV lamp, but the shorter the time, the better. Cold UV technology can be used.