In the UV ink in the series, due to UV screen printing inks are more, relates to the application field is broad, also requires diversification, many problems, below focuses on UV screen printing ink in printing common problems and treatment methods. 

1, ink long layer phenomenon. 

Light oil is more obvious, is a normal phenomenon, after opening the ink, must be fully mixed evenly, can be printed on the machine. It can avoid the effect of the surface of the printed matter, such as the elimination of bubbles and the equality of flow, because of the long layer of ink. 

2, paste version of the phenomenon. 

Braille varnish refraction, foaming, scrub and other products prone to this phenomenon, the reason is this kind of product viscosity larger, in printing, if there is screen tension is not enough, the net margin is too low, soft blade, back ink unevenness or too thick, pressure is not enough and other factors, it is easy to appear the phenomenon, appropriate at this time to improve the printing process; in the ink can add the appropriate diluent to be adjusted. 

3, the printing pattern is not fine, and occasionally there are incomplete phenomenon. 

Main reason lies in the printing and ink, printing, pressure is not enough, the hardness of the blade is not enough, the screen mesh is low or lack of tension. Ink: varieties are not suitable, ink to the substrate wettability is not enough, or have been part of light cured under the influence of the network effect (this phenomenon may be due to window printing, light printing or UV light solid machine more than light screen. 

4, the surface of the printing pattern has the phenomenon of bubbles and concave points. 

Possible reason lies in: 

When the ink is not fully stirred, the ink jar edge and the lid of the auxiliary agent is not fully mixed with ink, thereby affecting the bubble and the flow flat function. 

II, ink viscosity is too large, especially in the case of lower temperatures, ink viscosity increases, the ability to eliminate foam significantly weakened, at this point can be added to the diluent or additives to solve this problem. 

There are more dust or impurities on the surface of the substrate. 

The ink, its pollution by impurities in the printing process, the need to use the new oil, cleaning screen can start printing. 

Gymnasium, the substrate its absorbent is too strong, UV ink penetration serious, small pits in the printed surface, then you need to replace the corresponding varieties of ink. 

5, poor adhesion of printing ink. 

Possible reason lies in: 

Ink selection is not appropriate, a wide range of substrates, their own polarity, flexibility, surface treatment, cleanliness, after the process requirements and other factors will affect the adhesion of ink. In general, the greater the polarity of the substrate, the higher the degree of surface treatment, the easier the ink attachment. 

II, UV curing equipment: UV lamp power is low, the penetration ability is not enough, or is curing printing overall energy is not enough (such as UV lamp power is not enough, transmission speed too fast, etc.), resulting in UV ink curing incomplete, ink performance failed to get into full play, resulting in adhesion is not enough. 

Thirdly, printing: the technology does not reach the best state, ink layer too thick or too thin, improper use of color sequence is wrong, auxiliaries, resulting in printing ink and substrate binding force down or UV equipment cannot be fully cured ink, resulting in decreased adhesion. 

6, the printing surface of sticky flowers, the main reason is that: 

After printing ink, the printing ink should be stacked and processed, and the sticking phenomenon mainly occurred in the process of folding and cutting. Especially prone to high temperatures in the summer or in the printing of a thin double copper paper, the main reason is that UV ink failed to fully cure and timely cooling. At this time, should be considered from the following aspects: 

First, the ink varieties, some UV ink flexibility, good adhesion and poor adhesion, ink select the corresponding balance of good performance. 

The types of substrate, for a thin double copper paper, soft PVC and other materials, should be done to prevent the viscosity of the corresponding test. 

In the process of printing, the printing ink layer should be avoided, and the thickness of the printing ink layer is too thick, and the laminated weight is too large. 

Fourth, UV curing equipment, to ensure sufficient curing conditions, good ventilation and heat dissipation work. 

7, UV special effect ink printing problems encountered 

, UV wrinkled inks, wrinkling of the size of the control problem, due to the particularity of wrinkled inks, wrinkles size and light lines power transmission speed, crumpling to the curing stage intervals, is closely related to the thickness of the printing, in the production process should be strictly control the related factors; adhesion problem of wrinkles, the wrinkles in curing produced large shrinkage and adhesion could drop, so according to different base material should be choose different varieties of wrinkles. Especially in printing dumb film paper, the choice UVH-16035 wrinkles to ensure adhesion; in addition, wrinkled inks also need to pay attention to the moldy phenomenon, mainly in gold and silver paper, at this time, should guarantee that wrinkles full of wrinkles, fully cured, and the surface of the gold and silver card invitations have certain resistance to chemicals in printing paper should avoid dampness, mounted boxes, should note glue containing water should not be too large. 

UV matte ink: should pay attention to the selection of varieties and matching products. Dumb film paper should choose a series of UVB, to ensure that the cutting performance and adhesion, printing UV matte, be sure to note printing net distance and blade intensity and mesh size, or prone to paste version or not sand phenomenon. 
Third, UV refraction ink. At the time of printing UV refraction, in addition to pay attention to net torque and drag force to prevent the paste version of the phenomenon, should also strictly control the screen mesh size, general in more than 380 mesh, to improve the fineness of the lines, also for the refraction oil, precision film sun system is the key link. 

Fourth, UV embossing light oil, in the UV printing Braille varnish, attention must be paid to the virtual edge or bubble problem in low mesh (40 ~ 80 mesh) printing may. Therefore, the angle of the scraper and printing speed should be adjusted, the angle should be small, and the speed is slow. 

Fifth, UV foaming ink: foaming ink is a kind of ink printing is relatively difficult, mainly because of higher requirement in the printing process, such as mesh network, distance and the speed of the screen tension, blade hardness and the edges and corners, printing speed, printing pressure, printing ink viscosity, printing to curing interval time many factors will significantly affect the foam pattern. Therefore, in the testing phase should do a good job of the corresponding record. 

The UV ink in the printing ink: snow snow, by two light machine curing way. Before a group of light solid machine is generally a light known as snow machine, UV energy is generally low, about 18 ~ 20mj/cm2, used to induce the patterning; after a group of light solid machine generally 5kW * 2 single lamp, energy set is about 100mj/cm2 for fully cured. Two groups of light solid machine operation of the system is independent, in order to facilitate the operation speed to adjust the size of UV energy, the need to pay attention to is that snow machine energy is too high or too low will affect snow flower type size, dumb, thick degree, so the test version, should do a good job in the corresponding testing and recording work. 

Seventhly, UV powder light oil, in printing UV powder light oil, usually add a colorful powder or other color, pastel, with 40 ~ 80 mesh screen printing, but need to pay attention to is, dark color toner (such as pink, purple and blue powder) of UV curing inks. At this point, you should choose the right ink varieties, or appropriate to enhance UV energy, or reduce the color toner adding amount, in order to ensure the cure. Also this light oil as a powder and light oil can be printing a variety of paper (such as coated paper, white cardboard, gold and silver, dumb paper film, optical film paper, absorbent paper, etc.), but if as powdering light oil or varnish, sticky powder or surface flow effect is not ideal. At this time should be selected with the process of the other UV ink. 

8, UV ink preservation and printing environment problems 

, preserved, stored in a cool ventilated environment, temperature below 30 DEG C; when in use, after opening the ink barrel should as soon as possible cover, lest contamination and reduce quality problems caused by the ink and UV exposure. 

II, printing environmental problems, should ensure the printing environment cool and ventilated, shady and cool environment can avoid sunlight or UV curing equipment in the light of a layout, good ventilation is help on the heat dissipation, reduced adhesion and at the same time, good ventilation can reduce some UV ink materials on human skin and eye irritation.