Talking about Screen Printing Process of "UV" Ink

Here to introduce to you a few common "UV" effect printing process so that we can really master the printing methods of these processes.

First, "UV" colorful crystal

"UV" colorful crystal is also called "Braille Varnish", "Marble Varnish" and so on. It is a kind of photocurable ink with high transparency, high concentration and high expansibility. Its effect is crystal clear, does not change color, feel smooth, especially after adding a variety of colorful green onion pieces, the screen printed effect is more charming and lovely, full of magical visual experience. Therefore, it is currently one of the first-choice results in the "UV" series of effects.

In the printing process, to achieve the effect of three-dimensional crystal, you must first select the excellent Braille crystal varnish. It must be high transparency, moderate concentration, good leveling, good flex resistance, strong adhesion, no blistering, no yellowing, and a state-valued varnish to produce a good product. Should select 30 mesh ~ 60 mesh monofilament imported mesh yarn, screen tension is about 21 Newtons. Use a single-component thick sensitized printing plate, the thickness of the sensitization is between 1mm~2mm. If you add seven colorful sequins should be selected high-temperature six-angle imported colorful film is better, it's good acid and alkali resistance, easy under the net, bright dazzling colors.

In the actual operation, the printing pressure can not be too large, just need to scrape the net plate on the net oil is appropriate, the hardness of scraped scraper blade should be 70-80 degrees, the knife edge should be kept sharp, the scraper angle is better at 45 degrees . In the printing, we must also pay attention to the adjustment of the net distance. It is advisable to adjust the ink to be printed on the substrate. If the pressure and the distance from the grid are not adjusted properly, the ink printed on the substrate can be easily returned to the screen. This is the real reason why we often feel that there is not enough bulge.

In the printing process must also pay attention to a phenomenon that is foaming. It is due to the crystal varnish after adding the colorful onion slices, in the process of blending and stirring the ink adsorption of certain air molecules bubble phenomenon. The solution is to place the ink for a certain period of time after adding the green onion to allow the bubbles to disappear and then use it on the machine. In addition, the antifoaming agent is directly added in proportion so that bubbles can be suppressed and relieved by the defoamer, thereby enhancing the stability of the ink. The works so printed will be more perfect.

Second, imitation metal etching (brushing)

If the ink contains “impurities,” defects will occur during printing, which will scatter light. The amount of such "impurities" is so large that it produces many innumerable small particles through screen printing. Printing it on gold card paper produces a sand surface effect. This is an imitation metal etched ink that is scrubbed UV ink.

Matte ink according to different particle sizes, can be divided into: coarse, medium, fine matte ink. An excellent UV matte ink, it has excellent particle distribution and three-dimensional sense, can produce satisfactory artistic effects through printing and light curing. It should also have strong adhesion and softness so that the print will not burst. In addition, the ink has the advantages of fast curing, long storage period, good hand feeling, and beautiful visual characteristics. Therefore, it is widely used in the surface printing of cigarettes, wine packaging, food, cosmetic packaging and metal signs.

The use of matte ink should pay attention to the following issues: The first is the choice of net sand, general coarse sand with 150 mesh gauze, sand with 200 mesh gauze, fine sand with 250 mesh gauze. According to the design requirements of the printed crystal, it can be determined through multiple proofs to select what kind of sand oil. When using sand oil, be sure to use it together with special thinner. The ink should be mixed evenly, and the thick ink should be scraped off during use to prepare a thinner and then used on the machine. The tension of the screen is slightly larger, around 25 Newtons. The net distance should be moderate and the scraper angle should be 45 degrees. Squeegee pressure should be slightly larger, scraper hardness day 0-90 degrees, and in use for some time, the scraper should be replaced in time, polished.

The curing speed of the matte ink can be selected according to the ink characteristics and the print design requirements. Curing speed should not be too fast and too slow. Too fast the ink will dry out and get detached. Too slowly, it will fall off due to excessive curing. The curing speed of 1KW to 3KW for small desktops is slightly slower, and the curing speed for 5.6KW is faster.

Third, "UV" wrinkles

When the wrinkle ink is dry, the wrinkle effect may occur due to the difference in surface and underlying shrinkage. It must first be exposed to a low-pressure mercury lamp to partially cure the surface of the ink, which is then completely cured by irradiation with a medium-pressure mercury lamp, thus creating a beautiful wrinkled texture.

"UV" wrinkle ink is mainly applied to printing materials such as cigarettes, wines, cosmetics, foods, calendars, and greeting cards such as PET paper, gold and silver cardboard. It is characterized by fast curing, good adhesion, good flexibility, good transparency, and a clearer texture art effect.

When printing, according to different design requirements, choose different types of wrinkle oil and mesh, mesh. The mesh is usually 100 mesh to 300 mesh, and the mesh is small and the wrinkle is coarse. The mesh is fine. UV lamp power when curing is 3KW~5.6KW, 1~3 can be. Wrinkle lamp power is 30W, 2~4 can be. Curing speed is generally adjusted from fast to slow, mostly in the range of 15~35m/min. Different meshes and curing speeds can produce different texture effects.

When using wrinkle ink, it should be mixed with special thinner and stir it well. After stirring, there will be bubbles, which should be used after the bubbles disappear. After use, it should be sealed and stored at low temperature to avoid direct sunlight so as not to affect the quality of the ink. Before batch production, proofing must be done first, and production must be confirmed. In case of printing, dark ink should be cured immediately after the material (for example, blue, black, etc.) is printed. Too long time will affect the adhesion of the ink. When printing is blocked at the time of printing, special cleaning solution should be used for cleaning in time. Then wait for the solvent to completely evaporate before printing can begin again.

In the printing of wrinkle ink, there are several points that must be emphasized to remind everyone: the speed must be adjusted from fast to slow; the power of the wrinkle lamp must be sufficient; the distance between the printed body and the light tube is generally between 1cm-3cm; natural after wrinkling The period of wrinkling must be sufficient; the distance from the general wrinkle light to the curing light must not be less than 3m. As long as you pay attention to these issues, you will soon make a satisfying wrinkle effect.

In addition to the above-mentioned several kinds of "UV" effects, there are many effects such as ice flower, coral and foam. Therefore, in summary, “UV” screen printing has its unique effects and advantages, and is a novel printing variety that cannot be accomplished by any other printer or printing. It can display visual effects and feel artistic effects on the surfaces of different materials and shapes. Therefore, it can be widely recognized and used, and it can also create rich wealth for printers.