Printing method of stereoscopic printing

      There are two common printing methods for stereoscopic printing.

      The first is to use ordinary machines to print on the surface of paper or synthetic paper. After the ink on the paper surface is dried. Use the grating matched with the image to mount with the paper. Usually. When printing with solvent based ink on paper, the ink is dried by penetrating and oxidizing the conjunctiva. Application Of Ink In Stereo Printing

       Generally speaking, the network expansion is inversely proportional to the perimeter of the network. In other words: the higher the number of screening lines, the smaller the dot. The more serious the dot expansion in the printing process and drying process. Therefore, when high-line printing is used on paper, the dark tone part of the image is easy to paste, resulting in the loss of image dark tone level. Application Of Ink In Stereo Printing

      At the same time, grating mounting is generally manual operation. Due to the high requirements for the matching degree of materials and images in stereo printing, if the process control is not appropriate, the product scrap rate is very high.Ink Bucket Cleaning And Field Printing

      The second method is to print directly on the back of the grating. As the grating is made of polymer material and non absorbent surface, ordinary ink will not be infiltrated and dried on the grating material, so we use UV ink printer to print directly on the back of the grating, and use the principle of UV drying to produce photochemical reaction. Instant drying. Application Of Ink In Stereo Printing

      At the same time, it should be noted that when the film is released, the direction of the film surface is upward, which is opposite to the film surface of the first method.Application Of Ink In Stereo Printing

       UV curing refers to the splitting of photoinitiators into free radicals after absorbing UV radiation under UV irradiation. Polymerization, crosslinking and grafting reaction of prepolymer were initiated. It can be solidified into three-dimensional network polymer in a very short time. Obtain hardened film. Application Of Ink In Stereo Printing

       The essence is to realize chemical drying by forming chemical bonds. Stereo printing adopts the technology of direct printing on the back of the grating, and U V curing can effectively control the loss of small dots. Improve the ink transfer rate of chromatic overprint.Ink Bucket Cleaning And Field Printing

Precautions for stereoscopic printing by UV offset printing

       Different inks should be selected for substrates with different properties. We should comprehensively consider the light transmittance, curing rate, coverage of ink and the gloss of printing surface. Water ink balance is a well-known principle. Specifically, the pH value of water should be equal to the pH value of ink. Otherwise, it is either water color oil or oil color water (here for offset printing), forming ink emulsification, resulting in the opacity of UV ink film, which directly affects the passing rate of ultraviolet radiation energy. This will slow down the drying time of the film.Application Of Ink In Stereo Printing

         Even though the light is fixed, there is still water in the ink film. Once it is rubbed or fixed with adhesive tape. You will find that the ink film is pulled off. At the same time. Strictly control the temperature and humidity of UV ink warehouse and printing workshop. Prevent ink from long-term exposure to natural light. Because ultraviolet light contains a small amount of ultraviolet light, if it is exposed for a long time, dry scaling will occur on the surface of UV ink, affecting the use.Application Of Ink In Stereo Printing

       Even cause printing accidents. At the same time, the impurities of the ink and the falling of dust splash in the production process will weaken the light intensity of the ultraviolet region, which greatly reduces the drying time of the light curing ink. Ink Bucket Cleaning And Field Printing

      It is generally required to clean the dust and cover the ink tank (bucket) timely and often. When printing grating products, the company where the author works uses Gao’s rap series ink, which has good printability.Ink Bucket Cleaning And Field Printing

      Light curing ink generally strictly stipulates the printing order. Color sequence. UV printing ink is strictly according to its wavelength. Otherwise, it is difficult to achieve uniform drying after light curing. Especially the gray balance of hue. In color printing. The ability of various pigments to absorb UV photons is different, and their transmittance is yellow, green and black (m, y, C, K) from high to low.Application Of Ink In Stereo Printing

      Therefore, the curing degree of each color ink is also different. The transmittance directly affects the excitation energy of photons to photoinitiators, because yellow (y) has the weakest visual stimulation to human eyes. Therefore, the printing color sequence should be arranged as black, cyan, magenta and yellow (KCM, y), so that the ink with poor light transmittance can absorb as many photons as possible. Enhance its curing effect.Application Of Ink In Stereo Printing

      The use of alcohol fountain system can reduce the surface tension of the ink and promote the curing effect. In the printing process, the fountain solution can be used to strengthen the oil repellent area (blank part) of the printing plate to ensure that the oil repellent area is fully ink repellent. The hydrophilic area is not inked.Application Of Ink In Stereo Printing

      Improving ink formula and adding corresponding additives can increase the hydrophobicity of ink. However, too strong hydrophobicity will lead to ink shrinkage at the edge of the image, loss of fine layers, unclear dot boundary and so on. Photosensitizer and initiator crosslinker are involved in UV ink and catalytic drying (curing). Application Of Ink In Stereo Printing

       Usually people only pay attention to pigment wavelength and ignore printing inks with different viscosity and purity. We should scientifically select different photosensitive initiators or crosslinkers. For example, benzoin is different from benzophenone because it is both a photosensitizer. Initiator again.Application Of Ink In Stereo Printing

      Stereo printing requires high surface strength of grating, and the surface strength is not enough, which is prone to printing accidents with poor bending force. Due to the smooth surface of the grating and small affinity for the ink, it is easy to pull off the first color ink when overprinting the second color. Application Of Ink In Stereo Printing

      Therefore, in three-dimensional printing, we should select the grating material with large surface tension, reasonably arrange the color sequence, and adjust the relevant process parameters in the printing process, so as to avoid and reduce the occurrence of the above phenomena.Application Of Ink In Stereo Printing

      Different types of inks have different drying characteristics. To make UV ink fully dry, you need to choose a UV light source matching with the ink. There are three common UV light sources: high pressure mercury lamp, non ozone lamp, metal halogen lamp, and the lamp tube cooling methods include ventilation cooling and water cooling. Application Of Ink In Stereo Printing

      When a UV light source is selected. It depends on the drying conditions of UV ink and UV varnish. Also compare the irradiation efficiency of UV lamp. The irradiation efficiency of various UV lamps is different.Application Of Ink In Stereo Printing

      When drying, 30% of the UV light absorbed by the ink comes from the direct light source. 70% from reflector. Aluminum reflector is widely used now. Due to different processing technologies, the reflectivity of reflector varies greatly. Application Of Ink In Stereo Printing

     Therefore, when detecting UV light energy, it is necessary to detect not only the lamp tube, but also all ultraviolet light including reflected light.Application Of Ink In Stereo Printing

       In three-dimensional printing, it is necessary to use a cold reflection plate to reflect only ultraviolet rays and make infrared rays transmitted, so that the surface temperature of the printed matter decreases by 10 ℃. In addition, the general service life of ultraviolet lamp is about 1000 hours. In other words, it is very limited. This also directly affects the drying and curing time of UV ink.Application Of Ink In Stereo Printing

      Except for the positive PS plate for UV ink, the printing resistance of other positive PS plates is low if they are not baked. Therefore, they need to be baked at 250 ℃ for 6-8 minutes. For negative PS plate, try to use high printing resistance plate. Ink Bucket Cleaning And Field Printing

      At the same time, there is no special fountain solution for UV ink. During UV ink printing, avoid adding excessive Arabic gum to the fountain solution, because Arabic gum will react with UV ink, resulting in the failure of ink stacking and blanket stacking.Ink Bucket Cleaning And Field Printing.Application Of Ink In Stereo Printing

       As UV offset printing is not very common in China and there are few technical operators of the equipment, enterprises need to invest considerable funds in the training of operators, which is also the top priority in the stereo printing process.Application Of Ink In Stereo PrintingApplication Of Ink In Stereo Printing