How much is the three-dimensional printing technology (below)

Platemaking and printing process

Due to the fineness of the stereo image pixels and the magnification of the lenticular lens grating, the number of plate-making screen lines must be 120 lines/cm or more. Stereoscopic printing and general color printing have different screening angles, and green and black versions use the same mesh angle. In addition, three-dimensional prints with different grid pitches must have different combinations of yellow, magenta, cyan, and black grid lines to avoid interference fringes. Nowadays, the screen angle used by general manufacturers at home and abroad is: 0.6 pitch/cm, 100 line/cm color separation, then the degree of screen angle is Y81, M36, C66, K66; 0.44 pitch/cm, 58 line/ For color separation of cm, the degree of screen angle is Y50, M20, C65, K65; color separation of 0.31 pitch/cm, and 81 line/cm, and the degree of screen angle is Y66, M22, C51, K51.

Since the three-dimensional manuscript is composed of a closely-arranged pixel, after the plate-making and printing, the lenticular plate is compounded. Therefore, besides the moiré formed between the screens, the network line angle must be considered. The screen angle forms a moiré pattern formed by the pixel lines and the lenticular lines. For example, three-dimensional printing should not choose 0 degrees, because the horizontal network line is the most obvious, and 0 degrees and the pixel line, cylindrical lens line orthogonality, interfere with the clarity and depth of the image. The three-dimensional printing in the blue and black version of the same screen angle is determined by its own characteristics. Because the three-dimensional prints are finally composited with plastic plates, the lenticular plates are mostly with a certain grayscale, and because the three-dimensional printing uses a very fine 300-line screen, it only needs to be 8.5 to 9 or 9 when printing. Into the point, otherwise it is easy to paste version when printing, so you need to increase the amount of dark tone in the area, in order to achieve 9-9.5 into the effect. Therefore, the three-dimensional printing is more dense than the solid color density of the four-color printing on the plane. Generally: lithographic offset: Y: 1-1.1, M: 1.4-1.5, C: 1.5-1.6; three-dimensional printing: Y: 1.33-1.35, M: 1.31-1.33, C: 2. If the three-color printing ink is close to neutral gray after overprinting, in order to reduce the error caused by the fourth overprint, it is not necessary to print the black version again, and the black and green versions can be taken the same angle for flexibility. In the small area even when the sun, due to the temperature of the exposure light source will cause the film to shrink, resulting in changes in the pitch of the front and rear width, affecting the accuracy of the print position, so the separation of the separation film made into the whole film for the best print.

When copying the positive image, it is necessary to make a line that is equal in width and pitch between the negative film and the photosensitive film. The printing plate should be printed with a PS plate with a better level of expression. The printing method selected for the three-dimensional printing shall ensure that there is no loss of three-dimensionality due to printing, and the accuracy of overprinting is good, and a large number of printings are preferable. Lithographic Offset: Platemaking, printing overprint accuracy, resistance to printing force are better, printed products better three-dimensional, plate making stable, and mass production; Photogravure: plate making, printing overprint accuracy is not good, good resistance to India, India The product has a good three-dimensional effect, but the multi-color printing effect is not good; the Milo version: the plate-making modulation is unstable, the printing-resistant force is low, the printing accuracy of the printing product is good, and the three-dimensional feeling is better, but it is not suitable for mass production. Stereo printing is generally printed using a lithographic offset process. The quality of three-dimensional printing is good and has obvious influence on the visual effect of three-dimensional pictures. Due to the focusing and obstruction of the grating, the network cable is required to be clear and overprinting is accurate. The trapping error must not exceed 0.02 mm, and the ink must be bright and clean without fading. The use of high-precision four-color printer printing, the rules line must meet strictly, and the workshop must have constant temperature and humidity conditions. With regard to the above comparison of conditions, stereographs are generally used for offset printing. The stereoscopic negative film taken was separated by electronic color separation or direct screening.

Three-dimensional printing materials and technologies

(1) Paper. Paper for printing needs to be compact, smooth, smooth, and less stretchable; usually coated paper or cardboard is used.
(2) grating sheet material. There are mainly rigid plastic lenticular films. Polystyrene raw material was processed into an lenticular mirror-like grating by injection molding. Polystyrene is colorless and transparent (transparency 88%-92%), refractive index 1.59-1.6, non-ductile, flammable. Because of this high refractive index it gives it a good sheen. The processing of transparent plastics produces a birefringent stress-optical effect. It has a tensile strength of 3.52-6.33 MPa, a bending strength of 6.12-9.84 MPa, and a thermal deformation temperature of 70-98°C. The chemical properties of polystyrene are resistant to certain mineral oils, organic acids, bases, salts, lower alcohols and aqueous solutions. Encountered by hydrocarbons, ketones, higher fatty esters, etc., eroded and softened, soluble in aromatic hydrocarbons and toluene, ethylbenzene, and styrene monomers. In some cases, the degree of erosion of polystyrene by chemical agents can be reduced by annealing, stress relieving, and other measures. Soft plastic stericles. The main use of polyvinyl chloride film base metal grating roller or grating plate made of soft plastic three-dimensional grating. Polyvinyl chloride is a polymer compound formed by the polymerization of chlorinated olefins and is difficult to burn. Although polyvinyl chloride and polyethylene are both milky white, polyvinyl chloride can be used as a colorless, transparent and glossy film, and can produce various softness films based on the plasticizer content. This material is also characterized by pulse heat sealing, high frequency heat sealing, and adhesion. The chemical properties of polyvinyl chloride have good chemical resistance, but poor thermal stability and lightfastness. Hydrogen chloride starts to decompose at 140°C, and stabilizers are required to make it. PVC content of 56% -58%, low molecular weight of soluble ketones, esters and chlorinated hydrocarbon solvents.

(3) ink. At present, some ink manufacturers can provide inks and additives for three-dimensional (three-dimensional) printing, and some manufacturers have developed new ink production lines. However, it should be noted that stereoscopic printing inks are not foaming inks. In fact, any visible degree of foaming affects sharpness and three-dimensional effects. For three-dimensional printing inks, the curing temperature is within the curing range of the standard plastic ink (149°C-171°C), but it must be increased to a curing temperature suitable for an ultra-thick ink layer. If the ink layer is completely cured, the three-dimensional ink will have the same good elasticity as the standard plastic ink. Although 3D printing inks are not yet common, this ink is very different from the thicker plastic ink layer that people commonly find. If it is done correctly, the three-dimensional printed image will have a distinctly fine layer and a clear edge. The printed edge will be raised vertically from the surface of the fabric and the ink wall will be smooth. Although the ink is thick and the ink plate is thick, 3D printing can still print exciting levels and screen prints.

(4) Adhesives. The role of the adhesive is to enable the printed material and the lenticular sheet to be firmly bonded together; secondly it is also possible to protect the ink layer from discoloration at high temperatures.

Three-dimensional printing should pay attention to the issue Note: Photography using single-lens or multi-lens machine requires the camera has a higher accuracy, to avoid vibration caused by errors. And accurately adjust the focal length, angle and raster data movement distance; improve the precision of plate-making color separation and copying; the 300-line network requirements are solid and the scenery images are kept at a rich level; Typographical printing must be carried out according to plan and avoid production. Paper expansion and contraction, resulting in inaccurate overprinting; grating film pitch and angle have higher accuracy, composite molding requires accurate positioning. Hard plastic and soft plastic transparency performance is better.

Source: Bison