Comparison of common three-dimensional printing technologies
among the three-dimensional printing technologies currently used, the most common three-dimensional printing technologies that press the "check and hit/1" key are ordinary three-dimensional printing, dynamic three-dimensional printing and holographic three-dimensional printing. Here, we will use the method of comparison to elaborate these three-dimensional printing technologies
stereophotography of ordinary stereoscopic printing mainly adopts the method of circular motion shooting, that is, taking the central point set by the subject as the center of the circle, and taking the radius from the central point to the focal length of the photosensitive film as the circular motion, the cylindrical lens plate is directly installed in front of the photosensitive film, and moves randomly and synchronously. Each exposure will focus a pixel under each semicircular column of the grating plate, and finally cover the entire grid distance. Stereoscopic photos can be obtained by developing. Like other printing methods, the plate making process of stereoscopic printing also includes color separation, addition, plate printing and other processes
it is worth noting that in the color separation of stereoscopic printing, the number of scanning lines is generally more than 400 lines/cm. In addition, due to the delicate pixels of stereoscopic images and the amplification effect of cylindrical lens grating, in order to obtain better prints, we should use more fine-grained processing. The line angle in stereoscopic printing should not be 0 angle. In addition, the angle of C and K plates in stereoscopic printing should be the same, and the field density of color ink should be high. The overprint accuracy of ordinary stereoscopic printing is very high, and PS version is generally used. Stereoscopic printing can be printed in different formats. The finished product can have a stereoscopic feeling only after the surface is covered with cylindrical lens grating. At present, there are two kinds of cylindrical lens grid plates: hard plastic and soft plastic. The former mainly includes polystyrene and the latter mainly includes polyvinyl chloride. Before compounding cylindrical lens, it is necessary to make a cylindrical lens female template according to relevant parameters, and then form it while laminating. The commonly used methods mainly include flat pressing method, roller pasting method and back pasting method
dynamic stereoscopic printing is an extension of ordinary stereoscopic printing, that is, dynamic pictures are printed on the basis of stereoscopic pictures, and dynamic products can be produced as long as the observation angle is changed. The production principle and method of dynamic stereoscopic printing are the same as that of ordinary stereoscopic printing. Dynamic stereo printing also needs to take stereo photography of the original first, but unlike ordinary stereo printing, it needs to determine the number of actions to design the original; Each action has a picture, and the number of actions determines the number of negatives used. The original of dynamic stereoscopic printing now generally adopts the desktop printing system for color separation to obtain multiple sets of color separation negatives (negatives). The negatives obtained are copied to combine multiple action pictures on one negatives, which need to be exposed step by step. Finally, the positive pictures corresponding to the action pictures are obtained by developing and fixing, and then the dynamic stereoscopic printing is obtained by printing, printing, and composite cylindrical lens plate
holographic stereolithography is a reproduction technology that transforms the interference fringes formed by laser photography into stereoscopic images and appears on specific substrates. It is a new stereolithography technology developed on the basis of holography
In the 1980s, holographic stereoscopic printing technology entered the stage of popularization and application, and holographic stereoscopic printing began to be popularized and gradually commercialized. The process flow of holographic stereo printing is shown in the figure below. Holographic stereoscopic printing is not made by printing with ink. This kind of printing is similar to the method and process of conventional printing. Holographic stereoscopic printing first needs to shoot holographic images. Before taking the hologram, you should choose the appropriate theme and the best layout of its space, and pay attention to the influence of light. When the hologram is not properly illuminated, it does not show any features of the recorded scene. 4. Pendulum swing radius: r280mm. Rainbow holograms are taken according to the diffraction characteristics of light. It is made by placing photoresist light sensitive plates through exposure, development, fixing and other processing. In holographic stereolithography, a soft photoresist material will be used, but it is not suitable for direct imprinting, so it is necessary to make an imprint template, which is often a metal template. After transferring the rainbow holographic image information, it is imprinted on the molding machine. The purpose of imprinting is to transfer the image information on the imprinting template to the transparent film or vacuum aluminized film at a certain temperature. The thickness commonly used for embossing increased by 72% over the same period last year In addition, the films mainly include PVC, pet, PS, PP, etc. the stamping process is carried out according to the process of hot pressing, cooling and stripping. After embossing, vacuum aluminizing is required, which is mainly to achieve the purpose of double clicking the hologram directly on the curve board under white light. It is a process of atomizing aluminum wire and depositing it on the embossed film under high vacuumat present, aluminized film can also be directly used for embossing. After that, it is necessary to apply glue and film to facilitate the transfer of stereo image information. The process mainly includes the processing of two kinds of holograms: paste type and hot stamping type. At present, the quality of holographic stereoscopic printing is not ideal and needs to be further improved. With the popularization and development of computer technology, many manufacturers have used computers to make stereoscopic images, which has made stereoscopic printing technology develop well
LINK
Copyright © 2011 JIN SHI