Comprehensive understanding of three-dimensional printing

Stereographic history

Stereoscopic printing originates from the three-dimensional image negatives provided by stereo photography. Although the stereographic imaging theory has been proposed more than 100 years ago, in this long period of time. Stereo photography has a certain degree of development. However, due to the stereoscopic photos in the shooting and production of traditional optical principles of the production and synthesis methods, so that there is a very limited application of three-dimensional photos. Plus the production equipment is expensive. Process technology is complicated. Reasons for higher production costs. The stereoscopic photography cannot be promoted and popularized, so the three-dimensional printing is also subject to a long process flow in the prepress plate making process. Accumulated error between processes. Reduced picture clarity. And affect the printing effect.

In the 1980s, due to the arrival of digitization. The development of three-dimensional printing was promoted, and the production technology became more and more perfect and stable. Three-dimensional printing thus entered a new era. Despite the fact that the three-dimensional printing waste rate is as high as 40%, it is mainly due to the fact that the plate separation and the precision of the amplitude modulation dot network are difficult to reach 300 lines/inch or more. Network line angle and color printing overprint are difficult. In the 1970s, China had a limited number of high-precision four-color offset presses. It is difficult to meet the technical requirements for three-dimensional printing. Fortunately, in the 1980s, the three-dimensional printing press of Heidelberg with four-color offset presses with CPC remote control was gradually developed so that the genuine rate of three-dimensional printed matter reached more than 85%. It thus establishes confidence in improving the quality of printed products.

The twenty-first century. Stereo photography into the digital age, stereoscopic multi-image synthesis using computer software. Computer-to-plate (CTP) technology. And use high-precision printing network equipment. Three-dimensional printing quality system has been guaranteed.

Know the three-dimensional printing

In the current use of three-dimensional printing technology. The most common three-dimensional printing technology is ordinary stereo printing, dynamic stereo printing and holographic stereo printing.

Ordinary three-dimensional printing

Ordinary three-dimensional printing of stereo photography mainly uses arc moving shooting method. That is centered on the center of the object. The circular motion is performed with the radius from the center point to the photosensitive film. The cylindrical lens plate is mounted directly in front of the photosensitive plate. And move synchronously at random. Each exposure will focus a pixel below each half of the lenticular plate. Finally covered with the entire pitch. ; Wash to get a three-dimensional photo. Same as other printing methods. Stereo printing process also includes color separation, screening, printing and other processes. It is worth noting. Stereoscopic printing in color separation. The number of scan lines is generally above 4001pi. Also due to the fineness of the stereoscopic image pixels and the magnification effect of the cylindrical lens grating. For better prints. A finer mesh should be used for screening. 3. The angle of the screen in the three-dimensional printing should not be selected as the angle of 0 degree. In addition, the screen angles of C and K in three-dimensional printing should be the same. The density of the color ink in the field is higher. Ordinary three-dimensional printing overprint accuracy is very high. PS version is generally used. Stereo printing can be printed in different formats. Printed product. The surface is covered with a cylindrical lens grating plate. Can have a three-dimensional feeling. The cylindrical lens grating plates currently used are hard plastic and soft plastic. The former mainly have polystyrene. The latter mainly consists of polyvinyl chloride. Prior to the compounding of the cylindrical lens, a cylindrical lens negative template needs to be manufactured according to relevant parameters, and then formed by edge pressing. Commonly used methods include flat pressing, legal sticking, and sticking.

Dynamic three-dimensional printing

Dynamic three-dimensional printing is an extension of ordinary three-dimensional printing, that is, printing a dynamic picture on the basis of printing a three-dimensional picture, as long as the change of viewing angle can produce dynamic. The principles and methods of producing dynamic three-dimensional prints are the same as ordinary three-dimensional prints. Dynamic stereoscopic printing also requires stereoscopic photography of the original document first. However, unlike ordinary stereoscopic printing, it is necessary to determine the number of actions to design the original document. Each motion has a screen. The amount of motion determines how much film is used. Dynamic three-dimensional printing manuscripts are now generally used desktop printing system for color separation, get multiple sets of separation film (female film), the resulting film after the copy of the multiple motion picture in a film, which asks step-by-step exposure, At last, the Yang picture corresponding to the action picture is obtained by the display and fixing, and then the printing, printing, and composite cylindrical lens plate are obtained to obtain the dynamic three-dimensional print.

Holographic printing

Holographic three-dimensional printing is a new three-dimensional printing technology that transforms interference fringes formed by laser photography into three-dimensional images and appears on a specific substrate. It is based on holography. 1980s. Holographic three-dimensional printing technology has entered the stage of popularization and application, and holographic three-dimensional printed materials have begun to become popular and gradually realize commercialization. Holographic printing is not printed with ink. Its printing is similar to that of conventional prints. Holographic three-dimensional printing first of all to take holographic images, before shooting to choose the right theme and its optimal layout in space. Pay attention to the effect of light. Holograms are not properly illuminated. It does not show any feature of the recorded scene. The shooting of rainbow holograms is based on the diffraction characteristics of light. In holographic printing, softer photoresist material will be used but it is not suitable for direct imprinting. Therefore must make the imprint template. Often used is a metal template. After transferring the rainbow holographic image information, it is imprinted on the press. The purpose of imprinting is at a certain temperature. The image information on the imprint template is transferred to a transparent film or vacuum-aluminized film. Commonly used films for imprinting are PVC, PET, PS, PP, etc. The embossing process is performed according to a hot press-cooling-peeling process. After embossing, vacuum aluminum plating is required. This is mainly because holographic images can be viewed directly under white light. Vacuum aluminum plating is the process of atomizing and depositing aluminum filaments on an imprinted film under high vacuum conditions. At present, it is also possible to imprint directly with already-aluminized films. after this. Need to be glued and covered. In order to transfer the three-dimensional image information, the process mainly includes two kinds of holographic images of paste type and hot stamp type.

In the domestic wine packaging market, in recent years, there has been a 3D "three-dimensional" material to enhance the security of the packaging products. So what kind of packaging is 3D anti-counterfeiting packaging? What new technologies are used in printing? According to Yang Hongwei, head of prepress output department of Wuliangye Push-3D Company, the three-dimensional effect of three-dimensional stereoscopic image printing is mainly reflected on the textured sheet. Using the optical imaging principle of eye and mesh sheet, the naked eye can see 3D stereoscopic images. In addition to full-color rendering and three-dimensional presentation, its anti-counterfeit pattern is active, and the pattern moves under different angles. Therefore, no matter whether it is photographing, scanning, photocopying, etc., it cannot be imitated. The patterns are ever-changing and then matched with the plane three-dimensional, REAL3D. The technology is not only difficult to prevent, but also allows the naked eye to discriminate authenticity at a glance. Using special production methods and meshed sheets with gratings to create a three-dimensional effect with different depth and watermark effect can not reach the security The printing method can be widely applied to three-dimensional anti-counterfeit packaging such as wine, tobacco and general merchandise. Equipment, calendars, promotional advertisements, posters, various types of cards, elevators, etc. The current Wuliangye Group's Yangtze River Delta, Wuliangchun, and Wuliang Alcohol's packaging boxes are all produced by Wuliangye Pushi 3D using three-dimensional images. Printed to print.

In the past. Stereo printing is a systematic project. The development of each aspect, including stereo cameras, three-dimensional computer lithography, and grating compositing machines, requires unique expertise: unless the company has the ability to design and fabricate in computer lithography, raster stencils, and grating machinery. Otherwise it will be very difficult to start production. Moreover, the production equipment is expensive and the process technology is complicated: the production cost is high; these all affect the promotion and popularization of three-dimensional printing. The commercialization of three-dimensional printing is a arduous process, so in the past several years, three-dimensional printing can only be applied in a small area. Nowadays, with the application of computer technology and CTP, the issue of plate making has been well solved. The application of three-dimensional products can be further promoted. Three-dimensional printing has higher requirements for network lines, outlets, overprints, and other aspects than general flat printing. Therefore, special attention must be paid to the investment in printing equipment. For example, Wuliangye Pushche 3D Company, in addition to enhancing the level of prepress design, entrusts the heavy responsibility of the platemaking process to the advanced CTP direct plate making technology. After a lot of investigations; Push 3D company introduced Creo Corporation Lotem 850 Quantum in 2003. After more than two years of practical use, the technicians found that CTP can fully meet the company's current production needs, which also proves that the company was wise to purchase CTP. The thermal imaging technology of the Lotem 850 Quantum is used. High production efficiency. Kodak Polychrome light preheated version of the plate after baking with UV ink resistant to India in more than 10 million India. The printing effect is better than the traditional exposure plate. Strong network outlets. Fast on ink. Instantaneous ink wash balance. Reduce machine scrap. This is very favorable for the long version of Push 3D. At the same time, the range of the Lotem 850 Quantum resolution is l 200-2540dpi. You can select the appropriate resolution according to the needs of your job. The Creo square spot imaging technology has good predictability and consistency to ensure data integration. The advanced automation technology's easy operation, high flexibility and accuracy all increase plate-making performance. Automatic temperature and geometric compensation ensure consistent imaging. The fully automatic version requires no manual intervention. The plate is automatically plated from the platen and the liner is removed. The customized online punching system automatically punches holes in the plate according to the selected ink line of the printer to ensure accurate registration: the plate is then automatically loaded onto the drum for imaging and then directly printed onto the line processor.

Push 3D's cTP has been used very well since it was put into operation. Color management, traditional and digital proofing technology can fully meet the requirements of three-dimensional printing. Effect. Of course, like the other CTP users in China, the relatively high price of the current plate market makes Wuliangye Push3D “walk on two legs”: the traditional platemaking process and the CTP process. Yang Hongwei calculated a set of CMYK in the production process of Push 3D. Four-color CTP version plus a white ink version costs more than 500 yuan. This cost is much higher than the traditional plate-making, the average customer is difficult to accept. Therefore, CTP is mainly used in the official plate production, and it is a long-printing and proofing to the customer when they use a film to reduce costs. Therefore, the current usage of CTP plates for Push 3D is approximately 30,000 pages in a year.

The birth and development of any new kind of thing will meet a lot of resistance. For Push 3D, CTP is a completely new technology and it also applies CTP to 3D image printing, stereograms and RIP, and output. There is a delicate relationship between the three devices. Therefore, there are still some difficulties in the initial production. To this end, the company organized equipment manufacturers engineers, three-dimensional production experts and colleagues in the printing industry. Many parties worked together to finally solve the problem. It is thanks to the development of new materials and the introduction of new technologies that Push 3D has been able to seize the opportunity in the field of 3D image packaging and printing. I believe there is a successful model of sample delivery. There will be more and more companies applying new technologies to increase the value of products, and the application fields of new technologies such as CTP will also continue to expand.

Three-dimensional printing applications

The prints of three-dimensional images are rich in color and three-dimensional. With the development of society and people's improvement in the level of print appreciation, the use of three-dimensional printing will continue to increase.

Stereo printing is the further development of stereo photography. It is the result of further exploration of stereoscopic display technology. Three-dimensional printing Because it can realistically reproduce objects with a strong three-dimensional effect, the product's rich image clarity and vivid image are widely used in animation production, packaging and decoration, advertising and interior decoration. In particular, holographic three-dimensional printing transforms the visual angle under the irradiation of natural light to see patterns of various colors such as red, orange, green, blue, and violet, and has a three-dimensional effect. It is widely used in decorative anti-counterfeiting businesses.