The evolution of plate making technology of the mo

  • Detail

The evolution of gravure printing plate making technology

although gravure printing process is simple, the printed images are rich in layers, bright colors, good definition and high quality. The only challenge is that the people of gravure cylinder are also very concerned about the difficulty of making. With the development of science and technology, gravure plate making technology is becoming more and more advanced and complex. People who have experienced the era of etching gravure plate making know that the etching plate making process is quite complex. In the etching plate making process, a large number of materials and equipment are required, and many processes need to be manually operated. Compared with the etching plate making process, the electronic engraving plate making process is much simpler, realizing the digital control of the process, simple operation and reliable quality. At present, no film engraving has been realized, and the original information is no longer scanned. The data information can directly drive and control the electric engraving needle, and the engraving process is controlled through software

the electronic engraving plate making process greatly simplifies the production process of gravure cylinder and improves the production efficiency. The quality of plate cylinder on June 29 and the reliability of plate making process. The working environment is improved, which is more conducive to the health of operators

At the end of the 19th century, with the development of photographic technology, people put forward higher requirements for the printing of continuous tone images. The first proposed is the eye tone theory of adding continuous tones. The gray value of the image is reflected by different area points. This method has been used until now, but the adding method of the original has changed greatly. The original non-contact addition was used, which was later replaced by contact addition. Now it is completed by Rip (raster image processor). Usually, any value between 0 and 255 is used to represent the gray value of the image, and rip converts it into points of different shapes, sizes and positions

compared with the plate imaging of embossing, offset printing and flexo printing, the electronic engraving intaglio process is much simpler. The value corresponding to the gray value of the original image can be directly transmitted to the electronic engraving machine to control the diamond engraving needle to engrave on the surface of the copper layer, and the area and depth of the engraved hole can be changed. Electronic engraving can obtain high-quality gravure cylinder suitable for specific printing conditions (including printing machine, ink, paper, etc.) by simply adjusting the gradient curve

controlling the electric engraving needle with gray value data can achieve accurate matching with gravure eye tone images, which greatly improves the reliability of the process and the quality of the plate cylinder

unlike offset printing, in terms of copying text and lines, electronic engraving can not achieve more precise copying than selecting the number of engraving lines, and the copy quality of text and lines is limited. Hall company has improved the dynamic control of electric carving needle and developed hqh software to effectively eliminate the "jagged edge" of small yin-yang lines. Gravure text is softer than offset printing

traditional photogravure plate making technology

traditional photogravure plate, also known as "Photocopying plate", depends on the change of hole depth to show the level of gradation. It is necessary to deal with the carbon paper grid and the sun chart with the screen and the continuous positive image respectively, and obtain the holes with the same area and different depth according to the permeability of the carbon paper to the corrosive solution

the process is complex. There are 11 steps from carbon paper preparation to corrosion. The predictability and repeatability of the process are poor, and the corrosion depth of holes and wall control are quite difficult. What is more difficult is to control the bright part. The bright part requires that the corrosion depth of the hole is very shallow, which cannot exceed 1 μ m. But it is too difficult to achieve

the basic principle of photographic direct plate making technology is: after copper plating and polishing, the plate cylinder is first coated with a photosensitive layer, and then exposed for imaging, which corrodes the copper layer

at first, a photosensitive film was coated on the surface of the copper layer of the plate cylinder and exposed with a high-pressure mercury lamp. Later, laser etching technology appeared. Without film, image data directly controlled the fine laser beam to image on the photosensitive film. No matter whether the imaging process is digital or traditional film adding, only the point structure with area change is created on the coating, and the depth information cannot be reflected. Using this kind of printing plate, the energy words absorbed when the lines and text are destroyed can be well reproduced, but the image reproduction effect is poor

compared with electronic engraving plate making process, all direct photographing and gravure plate making processes (even if digital imaging technology is adopted) have three fundamental problems: the imaging method is not suitable for high-quality printing, the shortcomings of the corrosion process itself, and complex process steps

directly carve the zinc layer with a laser beam

carve with a short wavelength laser pulse, and the resulting gradient is very steep, not soft, not delicate. Engraving directly on the metal layer also involves the sensitivity of the metal layer to the laser. Small changes in the sensitivity of the metal to the laser beam have an impact on the energy threshold. Because only pulse energy higher than the threshold can produce holes, changes in the energy threshold will affect the hole size. If the energy density focused by the laser beam fluctuates, it will also cause the cumbersome operation and the change of the hole size. The above two static changes will lead to the hole size deviation. If this change works at the same time, it will lead to a larger deviation. Since the laser beam is focused through a glass lens, only a fixed imaging area can be set. This allows the laser beam to have only a fixed diameter. A method to increase the stability of engraving and improve the resolution of zinc layer is to use several small holes to form a lattice. The hexagonal lattice produced can accommodate seven relatively small independent holes, but this method greatly reduces the engraving speed

Future engraving methods

electronic engraving is widely used because of its simple process, high reliability, low cost, good quality, especially the good reproducibility of images. Compared with etching plate making, the only disadvantage of electronic engraving plate making is poor contour. In the field of packaging and printing, in addition to electronic engraving gravure, the application of corrosive plate is also more common. That is, using laser etching digital imaging instead of traditional film imaging, the depth of the hole is still unable to be controlled during imaging, which limits the replication of eye-catching products to a certain extent

in view of this situation, hall company aims to solve the fundamental disadvantage of electronic engraving - the definition of text and lines. This goal can be achieved by two different methods: developing electronic engraving intaglio technology and laser direct engraving copper layer technology

xt ultra-fine electronic engraving technology

similar to laser Phototypesetting Technology, XT ultra-fine electronic engraving technology can engrave text and image with different resolutions, with 1000 lines/cm for text and 60 lines/cm for image. The resolution of words and images is improved, and the hole depth can also be changed according to requirements. XT technology means that basic parameters such as resolution, maximum hole volume and hole depth can be adjusted separately

XT technology is widely used in the electronic field, such as printing circuits on aluminum foil. In the field of packaging and printing, XT technology can be used for graphics and texts requiring very fine details, which also plays an important role in anti-counterfeiting printing. In the printing of magazines and catalogues, XT technology is used for text and line engraving

laser engraving directly on the copper layer

according to the principle of XT technology, hall company developed the prototype of laser engraving machine, which directly engraves holes on the surface of copper or chromium, and the writing resolution of laser beam can be adjusted separately. XT technology also requires an addition controller, which is placed in the XT carving head, while adding and carving, to complete the hole carving of any shape. This technology is the first time that the adding process is completed in the carving head. It can not only carve amplitude modulation holes, but also carve frequency modulation holes

the XT technology of hall company is first developed for the packaging field. Under appropriate conditions, it will be extended to the field of large format catalogue and magazine printing

Copyright © 2011 JIN SHI