Knowledge related to technical control of the hott

2022-08-14
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Related knowledge of carton and carton printing process control

small ink "> carton and ink"> carton products often have the coexistence of various structural layouts. For example, there are not only pages mainly printed by ink "> on the spot, but also printing pages with lines, words, lines and on-the-spot patterns; there are gold and silver pages with spectral colors that cannot be displayed, but also pages with spot colors and four primary colors. If offset printing, embossing (or gravure printing, etc.) are used Different process printing methods, printing products have their own advantageous process characteristics. The combination of multiple processes to print cartons, cartons and other packaging products can improve the internal quality of products. Offset printing process has good reproduction effect, soft tone, clear dots, rich printing layers, and it is not easy to stick dirty products in a large area of printing. The embossing and gravure printing process has the advantages of thick and full ink layer, bright color and high gloss. Therefore, using the advantages of different printing processes to print products with lines, words, lines and field patterns, as well as layouts of various colors, integrating the advantages of different printing methods, and printing the same product with process synthesis # steel handle: hard wood can not only give full play to the utilization of equipment, but also synchronously improve product quality and economic benefits

reasonable arrangement of various combined printing processes

offset printing process has light printing pressure, relatively small printing deformation value, and the product is not easy to be sticky and dirty, so it is suitable for printing chromatic plates, lines, small words, negative images and large-area field layouts

the embossing process can achieve a large amount of ink supply at one time, which is more suitable for printing gold and silver ink layout, field, line or text layout. In terms of printing characteristics, the ink layer of offset printing process is thin, the ink is easy to dry, and the product does not produce convex marks, which does not affect the normal overprint of embossing. However, the slow drying of the product ink in the embossing process will have some adverse effects on the normal chromaticity. Therefore, the overprint sequence of the products with the combination of offset and embossment should generally be: offset printing first, embossing printing second; Small pages are printed first, and large pages are printed later; The ink with strong hiding power is printed first, and the ink with strong transparency is printed later. For example, black words or patterns are overprinted on the red and yellow (with the exception of white ink dilution). The black page can be printed first, and other colors can be printed later. In this way, due to the strong transparency of the overprint color, black can still show a pure black color

the technical control essentials of printing combined with various processes

1. Do a good job in the process and technical control of prepress design

the embossing field layout should avoid small negative lines and words in the same color plate, so as to avoid that the pressure and ink supply cannot be fully taken into account, which is easy to produce paste and uneven pressure, which will affect the printing quality of products. The overprint part of the embossed layout should be as far as possible to leave a certain gap around the edge of the overprint layout or appropriately expand the edge of the light color layout (so that the edge of the overprint layout can be overlapped and covered), so that the slight overprint is not accurate and is not easy to be detected by the naked eye

2. Do a good job in the technical control of the mosaic process

the overprint parts of the layout should be spliced close to the bite and the pull gauge (side gauge) as far as possible to avoid inaccurate overprint due to the expansion and contraction of the paper. In addition, it is not suitable to use two processes to overprint the layout with large or multi block chromatic layout across the river (core)

3. Pay attention to the reasonable selection of offset printing plate

ps plate has a thin plate. After it is installed on the surface of the drum, its wrapping angle is relatively small, and the elongation of the printing plate is also small, and it can maintain close contact with the drum, which is conducive to improving the overprint accuracy of embossed products. Therefore, PS plate should be selected for offset printing process

4. Pay attention to the process and technical control of the bottom support of the printing plate

small size packaging products are often printed by relief printing machines with four open or split circle flattening structure. The characteristics of the bottom support material of the printing plate have a great impact on the printing pressure, overprint accuracy and ink quality effect. The traditional wooden bottom support is not solid, with poor squareness, flatness and stability. It is prone to bow and deformation, and the printing quality is difficult to guarantee. Therefore, relief printing should use a solid, flat, square, stable aluminum or cast iron magnetic plate and other metallic materials, which is the basis for improving the registration and ink quality of products

5. Pay attention to the control of printing pressure. 1. On the one hand, we should aim at the technical level of the new generation of information technology, high-end equipment, new materials and other 10 strategic key areas.

the printing pressure should be adjusted evenly and moderately. Excessive pressure is easy to stretch and deform the printing sheet, resulting in inaccurate overprinting. Therefore, the printing pressure of the embossing process must not be too large, but as light as possible to meet the requirements of uniform ink color Ideal printing on the premise of fullness

6. Pay attention to the technical control of the lining process

the lining is the medium to realize the transfer of pressure and imprint. Its characteristics also affect the registration and ink quality of the product. Therefore, the deformation coefficient of the lining material should be as small as possible, and the material should be neutral and hard. At the same time, the thickness of the lining must be determined in strict accordance with the technical parameters of the equipment specifications. In addition, the lining must be tightly wrapped and tight, and there must be no virtual looseness or bulging. Do not repeatedly patch or excavate on the embossed lining to prevent inaccurate overprint and ghosting

7. Pay attention to the technical control of ink balance.

to control the ink balance in offset printing process is to print with a minimum supply of fountain solution under the condition of maintaining ink balance. The abnormal balance method of large ink and large water should be avoided to prevent deformation due to excessive water absorption on the paper

8. Pay attention to controlling the temperature and humidity of the printing environment

controlling the temperature and humidity of the printing workshop is an important part of improving the overprint accuracy of products. The temperature and humidity of offset and embossing workshops should be kept in a relative balance, and there should be no large gap between high and low, otherwise, it is easy to cause inaccurate overprint. In general, most small and medium-sized printing enterprises cannot effectively and accurately control the temperature and humidity of the production site due to the limitations of conditions. They often control through simple methods such as opening and closing doors and windows or splashing water on the ground based on experience, which can also play a certain role

9. Pay attention to the technical control before the paperboard is put into use

the paperboard is very sensitive to the temperature and humidity changes of the external environment. According to the loading speed required by the experiment, especially the white paperboard just produced is most likely to have telescopic variation due to the changes of temperature and humidity, resulting in inaccurate overprint of products. In order to reduce the chance of this situation, for the newly produced white paperboard, after the printing factory transports it back, it generally needs to be stored for a period of time, so that the characteristics of the paperboard are relatively stable, and it is not easy to overprint when it is put into use. In addition, the cut paperboard should be sent to the printing workshop immediately to make it balance with the temperature and humidity of the printing workshop before printing, which is conducive to improving the registration accuracy of products

10. Pay attention to the technical level of paper cutting process

how accurate the specification of paperboard is will also affect the overprint of products. Because of different machine structures, their front gauge and pull gauge positions are not the same. In this way, if the edge of the paperboard is not cut squarely enough, and there are beveled edges or wavy edges, it will cause inaccurate overprint. This requires that the edges of the paperboard of the products with glue convex combination must be cut into right angles and straight lines, and there must be no beveled edges or wavy edges. In order to improve the cutting accuracy of paperboard, we must strictly control the cutting thickness, because the thicker the paper stack, the softer the paper, the more severe the paper surface deformation when the paper presser is pressed down. Therefore, the less the cutting thickness of each stack of paperboard, the more conducive to improving the cutting accuracy of paperboard. In addition, the blade edge should also be kept sharp, and the appropriate blade angle should be selected according to the hardness of the paper, which is also an important measure to improve the cutting accuracy

11. Pay attention to the production cycle of product overprint

when the previous color or several colors of the printed matter are printed, those that can be overprinted should be overprinted immediately, so as to avoid stretching and variation of the printed matter due to too long delay, resulting in inaccurate overprint

12. Pay attention to the protection of semi-finished products after printing

the semi-finished products after printing should be sealed with plastic film to prevent the cardboard from absorbing moisture from the outside air or losing moisture, so as to avoid or reduce the adverse phenomenon of expansion and variation of semi-finished products

to sum up, no matter what kind of process is used for printing cartons, cartons and other packaging products, a printing process can be used alone to carry out research, promote and promote printing in green logistics, green consumption, green supply chain and other aspects, or a combination of various processes can be used for printing; Multi color printing machine is used for printing production, or monochrome printing machine is used for printing production; It is to use advanced multi-function printing machine for printing production, or use simple and ordinary printing machine for printing production. In any case, the most important and critical link is to control the operation technology and process technology according to the characteristics of the product, and print with appropriate printing pressure and appropriate ink coating amount; Based on the characteristics of ink, printing plate and paperboard, printing with appropriate speed can improve the printing quality and production efficiency

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