Series printing process

In the packaging and printing process, there are often different materials used to print the same or similar layout, such as internal and external packaging products, trademarks, brochures and other series of printed products, the general color layout of the printed text or logo are basically the same, but due to The difference in the characteristics of the substrate, some products used in the printing equipment, ink properties and process forms are not necessarily the same, and customers often require that the color printing products of a series of products basically the same, can not appear obvious color difference. The actual production process shows that there are certain difficulties in the control of the quality of the ink of different series of printed materials. It is necessary to carefully control the design and operation of the technology in order to obtain good printing quality and meet the quality requirements of customers.

First, the characteristics of the series of print analysis and process determination

The so-called series of prints means that the same type of product has different specifications for the internal and external packages, or the printed materials used in the set of products are not the same, but the graphic layout or color is the same or similar. Due to differences in material properties or printing layout specifications, the adaptability of the printing process is also very different. For example, corrugated cartons on the outside of the box, color box surface layer printing materials include whiteboard, leather or cardboard, and the carton packaging materials include whiteboard, leather, white card, glass card, copper plate, PE coated paper. And so on, flexible packaging plastic film, cellophane, tissue paper, glossy paper, copy paper, offset paper, vacuum aluminum paper, laser paper and so on. Corrugated board thickness, surface flatness characteristics, and PE coated paper, plastic film, cellophane, tissue paper, vacuum aluminized paper printing process, from the material characteristics and product packaging safety, hygienic quality considerations, suitable for flexible version Printing with water-based ink can better ensure product quality. For the pre-printing process color box paper, color box printing white paper, leather card; vacuum aluminum paper, laser paper and other materials, a large number of gravure or flexographic technology can be used to enable printing quality and production costs are Better balance. As for the whiteboard paper, leather card, white card, glass card, and copperplate card products with a quantity of about 100,000 sheets, and glossy paper, copy paper, offset paper, vacuum aluminum-plated paper, and laser paper, the offset printing process may be more appropriate. Among them, the glossy paper and copy paper have lower quantification and are not suitable for high-speed automatic paper feeding. A low-speed 01 offset press can be used for printing to better ensure the quality of overprinting of products.

Second, we must pay attention to the pre-press layout design process technology control

Nowadays, many printed materials are provided by customers with electronic manuscripts designed or produced by their own design or advertising company. Due to their incomplete understanding of the printing process, they often result in manuscripts that are produced and cannot be adapted to the requirements of the printing process. Taking the series of prints with the same textured structure as an example, since the printed materials used are not the same, the printing colors will be greatly different. It is the same type of paper plate (white paper material) and paper cup (single-sided PE coated paper) that are also printed by the offset printing process. Because the surface smoothness of the white paper material is good, the amount of ink absorption is small, and the single-sided PE coating film The surface of the paper is relatively rough, and the amount of ink suction is larger. Using the same material for printing the same structure of the textured structure, the color will vary greatly. Generally, the printing color of the single-sided PE coated paper is obviously lighter than the white paper. The amount of ink and pressure adjustment often cannot overcome the problem of color aberration that occurs due to the difference in the printing performance of the material. Generally, the main color dot area of ​​the printed single-sided PE coated paper should be properly adjusted to a larger size through the plate design so that the printing color can be brought close to the value. Therefore, when receiving a series of prints with the same structure of the texture pattern and different printing materials, it is necessary to carefully analyze the structure of the original layout and the characteristics of the material of the printing material, and then determine a reasonable design scheme for the pattern, that is, according to Material gloss, printing ink-absorbing performance, reasonable adjustment of the dot area of ​​a certain product layout, to ensure that the different materials printed by the color are close to each other.

Third, we must pay attention to the direction of the process technology control

Multi-fighted structure of the printed matter, a printed sheet is usually spelled several different varieties of layout, if you do not take into account the differences in the color printing of different species, but the different colors of different varieties in the same vertical, then, once the vertical layout of which When a certain layout printing color appears dark or dark, it is difficult to locally adjust the ink output through the ink fountain to realize the ink control of a certain type of layout of the corresponding vertical layout. The ink adjustment tends to result in a situation of misunderstanding, and there is no way to Take into account the printing color of the vertical overall layout.

Therefore, for multi-stitched paper plates, paper cups, trademarks, and other products, each vertical position is best to spell the same species or spell color close to the species, in order to facilitate the effective adjustment of the amount of ink coating. Do not fight in the same longitudinal position a few products with a large contrast of colors, because such imposition will be the most likely to produce color, even if the ability to control the printing color through the adjustment of the ink coating amount, but it is easy to produce chain printing quality problems, such as Pull paper, paste, dirty version and other bad conditions.

Fourth, adjust the control network size through the printing process

The main features of a series of prints are generally the same graphics and text, but the difference in size, and the substrate material characteristics are very different. If the film texture structure has been produced is the same, it can be considered in the printing process technology, according to the glossiness and ink absorption of the substrate, properly control the exposure time of the main color version of a certain product. Realize the adjustment of the dot size. For example, there are two types of substrates: glass cards and offset papers. The offset paper layout is relatively rough and the amount of ink is large. The exposure time of the main color version can be shortened to increase the dot area. The ink color of the offset printing paper can come close to the ink color of the glass card printing plate layout, and it is not prone to the problems of pasting. However, it must be pointed out that there is a limit to the size of outlets that can be adjusted in the printing process, and only minor adjustments can be made. If the exposure time is too short, the layout is prone to dullness, and the leveling of the layout is poor. Therefore, the exposure time adjustment to grasp a suitable degree, such as the original normal exposure should be 140S, the shortened exposure time to control the 110s ~ 120s appropriate.