Pre-printing is to pre-print the required patterns before making corrugated cardboard. In a broad sense, it can be divided into two methods: sheet printing and roll paper pre-printing according to the form of the printing material. Single-sheet preprinting is traditionally printed on a single piece of carton facial paper with offset printing, and then the brushed facial paper and corrugated paper are laminated with a laminating machine and die-cut into various box shapes. Its main features are: exquisite printing, low plate-making cost, and strong adaptability to different quantities of orders; but it also has the following deficiencies: slow production efficiency, low carton strength, and certain colors for products from different batches and different manufacturers Differences, etc. Roll paper pre-printing is to print on the roll paper, and it is still collected as a roll material after printing; then the printed roll paper is used as the carton face paper directly on the corrugated paper production line to make corrugated cardboard, and then die cut into boxes . Its main features are: exquisite printing, high production efficiency, the carton produced has high strength and economy, and is more suitable for large-volume products. The printing method can be divided into two types: gravure and flexo pre-printing. With the growing maturity and expansion of China's consumer market, the traditional production method of single-sheet carton has been difficult to meet the requirements of carton users for color boxes. At the same time, the domestic gravure printing technology has become quite mature. In 2001, the company's company launched the first unit-type carton pre-printed gravure printing machine in China, which has made great progress in China's pre-printing technology. Many well-known enterprises have adopted pre-printed packaging products, such as Guangming, Yili, Sanlu, Mengniu and so on. In the 1980s, due to the birth of the "global unified logo and brand" theory, almost all multinational companies insisted that their branches and products distributed around the world use completely consistent packaging. The so-called "completely consistent" means that the structure, color and content of the packaging are completely consistent. Through this "complete consistency" and high-quality printed images to attract customers' attention and ensure customer loyalty to their brand. Therefore, these multinational companies require their packaging suppliers to provide corrugated boxes produced using a pre-printing process. Pre-printing has become popular in the United States and Europe. In these developed countries, due to the relatively mature flexo technology and higher requirements for environmental protection, the pre-printing equipment is dominated by wide-format satellite flexo printing machines. Its main features are: simple structure, higher printing speed, accurate color registration, and stronger adaptability to paper. Since the 1980s, China has also introduced some flexographic printing machines from abroad, but most of them are used in the field of flexible packaging (printing format and small repeat length). At the same time, due to the high price of imported equipment and the imperfection of related supporting equipment, the wide-width satellite type It is difficult to open the market for flexographic printing machines in China; domestic manufacturers can only produce narrow-format flexo printing machines (the format is mostly within 600mm), so flexographic pre-printing is not popular in China. Two of them are using such imported equipment. After launching the gravure pre-printing equipment, the company where the author works did not stand still but continued to aim at the international advanced level to improve the existing technology. In order to introduce advanced foreign equipment into China, we are actively seeking cooperation with foreign manufacturers while researching and developing independently. Through cooperation with well-known foreign flexo printing machine manufacturers, a wide-format satellite flexo printing machine was produced. Satellite flexo printing machine is mainly composed of unwinding and input part, printing part, drying part (inter-color drying and final drying), cooling part, output and winding part, main drive and control part. Multiple printing units sharing a central impression cylinder is the main feature of the satellite-type flexographic printing machine. The printing materials will be tightly attached to the central cylinder during the printing process and the feeding path is short, so its overprint accuracy is higher; satellite The flexo printing machine has wider adaptability to the printing materials. After simple adjustment of the printing parameters such as tension, it can print materials including paper, plastic film, aluminum foil and so on, so that it can be used for one machine; the satellite flexo printing machine is relatively intaglio The simple structure of the printing machine and the few control points make high-speed printing possible, and its printing speed is mostly between 250m / min ~ 350m / min; at the same time, the water-based ink used by the satellite flexo printing machine is more pollution-free and more in line with the current green printing Requirements. For printers, flexographic printing still has some differences compared with offset printing and gravure printing, so we must pay attention to the technical support of flexographic printing itself, and we must avoid hard copying the experience of offset printing or gravure printing. Only understanding and mastering The characteristics of flexo printing technology can make full use of the advantages of flexo printing. Need to pay attention to the following items in use. In order to restore the rich layers and colors of the original in the printing plate, the plate material should try to use thin plates of 1.7mm and 1.14mm; because the flexible plate will be deformed during printing, the use of excessively thin lines and text should be minimized when designing the pattern. When the printing unit of the flexo printing machine is sufficient, the screen version and the solid version of the same color should be divided into two productions, because the screen version requires a thinner ink layer, while the solid and line version requires a thicker ink layer. However, in some special cases, it is necessary to print the same color of the network cable and the solid image on the same plate. In this case, on the one hand, when printing, the selection of the anilox roller must be compromised. Usually, the printing requirements of the screen printing plate should be first met, at the expense of the thickness of the solid ink layer; on the other hand, when making a plate, you must master different The exposure time is to ensure the quality of the Internet and field parts of the same printing plate. Therefore, several sets of anilox rollers should be equipped in order to meet the printing needs of different products. When selecting the ratio of the number of printing screen lines to the number of screen lines of the anilox roller, different ratios should be selected according to the fineness of the product. The reason is that the most difficult problem to solve when printing a gradation plate with a flexo printing machine is the expansion of the dots. In the pattern roller, the ink layer is thinner, and the expansion and deformation of the dots are easier to control. For fine prints, the ratio is approximately 1: 4.5 or 1: 5. If the ink color is not strong enough during printing, a water-based ink with higher color density can be selected to ensure the quality of the printed product. When purchasing equipment, you should also pay attention to some auxiliary but critical equipment, such as high-precision plate mounting machine. If double-single-single-print (print a plate and make a double-print) printing plate is used in production, the cost and difficulty of plate-making can be effectively saved. But the premise is to have a high-precision plate-mounting machine to ensure the registration between the left and right color sequence. If there is no plate-setting machine or the precision of plate-laying is not high, you need to make two patterns on the same plate, that is, single-split double-linked, which increases the difficulty of plate-making and the cost of plate-making. With the maturity of domestic flexographic printing supporting technology, the localization of satellite-type flexographic printing equipment, the acceleration of the integration with the world's printing and packaging technology, and the deepening of people's understanding of flexographic printing, I believe that flexographic printing will have a great deal in China development of. Although flexographic printing has many advantages, it will still be the situation of coexistence with offset printing and gravure printing in the future. For printing companies, only by fully understanding the various printing methods and the composition of their own products can choose their own printing methods to achieve greater development. Plant Cover,Shrub Covers,Covering Plants,Cover For Plants Changzhou MD International Trade Co., Ltd. , https://www.mdgarden.com