Mengniu carton preprinted solutions

The carton pre-printing is the use of the unit gravure printing machine to print the pattern on the web, and then the printed web is used as the tissue paper, and the corrugated cardboard production line is compounded with the corrugated board, after the computer longitudinal cutting, the computer horizontal After cutting, the blanks of the carton are formed, and then the carton is formed through a process such as cutting and bonding. The preprinted carton has high overlay accuracy, full ink color and vivid colors. The printing and coating are completed once. It is the best production process for obtaining high-quality carton at home and abroad. Its high production efficiency is suitable for mass production and production. The physical index of the carton is higher than 30% of the carton using the same material offset printing, but the production cost is obviously lower than the offset carton.

Prepress business development

In May 2003, Mengniu Dairy (Group) Co., Ltd. of Inner Mongolia, in order to improve the packaging quality of its products, was prepared to adopt color printing to gradually replace the printing and packaging of ink and wash, and to change the situation of poor packaging due to ink loss when ink-printed cartons were circulated on the market. . Since Mengniu's annual demand for product packaging is more than 100 million, it is difficult to meet the needs of customers if color offset printing is used. In addition, post-processing of cartons is also limited. In order to meet the market and meet the requirements of customers, Hebei Gao's Paper Products Co., Ltd. decided to introduce a carton gravure printing machine. Through market inspection and according to the actual situation of the company's products, in June 2003, Hebei Gao's Paper Products Co., Ltd. and Shaanxi Beiren Printing Machinery Co., Ltd. signed a purchase and sales contract, and purchased a large-scale paper with a format of 1.65 meters. Gravure printing machine. This machine adopts double-receiving, double-discharge and multi-color printing, has two sets of independent retractable material structure, two sets of tension system, can be switched without stopping, and the longitudinal register adopts the automatic register system produced by Japan Sun Corporation, which can meet the high Speed ​​printing needs. At the beginning of 2004, the equipment was installed and commissioned in our company and entered the production stage. The daily output of a single shift was around 250,000. According to incomplete statistics, from May to November, Gao's Paper Products Co., Ltd. produced more than 15 million cartons for Inner Mongolia Mengniu Dairy (Group) Co., Ltd., becoming the largest supplier of pre-printed cartons for Mengniu Dairy. At the same time, Gao's company also produced more than 200,000 pre-printed packaging boxes for Tianjin Yamaha Electronic Musical Instruments Co., Ltd., which was well received by customers and became the sole supplier of intaglio printing cartons for Tianjin Yamaha Electronic Musical Instrument Co., Ltd. in mainland China.

Preprinted material

Carton gravure printing is at the starting stage in China, and the carton gravure preprinting is obviously different from the gravure printing of cigarette packets and the gravure printing of plastic packaging. Therefore, after nearly three months of exploration, Gao's company mastered the printing technology. In the printing process, preprinted paper is affected by temperature, humidity, and paper material, and the deformation is large. In the process of overprinting, it is not easy to register, especially in the summer and winter, in order to solve this problem, on the selection of paper, Through the use of paper tests by different manufacturers, the coated paper roll produced by Shandong Sun Paper Co., Ltd. was finally selected. The coated paper roll produced by the company has uniform moisture content, and the degree of paper deformation is small during the production process. The rate is within 1%, the coating is uniform, firm and does not drop slag. The comprehensive utilization rate of paper is above 97%, which is obviously higher than that of other manufacturers.

Since the printing speed of the gravure printing machine is 80-150 m/min, if the water-based ink is used, it is difficult to solve the leveling problem in the large-area printing, and the water ripple phenomenon will inevitably appear in the actual printing, affecting the appearance, so it is with the Shanxi Essence Branch. Industry and Trade Co., Ltd. cooperated, through experiments, selected the alcohol soluble green ink with the same characteristics as the cigarette pack printing, which solved the technical problems in production and reached the requirements of green environmental protection. The ink produced by the company was in the printing process. Fast drying, low volatility, clear printed product levels, true reproduction of original effects.

Preprint technology research

Even if the temperature and humidity of the paper are significantly changed, there will be slight contraction and expansion. During printing, the temperature of each group of ovens should be adjusted in time according to the change of the paper to ensure the accuracy of overprinting. Under normal circumstances, the preheating group The temperature is adjusted between 100 and 130°C to evaporate the moisture in the paper as much as possible. The first set of the printing unit is generally set at about 20 to 25°C. After that, the temperature of each unit gradually increases by 5 to 8°C after printing. After the last set of colors, the temperature of the oil group is raised to between 90 and 110°C to ensure that the tissue paper does not stick after rewinding, and the varnish dries well without affecting the quality of the printed product, but the temperature is not set too. High, if the temperature is too high, the moisture content of the tissue paper is very low, and the horizontal and vertical threads of the produced container board are prone to burst during the post-processing of the cardboard box, especially in winter. In order to solve the problem of dry weather in the north of the winter and the horizontal and vertical lines of the carton are prone to burst, it is possible to spray the back of the printed product before rewinding after finishing the oil. The specific operation is to draw an iron pipe from the steam pipe. Each interval of 50mm on the wall of the iron pipe adopts a drill to drill a hole with a diameter of 3mm, and a vent valve for heating is installed. The vent valve hole is upward, and the flow rate of the purge valve is adjusted to adopt upward spraying method. A layer of water vapor is evenly sprayed on the back of the printed product, and then rewinded. The moisture content of the paper is controlled between 7 and 10%. This can solve the problem of the horizontal and vertical lines bursting during the processing of the carton.

The surface coating of paper will inevitably come off. When it passes through the printing unit, it will fall into the ink fountain. When the ink is applied, it will come into contact with the printing plate again. Therefore, the knife wire will be produced, resulting in a large number of defects in the printed matter. Therefore, the ink should be kept good. Cycle and filter the ink at any time. Because the coated particles are much larger than the ink particles, the use of high-density copper meshes can easily cause the pores to clog, resulting in poor ink circulation. If the mesh pores are too large, they will not be able to filter, so during production, Two layers of ladies' summer stockings can be put on the ink outlet of the ink circulation pump. On the one hand, it plays a role in filtering, and it does not need to be replaced frequently. The filtering effect of ink is better than that of copper mesh, and the cost is not high. This not only saves costs, but also increases the efficiency of production.

Source: Global corrugated box industry