Paper packaging: green packaging
new paper packaging technology
1 Paper packaging development trend and requirements for technology
in recent years, the global paper product packaging industry has developed rapidly, and the production capacity of cartons and cartons has increased significantly. Among the world's packaging industry output value, paper packaging products account for more than 32%, and in Europe, the consumption proportion of paper and paperboard is as high as 41%. Per capita consumption of paper and paperboard in 2000: 331.7 kg in the United States, 249.9 kg in Japan, 229.4 kg in Taiwan, and 28.4 kg in Chinese Mainland
in 2000, China imported 13.03 million tons of paper, paperboard and pulp (about US $6billion), accounting for about 66.7% of China's paper and paperboard consumption. In recent years, the growth rate of Hong Kong's packaging industry is about twice that of the printing industry. In 2000, the sales volume of Guangdong packaging industry reached 50billion yuan, including 18billion yuan for paper packaging products and 14billion yuan for packaging and printing
with the further enhancement of people's awareness of environmental protection, cartons, cartons, paper bags, paper cups, paper cans and other packaging containers are more and more widely used in the world. In Europe, carton packaging for all kinds of fruit juice, milk, cooked food, fast food, snacks and other beverages and food can be seen everywhere. According to the relevant data of China's tobacco Department, the proportion of hard packed cigarettes in China has reached 56%
with the continuous improvement of people's living standards and the automation of commodity packaging, not only the demand for cartons/cartons has increased significantly, but also higher requirements for the printing quality and processing accuracy of color folding cartons/multicolor cartons. In order to avoid rabbits from discharging waste products on the automatic folding and pasting machine, and make the folding carton automatically complete the opening, forming, filling, sealing and other processes on the high-speed packaging machine, it is not only required that the structural size of the carton is designed reasonably, but also to ensure that the box pieces have sufficient die-cutting accuracy and folding and pasting accuracy. Multicolor printing, the increase of short version movable parts, the improvement of printing quality and processing accuracy, and the reduction of processing costs are also the problems faced by carton packaging and printing enterprises, but the fracture location has never been a utopian pressure and problem. Therefore, only by applying modern processing methods and new technologies, continuously improving the automation of the equipment, reducing the adjustment time of the equipment and the auxiliary preparation time of live parts in the process of paper packaging printing and post press processing, constantly adapting to the new changes in the market and meeting the requirements of different users, can the competitiveness of packaging and printing enterprises be improved
2. Paper packaging container CAD technology
the carton structure CAD software, which is more popular in the international market, in addition to the basic functions of commonly used interactive graphics software (generating, modifying and dimensioning graphics with high quality and speed), should also meet the special requirements of carton design, easily call the box graphic library and select a satisfactory box structure. After inputting the box size (length, width, height) and cardboard thickness, It can immediately display or print the box sheet structure drawing, automatically arrange the material, and output the box sheet die cutting layout drawing, printing outline drawing and backing (bottom mold) processing drawing; After the user designs or invokes the required box sheet structure diagram, as long as the paperboard size and discharge gap are input, the material can be discharged and different discharge schemes can be compared, and the optimized die cutting discharge diagram and related parameters (such as the number of discharged materials, the utilization rate of paperboard, etc.) can be displayed
in addition to selecting the standard box type and changing the carton shape, you can also design special box types, rotate the carton stereogram, and display the opening and closing process of the carton at will; For different cutting edges, indentation lines and slotting and line breaking parts, corresponding line types should be selected to control the production of carton samples, die-cutting plates, bottom mold (backing) plates and die-cutting tools, and improve the processing accuracy of die-cutting plates and backing plates and the manufacturing accuracy of cartons
3 Paper packaging printing technology
in the field of paper packaging printing, offset lithography, relief flexo printing, gravure printing and silk printing coexist, each with its own characteristics. Offset printing is mostly used in sheet board printing, and flat press flat wire printing and sheet fed gravure printing are also used
in web printing, gravure printing and flexo printing are mostly used, offset printing and silk printing are also used, and several combined printing methods are used in one printing production line at the same time. Carton printing is generally between colors, of which color is the most used. Folding cartons, especially medicine boxes, mostly use spot colors, so the number of printing color groups is mostly color. The number of color groups of sheet fed offset press is generally 4 colors, which basically does not exceed
colors, while multi-color web press (including gravure and flexographic printing 8 K value of spring: the ratio of force component to deformation in the same phase with deformation and silk printing) has increased rapidly, and some printing color groups have reached color
3.1 offset printing technology
(1) digital printing and CTP technology
digital printing technology prints according to the database information with personalized selection, which provides the choice of realizing personalized packaging printing for paper bags, cartons and corrugated cartons, and can change the design and processing parameters of paper packaging containers according to regional or product differences. By adopting special processes, folding cartons can have changeable printing colors and hot stamping effects, In order to meet the needs of the market with many specifications of packaging cartons (boxes) and a large number of short version live parts
the high-definition CTP technology developed by Agfa can provide high-quality points for modern packaging and printing. The unique laser and optical imaging system, intelligent multi beam simultaneous imaging method, IntelliSpot intelligent point and other technologies have increased the security of the system, simplified the system structure, and improved the automation and overall efficiency of the system
(2) FM plus technology
the quality of printed matter mainly depends on the number of points per unit area and the number of continuous change stages of points from small to large. The more the number of points on the bit area, the higher the sharpness of the printed matter, the more the number of point changes, the stronger the level expressiveness of the printed matter, and the more delicate it looks
in order to improve the quality of prints, amplitude modulation plus classic cases, frequency modulation (FM) plus and hybrid plus technologies are often used
the dots of AM plus are regularly arranged, and the size of dots is used to change the printing ink volume, while the size of dots of FM plus is fixed, and the distance between dots can be changed. The ink volume printed on the paper can be adjusted by the change of dot distance and dot number to realize the change of color. Am plus has three elements: the number of lines, the shape of points and the angle of addition, while FM plus has only one element: the size of points. The smaller the dot, the finer the print, and the better the visual effect, which is equivalent to the number of high plus lines in am plus time. However, the smaller the FM plus dot, the higher the requirements for printing conditions. Hybrid plus is a hybrid plus technology that combines am and FM plus technology to form on the same image. In the uniform tone area, especially in the high light area, conventional addition can produce a smoother appearance than FM addition. But for high detail parts, FM plus effect is better. Advanced additive software can analyze images to decide where to use appropriate additive geometry, and combine FM additive with conventional additive to achieve the best overall effect
the application of FM plus technology can eliminate moire, improve the uniformity of hierarchical reproduction, improve the resolution and clarity of images, and easily realize high fidelity printing (HI FI). Although FM plus has strict requirements for printing conditions, it is suitable for anhydrous printing process. High definition FM dots can significantly improve the clarity and hierarchical expressiveness of printed matter. Unlike am points, the arrangement of FM points is limited by point spacing and arrangement angle. Selecting frequency modulation points in printing reproduction can show more detailed changes, improve the clarity, and have anti-counterfeiting function
(4) printing color management technology
the central control system of CP2000 integrated offset press developed by Heidelberg company adopts TFT ultra-thin screen display technology, and is equipped with prepress interface technology, image control technology, printing color management 3-yuan line and lithium iron phosphate line. The price of the power battery is more than 15% lower than that in December 2016, help system and information management system, forming a quality control mode under the condition of printing integration. The multi-level printing color management system PCM includes consultation, standardization, optimization of prepress and printing, generation and implementation of ICC color characteristic files, etc. In order to optimize the color process and improve the production efficiency of the printing plant, effectively coordinate prepress and printing equipment. It can not only get high fidelity colors, but also save time, reduce waste, and obtain efficient production
(5) water free offset printing technology
water free offset printing is a lithographic offset printing method using special silicone rubber coated plates and inks, which does not need isopropyl alcohol or other chemical fountain solutions necessary for traditional lithographic offset printing. The printing process is simple, and the ink is transferred to the printing plate within a certain temperature range without adjusting the water ink balance relationship
the printing plate used for waterless offset printing is a flat intaglio plate, and the graphic part is lower than the surface of the printing plate. Although the plate making process is the same as that of PS plate, it is different from PS plate. Therefore, waterless offset printing plates have unique processing difficulties. Plate, ink and temperature control are the key of waterless offset printing technology, which directly affects the development speed of waterless offset printing. The printing plate is the core of waterless offset printing. The printing plate of waterless offset printing has the advantages of easy operation, good image stability, high printing density, gorgeous colors, good print quality, etc., but the printing resistance of the printing plate is easily affected by operating conditions and special prints. The special ink used in waterless offset printing has the characteristics of low viscosity, high viscosity, large thixotropy, stable performance and so on. Because inks of different colors react differently to temperature changes, it is necessary to control the temperature of different printing color groups. Although the consumables cost of waterless offset printing itself is high, the waste rate of printing products is low and the production efficiency is high. It can be seen that with the progress of technology and the improvement of labor productivity costs, especially for high-quality exquisite paper packaging, waterless offset printing technology has certain advantages, and will be further developed and promoted
source: China United Printing
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