We are in an era of integration, including many commercial mergers and technology combinations that take place in all walks of life. This is especially true in the light industry such as beer, beverages and dairy products. Qingdao, which has taken the lead in the acquisition of the flag, currently owns 48 breweries. It has 23 breweries of China Resources Holdings with outstanding capital operation performance. Yankei, with its solid performance, has 13 subsidiaries distributed all over the country, which constitutes a situation in which the world's beer giants present a decent competition. . The re-emergence of the foreign beer once again set off a new round of game climax, Budweiser, Interbru, SAB, Heineken, Ka Shibo continue to write the name of the media. Beer is a large package. Brand beer packaging requires not only ordinary shipping functions, but also product promotion. With the integration of many beverage giants presumed to be national brands, paper packaging as an important logistics unit ushered in new opportunities and challenges.
The concept of a carton only as an outer packaging no longer exists, and today's carton factory has become complicated to supply to product packers. First, after quality inspection, including physical and chemical indicators such as dimensions, graphics, colors, abrasion resistance, anti-skid, and packing performance; Secondly, through commodity inspection, transporters, distributors and consumers will examine the commercial use of the carton with unprecedented picky. These are the market backgrounds for the evolution of carton technology.
Carton processing
Simply put, corrugated boxes consist of two processes: printing and forming. The printing process equipment includes offset printing, flexo printing, and gravure printing; the molding process equipment includes single-sided machines, cardboard lines, and slotted/die-cut/sticker machines. Printed substrates can be sheet-fed, web, and multi-ply paperboards; paperboard machines can laminate face and non-printing paper. If you print after forming, it is called preprinting; after forming, it is postprinting.
Sheetfed offset printing is a traditional preprinting method. It is currently the main processing method of domestic high-end color carton, offset printing preprinting mode is not large, but the process is complicated. The carton factory needs to configure a four-color full-open offset press (such as Roland 800), single Surface corrugating machine, veneer machine, polishing machine, sticky box machine and die-cutting machine have many processes, low efficiency, and poor environmental safety. Since its rise in the 1990s, flexo printers have developed rapidly and have become a convenient and mainstream method for carton colorization. It is generally composed of three or more color groups and slotted/die-cut groups. It prints ink on the three-layer and five-layer cardboards. This type of carton printing, which is called flexo-printing, requires only two sets of printing methods. Equipment, cardboard lines and wide-format flexo presses. The post-printing process uses flexible photosensitive resin plates to lightly print on corrugated paperboards. The inevitable spread of dots causes the hierarchical printing to be limited to less than 80 lines. The degree of exquisiteness is not as good as offset printing. Most of the post-printing can only be equivalent to the mid-range level of color carton. The high-grade post-printing technology of the UV coating system, such as BOBST's MASTERFLEX flexographic printing machine, is close to the offset printing level, but the machine cost is not affordable for a general carton plant. The most imported flexographic presses in China are from Taiwan, and domestic models such as the South China Sea East and Jingshan light aircraft are also common.
The carton industry in Europe and the United States in the 1980s introduced a new preprinting technology, the satellite web flexo. The machine is dominated by a Central Impression Roll for printing, drying, glazing, and curing of wide webs. The dot printing reaches 150 lines, and the visual effect is the same as the offset fineness. Feeding speed is 150 meters per minute, a six-color preprinting machine with a width of 1200mm can print 400,000 standard 640ml bottled cartons every day (3 shifts), and the production efficiency is 4 times that of a full-open offset press. The biggest difference from the offset printing preprinting process is that after the web is preprinted, the upper corrugated paperboard roll is directly applied to the roll surface, and the lower board is slotted/die-cut/glued to form a machine. All the equipments are equipped with three equipments, which has less process, high efficiency, safety and environmental protection. The two satellite preprinting machines (W&H and Belloni) introduced in the country are operating normally and represent cutting-edge processes for high-end color box production.
However, the advantages of flexographic preprinting have turned into a commercial advantage. Since the satellite web flexographic printing press has not yet been domesticated, the high price is a bottleneck that hinders the carton maker from investing. The Belloni six-color machine used the World Bank loan, and the W&H eight-color machine took two years to finally install. It can be seen that capital investment is not easy for the carton factory. The new technology is hopeless and unstoppable. The domestic carton preprinted in 2003 seeks new changes.
Gravure preprinting and flexo printing
According to statistics, after corrugated cartons flexo printing accounted for 60% of North American carton packaging, pre-printed accounted for 35%, showing an upward trend. The share of conventional offset (A, C, B) cartons is minimal, but in recent years, with the introduction of direct offset printing technology for corrugated cardboard by Roland and KBA, mini-corrugated cartons have begun to dominate the carton market. The proportion of high-end color boxes in Europe and Japan is even higher. According to Chinese consumers' appreciation and consumption habits, it is easier to absorb buyers with good color and delicate packaging. This is the reason why offset printing has long dominated the corrugated box market, and it is also the starting point for prepressing the gravure web.
At present, there are four manufacturers of domestic production and sales of carton gravure preprinting machines: Shaanxi Beiren, Xi'an Qinhua, Handan Light Machine and Xi'an Huayang. Among them, Shaanxi Beiren sold 6 paper concave machines, 3 Qinhua machines, 4 Huayang machines and 3 light machine machines. The well-known domestic companies that use gravure carton packaging products include Tsingtao Brewery, Sanlu, Mengniu, and Yili. It is expected that there will be 15 new gravure preprinting machines in China in 2004, and 4 exported to the United States and South Korea. Domestic machine-type six-color paper concave machines are priced at 1.5 million, 3 million and 5 million yuan respectively with the widths of 1300 mm, 1650 mm and 2500 mm three steps, which is equivalent to 1/1 of the price of imported satellite type flexo presses. 3, is 1/6 of the price of the imported unit gravure printing machine.
Foreign printer manufacturers such as Bobst, Cerruti and W&H have been focusing on the development of flexo-printing, preprinting and narrow-thick-thick-paper printing machines. Blanket blanking machines used for carton printing are basically blank. The high cost of the gravure plate steel plate roller is one of the main reasons restricting the development of the gravure preprint. The cost of the plate roller is 900 euros per color. The color of the packing box is rich and the edition is limited. The gravure is preprinted on the European market of Sungyo Kobayashi. It's not economical. The popularity of the domestic laser platemaking industry paved the way for intaglio preprinting, and the fee for approaching the price of the flexo plate makes the carton plant more flexible in the printing process. With the emergence of corporate groups and national brands, large-volume long version Printing makes product packagers applaud for the concept of gravure preprinting.
Paper concave machine users have strong flexibility, can not only undertake carton pre-printing, but also print cartridges, Tetra Pak, cigarette packets and decorative paper and other packaging products.汕樟Light machine is an early attempt to develop a paper concave machine in China. In 2001, the first gravure preprinting machine was installed by Zhejiang Tongtianxing Group to solve the high-grade color carton packaging required for the export of Luzhou orange specialties to Canada and local commercialization.
While the prices of ponkan oranges have risen by 30%, the loss of transportation has been reduced by 25%. The Group has now drafted a second intaglio printing machine.汕樟 汕樟 light machine for Taiwan South Asia Group, a pearl film preprinting machine and carton preprinting principle is the same, this equipment will be shipped to South Asia in the United States carton factory, the production process is slightly different, it is in strength The color pattern is printed on the pearl film with excellent bursting resistance, and then the film is compounded on the cardboard paper, preferably by die-cutting.
Cost-effectiveness better than offset printing
Gravure printing is direct imprinting, that is, the printing plate roll and the substrate are rolled under pressure, and image transfer occurs rapidly. The gravure printing ink layer is thick, the dots are fine, and the exquisite degree is almost equal to the offset printing, and the gravure preprinting does not need to worry about the quality of the printing product. However, the gravure preprinting process is absolutely superior to offset printing in the strength of the carton. Experiments have shown that the same grammage of the matched paper structure, the strength of the web preprinted carton is 10% higher. The offset sheet is printed on the corrugated board and the corrugated board is affixed. The gluing machine uses cold glue. When the pressure roller presses the board, the corrugation peak will be pressed down when pressure is applied to the board to reduce the compressive strength and stacking strength of the corrugated box. The loss of offset strength can reduce the weight of the corresponding paper and maintain the required strength when configuring the structure for gravure preprinting. The base paper generally accounts for 60% of the total cost of the cartons. Lowering the grammage can reduce the cost by 10%. The method of reducing the grammage is limited on the offset printing machine, and the whiteboard paper less than 200 g uses the offset veneer, and after the box is formed, there is an obvious “pan plate†stripe. Cardboard Roll-to-roll Making Corrugated Cardboard Corrugated cardboard is rapidly gelatinized by steam preheating the cardboard. The hot end ironing board exerts pressure on the cardboard plane without damaging the corrugation, and it does not form a "washboard" stripe. If the efficiency of gravure preprinting is included in the cost, the total cost of the carton will also drop.
The domestic gravure carton was actually developed by the technology of foreign flexographic preprints. With the rapid development of new technologies, there are many advanced packaging concepts worth learning from. ADALISCORP Corporation of the United States is committed to the optimization of corrugated cartons and has introduced a carton reinforcing belt called Sesame, which is suitable for the preprinted cardboard process. A filamentous PVC precoated with a hot melt on the cardboard line is stuck to the corrugated carton layer using steam at a high temperature inside the cardboard line, increasing the strength of the carton by 20%. North American dairy product packaging companies have started to adopt it.
Speaking of advantages
As with flexographic preprints, gravure preprinted cartons have the following major advantages:
â—† Color box with high quality and high sensory effect can be obtained;
â—† Accurate barcode replication capabilities;
â—† Better imprinting effect, corrugated won't form imprinting damage, and the carton will get higher strength finally;
â—† Improve the production efficiency of automatic corrugated cartons;
â—† High production efficiency, meet the short time limit, long production volume, and can maintain a constant color and print quality;
â—† The process is simple and convenient for production management.
Compared with imported flexographic preprinting machines, the processing accuracy of domestic gravure preprinting machines is not enough, and some common problems are exposed in the production process of carton factories. With the assistance of the printer factory, the corresponding solution was also found.
Wrinkling: high gram preprinted paper roll tension is about 50kg, more difficult to control than the film (10kg) and thin paper (25kg). When the water is uneven and the thickness is uneven, greater tension changes will cause the cardboard to swing laterally. Form the surface creases of printed products. The preheating device of the paper concave machine can help reduce the tension change caused by moisture loss (when the moisture content is too low, install the humidifier); if you add a flattening roller, you can help the paper roll as far as possible The swing is reduced.
Ink draw: In addition to the above-mentioned temperature-resistant ink and varnish, the latest air-cushion heating plate heat conduction control system can reduce the heating temperature and stress strength of the cardboard through the hot end. The process is that an air spray channel is arranged at the gap between the heating plate and the cardboard, and air can be sprayed in an instant to form a gas film to hold the cardboard, so as to avoid defects such as scratches, inks and the like caused by overheated pressure of the cardboard. This system has been developed and applied by the American Magui company.
Lubai: mainly due to the dust on the surface of the paper roll and blocked by the ink. The dust and explosion-proof electrostatic ink-absorbing devices installed in the field printing group can separate the air from the dust, improve the ink repellent effect, and reduce the dot loss.
Spiral rewinding: Because the rewinding tension of the paper machine is not consistent with the unwinding tension of the printing press, the preprinted paper roll rewinds in response to the formation of a tight rewinding effect after loosening and loosening of the inner core, namely the cauliflower phenomenon, and the paper roll handling. When the outer cardboard was scattered, affecting the material transport. The unwinding crosscut on the cardboard line is also inaccurate. The PLC computer correcting device can control the tape tension taper. It can measure the paper tension immediately after unwinding, and adjust the winding tension accordingly.
Incomplete edges: The edges of the cross section are not uniform, and the backup roller (receiving rubber roller) can be increased to drive out the air from the paper roll and eliminate static electricity on the surface. When the paper roll receives the material, the roller device is tightly contacted to reduce the edge. swing.
The installation of a PLC correction device also helps to alleviate uneven edges. Another solution to the problem of missing edges is offline rewinding.
Roll overlap: If the roll is improperly overlapped during printing, it will cause downtime and affect the consistency of the printed product. Zero-butt connection can be used to pick up the paper without interrupting the printing process. (Xiao Tieshu)