Different corrugated box printing processes

1. Flexographic direct printing process generally uses flexographic printing lines or printing slotting machines to print directly on corrugated cardboard using water-based inks. It is suitable for printing with large format and quality requirements. It is mainly based on text and lines, and the number of screens is 35. The ~65 line/inch carton is currently widely used in cartons in China. The maximum width of the wide-format flexographic printing press can reach 2.5 to 2.8m, making it ideal for printing large-scale transport containers. Since flexo printing is light press printing, it has little effect on the strength of corrugated board, and the strength of the finished box is high. In recent years, with the development and application of middle and high-grade flexo ink, plate making technology, printing machines and supporting materials, the quality of four-color image printing has been improved, but there are still limitations.

2. Pre-printing with flexographic and pre-printed gravure Pre-printed corrugated box pre-printing refers to the roll-to-roll printing of corrugated board prior to the production of corrugated board, and the printed roll-up reel is then sent to the face paper of the corrugating machine. Work station, complete the corrugated core paper, veneer, and then through the die-cutting / slotting, sticking box / ordering box made of finished cartons.
Flexible printing preprinting and gravure preprinted corrugated box processes have developed rapidly in recent years. Both of these processes first print web paper in roll paper, and then complete the production of corrugated paperboard in the automatic corrugated board production line. The printing quality and the molding quality are relatively high, but the investment is relatively large and it is not suitable for small batch production. Moreover, since the cardboard is subjected to a high temperature and high pressure treatment after the printing, the ordinary ink cannot withstand such severe processing conditions, resulting in the printed surface being softened and strained.

3. Offset printing of indirect printing—first printing and then on-off process. Because the offset printing process is relatively mature, a very fine printing pattern of 150 to 200 lines/inch can be printed. The application in our country is very popular, so the batch size is small and the quality More demanding sales cartons currently use offset printing indirect printing methods, that is, printing cardboard box first, and then printing the printed paper to the corrugated board. This process is not suitable for the production of paperboard linkage production lines. It is only suitable for single-faced corrugating machines and has low production efficiency. Moreover, the printing format is limited and the printing cost is also high.

4. Offset direct printing process The direct offset printing process of corrugated cartons is relatively mature in foreign countries. It is to print corrugated board directly on a specially modified offset press, suitable for printing thin corrugated cardboard. Manroland has tested different fine corrugated cardboard on its offset press, which not only improves the state of cardboard accumulation but also clarifies the performance requirements of offset printing on corrugated cardboard. Compared with direct flexo printing, direct offset printing of corrugated board has the advantages of high printing quality, low printing cost, and short setup and adjustment time; compared with the way of first offset printed paper and corrugated cardboard, direct offset printing has the advantages of The cost of counterfeiting, the short time for the entire printing process, and the small amount of paper to be added and discharged. Although the process can not only ensure the good carton formability, but also can complete the exquisite glossy paper printing, but the use of the printing press is relatively expensive, and China's current demand standards are not yet suitable, is not suitable for the domestic carton industry in the near future It is used internally, but in the next few years, this process may become a new direction for the development of high-end carton printing in China.

5. Screen printing corrugated carton process screen printing corrugated carton process is a direct printing method, because the screen printing ink ratio is proportional to the hole pitch of the screen, so the print resolution is not high, the image accuracy is low, The number of conventional screens is 60-80 lines/inch. But the ink is thick, the color saturation is high, the visual effect is strong, especially the spot color prints the field, the effect is better. Screen printing can be used to complete the printing in the front and back boxes, as well as in the front and back boxes. The printing format can be large or small, but it is not suitable for the linkage production line and the production efficiency is low.

6. When the plastic gravure composite carton process adopts a single-faced corrugated board production line, if the glossy paper is still required to be coated after the glossy paper is printed, and the production volume is large, it may not be printed on the surface paper, but may be printed on the plastic film by a gravure printing method. On the completion of the gravure India, plus a white primer, and then the printed plastic film and the first composite paper, and then according to the conventional carton forming process to complete the box. Because plastic gravure is used, the printing effect can be comparable to that of offset printing. This process has a low manufacturing cost, and when the production volume is large, the printing cost of the tissue paper and the material cost of the tissue paper can be greatly reduced. Because the noodle paper does not need to be printed, non-coated white paper can be used, so that the cost of the noodle paper is greatly reduced. It is necessary to pay special attention to the use of this process, in the printing process, it is necessary to fully consider the size change and deformation of the plastic film, otherwise, the cardboard box and the lower cardboard will be uneven.
However, because plastic films are difficult to recycle and affect the recycling of resources, this process will gradually be eliminated.

7. Coated paper gravure composite carton process When the production volume is relatively large, do not need to film, and requires good printing effect, low cost, you can use paper gravure printing machine to print thin (60 ~ 90g/m2) coated paper , And then will be fine-printing coated paper and ordinary slag board or boxboard composite, as a whole carton paper, and then carry out the normal carton molding and processing. The carton printing effect produced by this process is very beautiful, and the cost of materials is reduced due to the combination of whiteboard paper with low-weight coated paper and low-cost linerboard. However, gravure plate making is more complicated and costly, and it is not suitable for printing carton products that are often revised. If the operation and control methods for the process of paper compounding and box making are unreasonable, it can easily lead to an increase in the rejection rate.

Author: Sun Xudong Source: Northeast Printing and Packaging Network