1、 The processing technology of corrugated paperboard the processing technology of corrugated paperboard is mainly divided into two categories
1. Production process of automatic corrugated board production line
The corrugated board production process is widely used, with the advantages of large production volume, large box forming volume and good corrugated quality. The corrugated board produced by this process is usually made into cartons through water-based printing, slotting, pasting, forming and other processes. The cartons produced by this process are mainly used for transport packaging.
2. Production process of semi-automatic corrugated board production line
The corrugated board production process is to print face paper first, and then mount with corrugated core paper and paperboard. The corrugated paperboard produced by this process is usually packed in the process of die cutting, indentation and nailing. The carton produced by this process has good quality and surface treatment effect. The cartons produced by this process can be used as sales packaging.
2、 Conventional carton printing methods conventional carton printing methods mainly include flexo printing, offset printing and screen printing
1. Flexographic printing
The conventional flexographic printing technology of corrugated box is printing directly on the corrugated board, using water-based ink, so it is also called watermark. Flexographic direct printing has the following characteristics:
(1) It's big. The maximum width of flexographic printing machine with wide width can reach 2.5m ~ 2.8m.
(2) The price is low. Flexographic printing power is very high, can be reused; ink prices are low.
(3) Can linkage production, such as printing, slotting, indentation, order (stick) box, bundling, etc. can be completed in one machine.
(4) The strength of the carton is reduced less. As flexo printing is light press printing, so the strength of corrugated board has little effect.
(5) The printing accuracy is not high. The conventional offset screen line number is 175 lines / inch, while the conventional flexo carton screen line number is 35 lines / inch ~ 65 lines / inch. It is a low precision printing method, which is most suitable for printing text lines. Although the quality of four-color image printing has improved in recent years, there are still some limitations.
(6) Plate making is easy and difficult, text line draft plate making is easy, four-color image plate making is difficult.
(7) The poor stability of printing quality is mainly reflected in the difficulty in controlling the depth of printing ink. Flexographic direct printing process is suitable for the first kind of carton production process, which is widely used in China's carton factories.
2. Offset printing
Corrugated box conventional offset printing corrugated box uses indirect printing method, that is, first printing the carton face paper, and then mounting the printed face paper on the corrugated board.
Due to the high resolution of PS plate, it can print a very fine printing pattern. At present, the vast majority of high-grade corrugated boxes used for packaging in China are offset products. Offset printing corrugated box has the following characteristics:
(1) It is not suitable for the paperboard linkage production line, only suitable for the single-sided corrugating machine, the production efficiency is low.
(2) Limited format, generally smaller than flexo carton format.
(3) Printing products are very fine, the number of screening lines can reach 150 lines / inch ~ 200 lines / inch.
(4) Easy plate making, PS plate for conventional plate making.
(5) Can carry out surface finishing, such as lamination, glazing, etc.
(6) Printing costs are high.
(7) The printing quality is stable.
3. Screen printing corrugated box
The screen printing technology of corrugated box is direct printing. Because the inking rate of the screen plate is directly proportional to the hole distance of the screen, the resolution of the screen printing is not high, and the image accuracy is low. The conventional screening line number is 60 lines / inch ~ 80 lines / inch. Screen printed corrugated box has the following characteristics:
(1) It is not suitable for linkage production line, and the production efficiency is low.
(2) The printing format can be large or small.
(3) It can be printed before mounting and packing, or after mounting and packing.
(4) Suitable for printing non fine products. Screen printing ink thick, so its color saturation is high, strong visual effect, especially spot color printing field, the effect is better.
(5) Easy plate making, low plate making cost.
(6) The printing cost is low.
(7) The printing quality is stable.