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What do kraft carton factories need to pay attention to when printing?

1. Pay attention to the printing color. In order to get better color reproduction when printing in kraft paper, it is more difficult to print than SBS paper. Especially in ordinary kraft paperboard, it is better to achieve color reproduction. It is more careful to print on kraft paperboard. Since the ordinary kraft paper itself is dark brown, the effect of printing ink is very different from that on bleached paper. Therefore, it is better to use brightly colored inks, and use more conspicuous colors. This kind of printing effect is better. Soft colors and light colors are more difficult to achieve the desired effect of ink density, opacity and abrasion resistance. In addition, if necessary, add a little white to the ink. It will help to achieve the desired soft or light color, which is very useful for copying soft colors and light colors. With the increasing maturity of printing technology, some manufacturers even use UV inks to effectively improve the printing color effect.

2. Glue is reasonably bonded. The high-solidity and high-viscosity resin adhesive is suitable for low-temperature bonding. It needs to be cooled before it can adhere to the kraft paperboard. It cannot penetrate into the cardboard. The traditional hot-melt adhesive is also suitable for kraft paperboard and Ester-coated kraft paper, the effect is better. Because of the light weight, kraft paperboard is suitable for high-speed paste box machine production.

3. Reasonable use of paper, in order to meet the new needs of food manufacturers for packaging, primary color kraft paperboard has some characteristics different from bleached paperboard, such as baked goods or convenience foods. The natural brown appearance of primary color kraft paper has a healthy, retro Charm.

4. Ink is reasonably selected. Because kraft paper is different from SBS paperboard and general printing paper, it is uncoated, looser than bleached paperboard, has many pores on the surface, and has strong permeability. This is used in ink application and coating. The cloth needs to be considered comprehensively. For example, according to the analysis of the characteristics of kraft paper, it is generally better to use flexographic printing, and it is not suitable to use the offset printing machine for full-page kraft printing. The surface of kraft paper is rough, soft and ink-absorbing. Strong, the color of the printed products is dull, and the printing will also appear the phenomenon that the ink pulls down the paper fibers (also called the pull-off paper).

5. Cardboard processing and processing, because the unglazed kraft paper is loose and porous and has a large volume, it is easy to generate dust during the process of making cardboard, so it is necessary to prevent and reduce the harm caused by dust.

6. Post-press die-cutting processing, due to the special structure of the original color kraft paper, its high strength and predictable fiber characteristics, thus having good processing properties such as embossing, die-cutting and die-cutting. However, for high-strength toughness of primary color fiber Kraft paper is required to pass the deep crease line to avoid rebound. In addition, the die cutter must be sharp. Due to the high strength of the kraft fiber, a narrow indentation is needed on the perforation line, and the nick required for punching. Should be less, and be small.