Kraft paper is mainly used for kraft paper hardcover notebook , envelopes, document boxes, product packaging, handbags, information bags, portfolios, financial statement covers, etc. It has 60g / m2, 70g / m2, 80g / m2, 100g / m2, 120g / m2, 150g / m2 and even 250g / m2 to 450g / m2 and other standards. Kraft paper has the advantages of strong and robust texture, good toughness, abrasion resistance, not simple tearing and cracking. However, the whiteness, smoothness, and flatness of kraft paper are poor, and the appearance of the paper is rough. Therefore, if you want to print kraft paper with an offset press, you should grasp the following key points.

1.Hang the kraft paper to adjust the humidity before printing. First remove the paper and the uneven surface of the paper, then clean up the paper dust and impurities on the surface of the paper, and then hang and dry to make the temperature and humidity of the kraft paper consistent with the temperature and humidity of the offset printing workshop. This can prevent the paper from showing up and down due to uneven moisture content. After the paper is hung to dry and humidity, the paper plywood is pressed on the top of the paper stack and compacted with iron plates and large stones to prevent the paper from becoming loose and incomplete.

2.Select the model. For thick kraft paper above 80g / m2, do not print with small four- or eight-sheet offset presses. As the kraft paper is thicker than 80g / m2, the nozzle usually cannot suck the paper during paper feeding. In addition, due to the small size of the paper, there are simply two or more defects, or the paper is skewed on the paperboard. And use folio offset press or full offset press to print thick kraft paper above 80g / m2, the effect will be better.

3.Adjust the offset paper feeding system. Because the kraft paper is thick, the suction volume of the nozzle should be adjusted. At the same time, the paper thickness also simply caused a rolling stop accident, so it is necessary to properly adjust the electrical equipment such as double-sheet control, skew control, and punch control before printing to prevent multiple sheets of kraft paper from damaging the machine. In addition, the paper separation nozzle and the paper feeding nozzle should use a rubber ring with a larger diameter and thickness!

4.When printing kraft paper, keep the base distance between the plate cylinder and the rubber roller unchanged, and only adjust the base distance between the impression roller and the rubber roller. When printing 250g / m2 ～ 450g / m2 of bovine cardboard, the base distance can be enlarged by 0.2mm ～ 0.4mm. Kraft paper has a rough appearance and poor smoothness, and the tightness of the paper is far less than that of coated paper and offset paper. Therefore, when printing on kraft paper, the printing pressure must be increased accordingly.

5.The appearance of kraft paper is loose and rough, and the paper is easily linted and powdered. Therefore, it is necessary to scrub the rubber cylinder and plate cylinder frequently during printing to prevent paper wool and paper powder from adhering to the rubber cylinder and plate cylinder to affect ink handling and form. Graphics and text are out of print and missing strokes. If the kraft paper has severe lint and powder removal, when monochrome printing is encountered, if it is summer, you can overprint a layer of water before printing, which can reduce the paper lint and powder removal, and make the paper more flat.

Zhejiang Huangyan Huifeng Stationery Co., Ltd. is a China Manufacturer and Supplier specializing in the production of    kraft paper hardcover notebook     . View our exquisite high-quality kraft paper hardcover notebook surface, welcome to purchase: https://www.chinesestationery.net/product/kraft-paper-hardcover-notebook.html