The problem of base paper in carton factory

1、 Problems caused by low gram base paper when printing with low gram base paper, the corrugated board surface will be exposed and the dot will not be cleaned. It is easy to cause the low recess of ridge peak and ridge pit to not print the required graphic content. In view of the uneven surface of corrugated board caused by exposed corrugated, the flexible resin plate with good elasticity is selected as the printing plate to overcome the defects of unclear printing and bottom leakage.

2、 Problems caused by different surface roughness of base paper printing on paper with rough surface and loose structure has large ink permeability and fast drying of printing ink, while printing on paper with high surface smoothness, dense and tough fiber has slow drying speed. Therefore, on rough paper, the ink application amount should be increased, and on smooth paper, the ink application amount should be reduced. The drying of printing ink on non sizing paper is fast, while the drying of printing ink on sizing paper is slow, but the reproducibility of printing pattern is good. For example, the ink absorption of Coated Whiteboard is smaller than that of carton board and tea board, the ink drying is slow, and the smoothness is higher than that of carton board, hanging paper and tea board. Therefore, the resolution of printing small dots on it is also high, and the reproducibility of its pattern is better than that of hanging paper, carton board and tea board.

3、 Problems caused by the difference of base paper absorption due to the difference of papermaking raw materials and the difference of base paper sizing and coating, the absorption performance is different. For example, when overprinting on single-sided Coated Whiteboard and pickup truck, the drying speed of ink is slower due to the small absorption performance, so the viscosity of the previous ink should be reduced and the viscosity of the subsequent overprint ink should be improved. The lines, characters and small patterns are printed in the first color, and the full plate is printed in the last color, which can improve the overprint effect. In addition, the dark color is printed in the front and the light color is printed in the back, which can cover the overprint error, because the dark color coverage is strong, which is conducive to the overprint accuracy, while the light color coverage is weak, It is difficult to observe even if there is a running rule in the back print. Different sizing conditions on the surface of base paper will also affect the absorption of ink. The paper with small sizing amount absorbs more ink, and the paper with large sizing amount absorbs less ink. Therefore, the clearance of each ink roller should be adjusted according to the sizing state of the paper, that is, the clearance of each ink roller should be reduced to control the ink amount of the printing plate. It can be seen that when the base paper enters the factory, the absorption performance of the base paper shall be tested, and the printing slotting machine and ink distribution personnel shall be given an absorption performance parameter of the base paper, so as to facilitate their ink distribution and equipment adjustment. And adjust the viscosity and pH value of ink according to the absorption state of different base paper.