How to deal with base paper of different materials

2022-08-12
  • Detail

How to deal with the base paper of different materials in carton printing

the common types of base paper used for corrugated carton face paper are: carton board paper, face paper, kraft paperboard, tea board paper, white board paper and single-sided coated white board paper. The physical and chemical indexes, surface properties and printability of the above-mentioned base papers are greatly different due to the differences in the papermaking materials and papermaking processes of each base paper. Next, we will discuss the problems brought by the above paper products to the starting process of corrugated board ink printing

I. problems caused by low gram base paper

when using low gram base paper as corrugated board surface paper, there will be problems of showing corrugated marks on the surface of corrugated board. It is easy to cause corrugation and in China, 226 intelligent manufacturing comprehensive standardization experiments have been carried out to verify and use the new mode. The required graphic content cannot be printed in the low recess of the project. For the uneven surface of corrugated board caused by corrugation, flexible resin plates with good resilience should be selected as printing plates to overcome the defects of unclear printing and bottom exposure. In particular, the A-type corrugated board produced with low gram paper will suffer great damage to the flat pressing strength of the corrugated board after printing by the printing machine. In addition, the edge pressing strength of the corrugated board after passing through the printing roller and the embossing roller will also suffer great damage (the passive pointer should instigate the zero position)

if the difference between the surface roughness of corrugated board is too large, it is also easy to cause the corrugated board produced by the corrugated board line to warp. Warped paperboard will cause overprint inaccuracy and printing slotting, so warped paperboard should be flattened before printing. If the uneven corrugated board is forcibly printed, it is easy to cause gauge walking. It will also cause the thickness of corrugated board to decrease

Second, the problems caused by different surface roughness of base paper

printing on base paper with rough surface and loose structure, its ink permeability is large, and the printing ink drying is fast, while printing on paper with high surface smoothness, dense and tough fiber, its ink drying speed is slow. Therefore, on coarser paper, the ink application amount should be increased, and on paper with smooth surface, the ink application amount should be reduced. Printing ink on paper without sizing dries quickly, while printing ink on paper after sizing dries slowly, but the reproducibility of printing patterns is good. For example, the ink absorption of Coated Whiteboard is smaller than that of box board paper and tea board paper, and the ink drying is slow, and the smoothness is higher than that of box board paper, hanging paper and tea board paper. Therefore, the resolution of printing fine dots on it is also high, and the reproducibility of its pattern is also better than that of hanging paper, box board paper and tea board paper

III. The problem of the difference of base paper absorption

due to the difference of raw materials and the difference of base paper sizing, calendering and coating over the past 50 years, the absorption energy is different. For example, when overprinting on single-sided coated white board paper and pickup truck, the drying speed of ink is slower due to low absorption performance, so the concentration of the previous ink should be reduced and the viscosity of the subsequent overprint ink should be improved. And put the lines, words and small patterns in the first color for printing, and put the full page on the last color for printing, which can improve the overprint effect. In addition, put the dark color on the front for printing, and put the light color on the back for printing, which can cover the overprint error, because the dark color coverage is strong, which is conducive to the overprint standard, while the light color coverage is weak, which is not easy to observe even if there is a phenomenon of deviation from the standard when placed on the back

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, while 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 inking amount of the printing plate. It can be seen that when the base paper enters the factory, the absorption performance of the base paper should be tested, and a base paper absorption performance parameter should be given to the printing slotting machine and ink distribution personnel 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

Copyright © 2011 JIN SHI