How to adjust the ink flexo printing process with different carton paper
The common types of base paper used for corrugated box surface paper include: container board paper, liner paper, kraft cardboard, tea board paper, white board paper and single-side coated white board paper. Due to the differences in the papermaking materials and papermaking processes of each type of base paper, the physical and chemical indicators, surface properties and printability of the above-mentioned base papers are quite different. The following will discuss the problems caused by the above-mentioned paper products to the corrugated cardboard ink printing start-up process.
1. Problems caused by low-gram base paper chocolate box
When low-gram base paper is used as the surface paper of corrugated cardboard, corrugated marks will appear on the surface of the corrugated cardboard. It is easy to cause flute and the required graphic content cannot be printed on the low concave part of the flute. In view of the uneven surface of the corrugated cardboard caused by the flute, a flexible resin plate with better resilience should be used as the printing plate to overcome printing irregularities. Clear and exposed flaws. Especially for the A-type corrugated cardboard produced by low-grammage paper, the flat compressive strength of the corrugated cardboard will be greatly damaged after being printed by the printing machine. There is major damage.jewellery box
If the surface surface of the corrugated cardboard differs too much, it is easy to cause warping of the corrugated cardboard produced by the corrugated cardboard line. Warped cardboard will cause inaccurate overprinting and out-of-gauge printing slots for printing, so the warped cardboard should be flattened before printing. If the uneven corrugated cardboard is forcibly printed, it is easy to cause irregularities. It will also cause the thickness of corrugated cardboard to decrease.
2. Problems caused by different surface roughness of base paper paper-gift-packaging
When printing on base paper with rough surface and loose structure, the ink has high permeability and the printing ink dries quickly, while printing on the paper with high surface smoothness, dense fiber and toughness, the ink drying speed is slow. Therefore, on rougher paper, the amount of ink application should be increased, and on smooth paper, the amount of ink application should be reduced. Printed ink on unsized paper dries quickly, while printed ink on sized paper dries slowly, but the reproducibility of the printed pattern is good. For example, the ink absorption of coated whiteboard paper is lower than that of boxboard paper and teaboard paper, and the ink dries slowly, and its smoothness is higher than that of boxboard paper, liner paper, and teaboard paper. Therefore, the resolution of fine dots printed on it The rate is also high, and the reproducibility of its pattern is better than that of liner paper, cardboard paper, and tea board paper.
3. Problems caused by differences in base paper absorption date box
Due to differences in papermaking raw materials and base paper sizing, calendering, and coating differences, the absorption energy is different. For example, when overprinting on single-sided coated white board paper and kraft cards, the drying speed of the ink is slow due to the low absorption performance. Slower, so the concentration of the previous ink should be reduced, and the viscosity of the subsequent overprint ink should be increased. Print lines, characters, and small patterns in the first color, and print the full plate in the last color, which can improve the effect of overprinting. In addition, print the dark color in the front and the light color in the back. It can cover the overprint error, because the dark color has strong coverage, which is conducive to the overprint standard, while the light color has weak coverage, and it is not easy to observe even if there is a runaway phenomenon in post-printing. date box
Different sizing conditions on the base paper surface will also affect the ink absorption. Paper with a small amount of sizing absorbs more ink, and paper with a larger amount of sizing absorbs less ink. Therefore, the gap between the ink rollers should be adjusted according to the sizing state of the paper, that is, the gap between the ink rollers should be reduced to control the printing plate. of ink. It can be seen that when the base paper enters the factory, the absorption performance of the base paper should be tested, and a parameter of the absorption performance of the base paper should be given to the printing slotting machine and the ink dispenser, so that they can dispense ink and adjust the equipment. And according to the absorption state of different base papers, adjust the viscosity and PH value of the ink.
Post time: Mar-28-2023