How to do a good corrugated board printing

Printing is an important process in the production of corrugated cartons. The printing level is an important symbol of the corrugated cartons' technological level. Printing skills are an important manifestation of the company's technical level. On behalf of today's advanced level, and carton production line supporting the carton printing is ink flexographic printing. This kind of printing can achieve bright colors, accurate position, do not hurt the corrugated, and improve ergonomics. However, if it is not done well, it will also show inconsistent shades of colors, inaccurate printing positions, large deviations in registration, and ghosting, blurring, and unclearness. If this happens, the carton will be judged as unqualified and the user will request a return.
In order to do a good job in printing cardboard, we must understand its regularity. This article will try to talk about this issue.
Experienced printing staff summarized this regularity into five major elements: equipment, printing, ink, paper (cardboard), and people (operation). Combining our experience is described as follows:
1. The equipment should have a modern advanced level of cardboard ink and printing presses. Its main criteria are: superior manufacturing process, precise structure, stable and accurate operation, easy maintenance, and can meet the high-tech requirements of modern cardboard printing. Substances are the basis. With the high technological content and technically superior printing equipment, the basic conditions for doing a good job of printing cardboard are met.
2. Plate printing plate type is the basis for good cardboard printing. Without printing, printing cannot be carried out. Modern cardboard printing, using flexible photosensitive resin format, its advantages are accurate reproduction of the original, good printing effect, high printing rate. The print size should be consistent with the carton manufacturing size (it is larger than the carton size, smaller than the outer size), in the calculation of the size, the indentation on the preprinted cardboard should be fully considered. The manuscript must be carefully reviewed before the plate-making system. For areas that do not meet the plate-making requirements, it is recommended that reference be made. After the version is properly prepared, it must be carefully checked, and the condition of exposure and washing must be carefully checked. If the standard does not meet the standards, it must be re-made. After each printing is completed, the printing plate must be carefully cleaned and no residual ink is allowed to exist. Otherwise, it will have a serious impact on the effect of the subsidized printing; it will have serious defects such as unclear handwriting and burrs.
3. Ink ink is an important material for printing on corrugated cardboard. Modern corrugated board printing uses water-based inks.
First of all, according to the user's requirements to choose a good ink, for fixed products or high-volume products, you can order special ink manufacturers. For small batches of products, they must be able to allocate the same spot color inks as the color drafts. The printing color of the same product should be basically the same, and it must not be different.
For this reason, it is very important to control the viscosity of the ink. Because the viscosity directly affects the printing effect, the viscosity is too low to cause light color, large dot gain, high light spot distortion, uneven ink transfer, etc. The color is sometimes not deep, but also easily cause dirty format, paste type, blistering, quit and other failures, viscosity selection, should consider the situation of the printing carrier or substrate, and match the printing speed, the faster the viscosity should be The smaller.
In addition, during the printing process, due to the volatilization of the solvent, its viscosity will increase and the pH will decrease, which will affect the printing effect. In order to maintain the printability of the ink, it is necessary to use corresponding ink additives, such as stabilizers, retarders, dilutants, defoamers, and the like. Stabilizer can reduce and stabilize the viscosity of ink, adjust and balance the PH value. Generally, it is better to add 1%-2% every 0.5-1 hour.
Blockers can inhibit and reduce the speed of ink drying, prevent surface crusts, reduce paste, improve print clarity, and add less than 3% each time. Diluter is also a brightener, it can reduce the color, increase the brightness of the ink. Should be added according to circumstances. Defoamers can suppress and eliminate ink bubbles. When the ink is too viscous and has too much water, it can easily foam. When the ink viscosity is adjusted to normal, an appropriate amount (not more than 1%) of defoamer is added to suppress the foaming effect. There is also an auxiliary agent called cleaning agent, mainly used to clean the printing plate, anilox roller, ink roller. Use 8-10 times of water to dilute evenly, and the cleaning effect is very good, which has a great effect on improving the printing quality.
4. Cardboard paperboard is a direct printing material, and its status is very much related to the printing effect. If the surface of the tissue is rough, the moisture content is large, the dust is large, and the ink absorption is poor, so the printing effect is not good. If the cardboard structure is not smooth, such as lack of material, collapse, partial degumming, surface blistering, discount, warping, etc., will seriously affect the printing effect. If the cardboard contains too much water, the cardboard will not be stiff and will cause difficulties in printing. Therefore, in order to do a good job in corrugated board printing, we must have a good substrate—cardboard. First, we must use a good type of tissue paper, which requires that the fiber structure is uniform, fine, tight, and the surface is smooth, free from dust and impurities, and the moisture content is appropriate. , good ink absorption performance. Followed by the requirement of good flatness of corrugated board: no warping, no shortage of material, no foaming, good adhesion, no pleats, proper moisture content, certain stiffness.