Carton paper printing common faults and solutions (2)

Eight, the printing ink layer is not firmly attached to the fault phenomenon

The printing ink layer can not be adhered firmly and can be divided into the following types: the printing with insufficient abrasion resistance is not strong; the printing with weak light fastness is not strong; the printing with insufficient chemical resistance is not strong.

1. Due to the overabsorption of the surface of the printing ink, the excess binder in the printing ink layer penetrates into the capillary structure of the printing material, resulting in the pigment in the printing ink layer not having enough material for conjunctival protection, and thus a The phenomenon of discoloration of the imprinted powder was observed.

2. As the semi-finished products are processed in the post-printing process, such as the light machine, the folder-gluer, and the cover machine, due to the presence of friction, the printing ink layer of the printed product appears discoloration.

3. As the printing ink layer is not light fast, it is prone to fading in strong light or UV process environment.

4. Due to lack of chemical resistance of the printing ink layer, the color of the imprint or the imprinting is not firm. When the printed product is in contact with the packaged acids, alkalis, salts, soaps, greases, alcohols and other chemicals, fading occurs easily.

Nine, to prevent printing quality failure of a number of technological measures

It is necessary to stir the ink in the ink fountain frequently, and pay attention to increase the ink in the ink fountain at a proper time.

Color inks are often composed of multiple color inks. Due to the different nature of pigments, binders, and fillers in different inks, it is inevitable that different substances in the ink will be precipitated and suspended. Once this state obviously exists, it will inevitably cause the variation of the ink color of the printed product. Therefore, the ink in the ink fountain should be frequently used in the printing process to prevent the ink from being precipitated and suspended to ensure that the ink color of the product before and after printing is consistent. In addition, due to the reduction of the amount of ink in the ink fountain, it is easy to reduce the gap between the ink fountain steel sheet and the transfer iron roller to reduce the ink output amount and to make the ink color of the print product fade. In order to avoid this from happening, it is also necessary to pay attention to adding ink regularly during production so that a certain amount of ink is always maintained in the ink fountain.

Local ink shading adjustment in the lateral position of the print

Due to different layouts of printing products, such as horizontal layout, text, texture, and lines are the main points, and the amount of ink suction is relatively small. The corresponding ink steel adjusting screw can be screwed in to reduce the amount of ink. The amount of ink delivered to this site. If a certain position of the horizontal layout is based on the ground or the plate, the amount of ink is relatively large, the corresponding adjustment screw should be twisted outward to increase the amount of ink, so that the entire color of the ink remains uniform and the color difference of the printing is prevented. The emergence of the problem.

Full-page ink adjustment

Ink fountain ink to increase or reduce the overall amount of delivery, there are two ways to adjust, one by adjusting the gap between the ink fountain roller and the transfer roller to achieve; second is to adjust the size of the rotating roller arc roller to achieve. In the case of a thin ink, it is not appropriate to adjust the gap between the steel sheet and the transfer roller too large, so as to avoid the problem of ink unevenness or color miscibility caused by ink leakage. When adjusting the amount of ink, the rotational arc of the transfer roller should be controlled within 1/2 of the adjustment range. This can allow the ink to be flexibly adjusted during the printing process to variably variate to prevent ink from being printed. Inconsistent ink.

Correctly adjust and use ink to prevent the production of color difference

The scientific and rational use of ink is an important part of ensuring the quality of printed ink. The ink of printed color products is too thick or too thin, which is not conducive to uniform ink and ink. In general, when the temperature is low, the ink appears thick, and the fluidity is poor, which easily causes poor transfer and uneven distribution. In this regard, the auxiliary agent should be used to appropriately dilute the ink according to the characteristics of the printed product. Maintains good fluidity and delivery to maintain uniform ink consistency. If the ink is too thin, the ink will fade. The adjustment of ink fluidity should fully consider the characteristics of the printer's rotation speed and ink structure. If the printer is fast, the ink path is long, and the ink roller is large, the ink will tend to thin and fade due to the large friction coefficient. Therefore, the above situation should be fully taken into account when adjusting the ink, and the printability of the ink can be reasonably adjusted. In addition, when mixing inter and mixed color inks, it is best to avoid mixing with inks with large specific gravity, so as to avoid “layering” (precipitation and suspension) of the ink on the ink fountain due to the difference in specific gravity during printing. Chromatic aberration.

Turn off the process technology and prevent the production of color

When printing, if the operation and technical measures are not in place, frequent stoppages occur in the production process, which is very likely to cause printing and color difference. In order to avoid this kind of situation, first of all, we must pay attention to the reasonable maintenance of the machine. We must always maintain the Feida parts and the air pump to maintain the good use of the mechanical parts, so that the gas path is unobstructed. Secondly, according to the thickness and size of the printed sheets, Feida, the air pump, and the parts related to the transport of paper should be adjusted to ensure the normal transport of printed sheets; Thirdly, the adjustment of the printability of the whiteboard paper must be carried out as necessary. The paper board is shaken and kneaded and processed to achieve the effect of transfusing the paper board so as to eliminate the adhesion and adhesion phenomenon, and to make the paper board reach flatness, so as to facilitate the smooth paper feeding, and at the same time, it can better avoid empty sheets. Multiple suction and skew failures occur. Fourth, if a good paper stacking technique is used and the paper stack is not even, measures should be taken to level it out so that there is no significant difference in height. Through these process and technical measures, the control is checked so that the paper feeding is maintained in order to prevent printing chromatic aberration caused by parking.

In summary, the quality of whiteboard printing is varied, there are a variety of undesirable factors, and there are several defects. As long as we carefully analyze and summarize the experience of the production process, and turn off the printing technology and operation technology, we can not only prevent the occurrence of printing quality problems, improve the printing quality of the products, but also effectively improve the production efficiency.

(Text / Kang Qilai)

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