Talking about the Failure Caused by Ink Printing Process and Its Treatment Method (Part 2)

Phenomenon and reason: Ink flooding is the change of hue of ink, and the color changes, which causes the printed product to lose its due artistic value. Commonly there are pan-black, pan-blue, blue and yellow. The yellow ink and transparent yellow color disappear, and the pan-color caused by the heating of semi-finished products or finished products. The causes of the above drawbacks are:

(1) The ink pigment itself is not stable.

(2) Acid dyes flooded after infiltrating the ink.

(3) Oxidation fever reaction.

Approach:

(1) When oily gold-red ink is used, the pigment powder reacts with iron to produce a chemical reaction, and the hue is very easy to blackish. The resin ink is used instead, so as to avoid pan-color phenomenon.

(2) Tianlan ink will be reddish on the paper a few days later, and the ink color will look deeper than the original. This phenomenon should be noted that when encountering batch printing of bulk products, the formula of ink color must be consistent. Do not arbitrarily change, so as not to cause product inconsistencies.

(3) Malachite blue, pale blue ink met chromic acid water bucket liquid, the ink is easy to yellow, can use white potion.

(4) Daylight illumination can fade the finished product, which can be solved on printed paper surface or film.

(5) During semi-finished or finished products, during stacking process, it is easy to generate a great amount of heat, and there is a lack of oxygen in it. The time is longer and the product will become hot and dark. It should be mainly prevention, and the product should not be stacked too high, and it should be guaranteed 4 - Ventilate once in 6 hours to speed up the flow of air between the sheets, helping them spread heat and shorten the time for oxidizing the conjunctiva.

(6) Reduce the use of Cobalt Drying Oil (ie, 402 Red Dry Oil) because the red dry oil tends to darken the hue of the ink when heated. $Page break $

Six, ink through the India

Phenomenon and reason: The ink part of the print penetrates into the back of the paper, and there are obvious imprint patterns or oil stains on the back of the paper, especially for products that require double-sided printing. Affect the quality of the product, resulting in product printing through the printing, in addition to the paper itself is too thin or transparent, the common reasons for ink penetration are as follows:

(1) The ink is too thin and contains too much of the binder material. A large amount of binder material is absorbed by the paper and penetrates the back of the paper.

(2) There are too many non-dried binders in the ink. Too many non-drying binders will slow the oxidative conjunctiva on the surface of the paper, and the penetration drying will accelerate. A lot of the binder will seep into the paper and print through to the back. .

(3) The ink is printed too thick and is too slow to dry. It also causes a large amount of the binder to penetrate into the paper and print through to the back.

(4) The oily pigments contained in the ink are dissolved in the binder. During the printing process, the pigments are printed in the paper along with the binder and printed on the back of the printed product.

Approach:

If there has been a printout on the printed products, there is no way to remedy the situation. Only prevention is done in advance to prevent the occurrence of print-through.

(1) Ink is properly added to No. 0 varnish to increase its viscosity.

(2) Do not use non-dry oil as the linking material, and reduce the proportion of non-dried or highly permeable excipients.

(3) Increase the color value of the ink, make the ink layer thinner, and accelerate drying.

(4) If the pigment is oil-soluble, it is better to use resin ink to print. $Page break $

Seven, print gloss

Phenomenon and reason: The printed matter is a reproduction of art reproduction, which should be bright in color, distinct in structure, have a strong sense of texture, sense of space, and material sense. On the contrary, the printed matter will lose its due value. The common reasons that affect the gloss of printed products are as follows:

(1) Low-grade ink is used for printing, and the gloss of the product is poor (except for low-grade products).

(2) The surface of the paper is rough, and the larger the fiber gap is, the stronger the absorption ability of the linking material is. After the ink is transferred to the paper, the linking material is absorbed by the paper fibers in the unconjuncted condition, and most of the ink remains. The particles attach to the surface of the paper, thus making the product dull.

Approach:

How to make printed products have better luster, the actual operating experience tells us that the print gloss can be obtained from the following aspects:

(1) The luster of the ink itself is the most basic element. In the printing of high-grade fine products, the ink must be printed with high-grade fast-drying bright ink to obtain the best luster.

(2) Add dry oil to the ink properly during printing to help the surface of the ink to form a good film, so that the product obtains a proper gloss. To properly understand the performance and dosage of red and white dry oil, the type and amount of dry oil used have a certain influence on the gloss. No. 402 Red Dry Oil is mainly composed of cobalt citrate, and the stimulating function is mainly surface oxidized conjunctiva. The dry speed is fast, about 23 times that of dry white oil, generally added in red ink and black ink, medium blue and deep blue can also be used. In particular, the latter color of the same type of printing product, if it can maximize the release of red and dry oil, this will have a good effect on increasing the gloss of printed products. When the yellow plate is used as the first color sequence, it is not appropriate to add red dry oil, because the color of red dry oil will change the hue of yellow ink, followed by the largest amount of yellow ink, and it is extremely dry and prone to vitrification. White dry oil is a mixture of metal salts of cobalt, manganese, and lead. It has a full-drying effect, but it is not as strong as red dry oil. The amount of white dry oil added correctly has an effect on increasing gloss of prints.

(3) Apply a polish or film to the finished surface of the finished product.

Ink is a complex colloid that is obtained by mixing and grinding pigments, binders and additives. Its properties are mainly determined by the properties of pigments and binders. It uses the three forms of volatilization, infiltration and oxidized conjunctiva to complete the drying of print imprints. As the main material for printing, knowing the ink composition, familiarizing with the properties of the ink, and correctly mastering the use of the ink are the necessary conditions for ensuring the printing quality.

Excerpt from: Hubei Xueyin Printing Factory