Analysis of the main factors affecting the quality of ink color printing

In this regard, we selected the TM-200S coupling agent (tackifier) ​​from Yizheng Tianyang Chemical Factory to improve the strength of the adhesive joints of the resin solution and increase the adhesion of the adhesive to the adhesive surface, thereby effectively preventing the adhesive layer from being The peeling and peeling of the glued surface not only promotes the heat and moisture resistance of the glue in the ink system, but also increases the bond strength between the hard-to-stick material and the low-molecular-weight resin sol and the pigment and the glossiness of the packaged ink film. Water washability. This is that the paint film should be hard and the ink film should be soft.

Followed by the use of alkali-resistant pigments or dyes or fillers. Most of the dyes are used in light package inks that do not require light resistance.

Resins (whether natural or synthetic, be it macromolecules or low molecular weight resins) need to have dispersibility, transferability, fast drying, gloss, and abrasion resistance. A few days ago shellac and even acrylic resin, etc. have been replaced by pure rosin resin (to be tested before use). The traditional method of temperature-enhancing modified resin liquid binders has been replaced by a new method of producing rosin resin liquid binder at room temperature. A green ink that is almost completely free from environmental pollution has been favored in the market.

Solvent, traditional production is distilled water (ion water is the best), especially need to add ethanol or isopropanol, but now the market mostly uses tap water or groundwater. Under strict compliance with the pH index, trace addition is active, bridge and increase. Sticky TM-200S coupling agents have become a new method of manufacturing inks.

III. Main technical problems to be solved

In addition to the above-mentioned success or failure experience, some of the following are listed, although they can be overcome, but it is easy to repeat the above-mentioned mistakes. This article tips out for everyone to discuss.

1. For example, inks made of old rosin resin, and the addition of a basic excess of linking material to white titanium dioxide or black ink made of acid white titanium dioxide or carbon black, often cause poor ink fluidity due to the secondary neutralization of acid and alkali. Edition, forming a non-glossy packaging printing ink film.

2. Excessive addition of cheap talcum powder makes it easier for ink to flow and not easy to ink (as opposed to acrylic ink).

3. Excessive addition of a single defoamer, the foam in the ink film can not avoid chemical pinholes before the curing and drying, and when the curing is dry, the printing ink film will cause the texture orange peel, even if the use of fillers to eliminate the method However, the hue of the ink film left remains large.

4. As the hydrated silica or magnesium salt of the associate, after the purpose of thickening and anti-settling, the ink film will still have a certain degree of gloss, and the excess will be counterproductive.

5. Although the amount of chromogen or basic dye is small, the water can be washed well, but it is not easy to wash after contact with the flexible letterpress and human skin.

6. Although inorganic pigments can overcome water washability, printing inks are prone to precipitation or delamination, and the ink layers are thickened and the dots are enlarged or lost.

7. Excessive dispersion of ink often exacerbates the swelling of the pigment fillers of the system. When aggregated and thickened or coagulated, it is more difficult to control the formation of ink particle size aggregates than to use an incorrect reactive solvent molecule to associate.

8. When the content of pigments with too high alkali resistance is too high, the yield value of the ink will be too high, and the length of the silk will be shortened. After the ink formed into a cheese-like shape is expanded, the printing ink is easy to be plated, and the color becomes lighter than that when the oil is absorbed too much, and the particles are not dispersed. The uniform color of the packaging printing becomes lighter and more difficult to solve...

In short, in changing the above eight kinds of difficulties, we always try to use the same relative density, but the size of the particle core is not equal to the pigments, fillers to adjust, or use the relative density is not the same, the size of the particle core is not equal to the pigment, filler The adjustment will result in the eradication of flocculation and coalescence. However, the eight major issues concerning green water-soluble water-washable inks are:

1. pH control;

2. Material selection and production process;

3. Ammonia, amines, base addition order and speed and how much influence;

4. The effect of selection, content and purity of neutralizing agent;

5. The thickness and whiteness of the substrate and the influence of the pH value;

6. Auxiliary agent properties, properties and ink film thickness;

7. The pressure of packaging presses and the influence of cosolvents;

8. The intensity of contrast, and the influence of the harmonization procedure, when the amount of contrast between pigments and fillers (in terms of area, lightness, and saturation) changes.

9. The factors such as the environment of the workshop and the influence of temperature, humidity, and the cleanliness of printing machinery and printing plates are all worthy of our exploration and exchange.