Printing ink anti-coagulants need to pay attention to several items

Preventing ink crusts Adding ink anti-skinning agents to ink is a very important tool. Printing ink anti-skinning agents, please pay attention to the following introduction:

Oxidation inks, oil-modified resins, pigments, fillers, driers, ink volume to complete the storage environment temperature, humidity and other factors have some effect on the ink on the crust In the use of anti-skinning agent, you must take into account the above factors, add The amount of the following seven basic knowledge, but should also pay attention to the issue: How to effectively prevent the ink tank?

First, add the amount

The general ink material (the main component of the crust is the main raw material of the ink) or the total printing ink, while also taking into account the influence of other ingredients. The general amount is between 0.1-0.3%. Year-round temperature, humidity and different, there is a certain difference in the speed of the crust. In winter, so 0.1% and 0.3% in the summer, spring and fall to 0.2%, depending on the formulation of the component is scientific.

Second, the ink film drying speed

In practice, we have shown that in offset printing inks, the amount of alkyd resin produced, methyl ethyl ketone oxime, is usually 1%, and although the drying speed is slightly longer, it is still printed within a predetermined standard range. This is due to the formation of complexes of auxiliaries and driers, which are caused by the temporary loss of activity of the driers and, therefore, different principles of free radical polymerization with traditionally used phenolic compounds. Therefore, this compound will affect the drying speed is not very large, if the amount of fluctuation is too large, the impact of packaging and printing ink, the formation of complex disassembly speed is often slow.

Third, yellowing

Once the anti-skinning agent exceeds 0.3%, it often leads to yellowing of the printed printing ink film. Especially when using white ink, yellowing may occur after long-term storage. Therefore, strictly control the amount of addition or change the butyraldehyde oxime to avoid yellowing.

Fourth, color

Ink and anti-skinning agents often directly affect the color of the ink. Usually, the effect of the varnish is greater than that of the color ink, and the white or yellow ink is darker than the color of the ink. This phenomenon is generally difficult to observe with the naked eye, independent of the amount added. Although we already know that the color tone manager in the graphic application of the printed ink film has no effect, but in the presence of certain pigments (such as gender paints) and driers, the color tone of the packaging and printing color image ink film will have a significant The differences are bothering the tone. We will encounter such a situation, it should be the first color-difference test of ink proofing, its purpose is to avoid discoloration, affecting the quality of the appearance of the printing ink film.

Fifth, printing ink film state

Although the anti-skinning agent does not have any effect on the state of the printed ink film, when the ink is stored for a long period of time, crystals will precipitate, resulting in the gloss and influence of the ink in the cloudy film forming ink. As a result, larger granules appear as a result of improperly designed binders than materials, pigments, fillers, and dry agents in the ink supply system. In this regard, it should be the first test before the press.

Six, gloss and weather resistance

In addition, the anti-skinning agent, the gloss of the printing ink will not only not be affected, but it will also protect the light. Secondly, the additive added, the weather resistance of the printing ink film has been significantly improved and improved.

Seven, use

As an anti-skinning agent, a color tone ink is generally added, and it is added while stirring at room temperature and below. In order to control the volatile ink of the ink, the pigment grinds and the dispersion during the storage process, especially the printing process crust, can be used to add a portion of the remaining ink before printing, and then add a suitable portion.

There are several reasons for the above crusted shell inks. In practical work, we may encounter one or the other problems, but we should not understand the reason of the ink crust (mainly the drying principle), and it is very difficult to analyze and judge it.