The most common measures to prevent ink scaling

Common measures to prevent ink scaling

in the work of preventing ink scaling, adding ink anti scaling agent to ink is a very important means. The following is an introduction to the scope of use and precautions of anti scaling agent in printing:

oxidation of printing ink, oil of modified resin, amount of pigments, fillers and driers used, ambient temperature and humidity during storage of finished ink products have a certain impact on the scaling of ink. Therefore, the above factors must be considered when using anti scaling agent, At the same time, we should also pay attention to the basic knowledge of the following seven aspects, such as the amount of addition:

1 The addition amount

is generally calculated according to the ink material (because the main component of the crust is the main raw material of the ink) or according to the total amount of printing ink, and the influence of other components should also be considered

usually the addition amount is 0 Between 3%. Because of the difference in temperature and humidity throughout the year, there is a certain difference in the speed of skinning. Therefore, it is 0.1% in winter, 0.3% in summer and 0.2% in spring and autumn, depending on the composition of the formula

2. Ink film drying rate

we have proved in practice that in offset printing inks made of alkyd resin, the amount of methyl ethyl oxime is generally 1%. Although the drying speed is slightly longer, it is still within the standard range specified for printing. This is because the 2017 China (Ningbo) new materials industry development forum will be held in Ningbo during the exhibition of the complex formed by the additive and the drier, which causes the drier to temporarily lose its activity. Therefore, it is different from the traditional use of phenolic compounds to capture the activity and freely terminate the polymerization reaction principle. Therefore, such compounds do not have a great impact on the drying rate. If the dosage is too large, the volatilization time will be prolonged, and the complex will disintegrate too slowly, which will often affect the film-forming speed of packaging and printing ink

3. Yellowing

once the anti scaling agent exceeds 0.3%, it will often lead to the yellowing of the printing ink film. Especially when used in white ink, yellowing will occur after long-term storage. Therefore, strictly controlling the amount of addition or changing to butyraldehyde oxime can avoid yellowing

4. Color degree

after adding anti scaling agent, the ink color degree is often directly affected. Generally, the influence of ink blending oil is greater than that of color ink, and the influence of white or yellow ink is greater than that of dark color ink. Generally, this phenomenon is difficult to observe by visual inspection, and has nothing to do with the amount of addition. Although we have known that the application hue of the ink film is not affected after the drying of the printing image and text film, in the presence of some pigments (such as amphoteric pigments) and driers, there will be significant differences between the hues of the color image and text ink film of packaging and printing, which will cause trouble to the production of color adjustment. When we encounter this situation, we should make continuous proofing during ink making, and first do experiments on color difference. The purpose is to prevent the appearance quality of ink film from being affected by color change after printing and impact testing machine as an automobile detection instrument

5. Printing ink film status

although the anti scaling agent will not have any impact on the status of printing ink film, it will precipitate crystals when the ink is stored for a long time, resulting in the turbidity of the ink after film formation and affecting the gloss of the ink. Large particles will appear if the above material is not properly proportioned with the binder, pigment, filler and drier in the ink system. This should be tested before printing

at present, some tension machines in the market adopt ordinary 3-camera electric or frequency conversion electromechanical

6 Gloss and weather resistance

after adding anti scaling agent, the gloss of printing ink will not be affected, but also has light retention. Second, after adding the additive, the weather resistance of the printing ink film has been significantly improved

7. Usage

anti scaling agent is generally added when mixing ink, and is added while stirring at room temperature. For volatile inks, in order to control the scaling of inks during grinding, dispersion and storage, especially in the printing process, it is advisable to add a part during inking and another part before printing

above, we have made some discussions on the causes and treatment of ink scaling. In practical work, we may encounter various problems in one way or another. However, after the net profit is close to "halving" and the causes of ink scaling (mainly the drying principle) are solved, it should not be very difficult to analyze and judge