Compared with solvent inks, water-based inks have taken environmental performance even further. It not only does not contain aromatic solvents, but also greatly reduces the VOC, but still can not be zero content, still contains a small amount of alcohol, ether, and even organic amines. It has less impact on the environment, mainly polluting the workshop air.
Use of additives in water-based inks
Commonly used additives in water-based inks include pH stabilizers, defoamers, fast drying agents and slow drying agents.
First, pH stabilizer: pH stabilizer is mainly used to adjust the ink pH. The pH value of ink and ink is often mentioned by ink manufacturers to promote printing ink products to printing companies. A low pH value can easily cause ink agglomeration, and when the pH is high, the viscosity is relatively low. Generally, during the printing process, the pH value of the ink should be detected. When the pH is lower than 8, an appropriate amount of pH stabilizer should be added so that the ink can maintain a good printing state. The pH value of the European national ink is based on the neutrality. When the pH value is adjusted to 8.5, the flowability and glossiness are in the best state, but in the printing process (within 1 hour), the viscosity of the ink is evaporated because of the amine solvent. It will rapidly increase, the gloss will decline, and the fluidity will deteriorate. As a result, there will be a large number of unqualified products, such as adjusting the pH value, adding amine solvent, and continuously testing (within 1 hour) during the printing process. ), a little carelessness, waste products will appear, and the entire workshop is full of unpleasant odors, such products are considered poor in printability, such as the pH value of the ink between 7-8, ink and wash The best stability, the user can add pure water as a solvent to reduce the viscosity, so as not to increase the cost, but also make the ink resin taste reduced.
Second, defoamers: Ink viscosity is too high, the pH value is low, the printing speed is faster and printing technicians add too much water, are prone to air bubbles. When the bubbles are relatively large, there will be phenomena such as whitening of the printed matter and less ink, which will seriously affect the printing quality. It is generally recommended to use a mixture of foam suppressor and surface defoamer in the ink to solve the blistering of the ink. The use ratio is 1 to 2%.
Third, the quick-drying agent: During the use of ink due to ink manufacturers choose different resins or machine speed is too fast, may cause the ink drying speed is slow. Accelerating the drying agent can adjust the ink drying speed to the speed requirement of the printing press and increase the production efficiency. The use ratio is 2 to 3%.
Fourth, slow drying agent: Slow drying agent can inhibit and slow down the drying speed of the ink, play a role in moisturizing, to prevent the ink in the printing plate or anilox roller drying, reduce blocking and paste plate and other printing failure occurrence, the use of ratio Between 1 and 2%.