[Chinese Packaging News] The printability of water-based inks is influenced by various external factors such as printing conditions, the surface properties of the substrate, ambient temperature and humidity, and storage duration. To achieve optimal results, it's essential to use additives that fine-tune the ink’s performance. Commonly used additives in water-based inks include colorants, pH stabilizers, slow-drying agents, defoamers, and diluents. Understanding their functions and proper usage is crucial for effective printing. NINGBO BESCON GAMES AND APPLIANCES CO., LTD , https://www.bescondice.com
1) Colorants are used to enhance the color intensity of the ink. Typically, their concentration should be kept between 0% and 30%. Exceeding this range may reduce the binder content, leading to poor adhesion and wear resistance.
2) pH stabilizers help maintain the ink's pH level within an ideal range of 8.0 to 9.5, ensuring consistent print quality. They also help regulate viscosity and can be used to thin the ink when necessary.
3) Slow-drying agents are added to control the drying speed of the ink. By slowing down the evaporation process, they prevent the ink from drying on the printing plate, reducing issues like clogging and screen printing problems. The recommended dosage is usually between 0% and 10% of the total ink volume. Too much of this additive can lead to incomplete drying, resulting in smudged prints or an unpleasant odor.
4) Diluents are primarily used to lower the color intensity of the ink. Their usage is not strictly limited, but adding large amounts may slightly increase the ink's viscosity. In such cases, a small amount of thinner can be added to balance the consistency.
5) Thinners are used to reduce the ink's viscosity. It's advisable to keep the addition within 3% to avoid affecting the color depth or pH level. When using a thinner, it should be added gradually while stirring to prevent excessive thinning. Adding too much or using tap water with high mineral content may introduce air bubbles, which require the use of a defoamer to eliminate.
6) Foaming is a common issue when using water-based inks, mainly due to the use of water as a diluent. During emulsion polymerization, surfactants are often used to lower the surface tension of the system, which can lead to foaming during the printing process.