Bubble Problem and Solution of Waterborne Ink in Gravure Printing
Date：2023-06-24 From：Star Color
The "bubble problem" refers to the formation of air bubbles in waterborne ink during the gravure printing process. These bubbles can negatively impact print quality by causing defects such as pinholes, streaks, or uneven ink distribution. Fortunately, there are several solutions to address this issue. Here are some common approaches:
1.Ink formulation: Adjusting the ink formulation can help reduce bubble formation. It involves optimizing the viscosity, surface tension, and rheological properties of the ink to minimize air entrapment. Fine-tuning the balance of additives such as defoamers or surfactants can also aid in bubble prevention.
2.Ink agitation: Proper ink agitation or mixing is essential to ensure the uniform dispersion of pigments and to release any trapped air. Adequate mixing equipment and techniques, such as using high-speed mixers or shakers, can help minimize bubble formation by eliminating or dispersing air pockets in the ink.
3.Coating process optimization: Optimizing the coating process parameters can help minimize bubble formation during ink application. Factors such as blade pressure, coating speed, and temperature can be adjusted to reduce the likelihood of air entrapment.
4.Substrate preparation: Proper surface treatment of the substrate can improve ink adhesion and reduce the likelihood of air bubbles. Pre-treating the substrate with primers or corona treatment can enhance the surface energy and wetting properties, allowing the ink to spread more evenly and reducing the chances of bubble formation.
5.Printing conditions: Adjusting printing conditions can have an impact on bubble formation. Controlling the temperature and humidity levels in the printing environment can help reduce the evaporation rate of water in the ink, minimizing the potential for air bubble formation.
6.Equipment maintenance: Regular maintenance and cleaning of the printing equipment, especially the ink delivery and transfer components, can help prevent the accumulation of ink residues or contaminants that could contribute to bubble formation.
It is important to note that the specific solution to the bubble problem may vary depending on the specific circumstances, such as the ink formulation, printing equipment, and substrate characteristics. Consulting with ink manufacturers, equipment suppliers, or industry experts can provide more tailored recommendations for addressing bubble issues in gravure printing with waterborne inks.
