In the entire lifecycle of production, storage, and application of coatings and inks, foam is a highly prevalent process phenomenon. Operations such as material feeding and stirring, high-speed grinding, and material pumping cycles can easily introduce air into the system, generating bubbles with uneven particle size distribution. If foam is not effectively controlled, it will trigger a series of process defects across multiple dimensions, including production efficiency, storage stability, finished product appearance, and coating performance.
In the production section, excessive foam occupies the effective filling volume of reactors and mixing tanks. To mitigate the risk of material overflow, the production team must proactively reduce the feeding coefficient, directly lowering equipment utilization rates and extending production cycles. Foam hinders the wetting and dispersion of pigments and fillers, increasing grinding cycle frequency and raising equipment energy consumption. Additionally, fine microbubbles suspended in the material can interfere with key indicators such as viscosity and solid content, potentially leading to misjudgments of the material's true state and introducing deviations in subsequent formulation optimizations.
During the storage phase, residual bubbles within the system gradually release in the sealed packaging container, causing pressure fluctuations due to volume expansion and contraction in the barrel. After prolonged static storage, the bubbles carry pigment components upward, easily inducing floating color and phase separation phenomena, resulting in uneven conditions between the upper and lower layers of the same batch. Fluctuations in material performance during the opening and usage process directly compromise product consistency across batches, making it difficult to achieve stable delivery on the production end.
During the coating and film-forming stage, foam-induced defects will directly manifest on the surface of the finished product. Untimely ruptured bubbles solidify with the system, forming typical paint film flaws such as pinholes, craters, and pits. Residual traces from bubble rupture persist even after subsequent recoating. In printing and digital inkjet applications, foam causes uneven coating thickness, leading to white spots and blemishes in the finished product. Microbubbles during high-speed production can also cause ink breaks and printhead clogging, disrupting continuous line operation. Bubbles trapped within the paint film create microscopic pores, reducing coating density and indirectly weakening water resistance, salt spray resistance, and other protective properties. In multi-layer recoating processes, these pores may further induce poor interlayer adhesion, increasing workpiece scrap rates.
Many production processes often resort to increasing the dosage of defoaming agents as an emergency measure when encountering foaming issues. However, excessive addition of these agents can instead lead to secondary formulation defects such as shrinkage, fish eyes, poor recoatability, and system compatibility imbalances. This indicates that foaming in coatings and ink systems is not merely an apparent issue—it requires a comprehensive approach beyond simply boosting defoaming agent levels. Customized solutions must be tailored to match both operational conditions and the specific characteristics of the formulation system.
