During the production, storage and printing processes of ink, bubble problems often lead to defects such as coating shrinkage, pinholes, and decreased gloss. The intervention of defoaming agents becomes the key to solving this problem. Its mechanism revolves around the laws of bubble formation and rupture, and achieves efficient defoaming through multiple pathways. 
The formation of bubbles originates from the stirring and grinding during ink preparation, as well as the high-speed coating and substrate immersion during printing. Air is introduced into the system and forms a stable gas-liquid interface. The defoaming agent first acts by reducing surface tension: its molecules can quickly diffuse to the surface of the bubble, replace the surface-active substances that originally stabilized the bubble in the ink, disrupt the mechanical balance of the interface membrane, and make the bubble wall thinner until it bursts. 
For small bubbles that have already formed, the defoaming agent uses penetration and spread capabilities to penetrate the interior of the bubble. Some defoaming agents contain hydrophobic groups that can penetrate the bubble membrane, forming weak points within the membrane, while the hydrophilic groups are compatible with the ink system, promoting an imbalance of pressure inside and outside the bubble and accelerating the bursting of the bubble. For recurrent foam, the defoaming agent can form a monolayer protective film on the ink surface, inhibiting the formation and aggregation of new bubbles, achieving the dual effect of "anti-foaming + defoaming". 
Different ink systems have different requirements for defoaming agents: polyether-based defoamers are commonly used in water-based inks, having both environmental friendliness and compatibility; organic silicon-based defoamers are suitable for solvent-based inks, with stronger anti-foaming durability; UV inks require special defoamers that are resistant to radiation to avoid affecting the curing effect. High-quality defoamers need to find a balance between defoaming efficiency and ink performance, neither causing shrinkage, floating oil, nor failing to adapt to the strict conditions of high-speed printing, providing a core guarantee for ink quality.