How to achieve the equilibrium state of leveling agent and defoamer in water-based coatings

Some manufacturers in the development of water-based coatings always encounter the problem of multi foam and poor surface smoothness due to the imbalance between defoamer and leveling agent. During the use of water-based coatings, both defoamers and leveling agents need to be added in order to achieve both defoaming and improved surface feel. However, achieving a balance between leveling agents and defoamers in water-based coatings is quite difficult.

General functional leveling agents have the ability to improve leveling performance, enhance surface smoothness, improve scratch resistance, prevent sticking, and minimize surface defects to the greatest extent possible; Defoamers are highly efficient defoamers and defoamers used in water-based coatings. Defoamers can quickly remove bubbles from the system and demonstrate good defoaming performance over a long period of time. Defoamers are used to remove microbubbles from high viscosity systems; 

However, sometimes the relationship between defoamers and leveling agents in water-based coatings is contradictory. How to achieve a balance between leveling agents and defoamers in coatings? 

In fact, we can ensure that water-based coatings have good flowability and leveling properties without generating bubbles through a reasonable combination of types and amounts. Excessive use of defoamers can affect the paint film, resulting in shrinkage porosity. To eliminate the phenomenon of shrinkage, it is necessary to use leveling agents. But the addition of leveling agents will also reduce the defoaming effect, especially the long-term effectiveness of defoamers. So we need to choose good defoamers: good defoamers not only have good anti foaming and anti foaming effects when the product leaves the factory, but also have long-lasting effects. Even if stored for a year or so, they can ensure that water-based wood paint still has good anti foaming effects. At the same time, defoamers can also ensure a greater tolerance for the system, and will not weaken their defoaming effect due to slightly more or less dosage. 

In fact, to achieve a balance between leveling agents and defoamers in coatings, the main method is to adjust the dosage of additives.