Why use a defoamer for water-based wood paint? Water-based wood paint uses water as the dispersion medium, and there will be no volatilization of organic solvents during use, which has excellent environmental protection advantages. However, due to the presence of surfactants for different purposes in the system, water-based wood coatings are prone to foaming and difficult to defoam, which is a common problem in the industry.

The foam that occurs during the coating production process will bring problems such as poor dispersion effect and reactor overflow; during and after construction, the foam will cause many surface defects such as shrinkage cavities, surface spots and loss of hiding power. The use of defoamers can be very effective in solving the foam problems we encounter in actual production and life.

There are various types of defoamers on the market, and no defoamer is universal, so for a specific emulsion system, it is necessary to choose a defoamer that matches it. The selection of the defoamer includes three stages: the first stage is the preliminary selection of the defoamer, and the defoaming property of the defoamer and its compatibility with the emulsion are judged by simple experiments.

The second stage is paint selection, that is, the defoamer selected in the first stage is used to make paint, and its defoaming property and compatibility with the system are investigated during the paint making process; the third stage is defoamer After storage for a period of time, the defoaming performance of the defoamer in the prepared wood lacquer was evaluated by the specific gravity cup method. After the process of these three stages, the defoamer that matches the system is selected.

Generally speaking, for primers, putties, etc. that do not require high gloss, you can choose to use mineral oil defoamers. For water-based wood paints of polyurethane emulsion systems and top coats with high gloss and transparency requirements, it is best to use silicone defoamers. This kind of defoamer has the advantages of less dosage, fast defoaming and long-lasting foam suppression, and will not affect the gloss and system transparency requirements.

Whether it is mineral oil or silicone defoamer, they all have the characteristics of rapid defoaming, long-lasting foam suppression, no shrinkage of the paint film, blackening, no effect on adhesion, water resistance, and environmental protection. As for which composition of water-based wood paint defoamer to choose, it depends on your specific cost requirements, performance requirements, and so on.