What do we call a chemical substance that is added to improve certain properties of modern high performance coatings? The answer is simple and straightforward. They are called additives, but how do they really work? In order for coatings to work properly or improve their inherent properties, antifoam additive is one of the components added to their formulation. It is used to address the serious problems caused by the formation of foams in paints and coats as well as in other process liquids. Foam is one of the properties that is not desired in high performance coating production.
An antifoam additive is a material used to break the foam present in the formulation. The simplest way to demonstrate this is by adding an alcohol to a foam. You’ll see the foam breaking because the alcohol with low surface tension and less viscous molecules displaces the foam molecules during their interface. This causes the foam to collapse. While the alcohol in this case serves as a defoamer, it is not an antifoam agent. Specific to high performance coatings, mineral oil-based foam control agents offer this defoaming ability. While a defoamer and antifoam additive are very similar in terms of preventing the problems brought by foams, they differ in some ways.
Antifoams are a more complicated type of additive which prevents foam formation during agitation. The rupture the interface by migrating into it and spanning across the air gap. In order to achieve this function, antifoam additive designers have developed these agents to have low-surface energy oil or oil-soluble mechanical particles. The widely used antifoaming agents in coatings are the silicone-based antifoams. In some cases, however, antifoams can be all used up, rendering them ineffective and causing tiny bubbles or microfoams. But there’s a quick solution to this by choosing surface active materials that quickly migrate to the interface, eliminating microfoams.
Overall, while foams can develop in any form, antifoam additives are further enhanced to work much more effectively to totally eliminate unwanted foams. It is for this reason that they are a vital part of high performance coatings.