Fighting the Foam – Chemistry and Working Mechanisms of Defoamers
Time: 4:00 pm - 4:20 pm
Date: Tuesday 14 May
In film-forming applications like care products, e.g. floor polish, foam can have a negative impact on the film formation and thus on the product performance. Formation of foam during the manufacture of cleaners and care products can also cause problems during production and packaging.
A characteristic feature of foam is a very large liquid to gas interface compared to other physical states. The increased surface area in a foam is a high-energy state compared to normal conditions. Maintaining these conditions requires foam-stabilizing substances, e.g. surface-active ingredients (surfactants) that contain a hydrophobic part and a hydrophilic part. Due to their amphiphilic structure, these substances orient themselves to the liquid gas interface und reduce the surface tension, thus enabling a stable foam. Considering that almost all cleaners contain surfactants to improve surface wetting, formation of foam during production is a common issue.
Defoamers are used to prevent foam formation during the production and application of care products. A key feature of all defoamers is their targeted and controlled incompatibility with the medium that is to be defoamed. A defoamer that is too compatible has only a minor or even no defoaming effect. Too much incompatibility causes defects in the product, such as turbidity, or in the application, such as leveling issues. Choosing the correct defoamer is therefore a “balancing act” between compatibility and incompatibility. BYK offers silicone defoamers, silicone free polymer defoamers, and mineral oil defoamers to provide optimum solutions for different systems.