The main functions of defoamers include reducing surface tension, destroying foam liquid film, inhibiting foam regeneration and improving liquid fluidity. Specifically, defoamers can quickly spread on the surface of foam liquid, making the liquid film thinner and reducing its surface tension, thereby causing the foam to burst. Some defoamers contain hydrophobic components, such as hydrophobic silica, which can pierce the foam liquid film, causing small bubbles to merge into large bubbles, making it easier to overflow from the system and achieve a defoaming effect. In addition, defoamers can also prevent the generation of new foam by forming a thin film with low surface tension on the surface of the solution, thereby playing a role in suppressing foam.
Defoamers have a wide range of applications, including but not limited to the food industry, papermaking industry, water treatment, oil production industry, printing and dyeing industry, coating industry, detergent industry, rubber latex industry, pharmaceutical industry, dairy industry, etc. In these industries, defoamers can effectively improve production efficiency, ensure product quality and reduce costs. For example, in food processing, defoamers can control the foam in the beer brewing process to ensure the taste and stability of the beer; in coating production, defoamers can eliminate pinholes and shrinkage holes on the coating surface to ensure the appearance and performance of the coating.
There are various types of defoamers, the most common of which are silicones, polyethers or polyether-modified polysiloxanes. These different types of defoamers are selected according to the specific process conditions and the cause of foaming to achieve the best defoaming effect.