Foam is generated in most commercial processes including food processing, chemical manufacturing, fermentation, textile, adhesive manufacturing, printing inks, paints, coating and resins and wastewater management.
Foam can be generated by either mechanical agitation or through a chemically influenced mechanism such as a fermentation process.
Defoamers are used to either control foam formation or eliminate foam from forming during the intended process. When the formation of foam is prevented the chemical is usually referred to as antifoam however often the terms defoamer and antifoam are used interchangeably.
Almost all lubricating oil systems contain some air. Air is found in four phases; free air, dissolved air, entrained air and foam. Of these four types antifoams are designed to suppress only the foam in a system however the antifoam used might affect entrained air.
Foaming interferes with lubrication and cooling and can cause the overflow of machine sumps.
Defoamers are designed to knock out trapped air.