There are two common types of defoamers, silicone based and silicone free, with each type of defoamer being either a liquid or powder formulation.  

A.Silicone based defoamers

1. Liquid formulation

1. Has a silicone backbone consisting of hydrophobic silica in silica oil.

2. Chemically inert, thermally stable, low surface tension, and completely soluble in water.

2. Powder formulation

1. Composed of a silicone antifoam compound.

2. Have excellent defoaming action and are stabile in small concentrations.

1. Silicone free defoamers 

1. Liquid formulation

· Most effective in water based and solvent based systems. 

· Controls foam regeneration and doesn’t cause discoloration. 

B.Powder formulation

· Composed of silicone antifoam compounds.

· Excellent defoaming action and have lasting defoaming power and stability in small concentrations.