Foam can reduce production efficiency and product quality in industries such as textiles, wastewater treatment, coatings, and cleaning chemicals. That's why dimethyl silicone fluid (PDMS) is widely used as the key ingredient in silicone defoamers.
The performance of a defoamer depends largely on choosing the right viscosity and using an effective emulsification process.
Generally speaking:
Lower viscosity → Faster spreading and quicker foam breaking.
Higher viscosity → Longer-lasting foam control and better persistence.
Recommended viscosity: 1,000–5,000 cSt
Low-viscosity PDMS spreads rapidly across the foam surface, breaks bubbles quickly, and is easier to emulsify into fine droplets. It also reduces the risk of silicone spots, helping maintain fabric appearance and softness.
Recommended viscosity: 10,000–60,000 cSt
These systems generate foam continuously through agitation and aeration. Higher-viscosity PDMS stays in the system longer and provides excellent long-term foam suppression, reducing the need for repeated dosing.
Recommended viscosity: 350–1,000 cSt
In coating formulations, compatibility is just as important as defoaming efficiency. Low-viscosity PDMS, often combined with modified silicone fluids, helps remove microfoam while maintaining good leveling and minimizing surface defects such as craters.
Since dimethyl silicone fluid is not water-soluble, proper emulsification is essential for stable performance.
A typical silicone emulsion is produced using:
Nonionic emulsifiers with an HLB value around 10–12
Phase inversion emulsification
High-shear mixing or high-pressure homogenization
The droplet size plays a key role:
Smaller droplets provide faster defoaming.
Medium-sized droplets deliver better long-term foam suppression and storage stability.
A well-produced silicone emulsion can remain stable for more than six months without oil separation or layering.
Choosing the right viscosity is all about matching the application.
Low viscosity for fast defoaming.
High viscosity for long-lasting foam control.
Combined with the right emulsification process, dimethyl silicone fluid can deliver outstanding performance across textile processing, wastewater treatment, coatings, industrial cleaning, and many other applications.
If you're looking for high-quality dimethyl silicone fluids (PDMS) or need technical support for silicone defoamer formulations, IOTA Silicone Oil offers a complete range of low-, medium-, and high-viscosity silicone fluids along with professional formulation support.
Website: www.siliconeoil.net
Email: zyf@siliconeoil.cn
