A defoamer that foams is not a defoamer. And in most silicone and non-silicone antifoam systems, the component doing the actual foam-breaking is not the oil — it is the silica.

IOTA FINE SIL 7517 is a superfine precipitated silica made by special processing technology, with excellent reinforcement and dispersion. In defoamer formulations, silica particles strengthen the antifoaming action: carried by the silicone oil and water interface, they enter the bubble film. Because of their hydrophobicity, the contact angle with surfactant foaming droplets is greater than 90° — the hydrophobic particles are forced out of the film surface, causing rapid liquid drainage and local bubble rupture. Oil plus silica work together, and the synergy is what produces the defoaming effect.

Main specifications (per official product page):

Why defoamer formulators pick it:

• 3 μm particles with BET 200–220 m²/g — enough surface activity to puncture films, without over-thickening the carrier.

• Special processing delivers the hydrophobic particle behavior that antifoam synergy depends on.

• Precipitated-route economics: replace fumed silica fully or partly and cut formulation cost.

• Same logic applies across textile, coating, fermentation and wastewater antifoam systems.

Packing: white kraft paper bag, 15 kg/bag.

Related product: Precipitated Silica IOTA FINE SIL 7517