Industrial Manufacturing / Solution Family

Silicone Defoamers

PDMS-based silicone antifoams for industrial foam control: neat antifoam compounds and 10-50%-active aqueous emulsions for metalworking fluids, wastewater, pulp/paper, and chemical processing.

Overview

Silicone defoamers are polydimethylsiloxane (PDMS) additives that collapsenand prevent foam in industrial process fluids. The active is PDMS carried onnhydrophobic fumed silica; the silica is what destabilizes the foam film, so the two worknas a pair. They ship in two forms: neat antifoam compounds for concentrated or non-aqueousndosing, and aqueous emulsions (typically 10-50% active) for water-based systems. Match thenform to the medium rather than buying one grade for every line.

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Silicone antifoams are effective at very low dose, often well under 100 ppm, which keepsncost-in-use low even at high silicone prices. The honest trade-off is form againstnlongevity: emulsions disperse instantly into water-based metalworking fluids and effluentnbut can shear out or deposit silicone over a long sump life, while neat compounds are morenpersistent and economical but harder to disperse evenly. Specify the emulsion for aqueousnmetalworking and wastewater; specify the neat compound where silicone carryover or unitncost is the priority.

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One caution drives selection more than performance: silicone carryover can causencratering or fisheyes on any coated or painted surface downstream. Where the treated fluidncontacts parts that are later painted, evaluate a non-silicone defoamer or confirm thensilicone is fully removed before finishing. Food-contact and wastewater service usendedicated grades; confirm regulatory status for your application and jurisdiction.

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Where it's used
  • Foam control in water-soluble metalworking fluids, cutting and grinding coolants
  • Antifoam for pulp/paper, adhesive manufacturing, and polymer-processing lines
  • Foam suppression in industrial wastewater and effluent treatment
  • Process foam control in coatings, inks, and chemical manufacturing
  • Aqueous-line dosing via emulsion; concentrated or non-aqueous dosing via neat compound
Frequently asked questions
What is a silicone defoamer made of?
A silicone defoamer is polydimethylsiloxane (PDMS) combined with hydrophobic fumed silica. The PDMS spreads across the foam film and the silica particles destabilize it, so foam bubbles collapse. It is supplied either as a neat antifoam compound or as a pre-emulsified aqueous emulsion (typically 10-50% active).
Should I use a silicone antifoam compound or an emulsion?
Use the emulsion for water-based systems such as soluble metalworking fluids and wastewater, where it disperses instantly. Use the neat compound where you need persistence and lower cost-in-use, or in non-aqueous fluids. Both are PDMS-based; the difference is delivery form, not the active.
Can a silicone defoamer cause coating or paint defects downstream?
Silicone carryover can cause cratering or fisheyes on surfaces that are later coated or painted. Where the treated fluid contacts parts that will be finished, either evaluate a non-silicone defoamer or confirm the silicone is fully removed before the coating step. This is the most common reason a plant restricts silicone.
Does RawSource supply silicone antifoam in bulk?
Yes. RawSource sources PDMS silicone antifoam compounds and emulsions in drums, totes, and IBCs for industrial foam control, with documentation. Send your system type (aqueous vs non-aqueous), required active level, and volume for a bulk RFQ.
Disclaimer. Information on this page is provided for general reference and compiled from authoritative public sources (e.g. PubChem/ECHA). Values are typical and are not a guaranteed specification; the Certificate of Analysis (CoA) for the lot you purchase governs. Products are sold for industrial and professional use only. Nothing here is a medical, health, or efficacy claim. Always consult the current Safety Data Sheet (SDS) before handling, and confirm regulatory status, classification, and suitability for your application and jurisdiction.
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