Section
| HS Code | 953432 |
| Physical State | Liquid |
| Appearance | Milky white liquid |
| Active Silicone Antifoam Content | 10% |
| Viscosity | Low viscosity |
| Relative Density | Approximately 1.00 at 25°C |
| Ph | Approximately 6.0 to 7.5 |
| Ionic Character | Nonionic |
| Emulsion Type | Oil-in-water |
| Water Dispersibility | Fully dispersible in water |
| Storage Stability | Minimum 12 months in unopened original container |
| Agrochemical Grade | Yes |
As an accredited SILFOAM SE 21 10% Active Low-Viscosity Silicone Antifoam Emulsion–Agrochemical Grade factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | SILFOAM SE 21 agrochemical antifoam is supplied in 200 kg polyethylene-lined steel drums, with 25 kg pails available for convenient handling. |
| Container Loading (20′ FCL) | 20′ FCL container of SILFOAM SE 21, a 10% active low-viscosity silicone antifoam emulsion for agrochemical use. |
| Shipping | SILFOAM SE 21 ships as a non-hazardous agrochemical emulsion in 25 kg HDPE drums, 200 kg drums, or 1000 kg IBCs. Protect containers from damage and extreme temperatures. Keep product from freezing during transit; ideal storage range is 5–40°C. Ensure adequate ventilation and label accordingly. |
| Storage | Store SILFOAM SE 21 in its original, tightly closed container in a cool, dry, well-ventilated area away from direct sunlight and extreme temperatures. Do not allow to freeze; ideal storage conditions are above 5°C and below 40°C. Keep container upright to prevent leakage and separate from oxidizing agents or incompatible chemicals. Use within manufacturer-recommended shelf life. |
| Shelf Life | Shelf life is 12 months when stored in sealed original containers between 4–30°C, protected from freezing and direct sunlight. |
In aqueous suspension concentrate (SC) manufacturing, the mill base is prepared by dispersing technical active ingredient, typically at 30–50 wt%, with a naphthalene sulfonate or polycarboxylate dispersant system at 2–6 wt%, a wetting agent, and a rheology modifier in demineralised water, then passing the slurry through a recirculation bead mill charged with 0.6–0.8 mm yttria-stabilized zirconium oxide beads. Air entrainment during high-shear disperser operation and the surfactant load create persistent foam that reduces grinding chamber fill, causes diaphragm pump cavitation, and increases wet-sieve residue variability under CIPAC MT 185. SILFOAM SE 21 is introduced in split doses: 0.03–0.08 wt% of the mill base before bead milling and a trim addition of 0.02–0.06 wt% of the finished formulation after vacuum deaeration, giving a typical total dose of 0.05–0.14 wt%. The low-viscosity emulsion is metered through peristaltic or diaphragm dosing pumps directly into the recirculation line, which avoids local accumulation on the disperser shaft and maintains foam suppression under the low-shear conditions of the vacuum deaerator. Foam is assessed according to CIPAC MT 47.3; formulations containing high levels of alkylphenol-free phosphate ester wetting agents may require upward adjustment to 0.20 wt% when foam volume exceeds the target stated in the formulation monograph. Manufacturing lines processing chlorothalonil, azoxystrobin, or tebuconazole SCs at 1,000–5,000 L batch scale have shown that adding the defoamer after surfactant hydration but before final active ingredient charge minimizes air incorporation. The terminal products are suspension concentrate fungicides, insecticides, and plant growth regulators packaged in 1 L HDPE bottles, 20 L jerrycans, or 1000 L IBC containers.
| Control point | Standard/method | Measured property |
|---|---|---|
| Persistent foam of SC | CIPAC MT 47.3 | Foam volume after inversion cycle |
| Wet sieve residue | CIPAC MT 185 | Retained mass on 75 μm test sieve |
| Low-temperature storage | CIPAC MT 39.3 | Reversible phase separation after storage at 0 °C |
At batch scales above 3,000 L, the limiting process conflict is not persistent foam alone but the interaction between antifoam droplets and the thickener hydration step. If the emulsion is added before xanthan gum or attapulgite clay is fully hydrated, the silicone droplets can act as nucleation sites for microgel formation, increasing Brookfield viscosity at 20 rpm above the specification range. The split-addition protocol prevents this by delaying the trim addition until after the rheology modifier has been incorporated.
Spray-dried water-dispersible granule production ties defoamer dosing less to the mill base than to the atomization feed tank, because foam entering a rotary atomizer or pressure nozzle disturbs droplet-size distribution and causes build-up on the drying chamber walls. Aqueous slurries for WDG typically contain 40–60 wt% technical active ingredient, dispersants, lignosulfonate binders, and fillers; they are wet-milled and then spray-dried at inlet temperatures of 180–220 °C and outlet temperatures of 85–95 °C. SILFOAM SE 21 is added at 0.10–0.30 wt% based on slurry solids after wet milling, with low-shear agitation maintained for 5–10 min before transfer to the feed tank. The key compliance parameter is the foam formed when the WDG is reconstituted in water; this is assessed using CIPAC MT 47.3 together with the dispersibility procedure CIPAC MT 174 and the suspensibility procedure CIPAC MT 168. The terminal products are water-dispersible granules of sulfonylurea herbicides and contact fungicides packed in 1 kg water-soluble PVA pouches or 10 kg polyethylene bags. Published data for this specific configuration is limited, so the addition ratio is confirmed by reconstitution foam volume rather than extrapolated from SC formulations.
High-ionic-load soluble liquid (SL) formulations such as glyphosate isopropylamine salt or glufosinate-ammonium concentrates operate at pH 4.5–7.0 and conductivities that can exceed 50 mS/cm, a condition that narrows the stability window for conventional defoamer emulsions. SILFOAM SE 21 is post-added at 0.05–0.15 wt% after the salt dissolution and pH adjustment steps, and before the final adjustment of viscosity with amine or polyglycol thickeners. The addition point is located downstream of the main mixing vessel, metered into a side-stream injection loop with an inline static mixer, which limits the residence time of the emulsion in the high-electrolyte bulk phase and avoids the formation of macroscopic silicone oil droplets visible as surface sheen. On filling lines running 10–20 L containers at 60 °C, foam head space reduction is monitored by volume control in the fill nozzle; the applicable specification is CIPAC MT 47.3 after dilution to spray concentration. The terminal products include soluble liquid herbicide concentrates and plant growth regulator formulations packaged in 10 L HDPE jerrycans and 200 L drums.
Seed treatment slurries are formulated as high-solids aqueous suspensions containing fungicides, insecticides, pigments, polymer binders, and film formers, and are applied through continuous seed treaters at volumetric rates as low as 0.5–2.0 L per 100 kg of seed. During continuous seed treater operation, foam generated in the slurry tank reduces the accuracy of the precision dosing pump and can produce uneven film coating on the seed surface. SILFOAM SE 21 is incorporated at 0.02–0.10 wt% of the finished slurry before the polymer binder and film-forming latex are added, using a low-shear axial flow impeller rather than a high-shear disperser to avoid destabilizing the emulsion. The production process includes wet-milling of the active ingredient and pigment at 25–35 °C, cooling to 20–25 °C, and transfer to a jacketed holding tank that feeds the seed treater atomizer. Compliance for treated seed in commercial channels includes germination and seed flowability protocols under ISTA rules, as well as formulation foam assessment under CIPAC MT 47.3 before application. Terminal product types are treated maize, soybean, and canola seed in 50 kg paper bags or bulk bins; phase separation in the slurry can block atomizer discs on rotating bell treaters and is controlled by the emulsion’s low-viscosity incorporation.
Oil-in-water emulsion (EW) formulations are produced by dissolving a liquid or solvent-dissolved active ingredient in an oil phase, blending it with nonionic/anionic emulsifiers, and then dispersing the oil phase into water using a high-shear rotor-stator followed by a high-pressure homogenizer. At homogenization pressures above 300 bar, the combination of dissolved surfactants and cavitation creates microfoam that can reduce homogenizer efficiency and cause phase inversion if the foam layer is drawn into the pump inlet. SILFOAM SE 21 is added to the water phase at 0.05–0.20 wt% of the final EW formulation before homogenization, with the water phase maintained at 30–40 °C and under gentle agitation to ensure emulsion distribution without premature coalescence. The relevant standards are CIPAC MT 36.3 for emulsion stability after dilution, CIPAC MT 47.3 for foam generation, and CIPAC MT 39.3 for low-temperature storage. Terminal products include oil-in-water emulsion formulations of pyrethroid and chloroacetanilide active ingredients, packaged in 5 L HDPE containers and 20 L barrier jugs. The low active concentration of the defoamer emulsion allows the dosage to be adjusted in 0.02 wt% increments during homogenization trials, with emulsion stability confirmed by CIPAC MT 36.3 after dilution.
Microemulsion concentrates are thermodynamically stable, water-based formulations containing high surfactant loads of 15–30 wt% and a co-solvent, which makes them prone to persistent foam during low-shear blending and filling. In the preparation of microemulsion (ME) concentrates, the active ingredient is first dissolved with a surfactant-cosurfactant blend, then water is added under gentle agitation at 20–30 °C; the formed microemulsion is not subjected to high shear, so the antifoam must function under low-energy mixing conditions. SILFOAM SE 21 is introduced into the water phase at 0.05–0.15 wt% of the finished ME formulation before the water addition step, using a metering pump calibrated to ±0.01 wt% accuracy; post-addition after the microemulsion has formed is less effective because the silicone droplets are not uniformly distributed in the microemulsion interface region. The compliance assessment includes CIPAC MT 47.3 foam volume after dilution and CIPAC MT 39.3 low-temperature stability, because ME concentrates are marketed as transparent liquid products where haze or phase separation after storage is unacceptable. Terminal products are microemulsion insecticide and plant growth regulator formulations packaged in 5 L PET bottles or 250 mL HDPE dosing containers for high-value horticultural uses. Published data for this specific formulation class is limited; dosage is therefore verified by low-temperature storage and dilution foam tests under the relevant CIPAC methods rather than by fixed addition rules.
Competitive SILFOAM SE 21 10% Active Low-Viscosity Silicone Antifoam Emulsion–Agrochemical Grade prices that fit your budget—flexible terms and customized quotes for every order.
For samples, pricing, or more information, please contact us at +8615380400285 or mail to sales2@liwei-chem.com.
We will respond to you as soon as possible.
Tel: +8615380400285
Email: sales2@liwei-chem.com
Flexible payment, competitive price, premium service - Inquire now!
SILFOAM SE 21 10% Active Low-Viscosity Silicone Antifoam Emulsion–Agrochemical Grade is an aqueous silicone antifoam formulated with a nominal silicone active content of 10% by weight. It is intended for foam control in water-based agrochemical manufacturing, in dilution systems, and in spray-tank operations where persistent surfactant-stabilized foam reduces mixing capacity, pump efficiency, or field application uniformity. The product is supplied as a low-viscosity, pumpable emulsion, which distinguishes it from neat silicone antifoam fluids and from higher-active silicone emulsions that may require heated storage or special high-viscosity pumping arrangements. The low-viscosity specification is a deliberate formulation characteristic: it allows direct volumetric metering from unheated drums or intermediate bulk containers into ambient aqueous blending lines without the pre-emulsification step required for 100% active silicone oils.
The product’s functional class is a ready-to-use silicone antifoam emulsion, not a self-emulsifying silicone polyether defoamer and not a mineral oil or organic polymer defoamer. In comparison with a 20–30% active silicone emulsion, SE 21 requires a larger product mass to deliver the same silicone active mass, but the lower active content can improve metering precision on low-flow positive-displacement pumps because the target volumetric dose is larger relative to pump minimum stroke volume. Compared with a 100% active silicone compound, SE 21 eliminates the need for high-shear pre-dispersion in aqueous formulations, but it introduces the typical storage constraints of an aqueous emulsion, including freeze-thaw sensitivity and possible creaming under prolonged static storage.
Agrochemical formulations often contain high-HLB nonionic surfactants, alkylpolyglycosides, tristyrylphenol ethoxylates, lignosulfonates, naphthalene sulfonates, and polymeric dispersants that stabilize foam through surface elasticity, Marangoni flows, and electrostatic repulsion in thin films. In such systems, the silicone active phase functions by spreading at the air-water interface and creating localized film thinning, followed by film rupture when the silicone droplet bridges the foam lamella. The mechanism depends on the interfacial tension differential between the silicone phase and the surrounding surfactant solution. For polydimethylsiloxane-based active fluids, surface tension is commonly in the range of 20–22 mN/m, which is sufficiently low to disrupt typical aqueous agrochemical foam films. However, foam control is not a linear function of silicone concentration; the silicone droplets must survive the formulation environment, reach the foam interface, and avoid being fully emulsified by excess surfactant to the point where the active phase becomes molecularly dispersed and loses its film-breaking function.
Because of this complexity, a universal dosage cannot be derived solely from the 10% active content. Screening should be performed in the final agrochemical formulation at its intended field dilution and in the water quality expected for use. The persistent foam method commonly cited for plant protection products is CIPAC MT 47.3, which provides a standardized foam-height and foam-decay measurement under defined shaking or bubbling conditions. That laboratory result should be correlated with production-scale symptoms such as vacuum pump knockout-pot carryover, mixing vessel foam headspace loss, or sprayer pump cavitation. Published data for this specific product configuration is limited, so the supplier’s batch certificate for active content, pH, viscosity, and emulsion stability should be used as the controlling release specification, while foam efficacy should be confirmed in the customer’s formulation.
The product’s diluted form is a faintly turbid aqueous dispersion. In hard water, multivalent cations such as calcium and magnesium can interact with anionic emulsifiers and influence the dispersion state of the silicone droplets. This does not automatically cause defoamer failure, but it can shift the emulsion droplet size distribution and alter the release characteristics of the active phase. Therefore, hard-water jar tests and foam tests are technically necessary before committing a production batch. The use of deionized water alone can overestimate antifoam performance and create a false sense of process robustness.
| Parameter | SILFOAM SE 21 | Higher-active silicone emulsion | Neat silicone antifoam compound |
|---|---|---|---|
| Nominal silicone active content | 10% | 20–30% class | 100% |
| Physical form | Aqueous emulsion | Aqueous emulsion | Non-emulsified silicone fluid |
| Viscosity/pumpability | Low viscosity; direct metering | Moderate viscosity; may require larger pump lines | High viscosity; often requires heated storage or special injection |
| Dilution behavior | Cold-water dispersible | Cold-water dispersible | Requires pre-emulsification or high-shear dispersion |
| Metering precision | Larger volumetric dose can reduce relative error at low active demand | Lower volumetric dose; higher active loading | Precise low-dose metering difficult without dilution |
| Storage sensitivity | Freeze-thaw sensitive; creaming possible | Freeze-thaw sensitive; creaming possible | Less freeze-sensitive; may thicken at low temperature |
| Typical application niche | Aqueous agrochemical formulations and dilute spray tanks | Aqueous systems where lower product use rate is required | Solvent-based or oil-based formulations; dry products |
On a production line where a suspension concentrate is prepared with a rotor-stator mill or high-pressure homogenizer, the point of antifoam addition influences both foam control and batch-to-batch variance. Addition before the high-shear milling step can subject the silicone emulsion to intense mechanical stress, potentially reducing silicone droplet size and changing the release profile of the active phase. That may not be detrimental in every matrix, but it introduces an uncontrolled variable if the shear history is not fixed. More reproducible processing is generally obtained when the antifoam is added after the final wet-milling pass, during let-down, under moderate axial flow. In a recirculating vessel, the injection point should be placed in a low-velocity return line upstream of a static mixer, rather than directly into the high-shear disperser suction. This avoids localized shear damage and prevents air incorporation.
For continuous liquid fertilizer or water-soluble pesticide dilution lines, the product can be metered into the water stream upstream of the mixing tee. Because the continuous phase of the emulsion is water, dispersion occurs without additional surfactant. The process limit is usually the metering pump turndown ratio, not the antifoam chemistry. A 10% active emulsion requires a higher volumetric setpoint than a 100% active fluid to deliver the same silicone active mass. The pump should be selected so the target dose does not fall below 10% of the pump’s maximum stroke rate. If the injection point is too close to an in-line screen, nozzle, or throttling valve, localized silicone concentration can produce transient film formation on metal or polymer surfaces. Increasing the distance between the injection point and the first downstream restriction to at least 10 pipe diameters is a conservative engineering guideline, not a product-specific specification. Static mixers or low-shear centrifugal pumps provide adequate distribution without the energy input of a high-shear mixer.
Freeze-thaw cycling is a critical risk for any aqueous silicone emulsion. If the product freezes, ice crystal growth can compress and coalesce the silicone droplets, producing a separated silicone phase that may not redisperse under normal agitation. A single freeze event can reduce antifoam activity even when the thawed material appears visually homogeneous. Outdoor storage in unheated tanks is therefore not recommended unless the vessel is insulated or heated and protected from frost. Drums and totes should be stored in a frost-free warehouse, and containers that have been exposed to freezing conditions should be quarantined and tested by CIPAC MT 47.3 or an internal foam-destruction method before release to production. During bulk unloading, gentle recirculation with a low-shear centrifugal pump is preferable to air sparging, because air injection introduces microbubbles and increases foam load before the antifoam has been dispersed into the receiving batch.
Long-term static storage may also cause creaming because the dispersed silicone phase is less dense than the continuous aqueous phase. Creaming is not necessarily a product failure if the product is homogenized before use, but excessive creaming can create an inhomogeneous active content in the withdrawn stream. A slow sweep or recirculation of the tote or bulk tank before transfer is a good manufacturing practice. The batch certificate viscosity is commonly determined by a rotational viscometer method such as ISO 2555; however, the value is not a fixed material constant because emulsion viscosity depends on temperature, shear rate, and prior shear history. For plant design, the viscosity at the lowest expected warehouse temperature should be obtained from the supplier rather than inferred from room-temperature data.
Agrochemical registration dossiers frequently include foam persistence data generated according to CIPAC MT 47.3 or an equivalent method cited in a FAO/WHO pesticide specification package. SE 21 should be evaluated in such protocols at the intended commercial dose and in the presence of the co-formulated pesticides, not as a standalone water solution. Foam control data generated in clean water without the agrochemical surfactants can be misleading because the surfactant load and surfactant type determine both the initial foam height and the antifoam dose required for collapse.
Water hardness is a second variable that must be fixed in test design. Standard hard water with 342 ppm calcium carbonate equivalent is often used in agrochemical formulation testing, while soft water may contain less than 20 ppm calcium carbonate equivalent. In hard water, the emulsion may exhibit faster creaming or reduced foam knockdown if the emulsifier system is sensitive to calcium or magnesium ions. The test design should therefore include at least two water hardness classes and, where relevant, an electrolyte matrix such as a liquid fertilizer solution. Without these controls, a laboratory result cannot be translated to a production-scale batch or to field tank-mix performance.
Compared with a molecularly water-soluble silicone polyether defoamer, SE 21 remains a dispersion of discrete silicone droplets rather than a fully soluble surfactant. This distinction matters in high-surfactant formulations. A water-soluble silicone polyether may lose defoaming efficiency when it is incorporated into a highly surface-active surfactant package, because its surface activity may be insufficient to displace the foam-stabilizing surfactants. A dispersed silicone active can remain as a separate low-surface-energy phase and act on foam films. The trade-off is that the dispersed emulsion is more sensitive to creaming, freeze-thaw damage, and possible adsorption onto particulate carriers. In formulations containing clay, silica, or high-surface-area solid active ingredients, part of the silicone active may be lost by adsorption, and the effective dose can be higher than in a clean aqueous formulation.
In comparison with mineral oil or organic polymer defoamers, the silicone active in SE 21 may provide longer-lasting foam control in surfactant-heavy agrochemical systems and may be effective at lower active concentrations. However, silicone overdosing can produce surface defects on tanks, rails, or equipment, and can interfere with wetting or spray retention if the dose is not optimized. The product is an agrochemical-grade processing aid and formulation component; it is not automatically suitable for food-contact or potable-water applications. Regulatory status must be confirmed through the safety data sheet under REACH Regulation (EC) No 1907/2006 and, where applicable, through the registered pesticide formulation approval. The term “agrochemical grade” indicates the intended use domain, not a food-grade or drinking-water approval.
For solvent-based emulsifiable concentrates or oil-based agrochemical formulations, an aqueous emulsion is generally not the preferred antifoam form. In those systems, a 100% active silicone fluid or an oil-dispersible silicone compound is technically better suited, because the water introduced by SE 21 may create haze, phase separation, or water uptake unless the formulation contains a deliberate water phase. In aqueous suspension concentrates, soluble liquids, microemulsions, and tank-mix adjuvants, the product can be integrated into existing liquid-blending lines, provided that the addition point, storage temperature, and final formulation compatibility are controlled.
