Section
| HS Code | 225527 |
| Product Name | MY-500 50% Active High-Concentration Silicone Antifoam Emulsion |
| Product Type | Silicone antifoam emulsion |
| Active Content | 50% |
| Appearance | Milky white homogeneous liquid |
| Viscosity 25 C | 1000-3000 mPa·s |
| Ph Value | 6.0-8.0 |
| Density 25 C | 0.98-1.02 g/cm³ |
| Ionic Character | Non-ionic |
| Water Dispersibility | Easily dispersible in water |
| Foam Suppression Efficiency | High and long-lasting |
| Defoaming Performance | Rapid foam knockdown |
| Storage Stability | Stable for 12 months under recommended conditions |
| Freeze Thaw Stability | Sensitive to freezing; protect from frost |
As an accredited MY-500 50% Active High-Concentration Silicone Antifoam Emulsion factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | Packaged in 25 kg pails and 200 kg drums, sealed with tamper-evident lids and labeled with product and safety information. |
| Container Loading (20′ FCL) | 20′ FCL loading of MY-500 silicone antifoam emulsion, 50% active, in drums/IBCs on pallets, securely stowed and ventilated. |
| Shipping | MY-500 antifoam emulsion ships in sealed, corrosion-resistant drums or IBCs to prevent leakage. Store between 5–35°C, away from freezing or direct heat. Not classified as hazardous for transport; however, use proper lifting equipment. Ensure containers remain upright and protected from physical damage during transit. |
| Storage | Store MY-500 in its original, tightly sealed container in a cool, dry, well-ventilated area away from direct sunlight, heat sources, and incompatible materials. Recommended storage temperature is 5–40°C; protect from freezing. Keep containers closed when not in use to prevent contamination. Under proper conditions, shelf life is typically 12 months. Stir gently before use. |
| Shelf Life | Shelf life: 12 months from manufacture if stored in original, unopened containers between 5°C and 40°C, avoiding freezing. |
In 35,000 L waterborne flat wall paint compounding, entrained air from high-speed pigment dispersion persists through let-down unless a high-solids silicone antifoam such as MY-500 is introduced at the correct stage. Under EU Directive 2004/42/EC and REACH Regulation (EC) No 1907/2006 Annex II, the product is handled as an industrial processing aid within the wet-state formulation, while foam generation is evaluated by ASTM D3519-88(2007) blender foam testing and viscosity recovery by ISO 2431 flow cups. Addition is typically split 60% into the dispersion vessel just after pigment wetting and 40% into the completed paint with the let-down mixer at 200–400 rpm; total product dose is 0.05–0.20 wt% of the finished batch, equivalent to 0.025–0.10 wt% active silicone. In production, a 450 mm Cowles blade running at 15–20 m/s tip speed generates shear that can destabilize neat emulsion droplets, so dosing occurs after pigment agglomerates are reduced, not during maximum shear. Terminal finished product types are interior flat wall paints, high-PVC ceiling paints, pigmented waterborne primers, and elastomeric roof coatings. Over-addition above 0.50 wt% has been observed on filling lines to produce surface craters and intercoat adhesion loss after drying; batch-to-batch foam carryover in 1,000 L totes is controlled by leaving headspace and avoiding recirculation with air-ingressing diaphragm pumps.
Foam stabilization in paper machine white-water loops frequently originates from rosin soap, dissolved organic acids, and recycled-fiber starch release. FDA 21 CFR 176.210 governs defoaming agents used in the manufacture of paper and paperboard intended for food contact, and the EU BAT Reference Document for the Pulp and Paper Industry under Directive 2010/75/EU sets constraints on chemical oxygen demand and specific organic loadings in effluent. The product is added at 0.1–0.3 kg per dry tonne of pulp, corresponding to 50–150 g active silicone per dry tonne, preferably through a metering pump into the wire pit or headbox feed after stock screening. On a 7.5 m fourdrinier machine producing 550–650 m/min, foam blanket thickness at the wire pit is typically reduced from 40–60 mm to below 10 mm within 20–40 s when the emulsion is diluted to 1–5% solids with clarified white water immediately before use. Terminal grades include coated freesheet, tissue, and kraft linerboard. Operational boundaries: carry-over with cationic retention polymers above 0.4 kg/t may form floc, and excess silicone can deposit on dryer fabrics if stock pH exceeds 8.5; published data for this specific 50% active emulsion in neutral sulfite semichemical pulp is limited, requiring pilot white-water jar testing before machine trials.
During 1,200 kg polyester package dyeing at a liquor ratio of 1:6 to 1:8, air entrainment in the overflow chamber of a jet dyeing machine produces foam that can impede liquor circulation and lead to uneven dye uptake. The application falls under ZDHC Manufacturing Restricted Substances List 3.0 and REACH Regulation (EC) No 1907/2006 Annex XVII, with finished textiles assessed against OEKO-TEX Standard 100 if the emulsion does not leave hydrophobic deposits. In high-temperature high-pressure jet equipment operating at 130–135°C, the product is diluted to 0.5–1.0% active silicone in demineralized water and dosed at 0.01–0.05 g/L of dyebath, equivalent to 0.02–0.10 g product per litre. The downstream process sequence includes prescouring, dyeing, overflow rinse, and softener application; the diluted antifoam is injected after dyestuff migration begins, never during initial heating, because thermal shock can separate the emulsion before contact with foam lamellae. Terminal finished product types are reactive dyed cotton knits, polyester woven fabrics, and nylon/elastane knitted goods. Over-addition above 0.10 g/L has been linked to silicone spotting on polyamide and consequent redye failure; therefore an after-scour with an acidic rinsing agent at pH 4.0–5.0 is applied when residual foam persists.
Activated sludge plants with fine-bubble diffusers generate stable biological foam when extracellular polymeric substances and filamentous bacteria reach critical concentration. Discharge quality is regulated under the Urban Waste Water Treatment Directive 91/271/EEC and, in the United States, under NPDES permits issued pursuant to 40 CFR Part 122; foam is measured by ASTM D3519-88(2007) as a comparative aqueous foam test. The product is dosed at 1–20 ppm as supplied, or 0.5–10 ppm active silicone, into the RAS channel or aeration basin influent box, not directly into the final clarifier, to avoid floc carry-over. In a 5,000 m³ basin with MLSS at 4,000–6,000 mg/L, the metering pump should maintain continuous feed over 30–60 min rather than a single slug, because rapid defoaming causes biomass to settle and temporarily depresses oxygen transfer. Terminal products of the treatment process are clarified effluent meeting BOD/COD permit values and dewatered waste activated sludge. When cationic polymer is being fed for thickening, doses above 25 ppm of the product may form silicone-polymer floc that blinds belt press belts; published data for this specific 50% active emulsion in membrane bioreactors with mixed liquor flux above 25 LMH is limited, so pilot testing in the actual MLSS range is necessary.
Household and industrial detergent batches require controlled foam in wash liquor and during filling of low-foam detergent bottles. The EU Detergent Regulation (EC) No 648/2004 applies to surfactant biodegradability and labeling, while the US EPA Safer Choice Standard provides ingredient review when the formulation is marketed as environmentally preferred. The silicone emulsion is introduced post-neutralization at 0.05–0.30 wt% of the finished detergent, equivalent to 0.025–0.15 wt% active silicone, after anionic and nonionic surfactant blends have been fully hydrated at 25–35°C. In a 10,000 L jacketed stirred tank with a two-stage axial impeller at 80–120 rpm, the product is fed through a static mixer into the recirculation loop, not into the vacuum inlet, because high air entrainment during transfer can be mistaken for formulation incompatibility. Finished product types include low-foam laundry detergents, industrial floor cleaners, and automatic dishwashing gels. The main operational boundary is compatibility with hypochlorite: direct combination with sodium hypochlorite above 2.0 vol% available chlorine at pH > 11.0 can oxidize the silicone and reduce defoaming persistence; caustic-stable blends above 10% NaOH should be checked by storage stability at 40°C for 14 days before scale-up.
Industrial enzyme and organic acid fermentations rely on silicone antifoam to suppress exopolysaccharide and protein foams that block gas vent filters. For non-food industrial enzymes, quality systems follow ISO 22000 or FSSC 22000 only when the enzyme is destined for food processing; the fermentation itself is commonly operated under current good manufacturing practice for industrial enzymes, and filter integrity is verified by bubble point testing under ISO 29463-4. Typical addition is 0.10–0.50 g/L of the 50% active product, administered by foam-sensor-activated peristaltic or diaphragm metering pumps into the 200,000 L stirred fermenter broth, with aeration maintained at 0.5–2.0 vvm and agitator power input at 2–4 kW/m³. The downstream process includes broth cooling, cell separation by disc-stack centrifuge, ultrafiltration with a 10 kDa cutoff, and polishing chromatography. Terminal products include protease, amylase, citric acid, and yeast extracts. The critical boundary is oxygen transfer: addition above 0.75 g/L has been reported to reduce kLa by 10–25% in pilot cultures with Aspergillus niger morphology above 40 g/L biomass, and residual silicone can foul ceramic membranes; published data for this specific 50% active emulsion in high-cell-density E. coli fermentation exceeding 80 g/L dry cell weight is limited, so a side-stream antifoam requirement test is necessary before full-scale dosing.
In polycarboxylate superplasticizer mother-liquor compounding, air entrainment during the copolymerization and neutralization stages creates persistent foam that alters bulk density and causes batching weight errors in drum filling. The admixture must comply with EN 934-2 when used in ready-mixed concrete and with ASTM C494 when supplied to North American ready-mix producers; foam control is not directly specified, but the effect on air content of the resulting concrete is assessed by EN 12350-7. The product is added to the finished mother liquor at 0.05–0.20 wt% of the admixture batch, equivalent to 0.025–0.10 wt% active silicone, by a gear pump into the low-shear side of the 5,000–10,000 L reactor after neutralization at 60–80°C. In the downstream production process, the mother liquor is blended with defoamer, sodium gluconate, and biocide in a 20 m³ packaging vessel with bottom-entry agitator at 60–80 rpm. Terminal finished product types are polycarboxylate ether superplasticizers for ready-mix concrete, precast elements, and self-consolidating concrete. The primary incompatibility is with air-entraining admixtures: over-addition above 0.30 wt% can depress concrete air content below 4.0%, reducing freeze-thaw durability measured by ASTM C666/C666M; published data for this specific 50% active emulsion in winter-mixed concrete below 5°C is limited, so trial batching at the target w/c ratio is required.
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MY-500 is supplied as a water-continuous emulsion in which the dispersed phase is a compounded silicone defoamer containing polydimethylsiloxane fluid and hydrophobic silica. The declared active defoamer content is 50% by mass, equivalent to 500 g/kg of silicone defoamer on an as-received basis. This is not a dilution of a conventional 10–30% active emulsion; it is a deliberately formulated high-solids product for process systems where foam-control demand is high enough to justify controlled metering and where reduced water load and lower freight volume are required. The product is milky white to off-white and may develop a slight cream layer in storage. The cream layer is normally reversible under gentle agitation; free oil or gel bodies after agitation are signs of thermal or shear damage and should be treated as a batch rejection criterion.
The defoaming mechanism depends on spreading of the silicone oil at the air-water interface and rupture of foam lamellae by hydrophobic silica particles. The silica particles produce localized surface defects with high contact angles; the oil phase spreads over the lamella and displaces surfactant stabilizers. In a 50% active emulsion, the number of available defoamer droplets per gram of product is higher than in a 20% active product, but the spacing between droplets is smaller. This creates a stability trade-off: the product is more active per unit mass, but more sensitive to shear-induced coalescence and freeze-thaw damage. The exact particle-size distribution and emulsifier charge are proprietary, but the supplier certificate of analysis should report viscosity, pH, density, and particle-size parameters as described below.
The product is not a low-solids emulsion in which a single Newtonian viscosity controls pump sizing. Because the continuous phase is water but the internal-phase volume is high, the product may display shear-thinning behavior. Users should not interpret a low-shear viscosity reading alone as a pump-sizing parameter. The supplier aim is to produce a product that remains pourable at 20 °C and can be pumped with conventional chemical metering equipment after dilution.
The first difference is the mass of active defoamer per unit volume. A plant consuming 1,000 kg of a 20% active emulsion receives 200 kg of silicone defoamer; the same defoamer load is supplied by 400 kg of a 50% active product. The resulting reduction in drum handling, warehousing, and truck movements is measurable, but it comes with higher neat-product viscosity and greater tendency to separate if not kept in gentle motion.
The second difference is mechanical stability. Low-solids silicone emulsions are often sufficiently water-rich to tolerate short exposure to centrifugal pumps and high-speed mixers. A 50% active emulsion is typically shear-thinning but not shear-proof. Field experience on paper-machine stock-preparation lines has shown that passing the neat product through an in-line centrifugal pump or throttling through a needle valve can invert the emulsion, producing free silicone oil in the sight glass within minutes. The free oil then deposits on forming fabrics, vacuum boxes, and press felts. The correct transfer method is a low-speed progressing cavity pump or a solenoid diaphragm pump with a full-port ball valve and a flooded suction line.
The third difference is freeze-thaw resilience. A conventional 10% active emulsion may survive accidental freezing with only a temporary viscosity increase. A 50% active emulsion has a smaller continuous water phase to absorb ice-crystal damage, and one freeze-thaw cycle can be enough to break the emulsion. Storage should be maintained at 5–40 °C. If freezing is suspected, the product should be brought to 20–25 °C for 24–48 h and recirculated with a low-shear lobe pump before sampling. If free oil remains on the surface after remixing, the batch should not be pumped into the process.
| Property | Typical range or limit | Reference method or equipment |
|---|---|---|
| Active silicone content, % by mass | 49–51 | Supplier release method; not equivalent to total solids |
| pH at 25 °C | 6.0–8.5 | ISO 976 |
| Density at 20 °C | 0.98–1.02 g/cm³ | ISO 2811-1 |
| Viscosity at 25 °C | 1,000–4,000 mPa·s | ISO 2555, Brookfield RVT spindle 3 at 20 min⁻¹ |
| Mean particle size D50 | 5–25 µm | ISO 13320 laser diffraction |
| Flash point | >100 °C | ISO 2719 |
| Storage temperature | 5–40 °C | Supplier handling specification |
When receiving the product, the laboratory should measure pH, density, viscosity, and active content against the supplier certificate of analysis. Sampling should be performed after gentle homogenization. A thief sampler should be used to collect material from the top, middle, and bottom of the drum or tote. If the three samples differ in viscosity or oil content, the container should be recirculated before use. The pH is measured on the neat product according to ISO 976; density is measured at 20 °C according to ISO 2811-1; viscosity is measured at 25 °C according to ISO 2555; particle-size distribution is measured by laser diffraction according to ISO 13320. These methods provide a common language for lot-to-lot comparison.
Defoamer demand is not a fixed property of the emulsion; it is a response to the foam-stabilizing load in the water circuit. A single universal dosage cannot be stated. The minimum effective dose should be established by laboratory antifoam testing, preferably using ASTM E2407 or an equivalent internal method, with foam generated from actual process water. In paper machine wet-end applications, the neat product is usually diluted with clarified white water or demineralized water to a 0.5–2.0% active solution and added continuously at the wire pit, headbox overflow, or screen feed. The addition point should be selected so that the diluted emulsion has at least 5–10 s of flow time before the foam-sensitive section. In activated sludge basins, the diluted product is applied directly to the foam surface or mixed-liquor channel, not into the blower air stream, because silicone mist can coat air filters and diffuser membranes.
Dilution water temperature is critical. Water below 10 °C can produce gel particles that plug metering pumps and reduce defoamer availability. Water at 15–30 °C is preferred. The water should be low in hardness and free of high concentrations of cationic polyelectrolytes. Hardness ions can form soaps with the emulsifier package, and cationic charge can coacervate anionic silicone droplets. Softened water, condensate, or low-hardness clarified water is acceptable. When preparing a day tank, the diluted emulsion should be used within 8–12 h if no preservative or biocide is present, because stagnant dilute emulsion can support microbial growth in non-sterile mill water systems.
For continuous transfer, wetted parts should be selected from 316L stainless steel, polypropylene, polyethylene, or EPDM rubber. Brass, bronze, and aluminum fittings are undesirable because metal ions released from these surfaces can destabilize the emulsion. Progressing cavity pumps and diaphragm metering pumps are appropriate. Centrifugal pumps, rotary gear pumps with tight clearances, and high-pressure needle valves are not recommended for the neat product. If the transfer distance exceeds 30 m, the line should be sloped or insulated to prevent water separation in dead legs, and low-point drains should be opened during shutdown.
The critical process risk with a high-solids silicone emulsion is overdosing. At very low addition rates, the defoamer particles are adsorbed onto bubble surfaces and foam collapses. When the dose exceeds the available foam surface area, unadsorbed silicone droplets can coalesce on equipment surfaces. In papermaking, this appears as oily deposits on forming fabrics, vacuum box covers, and press felts; in cooling towers, it appears as a surface film that can interfere with heat transfer. The maximum safe addition should be determined by stepwise changes of no more than 10% of the current dose, with visual inspection of drainage elements and measurement of sheet quality before further increases.
The emulsion is incompatible with high-charge cationic flocculants and strong cationic retention aids in undiluted form. When both are added to the same stock stream without sufficient separation, anionic silicone droplets can form pitch-like agglomerates with the cationic polymer. The corrective action is to move the antifoam addition point, increase dilution, or separate the two feeds by at least 15 s of residence time. If a system operates with high cationic demand, a bench-scale charge demand test should be run before a plant trial.
The product should not be blended with hydrocarbon or mineral-oil defoamers, or with silicone oils of unknown emulsifier charge. Such mixing can break the emulsion and produce an irrecoverable oil layer. In membrane bioreactor wastewater plants, continuous silicone antifoam addition has been associated in field service with membrane fouling, though published data for this specific configuration is limited. If the product is used in an MBR, membrane flux, transmembrane pressure, and cleaning frequency should be monitored closely and the dose held at the minimum effective rate.
Do not allow the neat product to dry on pump diaphragms, level probes, or tank walls. Dried silicone films are difficult to remove with water alone; cleaning with a nonionic surfactant solution or isopropanol is typical. In a bulk storage tank, a slow recirculation loop at 5–10 L/min helps minimize separation without subjecting the emulsion to high shear. The tank should be vented to atmosphere and protected from rain ingress, because excess surface water can create a low-viscosity layer that is not representative of the stored product.
For food-contact paper and paperboard applications, the following compliance framework is usually cited. Direct food additive status is not claimed, and the product should not be used in cosmetic or pharmaceutical processes without a specific regulatory letter from the manufacturer.
| Requirement or standard | Application boundary |
|---|---|
| FDA 21 CFR 176.170 | Components of paper and paperboard in contact with aqueous and fatty foods; extraction limits apply |
| FDA 21 CFR 176.200 | Defoaming agents used in coatings; silicone permitted within specified limitations |
| FDA 21 CFR 176.210 | Defoaming agents used in the manufacture of paper and paperboard |
| EU Regulation (EC) No 1935/2004 | Framework regulation for food-contact materials; no direct food contact implied |
| REACH Regulation (EC) No 1907/2006 | Registration and safety data sheet obligations for industrial chemical supply |
| RoHS Directive 2011/65/EU | Not intended as a finished electrical/electronic product; not assessed for final EEE content |
During bulk handling, local exhaust ventilation should be used near opened drums and day tanks because water vapor and trace siloxanes can create slippery floors and may form mists. Operators should use chemical-resistant gloves and safety glasses. A safety shower and eyewash station should be accessible in the unloading area. Spill cleanup should use inert absorbent; water spray should be avoided because it creates a slippery surface.
