Section
| HS Code | 216087 |
| Appearance | milky white homogeneous liquid |
| Active Silicone Content | 30% |
| Viscosity 25c | 1500-3500 mPa·s |
| Ph 1 Percent Solution | 6.0-8.0 |
| Density 25c | 0.95-1.05 g/cm³ |
| Emulsifier Type | non-ionic self-emulsifying |
| Ionicity | non-ionic |
| Water Dispersibility | forms stable translucent emulsion in water |
| Defoaming Efficiency | rapid foam knockdown and sustained foam suppression |
| Temperature Stability | stable up to 130°C |
| Storage Shelf Life | 12 months in sealed original container |
| Recommended Use Ph Range | 3-11 |
As an accredited KS-530 Self-Emulsifying Silicone Defoamer factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | Packaged in 25 kg plastic pails or 200 kg iron drums, with sealed lids for safe transport and storage. |
| Container Loading (20′ FCL) | 20′ FCL shipment of KS-530 defoamer: liquid, packed in drums/pails, secured on pallets, loaded safely with proper labeling. |
| Shipping | KS-530 Self-Emulsifying Silicone Defoamer ships in sealed drums or IBCs, protected from extreme heat, frost, and direct sunlight. Ensure containers remain upright and leak-proof. Transport as non-hazardous industrial chemical, with proper labeling and documentation. Store in cool, dry, ventilated area. Avoid contact with incompatible materials during transit. |
| Storage | Store KS-530 Self-Emulsifying Silicone Defoamer in its original, tightly sealed container in a cool, dry, well-ventilated area. Protect from direct sunlight, moisture, and frost. Recommended storage temperature is between 5°C and 35°C. Avoid contact with strong oxidizing agents. Under proper conditions, shelf life is typically 12 months from manufacture date. |
| Shelf Life | Shelf life is 12 months from manufacture when stored unopened in original containers, avoiding extreme heat or freezing. |
In waterborne styrene-acrylic and pure-acrylic architectural coatings, KS-530 is introduced at the letdown stage after pigment dispersion has passed a Hegman gauge reading of 5–6 and after the Cowles blade tip speed has been reduced to 5–10 m/s. The defoamer is metered at 0.05–0.25 wt% of total batch mass into a tank containing 25–40% solids and a Stormer viscosity between 90 KU and 105 KU. The self-emulsifying silicone component spreads across air–liquid interfaces in acrylic emulsion systems without generating the coarse oil slicks observed with non-emulsified dimethylpolysiloxane. The upper dosage is constrained by intercoat adhesion loss and by the formation of silicone-rich surfactant islands that reduce local surface tension below 28 mN/m and produce fisheyes in ASTM D4062 drawdowns. The lower dosage is constrained by microfoam retention in wet films applied at 250–400 µm thickness, where entrapped air bubbles fail to escape before the open time closes. The defoamer must remain shear-stable through airless spray application at 120–180 bar tip pressure while still permitting air release during film coalescence. In production, the material is pumped into the top of the letdown tank during the final 10–15 min of mixing at 200–300 rpm; post-addition agitation above 600 rpm is avoided because it can shear the emulsion into droplets below 2 µm and reduce long-term defoaming persistence. At addition levels above 0.35 wt%, the defoamer can interfere with associative polyurethane thickener networks, reducing low-shear viscosity below 85 KU and increasing roller spatter. At addition levels below 0.05 wt%, laboratory blender foam collapse under ASTM D3519-19 may remain acceptable, but production batches can retain microfoam after overnight storage because the defoamer is consumed during pigment dispersion and subsequent high-shear letdown. Compliance with EU 2004/42/EC Annex IIA for water-based interior matt wall paint requires VOC content below 30 g/L, so the solvent carrier in KS-530 must be included in the final VOC mass balance. Storage stability is reviewed at 50 °C for 30 days with periodic drawdown checks for gloss retention under DIN EN ISO 2813, sag resistance under ASTM D4400-18, and phase separation by centrifuge at 3000 rpm for 15 min. The end products are interior and exterior matt, satin and semi-gloss decorative coatings applied by roller, brush or airless spray, as well as elastomeric roof coatings and silicone-modified façade paints.
Water-based flexographic inks are recirculated from press sumps through chambered doctor blades and anilox rolls at line speeds up to 300 m/min. Foam is introduced by return-line turbulence, pump suction and air entrapment at deck joints. KS-530 is post-added to the finished ink at 0.1–0.3 wt% of liquid ink weight after pigment dispersion and before the final viscosity adjustment with water or acrylic emulsion. Addition during pigment grinding is avoided because the defoamer can reduce pigment wetting and extend bead-mill pass time beyond the designed 30–45 min. The defoamer must survive shear in enclosed doctor blade chambers where the ink film is metered at anilox cell volumes between 3 cm³/m² and 8 cm³/m² and then transferred to corona-treated BOPP or LDPE. Foam control in the sump is evaluated by a modified sparge test using a 1 L/min air flow through a glass frit, with foam height recorded after 60 s. A retention above 85% of initial sparge-time foam suppression after 60 min recirculation is typically required for centralised ink supply lines. The use level must not reduce ink surface tension below the substrate wetting threshold of 34–38 mN/m; otherwise pinholing and poor adhesion on film substrates are observed. Pressroom operators monitor flow cup viscosity with a 4 mm DIN cup; a change greater than 2 s after defoamer post-addition indicates incompatibility with the acrylic emulsion or coalescent package. The addition point is usually the return-side mixing tank, not the doctor chamber, to avoid concentration spots on the anilox surface. Food-contact packaging inks require positive-list verification before production use. The compliance checklist in Table 1 is applied when KS-530 is used in indirect food-contact flexographic or gravure inks.
| Regulation or standard | Testing or verification point | Operational boundary for KS-530 |
|---|---|---|
| FDA 21 CFR 175.300 | Resinous and polymeric coatings for food contact | Defoamer components must be covered by the regulation or separated by a functional barrier |
| EU Regulation 10/2011 | Overall migration limit 10 mg/dm² | Migration testing must be completed on the final print construction |
| Swiss Ordinance SR 817.023.21 | Positive list for printing inks | All silicone and emulsifier components must appear on the applicable positive list |
| EuPIA Exclusion Policy | Raw material exclusion list | No listed hazardous printing ink raw material is permitted |
End products include flexible packaging, wrappers, beverage cup stock and self-adhesive labels.
Jet dyeing machines running at liquor ratios between 1:5 and 1:12 with circulation flows of 2–4 L/kg·min and venturi pressure drops of 0.5–2.0 bar generate persistent foam that collects on the pump suction side. Foam reduces circulation flow, changes fabric lift speed and produces uneven dye uptake on cotton, polyester/cotton and nylon/elastane constructions. KS-530 is dosed at 0.05–0.2 g/L of bath volume through the chemical dosing tank before dye addition; for high-foam reactive dye systems, the dose is split with 50% at startup and 50% after 30 min of circulation. The self-emulsifying character prevents the free silicone oil droplets that cause hydrophobic spotting on fabric and silicone build-up on heat exchanger surfaces. In high-electrolyte dye baths containing up to 60 g/L sodium sulphate, the defoamer should be pre-diluted in 5 L of process water before injection to prevent localised emulsion breaking. The upper dosage is limited by deposition on fibre surfaces; fabrics subsequently treated with fluoropolymer water repellent finishes may fail wetting tests based on AATCC 193 if silicone residues exceed the finish-specific tolerance. The lower dosage is insufficient when the jet nozzle generates foam heights above 30 cm in a bench-top recirculation test. The main failure mode in jet dyeing is shear-induced foam suppression loss; defoamer droplets are stripped from the air–water interface as the circulation pump passes the bath through the venturi nozzle every 60–90 s. Split addition is used because the first dose controls foam during the initial dyeing ramp, while the second dose compensates for droplet coalescence under high shear. Colour fastness must be revalidated after defoamer addition using ISO 105-C06:2010 for domestic laundering and ISO 105-X12:2016 for rubbing. End products include knitted apparel, activewear, medical textiles and automotive seat fabric.
Blade coater supply tanks in paper mills are fed with coating colour containing ground calcium carbonate, kaolin, carboxylated styrene-butadiene latex and cooked starch. Foam accumulates in the return flow from the blade pan and in the machine chest; entrained air produces pinholes, skipped coating and blade streaks at machine speeds between 600 m/min and 1500 m/min. KS-530 is metered at 0.05–0.2 wt% based on dry coating solids after the starch cooker and after latex addition, before the final machine chest. Direct injection into the starch cooker is avoided because the silicone emulsion can break at temperatures above 80 °C and with prolonged dwell times beyond 60 min. The defoamer must deaerate without reducing sheet gloss measured by TAPPI T 480 at 75° by more than 2 points or reducing dry pick strength measured by IGT tester below the grade-specific minimum. Foam in the blade coater supply tank can also produce air entrapment that reduces coat weight uniformity, measured as a cross-direction moisture or coat weight profile variation greater than 0.5 g/m² at the reel. The defoamer should be added before the pressure screens; adding it after the screens can create silicone-rich regions that appear as gloss mottling on the coated sheet. Coated paper roughness is checked with ISO 8791-2; a change above 0.1 µm PPS after defoamer addition is investigated as a surface effect. In coated board for indirect food contact, the final coating must comply with FDA 21 CFR 176.170 and BfR Recommendation XXXVI where applicable. For this specific coating colour configuration, published data are limited; mill trial work should measure air content before and after defoamer addition with a Paar density meter or deaeration tester. End products include folding boxboard, label stock, inkjet paper and silicone release paper base.
High-pressure coolant delivery in machining cells generates foam when water-dilutable semi-synthetic and synthetic metalworking fluids pass through through-tool drill bushings and high-pressure pumps at 70–80 bar. Foam in the central sump reduces hydraulic pump efficiency, increases heat in the cutting zone and can cause starvation at the tool interface. KS-530 is added to the metalworking fluid concentrate at 0.02–0.1 wt% or directly to the working emulsion at 10–50 ppm active silicone. The self-emulsifying form disperses in oil-in-water emulsions with pH between 8.8 and 9.5 and does not require separate dilution before injection if the sump return flow is above 300 L/min. The defoamer must be evaluated for compatibility with amine-based corrosion inhibitors and triazine biocides because silicone emulsion droplets can adsorb onto fine swarf and be removed by central filtration. Systems with full-flow filtration below 10 µm should be monitored for differential pressure rise; if filter loading increases above 0.5 bar above baseline, the addition rate is reduced or the filter media changed. Foam tendency can be measured by a modified ASTM D892 sparge method with 5 min air flow at 94 mL/min; a stable foam head below 50 mL is generally targeted for machining aluminium and cast iron. In transfer lines with low point drains, gravitational separation of silicone emulsion is possible if flow stops for more than 8 h; sump recirculation should be restarted 15 min before machining to re-disperse the silicone. Concentrates containing KS-530 should be checked for freeze–thaw stability at -5 °C if stored in unheated warehouses. Compliance with TRGS 611, REACH and EU CLP applies to the diluted sump fluid; the defoamer must not introduce substances that change the hazard classification of the metalworking fluid. End products include gearbox housings, bearing rings, valve bodies and cast aluminium engine components.
Mesophilic anaerobic digesters operating at 35–40 °C with hydraulic retention times of 20–30 days can produce stable foam from proteins, fats and filamentous bacteria. Foam reduces active digester volume, blocks gas collection pipes and carries digestate solids into condensate traps. KS-530 is dosed at 1–5 ppm active silicone based on digester liquid volume through the recirculation line or the digestate feed inlet. Injection into the gas headspace is avoided because the product must be dispersed into the liquid phase to spread over foam lamellae. The addition rate is constrained by the low anaerobic biodegradability of silicone polymers; residual silicone can accumulate in digestate and in downstream dewatering centrifuges. The foam layer in a digester is not always homogeneous; filamentous foam from Microthrix parvicella can be more persistent and may require a higher dose than protein foam, but the upper limit remains governed by silicone accumulation. In such cases, mechanical foam suppression or sludge age adjustment is used alongside the defoamer to prevent reliance on chemical dosing alone. For digestate intended for agricultural use under Regulation (EU) 2019/1009, the defoamer additive must not introduce components that exceed contaminant limits or compromise the agronomic quality of the digestate. Biogas yield must be monitored with a gas flow meter and gas composition analyser before and after addition; any reduction above 2% in specific methane yield should trigger a re-evaluation of foam management strategy. Silicone deposits on gas blowers, moisture traps and gas analyser sensors are an operational boundary; gas-train inspection intervals should be shortened after first application. End products include renewable electricity from CHP, biomethane after upgrading, and digestate soil amendment.
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KS-530 Self-Emulsifying Silicone Defoamer is a nonionic silicone-based foam control agent supplied as an off-white flowable emulsion. The product combines a polydimethylsiloxane carrier, hydrophobic fumed silica, and a polyether-siloxane emulsifying system; the emulsifier arrangement is the functional basis of the KS-530 self-emulsifying designation. Foam suppression results from spreading of the silicone oil phase over aqueous foam lamellae, while the fumed silica particles displace surfactant species and bridge film interfaces. Release specifications maintain a nonvolatile content of 25–30 wt% (ISO 3251:2019, 105 °C, 3 h), a density of 0.98–1.02 g/cm³ at 25 °C (ISO 2811-1:2023), and a pH of 6.0–8.0 as a 10% aqueous dispersion (ASTM D1293-18). The product is not a simple silicone oil; conventional silicone emulsions often require pre-dilution under high shear to avoid oil slick formation, whereas KS-530 forms a milky water dispersion under moderate agitation.
The self-emulsification window is defined by the phase inversion of the silicone concentrate into a fine oil-in-water dispersion without mechanical homogenization. Neat viscosity is controlled between 500 and 1 500 mPa·s at 25 °C (ASTM D2196-20, Brookfield LVF, Spindle 3, 30 rpm) to permit pump transfer while reducing hard settling of fumed silica. The self-emulsification test is a dilution of 5 g product in 95 g deionized water at 25 °C; after 10 inversions and 30 min standing, the dilution should be visually homogeneous and show no free-oil layer above 1 mm. If the polyether-siloxane emulsifier fraction is low, the dilution separates into a clear serum and cream layer within 2 h, and the batch is rejected. Self-emulsification is not instantaneous; at 10 °C, full dispersion of a 5% dilution may require 45–60 min, while at 30 °C dispersion is complete within 15–20 min. Low-shear droplet sizes typically fall below 10 µm. If the product is added directly to a process stream without predilution, the concentrated silicone phase can form droplets above 50 µm; these may provide foam control but can also produce visible deposits on hydrophobic substrates. Predilution is therefore specified unless the process has sufficient in-line dispersion.
| Parameter | Acceptance range | Test method |
|---|---|---|
| Appearance at 25 °C | Off-white to light cream opaque emulsion | Visual, 100 mL glass |
| Nonvolatile content | 25–30 wt% | ISO 3251:2019 |
| Density at 25 °C | 0.98–1.02 g/cm³ | ISO 2811-1:2023 |
| pH, 10% dispersion | 6.0–8.0 | ASTM D1293-18 |
| Viscosity at 25 °C | 500–1 500 mPa·s | ASTM D2196-20 |
| Self-emulsification | No free oil above 1 mm after 30 min | Internal method, 5% dilution |
| Ionic character | Nonionic | Conductivity/zeta potential |
| Flash point, closed cup | >100 °C | ISO 1523:2002 |
| Cyclic siloxane content | <0.1 wt% total D4/D5/D6 | GC-MS |
| Shelf life in sealed container | 12 months at 5–40 °C | Internal stability protocol |
The cyclic siloxane content is controlled below 0.1 wt% total D4/D5/D6 because of REACH Annex XVII restrictions on wash-off products; although industrial defoamers are not always in the wash-off scope, many paper and textile formulations require this limit. The nonionic character prevents coagulation with most anionic sizing agents and optical brighteners; however, compatibility with cationic retention aids should be confirmed by jar testing at the target addition level. The product is not classified as hazardous under OSHA HCS 2012 or CLP Regulation EC 1272/2008 in the supplied form, but the safety data sheet must be consulted for specific labelling.
Storage and pumping require low-shear transfer because the fumed silica network is shear-thinning and the emulsion can be over-dispersed. In a 1 000 L HDPE tote, slow propeller agitation at 30–60 rpm is sufficient to resuspend settled silica after storage. Production-scale failures occur when centrifugal pumps with rotor tip speeds above 10 m/s are used for neat product transfer; the high shear fractures the emulsion droplets, causing silica separation on strainer elements. Air-operated diaphragm pumps with ≤ 1.5 bar discharge pressure and EPDM or PTFE wetted parts are preferred. For continuous dilution, a static mixer containing 10–20 elements downstream of the product injection point yields a uniform 1:10 to 1:50 dilution at pressure drops below 0.5 bar. Dilution water at 10–40 °C and hardness below 400 ppm as CaCO₃ gives a feed stable for 6–24 h; if hardness exceeds 400 ppm, published data for this specific product configuration is limited and jar checks are required.
Usage rates vary with surfactant concentration, air entrainment rate, and filtration conditions. For wastewater aeration basins, KS-530 is commonly fed as a 1–5 vol% dilution at 2–20 mg/L neat product relative to basin volume. The addition point is placed after the aeration basin outlet weir and before the clarifier feed channel; this avoids removal of the defoamer by bubble attachment in the high-turbulence zone. If the feed is injected directly into an air-sparged zone, the defoamer is stripped from the aqueous phase by bubble attachment, and foam control falls by 30–50% at the same dose. A submerged quill located 0.5 m below the liquid surface and 2 m upstream of the clarifier inlet baffle provides distribution without adding air. Batch-to-batch variance in influent surfactant load requires feed adjustment between 10 and 25 mg/L; fixed-dose systems may lose foam control during high-surfactant events.
In paper machine white water, the addition point is selected downstream of flotation deaeration and pressure screens but upstream of the fan pump, because pressure-screen slots expose diluted silicone droplets to high extension rates. Production-scale experience with comparable self-emulsifying PDMS/fumed silica systems on twin-wire formers shows that post-screen injection reduces forming fabric deposition compared with pre-screen injection at equivalent addition levels of 0.01–0.05 kg/tonne dry fibre. Pressure-screen slot velocities of 1–3 m/s can shear emulsion droplets below 1 µm, causing the defoamer to emulsify into the bulk water rather than remain at the air-water interface; this reduces foam control efficiency. Therefore, post-screen injection or a low-shear injection quill in the fan pump suction is used.
In jet dyeing machines operating at liquor ratios below 1:8, foam in the circulation pump reduces fabric movement and can create rope marks. KS-530 is pre-diluted in a side tank and added at 0.02–0.10 vol% on bath volume. Addition is made during the filling stage or during the heating ramp before bath temperature exceeds 80 °C; above 80 °C, the polyether-siloxane emulsifier can lose cloud-point solubility and the silicone phase may separate onto fabric. For metalworking fluid concentrates, addition levels of 0.01–0.05 wt% are incorporated under moderate agitation before the concentrate is diluted to service concentration. In alkaline cleaning baths at 60–80 °C and pH 10–11, foam knockdown is evaluated by ASTM D3519-19; initial screen levels of 10–20 mg/L are recommended, with stepwise adjustment because overdosing above 50 mg/L may produce visible oil droplets in spent cleaning liquors.
Comparative testing against mineral oil and polyether-modified siloxane defoamers under controlled foam generation is used to select KS-530 for long-persistence applications. Mineral oil defoamers typically provide fast bubble collapse but generate oil films on heat-exchanger surfaces and increase chemical oxygen demand by 100–500 mg/L per 10 mg/L dose in clean wastewater matrices. Polyether trisiloxane grades show rapid knockdown in aqueous surfactant solutions but hydrolyze at pH below 3.0 or above 9.5, which limits their use in caustic scouring or acid desizing. Conventional silicone emulsions have high active content but require high-shear dilution to prevent localized oil droplets and coating defects. KS-530 gives a fine self-dispersed droplet population without high-shear predispersion, and the fumed silica component provides residual foam suppression after the initial silicone spreading event. The free-oil concentration after 24 h in a 1% dilution is below visual detection, whereas mineral oil control samples show a measurable oil ring. This reduction in free-oil fraction lowers sheet-defect risk in papermaking.
Surface tension is a further differentiating parameter. Polyether trisiloxane grades depress static surface tension of a 0.1% dilution to 21–23 mN/m, which can over-wet paper surfaces and affect ink holdout. KS-530 at the same dilution does not reduce static surface tension below 25 mN/m, reducing printability side effects while maintaining foam persistence.
| Parameter | KS-530 | Mineral oil defoamer | Polyether-modified siloxane | Conventional silicone emulsion |
|---|---|---|---|---|
| Foam collapse time | 30–60 s | 20–45 s | 5–15 s | 60–120 s |
| Persistence after 4 h agitation | >80% initial foam suppression | 40–60% initial foam suppression | 30–50% initial foam suppression | 50–70% initial foam suppression |
| Free-oil separation in 1% dilution after 24 h | None observed | Visible oil ring | None | Visible silicone slick |
| Deposit/ring formation on glass | Low haze | Heavy oil film | Low haze | High silicone residue |
| pH stability limit in use | 3–11 | 4–10 | 3–9.5 | 4–10 |
The replacement of mineral oil defoamers by KS-530 is most justified in process streams where free oil creates deposition or where the foam source includes nonionic and anionic surfactants under alkaline conditions. Mineral oil grades lose activity in high-pH scouring liquors because the hydrophobic wax particles become solvated or saponified, and their carrier oil contributes to soil redeposition on fabric. Polyether-modified siloxane grades fail in the same environment through hydrolysis of the silicone-polyether backbone, producing silanol species that wet substrates and increase foam stabilization. KS-530 differs by using a polydimethylsiloxane backbone with limited hydrolysis below pH 11; however, continuous exposure to pH 12 at 80 °C for more than 6 h will degrade the silicone chain and reduce foaming performance. In hydrocarbon-free systems, mineral oil is excluded for flammability and VOC restrictions; KS-530 has a closed-cup flash point above 100 °C and is non-flammable under normal storage, but the product is not VOC-free because the emulsifier system may release trace volatiles in thermogravimetric tests.
Operational boundaries must be observed. The product is not intended for anhydrous solventborne or oil-based systems; self-emulsification requires water contact. In strong electrolyte brines above 15% NaCl or 10% NaOH, the polyether-siloxane emulsifier can salt out, producing free silicone oil droplets that deposit on filtration media. In bleaching circuits where free chlorine exceeds 200 mg/L, published data for KS-530 is limited, and plant trials are required before continuous use. The neat product should not be passed through fine filters below 100 µm because fumed silica aggregates can blind filter media and reduce feed rate. For food-contact paper and paperboard, the grade must be verified against FDA 21 CFR 176.210 and relevant EU food-contact regulations before use, because not all industrial defoamer grades are cleared for food-contact service. The product may reduce gloss in high-gloss aqueous coatings if used above 0.5 wt%; the lowest effective addition should be determined by drawdown tests over black glass panels.
