Section
| HS Code | 541627 |
| Appearance | Milky white liquid |
| Active Matter Content | 30% ± 2% |
| Viscosity At 25 C | 500–1500 mPa·s |
| Ph At 25 C | 6.0–8.0 |
| Density At 25 C | 0.98–1.02 g/cm³ |
| Solubility In Water | Dispersible |
| Ionic Character | Non-ionic |
| Flash Point Closed Cup | >100°C |
| Recommended Dosage | 0.1%–0.3% based on total formulation |
| Foam Suppression Speed | Rapid |
| Defoaming Efficiency | High |
| Compatibility | Compatible with waterborne acrylic, polyurethane, epoxy, and other waterborne systems |
As an accredited XP-350W High-Efficiency Polyether-Modified Silicone Defoamer for Waterborne Systems factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | XP-350W packaged in 25 kg plastic drums, ensuring safe handling, easy dispensing, and stable storage for waterborne system defoaming applications. |
| Container Loading (20′ FCL) | 20′ FCL loaded with XP-350W silicone defoamer in drums/pails, palletized and secured for safe waterborne systems transport. |
| Shipping | XP-350W ships in sealed drums or IBC totes via ground freight. Non-hazardous, but avoid extreme heat or freezing during transit. Keep containers upright and protected from damage. Ensure proper labeling and ventilation. Standard logistics with no special hazmat endorsement required. |
| Storage | Store XP-350W in a tightly sealed container in a cool, dry, well-ventilated area, away from direct sunlight, heat sources, and freezing temperatures. Ideal storage range is 5–35°C. Avoid contamination with water or other chemicals. Under proper conditions, shelf life is typically 12 months. Stir before use if separation occurs. |
| Shelf Life | Shelf life is 12 months from manufacture date when stored in original container at recommended temperatures. |
In architectural flat and low-sheen emulsion paints, air entrainment during the high-shear pigment dispersion stage lowers manufacturing throughput because the entrapped air increases the apparent viscosity measured by a Stormer viscometer under ASTM D562-10 and reduces the wet film density determined by ISO 2811-1:2016. XP-350W is added in two separate charges: 0.05–0.10 wt% of total formulation before the disperser is ramped to a Cowles blade tip speed of 15–18 m/s, then 0.10–0.20 wt% during the letdown phase under a propeller operating at 2–4 m/s tip speed. The polyether-modified siloxane backbone remains active across the pH 8.0–9.5 range typical of acrylic and styrene-acrylic latex binders and does not generate visible craters in dried films when assessed by ISO 2813:2014 measurements at 20°, 60°, and 85°. Terminal products include interior wall paints with a critical pigment volume concentration in the range 0.35–0.55 and exterior masonry coatings with a pigment volume concentration of 30–45%. Formulators targeting GB 18582-2020 VOC limits must verify that the carrier system in XP-350W does not contribute more than 2 g/L VOC at the upper addition boundary. In scrub testing under ASTM D6736-08, residual foam voids in the dried film reduce the number of cycles before failure because the microvoids act as stress concentrators. Published data for the exact XP-350W molecule is limited; the operational boundaries stated here are derived from general polyether-modified silicone defoamer behavior in latex paint matrices.
When an air-assisted airless spray line applies a direct-to-metal alkyd primer at 8–12 MPa atomization pressure, the pressure drop across the spray tip generates a microfoam population that remains in the wet film after flash-off and reduces adhesion to zinc-phosphated steel. XP-350W is post-added at 0.20–0.60 wt% of the total formulation after the mill base is cooled to 35–40°C, because addition during high-shear mixing at disperser temperatures above 55°C can reduce long-term foam control efficiency by irreversibly splitting the polyether-siloxane copolymer. The formulation is then filtered through a 60 µm mesh before transfer to the spray booth. In a baking schedule of 8–12 min at 140–160°C, the defoamer must not produce surface craters; this is verified by cross-cut adhesion according to ISO 2409:2020 and cylindrical bend testing under ISO 1519:2011. Typical terminal articles are agricultural machinery chassis coatings and steel office furniture finished in RAL 9002 and RAL 7016 shades. For European Union REACH compliance, the silicone content in the dry film is typically below 0.5 wt% and must be declared only if a specific local regulation requires migration analysis. Published data for XP-350W in two-component waterborne polyurethane direct-to-metal systems is limited; a compatibility trial using ASTM E2407-04 sparge testing is recommended before tank-scale implementation.
Waterborne acrylic and polyurethane dispersion inks are compounded in stainless steel mixing vessels with side-sweep agitation at 40–80 rpm and recirculated through inline filters; entrained air is not visually obvious until high-speed flexographic or rotogravure transfer produces pinholing and missing dots on polyethylene terephthalate or corona-treated polyethylene film. XP-350W is added in two stages: 0.03–0.08 wt% of the liquid ink before pigment dispersion and 0.05–0.12 wt% after viscosity adjustment to a flow time of 25–35 s on a DIN EN ISO 2431:2019 4 mm cup. The low dynamic surface tension of the defoamer must not be allowed to flush the ink from the engraving in rotogravure cells; this is evaluated by printing solid blocks and measuring density with a reflection densitometer across a 500 m roll. Terminal articles include surface-printed corrugated preprint and non-food-contact paper shopping bags. For packaging inks applied to food-contact board, migration of silicone species into the dry film must be assessed under European Union Regulation 10/2011 when the printed surface is used outside the functional barrier, and under FDA 21 CFR 176.170 for paper and paperboard components. Published data for silicone defoamer migration through overprint varnishes is limited; therefore a migration assay using GC-MS with a 10 ppb reporting limit is recommended before commercial use.
| Application segment | Typical addition level | Critical process variable | Validation standard |
|---|---|---|---|
| Architectural emulsion paint | 0.15–0.30 wt% total formulation | Cowles tip speed 15–18 m/s | ASTM D6736-08 |
| Direct-to-metal waterborne primer | 0.20–0.60 wt% | Post-add below 40°C | ISO 2409:2020 |
| Waterborne flexo/rotogravure ink | 0.08–0.20 wt% liquid ink | Flow time 25–35 s on 4 mm cup | DIN EN ISO 2431:2019 |
| Acrylic emulsion PSA | 0.05–0.20 wt% wet adhesive | Slot-die line speed ≤ 200 m/min | PSTC-16 |
| Paper and board coating color | 0.05–0.15 wt% on dry pigment | Blade coater speed up to 1,800 m/min | ISO 8791-4:2018 |
| Textile pigment padding liquor | 0.05–0.20 g/L pad bath | Nip pressure 2.5–4.0 bar | AATCC 61 |
During roll-to-roll slot-die coating of a waterborne acrylic pressure-sensitive adhesive, entrained air in the wet adhesive produces longitudinal streaks and stochastic dry patches on release liner when the line speed exceeds 120 m/min. XP-350W is incorporated at 0.05–0.20 wt% of the wet adhesive mass in a low-shear letdown tank at 20–30 rpm after the acrylic emulsion has been thickened with an associative polyurethane rheology modifier. The coated film is dried in a multi-zone air flotation dryer with zone temperatures from 80°C to 120°C; the defoamer must not depress loop tack by more than 5% when measured after 24 h conditioning under PSTC-16. Terminal products include clear labelstock for PET bottles and solvent-free mounting tapes. For indirect food contact, the cured adhesive layer is evaluated under FDA 21 CFR 175.105, with the silicone defoamer treated as an incidental component of the pressure-sensitive adhesive. Batch-to-batch viscosity drift is monitored by ASTM D2196-20 at 25°C, and foam knockdown is typically assessed by ASTM E2407-04 with a 200 mL sample volume. Avoid co-mixing with amine-neutralized rheology modifiers in the same tank before the pH exceeds 8.0 because premature adsorption onto the thickener particles reduces defoamer efficiency and can generate surface gel specks.
A coating kitchen running a Cellier tank with a blade coater at 1,200 m/min continuously recirculates a 60–68% solids suspension of clay and ground calcium carbonate through screens and a deaerator. Air that survives the deaerator becomes trapped in the wet coating film at the blade nip and causes streak defects that appear in the subsequent supercalender. XP-350W is added into the return line at 0.05–0.15 wt% based on dry pigment mass, which permits foam suppression without reducing the surface strength of the coated paper as measured by IGT pick tests using ISO 3783. The target Parker Print-Surf roughness is below 1.2 µm according to ISO 8791-4:2018. Terminal substrates include coated fine paper for sheet-fed offset printing and food-contact board with a mineral coating. For food-contact board, the finished article is tested under FDA 21 CFR 176.170 and EU Regulation 1935/2004; the silicone defoamer must not be present in the aqueous simulant at a concentration exceeding the method detection limit of 0.5 ppm unless a functional barrier is demonstrated. A defoamer with excessive wetting power can lower the contact angle of the coating color on the blade, resulting in coater spatter; therefore the formulation viscosity is held between 1,200 mPa·s and 1,800 mPa·s at 30°C by ASTM D2196-20.
At 2.5–4.0 bar nip pressure and 30–50 m/min line speed, foam accumulation in the trough of a pad mangle changes the hydrodynamic pressure drop across the nip and produces a center-to-edge shade difference in pigment-binder pad liquors because the entrapped air displaces liquor in the fiber capillaries. XP-350W is dosed at 0.05–0.20 g/L of the waterborne pad bath immediately before the trough is filled; a second equal dose is added only if the total liquor turnover time exceeds 45 min. The mangle applies a wet pick-up of 60–80% on 180 g/m² cotton-polyester poplin. Terminal goods include pigment-dyed shirting fabrics and spunbond nonwoven binders. Compliance with the zero discharge of hazardous chemicals framework requires screening the defoamer against ZDHC MRSL 3.1; finished textile articles must also meet the OEKO-TEX Standard 100 limits for dimethylsiloxane residues if the brand restricts cyclic siloxane migration. Published data for XP-350W in pad-dry-cure pigment coloration is limited; therefore a trough foam half-life test using the ASTM E2407-04 sparge apparatus at 40°C is recommended before commissioning.
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XP-350W is introduced as a high-efficiency polyether-modified silicone defoamer for waterborne systems. The siloxane backbone supplies low surface tension and rapid lamella destabilization; the polyether segment introduces controlled hydrophilicity through ethylene oxide/propylene oxide chain design. For polyether-modified silicone defoamers in this class, technical data sheets commonly report density in the range 0.99–1.05 g/cm³ at 25 °C, dynamic viscosity between 100 and 2000 mPa·s, and non-volatile content from 20 to 60 mass-%. Product-specific XP-350W values are stated in the manufacturer batch certificate of analysis. The material is intended for waterborne architectural coatings, wood coatings, flexographic inks, pressure-sensitive adhesives, and polymer-modified construction dispersions where high-shear air entrainment produces surface defects.
Aqueous formulation foam is stabilized by surfactant monolayers, bulk viscosity, and Marangoni-driven film repair. XP-350W functions by a bridging-dewetting mechanism in which the dispersed defoamer droplet enters the foam lamella, forms an oil-water-air contact line, and ruptures the film when the entering coefficient E and spreading coefficient S are positive. For a foam lamella with air-water surface tension 30–40 mN/m and a defoamer droplet surface tension of 20–25 mN/m, S is calculated as γf − γd − γfd, where γfd is the foam liquid-defoamer interfacial tension. Persistence in waterborne epoxy and acrylic formulations is limited by competitive adsorption from dispersants, pigment adsorption, droplet coalescence during storage, and high-shear droplet fragmentation. For this product class, typical addition is 0.1–0.5 wt-% of total batch. Defoamer efficiency is ranked by ASTM E2407 blender foam height and collapse time; residual foam under continuous air sparging is measured according to ASTM D3601. Batch-to-batch variance can be assessed by comparing density using ISO 2811-1 and viscosity using ASTM D2196.
During the pigment-grind stage in waterborne industrial coatings, the defoamer may be added before disperser startup, but the grind base has low viscosity and high surfactant competition. A Cowles blade operating at tip speeds above 18 m/s can shear the defoamer droplets and reduce knockdown persistence; defoamer droplets can also adsorb onto titanium dioxide and extend the grind time. For this reason, a portion of XP-350W is commonly split between the grind and the letdown, with the letdown fraction post-added under moderate agitation after final viscosity adjustment. The post-added fraction controls macrofoam generated by recirculation and drum filling, while the grind fraction suppresses air entrainment during pigment dispersion. When defoamer efficiency is screened by ASTM E2407, the test temperature and shear history must be reported; otherwise the ranking does not correlate with production-scale dispersion equipment. Published data specific to XP-350W in a split-feed protocol is limited.
Defoamer-related cratering in clear wood coatings is controlled by the final defoamer droplet diameter relative to the dried film thickness. In a 40 µm wet film, a defoamer droplet above 30 µm can protrude through the drying surface and create a crater or fish-eye. XP-350W is therefore post-added under controlled shear to break the defoamer to a droplet size below the film-building window. The polyether segment lowers interfacial tension against the aqueous serum and reduces the energy required for droplet break-up. A disperser speed of 800–1200 rpm for 15–20 min is used in typical waterborne clear wood coatings; this is not a product-specific recommendation but a class-processing window. After drawdown, specular gloss is measured with ASTM D523 and haze with ISO 13803. Intercoat adhesion after scuff sanding can be tested by ASTM D3359 cross-cut tape adhesion; published XP-350W-specific adhesion data is limited.
In semi-gloss styrene-acrylic emulsion paints, the optimal defoamer concentration is set by the competition between lamella rupture and surface-leveling defects. Polyether-modified silicone defoamers with high ethylene oxide content are more water-compatible and less likely to depress gloss, but their knockdown persistence decreases because partial solubility retains a fraction in the aqueous serum. At 0.05–0.20 wt-% addition, XP-350W may be evaluated for 20° and 60° gloss retention using ASTM D523; haze is measured with ASTM D1003 or ISO 13803. In contrast, pure polydimethylsiloxane defoamers with surface tension below 21 mN/m offer aggressive foam knockdown but can generate fish-eyes and recoat adhesion loss; mineral oil defoamers often require 0.5–1.0 wt-% and can reduce gloss and increase volatile organic content under EPA Method 24. Polyether-only defoamers lack the spreading pressure provided by the siloxane backbone and may be insufficient under high-shear air entrainment.
Where waterborne flexographic inks are recirculated through enclosed doctoring systems and return lines, foam is introduced by pump seals, mechanical agitation, and dissolved air release. The polyether segment of XP-350W exhibits a controlled cloud point, so as ink temperature increases from 20 °C to 40 °C in the print deck, partial dehydration of the polyether chains reduces solubility and increases the thermodynamic driving force for adsorption at the air-water interface. This reduces the dosage required to suppress pinholes on polyethylene terephthalate film. Ink drawdowns at 200–400 µm wet film thickness are inspected for pinholing after drying; foam persistence can be quantified by image analysis of pinhole count. The product class is typically evaluated at 0.1–0.3 wt-% of liquid ink. Because the product is silicone-based rather than mineral-oil-based, migration risk is assessed under EU 10/2011 compliance protocols for plastic food-contact materials.
Polyether-modified silicone defoamers exhibit inverse solubility in water. The ethylene oxide/propylene oxide chains are water-soluble at low temperature because of hydrogen bonding between ether oxygen atoms and water. Above the cloud point, the polyether chains dehydrate, the defoamer partitions away from the aqueous phase, and its adsorption onto foam lamellae increases. This means a grade optimized for ambient coil coatings may show different knockdown at 50 °C than at 20 °C. XP-350W should be selected by matching the cloud point of the diluted defoamer to the processing temperature. If the cloud point is too low, the defoamer may deposit on emulsion droplets and create seediness; if the cloud point is too high, a portion remains dissolved in the serum and may act as an additional surfactant, reducing coalescence. Phase separation in dilute waterborne media at 0.1 wt-% can be tracked with dynamic light scattering or a turbidimeter according to internal manufacturer methods; published XP-350W-specific cloud-point data is limited.
The following standard methods are relevant to the evaluation of XP-350W in waterborne systems. The acceptance criterion for each method is formulation-specific and must be established on the manufacturing line, not transferred from unrelated formulations.
| Standard designation | Measurement target | Application to XP-350W |
|---|---|---|
| ASTM E2407 | Defoamer effectiveness in aqueous media | Blender foam height and collapse time; knockdown efficiency ranking |
| ASTM D3601 | Foam in aqueous media | Residual foam volume under continuous air sparging; persistence |
| ISO 2811-1 | Density of liquids | Batch density consistency and drum-settling checks |
| ASTM D2196 | Rheological properties | Viscosity at defined shear rates for pump transfer and dosing |
| ASTM D523 | Specular gloss | Gloss retention after defoamer addition; compatibility check |
| ASTM D1003 | Haze and transmittance | Optical compatibility in clear waterborne coatings |
| ISO 13803 | Haze on paint films | Film clarity after drawdown |
| ASTM D3359 | Cross-cut adhesion | Intercoat adhesion after defoamer addition |
| ASTM C231 | Air content of fresh concrete | Defoamer effect in polymer-modified cementitious systems |
| EU 10/2011 | Food-contact plastics | Migration compliance for printed packaging |
Waterborne pressure-sensitive adhesives present a different defoamer constraint because the adhesive-air interface is also the surface that later wets a substrate or release liner. Polyether-modified silicone defoamers can migrate to that interface and alter peel adhesion. When XP-350W is evaluated in a waterborne PSA at 0.1–0.3 wt-% on adhesive solids, peel strength retention is measured using ASTM D3330 or ISO 11339. In polymer-modified cementitious mortars, the product may be evaluated at 0.05–0.15 wt-% on polymer solids to decrease entrained air while retaining the air-void system required for freeze-thaw resistance. Air content is measured according to ASTM C231 or DIN EN 12350-7. Published XP-350W-specific data for these construction formulations is limited; dosage transfer from paints is not technically valid because the ionic strength and surfactant load differ.
If XP-350W is post-added to a shear-thinning waterborne coating after final cellulosic or associative thickener addition, the available shear stress is lower than in the grind stage, and the defoamer may remain as large droplets unless mixing is correctly designed. A production tank with a dissolver disk diameter-to-tank diameter ratio below 0.3 may not generate sufficient bulk flow to distribute a low-viscosity defoamer through a thickened coating. In such cases, the material is diluted with formulation water at a ratio of 1:1 to 1:3 before addition to lower the droplet size and improve distribution. The mixing time is confirmed by visual absence of surface oil and by a stability panel after 24 h at 23 °C. No product-specific defoamer droplet-size specification is published for XP-350W; manufacturers commonly use focused beam reflectance measurement to verify that post-added defoamer is fully incorporated.
XP-350W is not recommended for sustained exposure to pH above 9 at temperatures above 50 °C, because the polyether linkage and silicone backbone can undergo gradual hydrolysis or oxidative degradation that reduces knockdown efficiency. Hard water with high calcium ion content can form fatty acid soaps from formulation surfactants; these soaps can destabilize the defoamer emulsion and produce seed formation. Fluorosurfactant-containing coating systems may alter the interfacial tension balance sufficiently that the standard spreading-coefficient calculation no longer predicts performance. Freeze-thaw stability of the diluted defoamer or the finished coating should be tested according to ASTM D2243; a defoamer that separates under freeze-thaw may still be reincorporated by mixing, but the particle size distribution should be rechecked. Batch-specific limits for XP-350W are stated in the manufacturer technical data sheet.
On a waterborne direct-to-metal primer line spraying at 180–250 bar with an airless pump, foam is generated by high-pressure atomization and by return flow from the diaphragm pump. In this type of production environment, XP-350W is evaluated as a knockdown and deaeration additive at 0.1–0.3 wt-% on total coating. Gloss retention is measured with ASTM D523; recoat adhesion is tested after 24 h at 23 °C using ASTM D3359. The polyether-modified silicone structure reduces the persistent oil film that pure polydimethylsiloxane grades can leave on the wet surface, while the silicone backbone provides a lower surface tension than polyether-only defoamers. Published XP-350W-specific direct-to-metal data is limited; the dosage and incorporation protocol must be confirmed by a production-scale trial.
