Section
| HS Code | 643307 |
| Product Name | DU-2368 Broad-Spectrum Fatty Alcohol Defoamer Emulsion |
| Appearance | Milky white liquid |
| Solid Content | 30%±2% |
| Viscosity | 500-1500 mPa·s (25°C) |
| Ph Value | 6.5-8.0 |
| Density | 0.95-1.05 g/cm³ (20°C) |
| Particle Size | 1-10 μm |
| Ionic Type | Non-ionic |
| Water Dilutability | Dilutable in water at any ratio |
| Shelf Life | 12 months from production date |
| Storage Temperature | 5-35°C |
As an accredited DU-2368 Broad-Spectrum Fatty Alcohol Defoamer Emulsion factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | DU-2368 defoamer emulsion is packaged in 55-gallon drums, 275-gallon totes, or bulk quantities for flexible industrial use. |
| Container Loading (20′ FCL) | 20′ FCL shipment of DU-2368 fatty alcohol defoamer emulsion, packed in drums, with secure palletization and proper hazard labeling. |
| Shipping | DU-2368 ships in sealed, corrosion-resistant drums or totes to prevent leakage and contamination. Store away from heat and incompatible materials. Transport as non-hazardous industrial emulsion, but secure upright during transit. Avoid freezing, extreme temperatures, and prolonged storage to maintain performance and stability. |
| Storage | Store DU-2368 in its original, tightly sealed container in a cool, dry, well-ventilated area away from direct sunlight, heat sources, and incompatible materials. Maintain temperatures between 5°C and 40°C to prevent freezing or separation. Keep containers upright and protected from physical damage. Use within manufacturer’s recommended shelf life, and follow all label, safety, and environmental guidelines. |
| Shelf Life | Shelf life is 12 months from manufacture when stored in original, unopened containers under recommended conditions. |
DU-2368 is introduced during the letdown phase of waterborne architectural coatings in which the defoamer must suppress air entrained by a high-speed disc disperser running at a peripheral speed of 18–25 m/s during a 30–45 min pigment grind. In a matte acrylic wall paint based on a styrene-acrylic binder with a pigment volume concentration (PVC) of 70–80%, the product is typically split-fed at 0.1–0.3 wt% on total formulation: 60% into the mill base and 40% after the final hydrophobic alkali-swellable thickener addition. The fatty alcohol emulsion dewets Plateau borders in the foam lamellae, and the hydrophobic carrier droplets coalesce with dispersed foam nuclei to produce bubble rupture without introducing mineral oil haze. Drawdowns on Leneta charts are evaluated under ASTM D4062 for leveling, and specular gloss is measured at 20°, 60°, and 85° with ASTM D523-14 to detect cratering, fisheyes, and gloss suppression. At addition levels above 0.5 wt%, compatibility failure appears as surface defects, particularly when the formulation contains high-solids styrene-acrylic emulsions or associative polyurethane thickeners with high hydrophobic modification. In such systems, late addition after thickener hydration is preferred because associative thickener networks can immobilize the defoamer at the air–liquid interface, reducing knock-down efficiency measured by ASTM E2407-04. Viscosity recovery after defoamer addition is recorded with a Stormer viscometer at 25 °C under ASTM D562-10; a shift greater than ±5 KU against the control batch triggers reformulation of the rheology package rather than increased defoamer dosage. The emulsion is not suited to solventborne alkyd coatings or water-reducible systems with co-solvent content above 15 wt%, because solvent partition strips the fatty alcohol from the aqueous phase and deposits hydrophobic residues on substrate surfaces and spray equipment.
In a 10 m³ glass-lined batch reactor producing a 55% solids styrene-butyl acrylate latex, residual monomer steam-vacuum stripping at 60–80 °C and 20–50 kPa absolute is limited by foam carry-over into overhead condenser lines rather than by heat transfer alone. When DU-2368 is post-added at 0.05–0.3 wt% on wet latex directly before stripping, the defoamer must withstand agitated dispersion with impeller tip speeds of 2.5–4.0 m/s without being subdivided into droplets smaller than 5 µm; such subdivision would reduce bridging capacity and allow microfoam to persist in the scrubber water. The emulsion is charged as a 1:3 dilution in demineralized water through a dosing lance below the liquid surface, which prevents surface foaming at the charge point. The stripping column pressure drop should not exceed 15 kPa under stable operation; a sustained increase above 25 kPa indicates foam carry-over that must be corrected by rate reduction or additional defoamer injection in 0.05 wt% increments. Overdosing beyond 0.5 wt% in latex stabilized with polyvinyl alcohol can destabilize the protective colloid shell, forming coagulum that is retained on 45 µm bag filters downstream. After stripping, residual monomer content is measured by gas chromatography, sieve residue is checked under ISO 4576, and defoamer influence on film defects is assessed by casting 200 µm wet films and inspecting under low-angle light. Viscosity is measured at 25 °C by ISO 2555; a deviation above ±500 mPa·s relative to the undosed latex indicates an emulsion interaction requiring adjustment of the surfactant package rather than further defoamer addition.
Blade coater trials at 700–1200 m/min on LWC basepaper with a calcium carbonate-containing coating colour at pH 8.5–10.0 and 58–62% solids demonstrate that entrained air in the recirculated coating colour reduces blade uniformity and creates pinholes in the finished sheet. DU-2368 is added continuously to the machine chest at 0.02–0.1 wt% on wet coating colour using a diaphragm metering pump; the addition point precedes the pressure screens but follows the starch and latex addition. Because the fatty alcohol defoamer is hydrophobic, addition directly into a high-shear jet mixer at 30–50 °C improves emulsification and avoids local surface film in the machine tank. Air content of the coating colour is monitored with an air content tester; a target of 0.3–0.8 vol% is maintained for blade runnability. Overdosing above 0.2 wt% reduces hold-out and causes blade scratches if undispersed droplets coalesce on the blade tip. In food-contact paperboard, the product must comply with FDA 21 CFR 176.200 and 21 CFR 176.170, and for EU end uses with BfR Recommendation XXXVI; migration testing follows DIN EN 1186 with a global migration limit of 10 mg/dm². The table summarizes compliance boundaries for coated board applications.
| Regulatory framework | End-use condition | Defoamer-related compliance requirement |
|---|---|---|
| FDA 21 CFR 176.200 | Aqueous coatings in paper and paperboard | Fatty alcohol defoamer may be used under good manufacturing practice; no functional barrier impairment |
| FDA 21 CFR 176.170 | Paper and board in contact with aqueous and fatty foods | Component extractives must not exceed food-type-specific limits |
| BfR Recommendation XXXVI | Paper and board for food contact | No sensory transfer; global migration 10 mg/dm² under DIN EN 1186 |
In waterborne pigment concentrates for flexographic and inkjet inks, the mill base is processed in a horizontal bead mill filled with 0.6–0.8 mm zirconia beads at a peripheral speed of 10–14 m/s, and product temperature rises from 20 °C to 45–55 °C during a 45–60 min dwell. DU-2368 added at 0.2–0.8 wt% on pigment concentrate before the mill can be mechanically degraded if the residence time exceeds 30 min; the emulsion droplets are sheared to submicron size, and the fatty alcohol core is redistributed into the surfactant phase, reducing its ability to spread on bubble lamellae. Split addition overcomes this limit: 60% pre-mill to control froth in the feed tank and 40% post-mill after a cooling pass through a plate heat exchanger. Foam height in the letdown concentrate is measured by ASTM E2407-04, with a target of < 10 mm initial foam after 60 s at 25 °C. Published data for this specific product under bead mill shear is limited; validation on a 1 L Eiger horizontal mill with a 0.5 L recirculation tank is required before production release. The grind fineness is checked with a Hegman gauge under ISO 1524, and material above 10 µm is rejected before ink letdown. Overdosing above 1.0 wt% in a waterborne flexo ink creates pinhole defects on polyethylene film after printing at 80 m/min and reduces colour strength by 2–5% when measured by a reflection densitometer.
Aeration basins in a food-processing wastewater plant with mixed liquor suspended solids of 6–10 g/L and dissolved oxygen below 1.0 mg/L create foam caps from extracellular polymeric substances and fatty acid soaps. DU-2368 is injected into the mixed liquor recirculation line at 5–15 ppm v/v using a solenoid diaphragm pump with a 1:10 dilution in plant water. The defoamer lowers surface tension locally, collapses the foam cap, and contributes less organic load than hydrocarbon-based foam control; COD contribution at 10 ppm addition is approximately 18–25 mg/L measured by ISO 6060. Foam suppression is confirmed by foam cap thickness reduction from 300 mm to below 50 mm within 10–15 min using a calibrated digital probe. Overdosing above 25 ppm may create oil-like surface films on secondary clarifiers and interferes with membrane ultrafiltration if the plant operates a membrane bioreactor; the threshold is lower in MBR systems because hydrophobic fouling of PVDF membranes accelerates under residual fatty alcohol droplets. In anaerobic digester feed lines, fatty alcohol defoamers are used only at the feed inlet and at < 5 ppm, because accumulation in the gas headspace fouls flare lines and pressure transmitters.
In waterborne acrylic PSA manufacture, air entrained during emulsifier addition and high-speed mixing of tackifier dispersions is transferred to the coating station, where microfoam in the adhesive film causes coat weight variability on siliconized release liner. DU-2368 is metered into the holding tank at 0.05–0.3 wt% on wet adhesive and mixed for 15–20 min with a low-shear propeller at 300–500 rpm; high-shear transfer pumps should be avoided immediately after addition because they can destroy the defoamer droplets before coating. Coating is performed with a comma coater or slot die at 20–40 m/min and a wet film thickness of 60–120 µm. Foam-related defects appear as fisheyes and irregular adhesive distribution, which are quantified by cross-web grammage difference under ISO 536 between coated and uncoated silicone liner. The defoamer is compatible with rosin ester tackifier dispersions but may reduce shear adhesion if added above 0.5 wt%; the fatty alcohol droplets migrate to the adhesive–release liner interface and can act as internal release points. In label stock production, loop tack is evaluated under FINAT FTM 8, and FINAT FTM 1 is used for peel adhesion on stainless steel; a loss of more than 5% against an undosed control indicates a compatibility issue requiring defoamer replacement or dosage reduction.
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DU-2368 is a water-borne defoamer emulsion based on long-chain fatty alcohols in the C12–C22 range dispersed as hydrophobic droplets in a nonionic/anionic emulsifier matrix. The product is introduced into aqueous manufacturing streams to destabilize surface foam at addition rates that typically fall between 0.05 wt% and 0.50 wt% of total liquid weight, depending on headspace aeration, surfactant load, and downstream filtration shear. Because the active matter is a fatty alcohol rather than a silicone or mineral oil, the emulsion provides broad pH compatibility from pH 3 to pH 11 and can be used at process temperatures between 10 °C and 90 °C. The supplied form is an off-white liquid with a non-volatile content controlled to 24–28 wt% by ISO 3251 (105 °C, 2 h), and the product does not intentionally contain silicone, mineral oil, or APEO-based emulsifiers. In high-shear transfer systems, the emulsion must be metered after the last high-shear device because prolonged exposure to rotor-stator mixers above 500 s⁻¹ can reduce droplet size and shift the defoaming mechanism from rapid foam rupture to slow surface equilibration.
Lot-release testing separates active content, emulsion viscosity, and particle-size distribution. Viscosity is measured at 25 °C with a Brookfield RVT viscometer, spindle 2, 20 rpm; values outside the 500–1500 mPa·s band generally indicate either post-manufacture settling or premature coalescence. Density is 1.00–1.05 g/cm³ by ISO 2811-1, and pH as supplied is 6.5–8.5 by ISO 976. Median droplet diameter is controlled to 2–8 µm by ISO 22412 dynamic light scattering. Droplets above 15 µm are screened out because they cause visible oiling on the surface of clear waterborne coatings.
| Property | Test method | Typical lot value |
|---|---|---|
| Non-volatile content | ISO 3251, 105 °C, 2 h | 24–28 wt% |
| Viscosity | ISO 2555, Brookfield RVT, spindle 2, 20 rpm, 25 °C | 500–1500 mPa·s |
| pH as supplied | ISO 976, 25 °C | 6.5–8.5 |
| Density | ISO 2811-1, 25 °C | 1.00–1.05 g/cm³ |
| Median particle diameter | ISO 22412 dynamic light scattering | 2–8 µm |
| Ionic character | Supplier certificate of analysis | Nonionic/anionic |
Batch-to-batch variation in active content is controlled within ±1.5 wt% through in-process solids monitoring on the emulsification line. In a production-scale vessel of 5,000 L with bottom-entry high-shear dispersion at 1,500 rpm, over-processing can shift D50 below 2 µm and produce an emulsion that passes specification but exhibits slower defoaming in air-entrained coating lines. Published data for this specific configuration is limited; the effect is inferred from droplet-size influence on foam-film penetration.
In aqueous foam-control applications, the product is dosed either neat or after dilution to 1–5 wt% active solids in ambient process water. The emulsion functions by depositing insoluble fatty alcohol droplets at the gas-liquid interface. These droplets penetrate the foam lamella, displace adsorbed surfactant, and create a local surface tension gradient that thins the film below its rupture thickness. The droplet does not need to spread over the entire bubble surface; a partial wetting state with a low contact angle is sufficient to destabilize the pseudo-emulsion film. For this reason, DU-2368 is effective against macrofoam in air-entrained paper stock, pigment slurries, polymer dispersions, and recirculating metalworking fluids. The product is less suited to microfoam in high-gloss clear coatings because complete air release may require a secondary silicone or polyether defoamer with slower surface equilibration.
The primary difference is not simply active chemistry but the way the droplet enters and breaks the foam film. Silicone defoamers usually produce a very low surface tension and spread rapidly; this gives fast knock-down but can also create craters, fish eyes, or gloss loss in waterborne coatings when overdosed. Mineral oil defoamers often contain hydrophobic silica and can persist in the system, but they may raise the coefficient of friction in papermaking or leave oily residues on metal surfaces. DU-2368 occupies an intermediate position: the fatty alcohol droplets give rapid knock-down without the extreme surface tension suppression associated with polydimethylsiloxane, and the emulsion leaves lower organic residue than a mineral oil formulation. The broad-spectrum designation reflects the ability to function across surfactant classes, including anionic, nonionic, and amphoteric systems, without requiring a specific cloud point to trigger activity.
| Comparative property | DU-2368 fatty alcohol emulsion | Silicone emulsion | Mineral oil defoamer | Polyether defoamer |
|---|---|---|---|---|
| Knock-down speed in surfactant foam by ASTM E2407 jar test | Rapid | Rapid | Moderate | Moderate |
| Persistence under sustained aeration | Moderate | Moderate | High | High |
| Surface defect risk in waterborne coatings | Low to moderate | Moderate to high if overdosed | Low to moderate | Low |
| Effective pH tolerance | 3–11 | 2–12 | 5–10 | 3–13 |
| Volatile organic potential | Low | Low | Moderate | Low |
| Typical use level in waterborne coatings | 0.1–0.5 wt% | 0.01–0.1 wt% | 0.1–0.3 wt% | 0.1–0.4 wt% |
Representative values shown in the comparison are drawn from supplier literature and should be confirmed for the specific formulation. The difference in use level matters in cost-sensitive operations: silicone grades are often dosed at one-tenth the concentration of a fatty alcohol emulsion, but the risk of surface defects in pigmented coatings may require additional test panels and lower upper limits. DU-2368 is therefore selected when broad compatibility and low defect risk are more important than minimum addition rate.
In papermaking, the emulsion is normally metered on the suction side of the fan pump at 0.05–0.30 wt% of dry furnish, after retention aid but before the headbox screen. The objective is to lower air content in the headbox below 0.5 vol% on high-speed fourdrinier or gap-former machines; production-scale machines with wire speeds above 800 m/min typically require a continuous metering pump rather than batch addition. Air carried into the forming zone reduces dewatering uniformity and produces pinholes in the wet sheet. Published field data for DU-2368 in this exact configuration is limited; therefore start-up should be conducted with a calibrated flow meter and a headbox air-content meter.
In waterborne coatings, the product is added after pigment dispersion and letdown, usually at 0.1–0.5 wt% of total paint weight. If the product is added before the grinding stage, the high shear can over-emulsify the fatty alcohol and reduce defoaming efficiency. High-speed dispersers operating at 1,000–3,000 rpm are acceptable for post-add mixing, but the emulsion should not be circulated through a horizontal bead mill. In recirculating metalworking fluids, dosing is often controlled by tramp oil loading and hard-water soap formation; a typical maintenance dose is 0.01–0.10 wt% of sump volume. The product is not intended for use in solvent-borne or anhydrous systems because the continuous water phase would separate.
Storage and handling constraints are operational boundaries that determine whether the emulsion remains stable. The product should be stored between 5 °C and 40 °C. Freezing can destabilize the emulsion; if frozen, the material must be warmed to 25 °C and agitated gently at 150–300 rpm until homogeneous. Avoid mixing with strong cationic flocculants or high-alum process water at pH above 7, because charge reversal can break the emulsion and form floating fatty alcohol agglomerates. For food-contact paper and paperboard applications, compliance must be confirmed against 21 CFR 176.170 and 21 CFR 176.180 for the final article; product composition alone does not constitute regulatory clearance. The product is not classified as a hazardous mixture under typical OSHA HCS criteria, but local wastewater discharge limits for fatty alcohol residues should be evaluated before plant-wide use.
