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| HS Code | 972153 |
| Chemical Composition | Alkylene oxide block copolymer based on glycerol (GPE polyether) |
| Appearance | Colorless to pale yellow transparent liquid |
| Active Matter Content | ≥99% |
| Ionicity | Nonionic |
| Cloud Point 1 Aqueous Solution | 20-25°C |
| Ph 1 Aqueous Solution | 6.0-7.0 |
| Viscosity At 25 C | 500-1000 mPa·s |
| Specific Gravity At 20 C | 1.00-1.05 |
| Water Solubility | Soluble and dispersible in water |
| Surface Tension 0 1 Aqueous Solution | 32-38 mN/m |
| Foam Suppression Capability | Excellent long-lasting defoaming and antifoaming performance |
| Thermal Stability | Stable over a wide temperature range |
As an accredited Polyether Defoamer GPE-2020–GPE Type Polyether Defoamer factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | Polyether Defoamer GPE-2020 is packaged in sealed plastic drums, available in 25 kg or 200 kg net quantities with clear labeling. |
| Container Loading (20′ FCL) | 20′ FCL container loaded with Polyether Defoamer GPE-2020 (GPE type), drums secured, labeled, and stowed safely for transport. |
| Shipping | The chemical is shipped in sealed drums or IBC containers to prevent leakage. Ensure containers are labeled correctly and stored upright. Transport in dry, ventilated conditions, avoiding extreme heat or cold. Handle with care to avoid spills; use appropriate PPE. Non-hazardous, but comply with standard industrial shipping regulations. |
| Storage | Store in a tightly sealed original container in a cool, dry, well-ventilated area. Avoid direct sunlight, high temperatures, and freezing conditions (recommended 5–35°C). Keep away from oxidizers and incompatible materials. Prevent moisture ingress. Under proper storage, shelf life is typically 12 months. Ensure container remains closed when not in use. |
| Shelf Life | Shelf life is 12 months from manufacture when stored sealed in a cool, dry, ventilated area. |
In aerobic submerged fermentation vessels with 50 m³ to 120 m³ working volume, flat-bladed Rushton impellers at D/T ratios of 0.30–0.40, and air sparging rates of 0.6–1.2 vvm, headspace foam is generated from soybean meal, corn steep liquor, peptone, and extracellular lipopeptide biosurfactants. Uncontrolled foam on a 120 m³ fermenter displaces working volume, reduces titre productivity, and forces premature opening of exhaust filters; foam entering agitator shaft seals also raises contamination risk during 72–180 h antibiotic and industrial enzyme runs. GPE-2020 is introduced as a non-silicone polyether defoamer at 0.03–0.12% v/v based on initial batch volume, either as a sterilized adduct in the medium or as an aseptically metered shot after 8–24 h when foam height exceeds the headspace probe threshold. Addition before sterilization at 121°C for 30 min is acceptable because the EO/PO block structure retains defoaming activity after thermal exposure in pH 5.0–7.5 fermentation broths. Foam knockdown and persistence are normally assessed by ASTM E2407 using actual broth because synthetic media fail to replicate protein-stabilized foam films. Dosing above 0.2% v/v is not recommended in aerobic systems because excess polyether accumulates at the gas-liquid interface and reduces the volumetric oxygen transfer coefficient kLa, which can be measured by the dynamic gassing-out method. The terminal products include amino acids, organic acids, antibiotics, and industrial enzymes; for enzyme preparations intended for food processing, the formulator must verify that the specific GPE-2020 product complies with 21 CFR 173.340 defoaming agent provisions.
Alkaline fine paper machine white water carries rosin soap, oxidized starch, polyvinyl alcohol, and precipitated calcium carbonate, and this mixture stabilizes a fine-dispersion foam that persists on deaeration tanks, seal pits, and wire return legs. On a gap former running at 900–1,500 m/min, entrained air in the headbox must be held below 0.8 vol% to avoid pinholes, fiber flocculation, and loss of drainage. GPE-2020 is diluted to 0.5–1.0 wt% with 40–50°C water and dosed through metering pumps into the low-shear zone of the wire pit at 0.02–0.08 kg per tonne of dry furnish, with a secondary addition point at the headbox deaeration tank if air content remains above the target. The polyether defoamer collapses foam by reducing surface elasticity rather than by forming a high-viscosity surface film, which is technically relevant in alkaline systems containing calcium carbonate because mineral oil defoamers tend to form deposits with pitch and PCC. Overdosing above 0.10 kg/t dry furnish can interfere with internal sizing; Cobb values measured according to ISO 535 may rise by 5–10 g/m², and hydrophobicity on the forming fabric can reduce first-pass retention. Terminal output is woodfree uncoated fine paper and coated base stock. For food-contact paper and board, the defoamer component must be cleared under 21 CFR 176.170 or BfR Recommendation XXXVI according to the end-use exposure category.
High-shear pigment dispersion in low-VOC waterborne architectural coatings routinely entrains microfoam that survives letdown and causes pinholes, cratering, and gloss loss after airless spray application at 10–15 MPa. In a typical latex paint production sequence, a Cowles disperser operating at tip speeds of 8–15 m/s disperses titanium dioxide, calcined clay, and calcium carbonate in an aqueous binder system, and the resulting foam is subjected to a density recovery test after 10 min at 3,000 rpm. GPE-2020 is added as a split charge, with 50% of the total 0.10–0.30 wt% introduced during the grind phase after pigment wetting and the remaining 50% added during low-speed letdown below 3 m/s. The split addition prevents both macrofoam persistence in the grind and microfoam stabilization after thickener addition. The table below lists the minimum evaluation matrix for a polyether defoamer in architectural coatings. Because GPE-2020 is non-silicone, the incidence of fish-eyes is lower than with polydimethylsiloxane emulsions, but neat addition above 0.5 wt% can still reduce block resistance and scrub resistance because residual hydrophobic polyether migrates to the film surface.
| Evaluation parameter | Method | Equipment/condition |
|---|---|---|
| Foam knockdown and persistence | ASTM E2407 | Waring blender, 3,000 rpm, 25°C |
| Density recovery | ISO 2811-1 | Specific gravity cup, 100 mL, 25°C |
| Specular gloss | ISO 2813 | 60° geometry on 200 µm drawdown |
| Film defect assessment | ASTM D714 | 200 µm wet film, 25°C/50% RH |
| Low-shear viscosity | ISO 2555 | Brookfield RV spindle 3, 10 rpm, 25°C |
The terminal products are interior wall paints, exterior semigloss formulations, and construction primers. In exterior formulations exposed to 2,000 h of accelerated weathering, the defoamer must not reduce wet adhesion or early blister resistance; ASTM G154 QUV exposure is used to confirm that residual defoamer does not create surface haze after rain cycles.
Because spin finishes, yarn lubricants, leveling agents, and oligomer debris are carried into overflow jet dyeing machines where rope speeds can approach 600 m/min and liquor ratios are held between 1:8 and 1:15, foam generated in the dyebath can cause pump cavitation, uneven dye uptake, and visible rope marks when the fabric is transported through the jet venturi. Mineral oil defoamers form water-insoluble surface films that deposit in the heat exchanger and on the fabric, so a non-silicone polyether such as GPE-2020 is selected. The product is pre-diluted to 1.0–2.0 wt% with demineralized water and dosed at 0.3–0.8 g/L into the bath before dyes and leveling agents are added, with the machine circulating at low speed for 5–10 min. Above its cloud point, the polyether becomes finely dispersed and concentrates at the air-liquid interface, collapsing foam films without transferring silicone to the fabric. In disperse dyeing of polyester at 130–135°C, the defoamer must withstand high shear and elevated temperature; a pre-trial in a 10 kg laboratory overflow machine is required because the high-temperature bath can alter polyether solubility. In alkaline reduction clearing baths containing sodium hydrosulfite and caustic soda, foam control is often poorer because the electrolyte and reducing agent alter the cloud point and interfacial activity; additional dosing should be based on foam height measurement rather than fixed ratio. The terminal product is dyed woven or knitted apparel fabric, and textile processors must screen the formulation against the ZDHC MRSL v3.1 if the mill supplies brands requiring wastewater transparency.
Surfactant-laden industrial effluent discharged to a municipal activated sludge line generates non-filamentous foam on aeration basins and secondary clarifiers, and the foam can carry mixed liquor suspended solids over weirs, elevating effluent TSS above permit limits and reducing UV disinfection transmittance. GPE-2020 is applied as an emergency or continuous foam control agent at 1–5 mg/L based on influent flow, either by spray bar over the aeration basin surface or by metering into the mixed liquor channel upstream of the clarifier. The defoamer does not eliminate Nocardia or Microthrix parvicella filaments; it only reduces foam persistence at the surface, so return activated sludge wasting and F/M ratio adjustments remain necessary for biological foam control. Before full-scale use, a respirometry screening according to ISO 8192 is advisable because polyether defoamers can temporarily depress oxygen uptake rate at concentrations above 10 mg/L. GPE-2020 contributes chemical oxygen demand, and the increment should be quantified in the plant mass balance through DIN 38409 H 41 or Hach dichromate reactor digestion. The terminal product is municipal or industrial final effluent compliant with 91/271/EEC discharge limits. In membrane bioreactors, defoamer selection must also consider membrane fouling potential; a 24 h bench-scale filtration test on a 0.1 µm PVDF flat sheet using the plant mixed liquor provides a practical screen. Published plant-specific COD yield data for GPE-2020 in mixed liquor are limited; therefore the increment should be measured rather than taken from generic defoamer data.
After polymerization is complete in a 20 m³ stirred pressure reactor at 60–80°C and 2.0–4.0 MPa, vinyl acetate-ethylene copolymer dispersions contain residual vinyl acetate and ethylene that are removed by vacuum stripping; the stripping step generates stable foam because the dispersion contains protective colloids such as polyvinyl alcohol and hydroxymethyl cellulose. GPE-2020 is introduced during letdown after polymerization is complete, at 0.05–0.15 wt% of the dispersion, before vacuum stripping at 80°C and 0.03–0.05 MPa. Injection into the reactor during the nucleation stage is not permitted because the polyether can alter micellar nucleation and reduce shear stability of the final dispersion. After defoamer addition, air release is verified by measuring density recovery from a deaerated sample under 20 kPa vacuum. The dispersion is then filtered through a 100-mesh bag filter; excessive foam in this step leads to filter blinding and loss of production rate. Terminal products are waterborne adhesives, carpet backing compounds, and construction sealants. The final dispersion should be tested for viscosity stability according to ISO 2555 at 25°C after 30 days at 50°C because residual defoamer can soften polymer films if the addition exceeds 0.20 wt%.
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Supplied as a water-dilutable non-silicone block polyether, GPE-2020 is classified as a GPE-type polyoxyethylene–polyoxypropylene defoamer for aqueous process systems. The product does not contain polydimethylsiloxane or mineral oil. On supplier certificates of analysis, release limits are normally defined by appearance, pH, cloud point, density, Brookfield apparent viscosity, hydroxyl number, acid number, and water content. A clear to pale-yellow homogeneous liquid is expected at 25 °C. A 1% aqueous dispersion gives a pH of 5.0–7.0 when tested by ISO 4316. Cloud point, measured by ISO 1065 in a 1% aqueous solution, lies between 18 °C and 22 °C; this inverse-solubility threshold is the primary control variable for defoaming activity. Density at 20 °C determined by ISO 1675 is 1.01–1.03 g/cm³. Apparent viscosity at 25 °C measured by ISO 2555 is reported as 300–700 mPa·s. Hydroxyl number remains between 45 mg KOH/g and 56 mg KOH/g by ASTM D4274. Acid number does not exceed 0.5 mg KOH/g by ASTM D4662, and water content is below 0.5 wt% by ASTM D4672. The product is filled into 200 L high-density polyethylene drums or 1000 L intermediate bulk containers. Unopened storage life under 5–35 °C is normally 12 months. Published data for this specific configuration is limited beyond these release parameters.
In fermentation broths, the primary limitation of polydimethylsiloxane antifoams is the accumulation of siloxane oligomers on vessel internals, dissolved-oxygen electrodes, and downstream filtration membranes. The high spreading coefficient of PDMS produces rapid foam knockdown, but the residual hydrophobic film can reduce oxygen probe response and increase cleaning frequency in aseptic bioreactors. In paper machine wet-end chemistry, silicone carryover onto forming fabrics and press felts can create deposit-related sheet holes, poor sizing, and coating adhesion loss. GPE-2020 differs from silicone emulsion because its surface activity is governed by inverse solubility rather than by a dispersed oil phase. Below the cloud point, the polyether is water-soluble and contributes little interfacial activity. Above the cloud point of 18–22 °C, the polymer separates into a fine dispersed phase that enters the foam lamella and destabilises it. This phase transition allows the defoamer to be active in warm process water while remaining less likely to form a stable hydrophobic coating on metal, ceramic, or polymeric substrates.
| Parameter | GPE-2020 polyether | Silicone emulsion | Mineral oil defoamer |
| Active foam-control species | EO/PO block polyether | Polydimethylsiloxane | Mineral oil |
| Silicone content | 0 mg/kg | 100,000–300,000 mg/kg | 0 mg/kg |
| Cloud point in 1% water | 18–22 °C | Not applicable | Not applicable |
| Typical addition range | 0.01–0.3 wt% | 0.001–0.05 wt% | 0.05–0.5 wt% |
| Foam knockdown at 50 °C | Moderate | Fast | Slow-to-moderate |
| Persistent foam suppression | Moderate | High | Low |
| Deposition/fouling tendency | Low | High | Moderate |
| Water dispersibility above cloud point | Self-dispersible | Requires emulsion | Requires emulsion |
| Test method for comparison | ISO 696 modified Ross-Miles | ISO 696 modified Ross-Miles | ISO 696 modified Ross-Miles |
Surface tension values differ systematically across defoamer chemistries. Polydimethylsiloxane typically exhibits an equilibrium surface tension near 21 mN/m at 25 °C by ISO 304, while polyether defoamers in the GPE class are generally measured between 32 mN/m and 40 mN/m under the same condition. The lower surface tension of silicone gives faster spreading and rapid film disruption but also creates a stronger tendency to form residual hydrophobic films. The moderate surface activity of GPE-2020 restricts the thermodynamic driving force for coating metal, ceramic, and membrane surfaces while retaining sufficient spreading coefficient to bridge and thin foam lamellae. The associated Marangoni destabilisation is less aggressive than that of silicone, which is why the polyether exhibits moderate knockdown speed but lower deposit potential.
Fed-batch cultivation of filamentous organisms can generate stable foam that reduces working volume and forces early termination if uncontrolled. The polyether type is introduced downstream of the sterile filter because the dispersed phase is not sterile-filterable through 0.2 µm membranes. Peristaltic or diaphragm dosing pumps deliver an initial concentration between 0.01 wt% and 0.1 wt% of initial broth mass, and subsequent pulses are required during the run because some production strains partly metabolise the polyoxyalkylene chain. In mechanically agitated vessels, overdosing reduces the volumetric oxygen transfer coefficient and increases dissolved CO₂. The user should run a dynamic gassing-out kLa determination before and after defoamer addition; a change greater than 15% warrants dose reduction or delayed addition. Published data for this specific configuration is limited, so dose verification is required for each aerobic culture.
The inverse-solubility mechanism creates an operational window that is narrower than that of silicone emulsions. Below the cloud point, GPE-2020 remains largely dissolved and does not spread effectively at the air–water interface; at 18 °C or lower in dilute aqueous streams, foam knockdown is therefore weak. Above 50 °C, phase separation can become excessively rapid, producing large polymer-rich droplets with reduced interfacial coverage and increasing the risk of deposition on heat-transfer surfaces. The most stable response is usually observed between 25 °C and 45 °C in paper machine trays, flotation cells, and recirculating cooling basins. High shear should be controlled when the product is diluted on-line. A static mixer with 4–6 elements at 20–30 °C produces a suitable dispersion; direct steam sparging is not recommended because local temperatures above 80 °C can hydrolytically degrade the polyether and reduce hydroxyl number. Reported starting doses range from 0.02 kg/t to 0.20 kg/t dry fibre in papermaking and from 3 mg/L to 10 mg/L in recirculating cooling water. These ranges are starting points only and must be replaced by foam-cell results under actual process turbulence.
In jet dyeing of polyester and cotton blends, foam in high-turbulence dye baths can produce pump cavitation, uneven fabric wetting, and dye bath overflow. GPE-2020 is metered into the dye bath at 0.05–0.2 g/L, not into subsequent finishing liquor, because residual defoamer on the fabric can reduce hydrophilic finish pickup. A non-silicone polyether is preferred when the dyed fabric will subsequently be coated or laminated, since silicone contamination at the fibre surface can reduce adhesive bond strength. Compatibility with disperse dyes, reactive dye sodium sulfate concentrations, and carriers should be checked by a foaming test at the actual dyeing temperature using ISO 696 modified Ross-Miles. The defoamer should not be combined with concentrated dispersing agents before dilution; high local surfactant concentration can redissolve the cloud-point polymer and temporarily reduce defoaming until the temperature rises above the cloud point.
Falling-film evaporator recirculation loops expose defoamers to extended thermal stress and can concentrate non-volatile additives at the liquid–vapour interface. Because GPE-2020 contains no silicone, the risk of siloxane fouling on reverse-osmosis membranes and heat-transfer tubes is lower than with PDMS emulsions. The product is metered into the recirculation line at 2–8 mg/L with a diaphragm dosing pump, preferably after the recirculation pump discharge to avoid excessive shear. It is not compatible with concentrated hypochlorite or chlorine dioxide dosing solutions because oxidative cleavage of the polyether backbone reduces foam knockdown and may generate low-molecular-weight oxygenated species. The defoamer should be added separately from oxidizing biocide injection points. In zero-liquid-discharge facilities where distillate is reused, a foam-cell test using actual evaporator concentrate at the operating temperature should determine whether the dose must be reduced below 5 mg/L to prevent distillate total organic carbon increase.
At alkaline furnish conditions, mineral oil defoamers can reduce first-pass retention, increase wire and felt extractable hydrocarbon content, and create pinholes after calendering. GPE-2020 replaces the oil carrier with a polyoxyalkylene structure that does not leave a floating oil film on white water. Mill-scale substitution is normally evaluated at the headbox or wire pit after the centriscreen; introduction upstream of pressure screens can generate microfoam that survives screening and collapses too late to improve drainage. A feed point downstream of the screen is therefore preferred. The product is compatible with alkaline sizing systems, but its interaction with cationic starch and retention aids should be verified since high charge demand can immobilise the defoamer at fibre surfaces before it reaches the air–water interface. Foam-cell testing according to ISO 696 at 40 °C using actual white water establishes the required addition; sheet-level verification should include sizing degree by TAPPI T 530 and internal bond by TAPPI T 569 to confirm that residual defoamer does not interfere with interfibre bonding.
For food-contact paperboard produced with GPE-2020, the user must verify that the formulation meets the food-contact substance status applicable to the grade. Compliance with 21 CFR 176.170 and 21 CFR 176.180 is not automatic for all polyether defoamers; migration testing and supplier documentation are required for the specific addition level and furnish composition. In the European Union, the safety data sheet should be consulted for REACH registration and any restriction on polyoxyalkylene components. The product should not be mixed with strong oxidizing agents or with cationic biocides in concentrated form; dilution is required before blending with other wet-end additives.
