| HS Code | 824524 |
| Product Type | Redispersible Polymer Powder for Rapid-setting Self-leveling |
| Chemical Base | Vinyl acetate-ethylene copolymer |
| Appearance | White free-flowing powder |
| Bulk Density G Per L | 450-600 |
| Particle Size | D50 40-80 microns; ≥98% passing 100 mesh |
| Redispersibility | Forms stable milky dispersion when mixed with water |
| Ash Content Wt Percent | 10-15 |
| Moisture Content Wt Percent | ≤2 |
| Ph Of 10 Percent Dispersion | 6.5-8.5 |
| Minimum Film Forming Temperature Deg C | 0-5 |
| Glass Transition Temperature Deg C | -5 to 5 |
| Effect On Self Leveling | Improves flow, leveling, and surface finish without segregation |
| Effect On Early Strength | Enhances adhesion and flexibility while maintaining rapid-setting behavior |
As an accredited RDP for Rapid-setting Self-leveling factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | RDP for rapid-setting self-leveling compound is packaged in 25 kg moisture-proof laminated kraft bags with inner polyethylene lining. |
| Container Loading (20′ FCL) | RDP for Rapid-setting Self-leveling is packed in palletized bags and loaded into a 20-ft FCL for safe, secure transport. |
| Shipping | Shipped as moisture-proof RDP in 25 kg composite bags, palletized and stretch-wrapped for export. Store in a cool, dry, ventilated area below 30°C, away from direct sunlight and pressure. Keep sealed; shelf life 12 months. Non-hazardous, safe for standard freight transport. |
| Storage | Store RDP (redispersible polymer powder) in a cool, dry, well-ventilated area, away from direct sunlight and moisture. Keep containers tightly sealed when not in use to prevent caking or degradation. Avoid high humidity and temperature extremes. With proper storage, shelf life typically remains 6–12 months. |
| Shelf Life | Shelf life is 12 months from manufacture when stored unopened in original packaging in a cool, dry place. |
A rapid-setting self-leveling underlayment based on a ternary binder of calcium aluminate cement, ordinary Portland cement, and calcium sulfate is mixed at a water-to-powder ratio of 0.20–0.24 and applied at a thickness of 3–10 mm. In this system, redispersible polymer powder (RDP) releases primary polymer particles when the dry blend is introduced into mixing water under high shear. As hydration proceeds, the polymer particles accumulate around hydration products and fine aggregate surfaces; during the final drying phase they coalesce into a film that bridges capillary pores and microcracks. A vinyl acetate–ethylene copolymer with a minimum film formation temperature below 4 °C is required because film formation must occur without external heating at floor temperatures between 10 °C and 25 °C. The addition range of RDP in this underlayment is normally 2.5–4.0 wt% of total dry-mix mass. At additions below 2.5 wt%, crack bridging and adhesion to smooth concrete are insufficient under differential shrinkage conditions. Above 4.0 wt%, the 1-day compressive strength may fall below early foot-traffic requirements because the coalesced polymer phase separates early hydration products during the critical interlocking stage. Air entrainment from the polymeric protective colloid is controlled with a polyether siloxane defoamer at 0.05–0.15 wt%, keeping fresh mortar air content below 3.5 vol% when measured by EN 1015-7:1998. Fresh mortar flow is targeted at 140–160 mm after 10 minutes using the flow cone procedure in ASTM C1708/C1708M-19e1. RDP-induced viscosity increase is offset with a polycarboxylate ether superplasticizer at 0.2–0.5 wt%. Dry blending is performed in a twin-shaft compulsory mixer with a batch cycle of 3–5 minutes; low-shear drum mixers are unsuitable because they do not fully redisperse the polymer powder and can leave hard polymer particles in the wet mortar. The hardened layer functions as an underlayment for luxury vinyl tile, sheet vinyl, and rubber coverings, with surface regularity assessed under BS 8204-2.
| Property | Test method | Typical specification |
|---|---|---|
| Initial flow | ASTM C1708/C1708M-19e1 | 140–160 mm |
| Flow retention after 20 minutes | ASTM C1708/C1708M-19e1 extended hold | > 130 mm |
| Final setting time | ASTM C191-21 Vicat needle | ≤ 120 minutes |
| 28-day compressive strength | EN 13892-2:2002 / ASTM C109/C109M-20b | EN 13813 class C25–C35 |
| 28-day flexural strength | EN 13892-2:2002 | EN 13813 class F6–F7 |
| Pull-off adhesion to prepared concrete | ASTM C1583/C1583M-13 | ≥ 1.0 MPa |
| Fresh mortar air content | EN 1015-7:1998 | 2.0–3.5 vol% |
When calcium sulfate binders such as alpha-calcium sulfate hemihydrate and anhydrite replace cement as the principal binder, the redispersed polymer film forms in a nearly neutral pH environment, reducing alkali-induced hydrolysis of vinyl acetate units. Water demand is set by the specific surface of the calcium sulfate binder and by the protective colloid carried by the RDP; typical water-to-powder ratios remain between 0.20 and 0.25. The main processing boundary is the polymer-to-binder ratio. At RDP addition levels above 4.5 wt% of total dry mix, early compressive strength development may fall below the specified class because the coalescing polymer phase bridges calcium sulfate dihydrate crystals but also separates them during the critical interlocking stage, and final set time can shift beyond the rapid-setting window. Published data for this specific configuration is limited, but product-level technical data sheets commonly place the maximum RDP dosage at 4.5 wt% for rapid-setting calcium sulfate screeds. Retarding additives used to maintain flow between 20 minutes and 30 minutes are usually citric acid or protein-based; polyvinyl alcohol-protected RDP grades can interact with protein-based retarders and reduce flow retention if the batch is not pre-tested. The hardened screed must meet EN 13454-2:2019 classes for factory-produced calcium sulfate screeds. Residual moisture before installation of vapor-impermeable floor coverings must be below 0.5 CM-% by the calcium carbide method. Terminal use is as a levelling layer for ceramic tile, parquet, or resilient flooring over mineral substrates and old timber after application of an appropriate barrier primer.
On renovation sites where the existing surface is glazed ceramic tile or adhesive-contaminated concrete, a rapid-setting self-leveling compound containing 4.0–6.0 wt% RDP functions as a thin load-bearing repair layer, but only after mechanical removal of wax, grease, and weak adhesive films by shot blasting or diamond grinding. Bond to the prepared substrate is assessed by pull-off testing in accordance with ASTM C1583/C1583M-13; the minimum acceptable value is usually 1.0 MPa, with failure located in the substrate or in the repair mortar rather than at the interface. The higher polymer content changes the fresh mortar from a low-viscosity pumpable leveller to a more thixotropic material. Discharge flow must be verified by the ASTM C1708/C1708M-19e1 cone procedure, and water reducer addition may be increased by 0.1–0.3 wt% relative to standard cementitious self-leveling formulations to maintain an initial flow of 140 mm. Bituminous adhesive residues that cannot be fully removed require an epoxy or polyurethane barrier primer before the RDP-modified leveller is applied; direct application over uncured bitumen causes loss of adhesion and plasticizer migration into the new layer. The terminal product is a low-profile underlayment for luxury vinyl plank and ceramic tile where removal of the existing tile layer is not permitted or would increase floor height beyond door threshold limits. Batch-to-batch variation in RDP water absorption must be monitored because it changes water demand and can produce flow-retention drift greater than 10 mm between production lots when mix water is held constant.
Continuous mixing pumps that combine powder and water in a rotor–stator chamber are used for large-area rapid-setting self-leveling underlayments, but their shear profile must be sufficient to redisperse the polymer powder completely within the short residence time. Mixing water flow is controlled within ±1.5 % by a mass flow meter, and water temperature is held between 15 °C and 25 °C to prevent premature film coagulation or delayed hydration. Outlet consistency is checked every 10 minutes with the ASTM C1708/C1708M-19e1 flow cone; a drop from 150 mm to below 130 mm indicates that the rapid-setting reaction has advanced and the remaining hose material must be discharged. Air content after pumping should remain between 2.0 vol% and 4.0 vol% according to EN 1015-7:1998. High pump speed can draw air into the mixing chamber and create pinhole defects in the finished surface, while insufficient defoamer addition cannot counter the increased air load. The pump hose length is normally limited so that material does not remain under pressure beyond the published pot life of the formulation, which is typically 20–30 minutes at 20 °C. If the pump stops for more than 15 minutes, the hose and mixing chamber must be flushed because rapid-setting compounds cannot be re-fluidized by adding water after initial set has begun. The applied layer is usually 5–20 mm thick for commercial floor leveling. If a local depression exceeds 20 mm, the material is built up in two lifts with a primer between lifts because a single thick pour of rapid-setting RDP-modified leveller can trap heat and moisture and develop internal microcracking.
RDP-modified rapid-setting self-leveling underlayments placed over electric resistance heating mats or hydronic pipe grids are subjected to thermal expansion gradients between the heating element and the floor surface. A vinyl acetate–ethylene RDP with a glass transition temperature below 0 °C is selected for this application because the polymer film formed in the cement matrix must remain elastomeric during thermal cycling, absorbing strain at the aggregate–paste interface rather than transmitting it to brittle hydration products. The addition rate is usually 3.0–5.0 wt% of total dry mix. At the lower end, thermal cycling cracks can form around heating cables after repeated cycles between 20 °C and 50 °C, while at the upper end the 1-day compressive strength may be insufficient to protect the heating element from point loads during floor covering installation. The minimum cover over electric heating cables is typically 5 mm, but the flooring system designer may require a thicker cover for heavy wheel loads or high-density hydronic circuits. Before heating is commissioned, the leveller must be cured for at least 7 days and then heated gradually at no more than 5 °C per day to prevent moisture pressure from destroying the polymer film at the heating element interface. Published data for this specific configuration is limited; field verification should combine pull-off adhesion according to ASTM C1583/C1583M-13 after thermal cycling with visual crack inspection under EN 1264-4:2021 installation boundaries.
Pigmented decorative self-leveling toppings containing RDP are poured at 3–6 mm thickness and then sealed with a water-based polyurethane or epoxy topcoat, which requires the polymer film at the surface to be continuous but not tacky. Inorganic pigment addition at 0.5–3.0 wt% of total dry mix increases water demand and may change the air pore structure; the RDP and defoamer combination must be re-verified with EN 1015-7:1998 because small surface defects become visible under a glossy topcoat. The surface pH of the cementitious topping is buffered between 10 and 12; the RDP grade must resist alkaline hydrolysis during the first 24 hours of film formation or the sealed surface will show whitening and adhesion loss. Residual moisture before application of the topcoat must be measured by the calcium carbide method, with a common supplier limit of 2.0 CM-% for a non-breathable resin coat. Higher moisture causes delamination of the sealer and carbonation bubbles at the coating–mortar interface. A spiked roller is used immediately after pouring to release entrained air, but the working time for this operation is shortened by the rapid-setting binder; the roller must complete the full area within 15 minutes after discharge. The terminal finished floor is a sealed decorative topping for retail and exhibition spaces. Surface hardness after 24 hours is checked before topcoat application, and wear resistance is specified by the relevant EN 13813 class where the floor is exposed to rolling loads or foot traffic.
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Model designation RDP-RS 4.0 is a redispersible polymer powder for rapid-setting self-leveling compounds, based on a vinyl acetate/ethylene copolymer and stabilized with a polyvinyl alcohol protective colloid. The product is supplied as a free-flowing white powder, surface-treated with a mineral antiblocking agent, and identified by CAS 24937-78-8. It is intended for dry blending into calcium aluminate cement/calcium sulfate or portland cement/calcium sulfate self-leveling underlayments and toppings at 1.5–4.0% by total dry mortar mass. Higher addition levels above 5.0% are avoided because the protective colloid increases air entrainment and may delay early strength gain. Table 1 lists the release specification used for incoming quality control and formulation development.
| Property | Specification | Test method |
|---|---|---|
| Appearance | free-flowing white powder | visual inspection |
| Bulk density | 480–560 g/L | ISO 60 |
| Residue on 315 µm sieve | ≤2.0% | ISO 3310 |
| Glass transition temperature | -7 °C | differential scanning calorimetry |
| Minimum film formation temperature | 0–4 °C | ISO 2115 |
| Ash content at 1000 °C | 9–13% | ISO 3451-1 |
| pH of 10% redispersion | 6.5–8.5 | ISO 976 |
| Brookfield viscosity at 20 °C, 20 rpm | 200–800 mPa·s | internal method based on ISO 2555 |
During mixing, RDP-RS 4.0 redisperses in the gauging water to form a dispersion with a median particle size of 1–5 µm. As water is consumed by cement hydration and evaporation, the polymer particles deform and fuse into a continuous film that bridges microcracks and bonds to the prepared substrate. In a rapid-setting self-leveling compound, the powder is combined with fine quartz sand, calcium aluminate cement, portland cement, calcium sulfate, a polycarboxylate superplasticizer at 0.10–0.30%, a defoamer at 0.05–0.15%, and a lithium carbonate accelerator at 0.05–0.20% depending on ambient temperature. The powder contributes to flow without increasing the water-to-dry-mortar ratio above 0.24; the flow diameter under ASTM C1708 is typically maintained at 140–160 mm. If the defoamer is omitted, the polyvinyl alcohol colloid stabilizes fine air bubbles; air contents above 3.0% are associated with surface pinholes and reduced early compressive strength, although the exact strength loss depends on cement content and water ratio.
The limiting variable is the retardation caused by the polyvinyl alcohol protective colloid on the dissolution of aluminate phases. In control mixes based on high-alumina cement and calcium sulfate, initial set measured by ASTM C191 is often set at 30–45 min at 23±2 °C. RDP-RS 4.0 is intended to extend initial set by no more than 15 min at 3.0% addition; published manufacturer technical bulletins for this class of low-retardation VAE powder report an initial set extension of 5–15 min in calcium aluminate/calcium sulfate screeds, compared with 20–35 min for conventional VAE grades. These values are formulation-specific and must be revalidated when the cement source or accelerator dosage changes. The powder must be screened against the lithium carbonate accelerator because excessive accelerator reduces open time below 10 min, and the polymer film may not fully coalesce if the matrix sets before sufficient water evaporation has occurred.
The second limiting condition is redispersion speed in high-alkali solutions. Self-leveling compounds containing portland cement develop a pore solution pH above 13. The VAE copolymer is selected for hydrolytic stability in this environment, but no external standard method covers all polymer-grade differences; quality release therefore relies on the ISO 3451-1 ash content, ISO 2115 minimum film formation temperature, and a manufacturer-specific alkali immersion screening. If the powder is added directly to water before the cement, the colloid forms skins that clog pump screens; therefore the powder must be dry-blended first and the mixer sequence must include a high-shear phase of at least 45–60 s.
On installation sites, the mixed self-leveling compound is pumped through 25 mm or 35 mm hoses and discharged through a spreader bar or mixing head. RDP-RS 4.0 increases cohesive workability and reduces segregation of the fine sand fraction during pumping. Sieve retention on a 0.5 mm screen should be checked after the mixer; visible polymer skins indicate incomplete redispersion and are corrected by increasing mixing time from 45 s to 90 s or reducing the powder feed rate. Substrate preparation includes mechanical removal of laitance, vacuum cleaning, and application of an acrylic primer at 150–250 g/m². The primer must be tacky or dry but not fully crosslinked before application. Single-lift thickness from 3 mm to 20 mm is typical; thicknesses above 30 mm usually require aggregate extension or a second lift with a bonding primer. Early foot traffic is assessed by the project specification rather than by polymer film formation alone.
RDP-RS 4.0 cannot compensate for an improperly primed substrate or excessive residual moisture. Concrete substrates with a calcium carbide moisture reading above 4% CM may retard film formation at the interface and reduce tensile adhesion. A solvent-free acrylic primer applied at 200–300 g/m² is typical for absorbent substrates, but a glossy primer film blocks mechanical interlock and produces adhesive failure at the interface. Tensile adhesion is measured by EN 13892-8 on a 50 mm drill core. On prepared concrete substrates, values below 1.0 MPa at 28 days indicate unsuitable surface preparation, insufficient RDP dose, or premature drying. In gypsum-based systems, the powder modifies the crystalline matrix and reduces dusting, but it does not isolate cracks or bridge moving joints; a separate crack-isolation membrane is required where substrate movement is expected.
Over old ceramic tile, application is possible when the tile is well bonded and a suitable primer is used. The product is not formulated for continuous water immersion, and exterior installations without a wearing surface remain outside the intended use. The mixed compound should be placed only when substrate temperature is between 5 °C and 30 °C; outside this range, flow, setting time, and film formation become unpredictable. Storage conditions are limited to dry, sealed bags below 30 °C with a maximum inventory of 6 months. Bags exposed to relative humidity above 70% may develop clumping that reduces redispersibility and causes pump-screen blockages.
Rapid-setting self-leveling compounds rely on ettringite formation from the reaction of calcium aluminate cement and calcium sulfate. RDP-RS 4.0 must remain colloidally stable in the high-ionic-strength liquid phase during this reaction. Coagulation of the polymer dispersion creates stringy inclusions that reduce flow and form weak planes in the hardened screed. The polyvinyl alcohol stabilisation system is selected for electrolyte tolerance; however, published production data for this specific powder in a continuous mixer with 1000 kg/h output is limited. What is observed on manufacturing lines is that direct addition of redispersible powder to the gauging water produces lumping and blockage of 6 mm pump screens, whereas preblending the powder into the dry mortar avoids this failure. A low-shear paddle mixer operating at 300 rpm may need 90 s after water addition to achieve full dispersion; a high-shear colloidal mixer typically reaches a homogeneous state in 45–60 s.
Differences from other redispersible powders are primarily observed in the set-time window and the water demand response. Standard VAE powders used in tile adhesives and repair mortars often carry higher polyvinyl alcohol content and improve tensile strength in ordinary mortars, but they may delay rapid-setting systems beyond the 15 min allowance. Acrylic redispersible powders can provide greater water resistance and surface hardness, but they often increase water demand and require a 0.05–0.10% upward adjustment of polycarboxylate superplasticizer to maintain ASTM C1708 flow. Liquid polymer dispersions are not equivalent because they introduce additional water, require separate dosing, and may be susceptible to microbial contamination. RDP-RS 4.0 is selected when the formulation must remain dry-blended and the set time must stay within the narrow rapid-setting specification.
| Evaluation parameter | Standard method | Role in rapid-setting self-leveling validation |
|---|---|---|
| Flow diameter | ASTM C1708 | Confirms spread without vibration and detects water demand changes |
| Setting time | ASTM C191 | Quantifies set delay caused by polymer and accelerator interaction |
| Flexural strength | ASTM C348 | Measures film bridging and crack resistance |
| Compressive strength | ASTM C109 | Monitors strength reduction caused by polymer addition |
| Tensile adhesion of screed | EN 13892-8 | Evaluates bond to prepared concrete substrate |
| Wear resistance | EN 13892-4 | Assesses surface durability after film formation |
The powder is incompatible with strongly alkaline liquid amines added directly to the mixing water; such additives can destabilize the polymer dispersion and produce coagulation before the mortar is placed. It should not be combined with casein-based flow agents unless compatibility is proven, because casein may compete for calcium ions and alter setting behaviour. In calcium sulfate-based systems containing anhydrite, the powder addition should not exceed 3.0% unless the formulation includes sufficient polymer-compatible superplasticizer and defoamer; otherwise the surface may remain tacky under high humidity. Published data for this specific product in less common binder systems, such as magnesium oxychloride or phosphate cements, is limited; validation at the intended thickness and site conditions is required before production.
