| HS Code | 615790 |
| Polymer Basis | Vinyl Acetate-Acrylate copolymer |
| Product Form | Redispersible polymer powder |
| Appearance | White free-flowing powder |
| Glass Transition Temperature C | -10 |
| Minimum Film Formation Temperature C | 0 |
| Elongation At Break Percent | 300 |
| Redispersibility | Excellent |
| Particle Size Um | 80 |
| Bulk Density G L | 450 |
| Ash Content Percent | 10 |
| Ph Value Of Dispersion | 7.0 |
| Water Resistance | Good |
As an accredited High Flexibility VAc-Acrylate RDP factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | Supplied in 25 kg multi-layer kraft paper bags with polyethylene liner, ensuring moisture protection and safe handling. |
| Container Loading (20′ FCL) | 20′ FCL loaded with 25kg paper bags on pallets, shrink-wrapped, ventilated, secured for safe transport of High Flexibility VAc-Acrylate RDP. |
| Shipping | High Flexibility VAc-Acrylate RDP ships as a free-flowing powder in moisture-protective multi-layer bags or 25 kg cartons, palletized and stretch-wrapped. Stow in dry, ventilated containers, protected from humidity and direct sunlight. Non-hazardous under normal transport; handle with standard industrial hygiene. |
| Storage | Store High Flexibility VAc-Acrylate RDP in a cool, dry, well-ventilated area, away from direct sunlight, heat sources, and moisture. Keep the original sealed packaging intact to prevent water absorption and caking. Avoid exposure to high humidity and heavy pressure during stacking. Under proper conditions, shelf life is typically 6–12 months. |
| Shelf Life | Shelf life is typically 6 months when stored in original, unopened packaging under cool, dry conditions. |
Large-format gauged porcelain tile adhesives formulated for low-porosity ceramic and thin-panel installations impose a specific set of constraints on the latex film that a high-flexibility VAc-acrylate RDP must form under alkaline cement hydration. In a dry mortar produced to EN 12004:2017 classification C2E S1 or C2E S2, the redispersible polymer powder is metered at 2.5–4.0 wt% of total dry mix, with the upper boundary reserved for heated screeds, mosaics over bituminous waterproofing, and gypsum-based substrates where differential expansion is highest. Field failure on low-porosity tile typically appears as interfacial debonding when open time exceeds 30 min without transfer of mortar to the tile back; this failure mode is reduced by the latex film’s re-wetting contribution in the upper dosage range. Deformability is verified by transverse deformation testing under EN 12002:2008, where S1 requires ≥2.5 mm and S2 requires ≥5.0 mm, and tensile adhesion is measured under EN 1348 after water immersion, heat ageing, and freeze-thaw cycling. The dry blend is homogenized in a twin-shaft paddle mixer with a high-speed chopper operating at 120–140 rpm main shaft and 900–1,200 rpm chopper, with jacket temperature not exceeding 45°C; the RDP is introduced after the premix of Ordinary Portland Cement, 0.1–0.5 mm silica sand, and calcium formate has been sheared for 180 s. At the application stage, a water addition of 21–23 wt% is adjusted to produce a stiff trowelable mortar with a wet density of 1.70–1.85 g/cm³, followed by a 5 min slaking interval and 30 s remix. The terminal product remains a 25 kg bagged cementitious adhesive; after hydration, the polymer film must retain elongation without exceeding the transverse deformation limits of EN 12002:2008 for the specified S1 or S2 classification.
In external thermal insulation composite systems, the basecoat adhesive and embedment mortar must maintain adhesion to expanded polystyrene and mineral substrates while absorbing wind suction, thermal shock, and hygrothermal cycles. High-flexibility VAc-acrylate RDP is dosed at 2.0–4.0 wt% of dry mortar for basecoat and adhesive formulations conforming to EAD 040083-00-0404 and the earlier ETAG 004 assessment route. The dry mix is manufactured in a horizontal ploughshare mixer with a filling ratio of 60–70%, blending for 8–10 min after the polymer powder is introduced; dust collection air velocity is set below 2.5 m/s to minimize fine particle loss. Bond strength measurements on expanded polystyrene boards are conducted under EN 1348 after dry, 7 d water immersion, and freeze-thaw cycling; typical acceptance uses ≥0.08 MPa dry and ≥0.03 MPa after hygrothermal cycles. Addition of the RDP above 4.0 wt% can reduce pull-off adhesion on hydrophobic XPS, as measured under EN 1348, because the polymer film lowers capillary re-wetting of the substrate surface, causing starved interphase regions at the mortar-foam boundary. The application process involves trowel-spreading the adhesive onto the insulation board or substrate in vertical strips, embedding a 160 g/m² glass fibre mesh into the wet basecoat at a nominal embedment depth of 1.5 mm, and closing the mesh with a second pass to achieve a total basecoat thickness of 3–5 mm. The terminal product is a cementitious dry-mix basecoat/adhesive packaged in 25 kg bags or silo delivery; its finished function is a planar load-transfer layer for EPS, mineral wool, or phenolic board insulation. Production failure modes include lumping of RDP when added to hot sand above 50°C, leading to polymer agglomerates that produce pinholes in the cured render and locally reduced mesh bond.
Pump-applied cementitious self-leveling compounds rely on a low-yield-stress rheology that must survive shear in continuous compounding equipment. High-flexibility VAc-acrylate RDP is incorporated at 3.0–6.0 wt% of dry mix for underlayments meeting EN 13813:2002 classes such as CT-C20-F4 or CT-C25-F5, with the exact dosage influenced by whether the binder system is a ternary blend of Ordinary Portland Cement, calcium aluminate cement, and anhydrite. For selected EN 13813 designations, the practical RDP dosage range and minimum mechanical performance are summarized below.
| EN 13813 designation | Minimum compressive strength | Minimum flexural strength | Typical high-flexibility VAc-acrylate RDP dosage |
|---|---|---|---|
| CT-C20-F4 | ≥20 N/mm² | ≥4 N/mm² | 3.0–4.0 wt% |
| CT-C25-F5 | ≥25 N/mm² | ≥5 N/mm² | 4.0–5.5 wt% |
| CT-C25-F6 | ≥25 N/mm² | ≥6 N/mm² | 5.0–6.0 wt% |
Dry production uses a twin-shaft compulsory mixer with a batch time of 6–9 min and a discharge temperature limit of 40°C. At the jobsite, the powder is fed through a continuous mixing pump at 19–23 wt% water; the slurry is placed at 3–10 mm thickness and immediately de-aerated with a porcupine roller. The polymer film coalesces during drying, but the open surface can remain tacky until relative humidity drops below 65% or surface moisture falls below 4 wt%; installing vinyl planks over a still-tacky membrane can trap moisture and cause adhesive breakdown. For levelers installed under moisture-sensitive vinyl floor coverings, the dosage conflict is between flexural strength and residual moisture resistance: raising RDP from 3.0 wt% to 6.0 wt% typically improves flexural strength from the F4 to F6 range but delays drying. If the polymer film forms on the surface, it can entrap free water and create osmotic blisters under polyurethane adhesives. Therefore, formulations targeting CT-C25-F6 may require a retarder package or calcium sulfate addition to maintain a 24 h trowel-to-covering window. Published data for the exact interaction between VAc-acrylate latex film formation and calcium aluminate cement hydration at RH > 75% is limited. The terminal product is a pumpable cementitious self-leveling underlayment powder for LVT, carpet, ceramic tile, and engineered wood flooring installation.
In structural repair mortars specified under EN 1504-3 class R4, high-flexibility VAc-acrylate RDP is used at 2.0–4.0 wt% of dry mortar to bridge microcracks in concrete substrates while maintaining the stiff load-transfer characteristics required for chloride-contaminated exposure. The dry-mix production line runs a spiral ribbon mixer at 8–12 min batch times with a vacuum loading step to limit entrained air to ≤3.0 vol%. On the repair site, the substrate is pre-saturated for 24 h to a saturated surface-dry condition, then the mortar is applied by trowel or wet-spray at 10–50 mm thickness; in overhead repairs the RDP content is kept at the lower end to reduce slump loss. Compliance testing under EN 12190 for compressive strength requires ≥45 MPa at 28 d for class R4, while adhesion to concrete is measured under EN 1542. Freeze-thaw exposure is evaluated using the relevant EN 13687 test series. An incompatibility arises when high-flexibility VAc-acrylate RDP is combined with amine-based hardening accelerators in high-early-strength mixes; the alkaline amine environment can plasticize the acrylic copolymer film and reduce early adhesion. The terminal product is a polymer-modified cementitious repair mortar for spalled concrete, edge repairs, ramp toppings, and structural patch applications, packaged in 25 kg bags.
Flexible cementitious waterproofing slurries applied beneath ceramic or stone tile often consist of a dry powder component and a liquid polymer dispersion. In this configuration, high-flexibility VAc-acrylate RDP is incorporated into the dry component at 4.0–8.0 wt% to reduce crack-bridging failure and improve adhesion to damp concrete, while the liquid component may still be required for low-viscosity application. The slurry is mixed with a slow-speed paddle at 400–600 rpm for 3 min to a workable homogeneous consistency, then applied by brush, roller, or notched trowel in two coats to a total wet-film thickness of 1.5–2.0 mm. Each coat is allowed to set until finger-pressure leaves no impression but the surface remains slightly tacky; bond failure between coats in production is commonly due to the first coat being allowed to dry completely. The cured membrane is tested under EN 14891:2017 for water impermeability and adhesion to ceramic tile adhesives, with crack-bridging requirements that vary by class. Application thickness above 2.5 mm can cause internal air entrapment and polymer-rich skinning, resulting in restrained shrinkage cracking under tile loads. The terminal product is a flexible cementitious two-component or dry-mix waterproofing membrane for balconies, showers, wet rooms, and damp concrete substrates prior to tile installation.
In cementitious grouts specified as CG2 WA under ISO 13007-3:2010, high-flexibility VAc-acrylate RDP is dosed at 1.5–3.5 wt% of dry mix to reduce water absorption and improve tensile strain capacity in joints between large-format tiles. The powder is produced in a double-helix mixer at 5–7 min dry blending; pigment and fine 0.1–0.3 mm quartz sand are pre-mixed before RDP addition to avoid colour streaking. At installation, water addition is set to 18–22 wt%, yielding a paste that is pressed into joints with a rubber squeegee at a 45° angle. The first wash is timed to begin when the grout loses surface wetness, typically 20–30 min after placement, using a hard sponge; premature washing removes latex-rich pastes and leaves low-polymer mortar at the joint face. The terminal product is a 2–5 kg or 25 kg bagged grout powder for joints from 1 mm to 8 mm. At RDP contents above 3.5 wt%, the cured joint can exhibit polymer migration to the surface under extended damp curing, producing a glossy film that differs in shade from the cementitious body and is difficult to remove without acid washing, which is itself incompatible with the acrylic film.
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High Flexibility VAc-Acrylate RDP, Type HFA-450, is a redispersible polymer powder based on a vinyl acetate–butyl acrylate copolymer with a polyvinyl alcohol protective colloid and 8–13 wt% mineral anti-caking component. The powder is intended for cementitious and gypsum-based dry mortars requiring crack-bridging elongation, low-temperature film coalescence, and adhesion to dense or non-porous substrates. Production-scale acceptance data for Type HFA-450 typically include bulk density 450–550 g/L, residue on a 63 µm sieve ≤ 2%, moisture content ≤ 1.0%, and pH 6.5–8.5 in a 10% aqueous dispersion. In a 0.5 mm neat film cured 28 d at 23 °C and 50% relative humidity, tensile strength is typically 2.0–3.5 MPa and elongation at break 350–500% when tested according to ASTM D638-14 Type IV. Principal applications include flexible ceramic tile adhesives, polymer-modified repair mortars, low-stress waterproofing membranes, EIFS base coats, and crack-bridging skim coats.
For the same polymer content, the VAc-acrylate backbone provides a lower glass transition temperature than standard VAE powders without relying on high ethylene pressure during polymerization. Differential scanning calorimetry of representative production samples shows a midpoint Tg of approximately –15 °C. The corresponding minimum film formation temperature is typically 0 °C. This combination allows coalescence at reduced temperatures and improves crack-bridging ability in thin-layer mortars, whereas many VAE RDP grades have MFFT values between 0 °C and 4 °C and exhibit higher modulus below 0 °C. Compared with pure acrylic RDP, Type HFA-450 shows somewhat higher water uptake after 24 h immersion and is not specified for permanent immersion or constant water contact without additional hydrophobic modification.
| Parameter | Value / Range | Test Basis |
|---|---|---|
| Bulk density | 450–550 g/L | ISO 60 |
| Residue on 63 µm sieve | ≤ 2% | ISO 787-7 |
| Moisture content | ≤ 1.0% | ISO 787-2 |
| pH of 10% dispersion | 6.5–8.5 | ISO 787-9 |
| Ash content | 8–13% | ISO 3451-1 |
| Glass transition temperature | –15 °C | ISO 11357-2 |
| Minimum film formation temperature | 0 °C | ISO 2115 |
Standard VAE RDP derives flexibility from ethylene units, which reduce crystallinity but also increase chain mobility in a way that is difficult to extend below –10 °C without sacrificing tensile strength. VAc-acrylate RDP uses an acrylate ester, typically butyl acrylate, to depress Tg and increase segmental mobility. The resulting polymer develops an elastomeric film at lower temperatures and retains elongation at break above 300% in neat film testing. This is a key difference from stiff VAE grades, which may show higher tensile strength but limited deformation before failure.
Styrene-acrylate RDP offers higher hydrolytic stability and lower water absorption, but its high styrene content can reduce adhesion to certain polar substrates and may require higher coalescence temperatures. The VAc-acrylate powder provides a compromise between the flexibility of pure acrylic RDP and the cost position of VAE systems. In cementitious matrices, Type HFA-450 is specified where deformation and crack-bridging are required without moving to a full acrylic system.
| Property | High-Flexibility VAc-Acrylate RDP | Standard VAE RDP | Styrene-Acrylate RDP | Pure Acrylic RDP |
|---|---|---|---|---|
| Glass transition temperature, DSC midpoint | –15 °C | –7 to +4 °C | –20 to –5 °C | –25 to –10 °C |
| Minimum film formation temperature | 0 °C | 0 to 4 °C | 0 to 5 °C | 0 to 5 °C |
| Neat film elongation at break, ASTM D638-14 | 350–500% | 50–200% | 100–300% | 200–600% |
| Water uptake, 24 h immersion | 15–25% | 20–30% | 10–20% | 5–10% |
| Adhesion to non-porous ceramic | moderate-high | moderate | moderate | high |
When dry-blended into a cementitious mortar, the RDP particles must redisperse and then coalesce as the mortar dries. Film formation is influenced by the initial storage modulus of the polymer, the rate of water loss, and the capillary pressure in the pore network. In mortar mixes with water-to-cement ratio below 0.40, coalescence can be incomplete if the polymer MFFT is near 0 °C and the substrate temperature is below 10 °C. The critical processing window is narrow: at 10–15 °C, Type HFA-450 forms a continuous polymer network only when the drying front remains synchronized with particle packing. Extremely rapid air movement at the surface, for example air velocity above 2 m/s, can lead to film rupture and reduced crack-bridging capacity.
During spray drying, primary latex particles are agglomerated and coated with an anti-caking agent. Upon mixing with water, the hydrophilic colloid releases the primary particles, yielding a dispersion with a median particle size of 1.5–3.0 µm as measured by laser diffraction. This size range enables penetration into capillary pores between cement grains. In contrast, a standard VAE RDP may have a similar particle size but a higher MFFT, so the particles may not coalesce as completely under low-temperature curing.
At addition levels below 2.0 wt%, the polymer phase is discontinuous and crack-bridging properties are not developed. Above 3.5 wt%, the polymer film may become continuous but can also entrain air and reduce compressive strength. In such formulations, defoamer dosage must be re-validated. The standard additions for flexible mortars are 2.5–4.0 wt% of total mix.
In C2TE-class tile adhesive production, a formulation containing 3.0–3.5 wt% High Flexibility VAc-Acrylate RDP is dry-blended with ordinary Portland cement CEM I 42.5 R, 0–1.2 mm silica sand, and 0.3–0.5 wt% cellulose ether. The mixed adhesive is tested per ISO 13007-2. Observed tensile adhesion strengths after 28 d standard cure are 1.2–1.8 MPa, after water immersion 0.8–1.2 MPa, and after heat ageing 0.8–1.1 MPa depending on substrate type. The high-flexibility polymer contributes to the transverse deformation requirement of S2-classified adhesives; measured deformation is typically 2.5–5.0 mm when tested according to ISO 13007-2. In production-scale mixing with a 200 L horizontal paddle mixer, sequential addition of sand, cement, RDP, and then light additives provides homogeneous dispersion without pre-sieving the RDP.
When the dosage exceeds 4.0 wt% in a flexible adhesive, the polymer phase increases the mix cohesiveness significantly. At 4.5 wt%, laboratory batches show a 10–20% increase in dynamic viscosity at 20 rpm spindle speed and an increase in air content from 3% to 6% unless a defoamer is added. At higher dosages, the wet density of the fresh mortar decreases and the open time may be extended, but tensile adhesion strength after water immersion may also decline because of increased water retention and slower drying. The upper practical dosage for Type HFA-450 in tile adhesives is therefore 4.0 wt% unless a full defoamer and rheology modifier re-optimization is conducted.
For polymer-modified repair mortars conforming to EN 1504-3 class R3, the RDP dosage is typically 2.0–3.0 wt% of the total dry mix. Flexural strength determined by EN 196-1 after 28 d is typically 6.0–8.0 MPa, while compressive strength is 30–45 MPa. The polymer addition reduces the dynamic elastic modulus and improves resistance to restrained shrinkage cracking. Long-term performance on production repair mortars indicates that crack width development in a restrained ring test can be delayed when the RDP content is increased from 1.5 wt% to 3.0 wt%, although the exact delay depends on cement type, water-to-cement ratio, and curing conditions. Incompatibility with high early strength calcium aluminate cement is not observed at this dosage; however, when ternary cement systems containing calcium sulfoaluminate are used, trial mixes must confirm that the RDP redisperses fully in the lower mixing water regime.
Type HFA-450 is supplied as a free-flowing powder and is added to the dry blend rather than pre-dispersed in water. Pre-dispersion in alkaline water above pH 11 is not recommended, because the polyvinyl alcohol protective colloid partially dissolves and the redispersed polymer can thicken before addition to the mix. Production trials show that adding the powder to the dry mixture before water avoids this problem. Strongly alkaline amines can also destabilize the redispersed latex and increase viscosity; compatibility testing is required when amine-based additives are present.
Production lots are packaged in 25 kg multi-wall paper bags with a polyethylene liner or in 500 kg big bags. Loss-in-weight feeders with a target accuracy of ± 5 g per 25 kg batch are adequate. In twin-shaft paddle mixers of 1,000 L capacity, a dry mixing time of 3–5 min after addition of all components provides uniform polymer distribution. Extended dry mixing beyond 15 min can generate static charges and fines segregation, especially in low-humidity conditions below 30% relative humidity. The powder should be stored in closed silos or bags at temperatures below 30 °C and relative humidity below 60%. Under these conditions, the product retains flowability for 12 months from the production date. When stored at 35 °C and 70% relative humidity, soft agglomerates can form within 4 weeks, increasing sieve residue above the specified limit.
In EIFS base coats, the RDP is typically combined with 0.2–0.5 wt% methylcellulose and 0.1–0.3 wt% polypropylene fibre. At a dosage of 3.0 wt%, the base coat shows improved impact resistance and lower water absorption when tested according to ETAG 004. The polymer bridges microcracks and improves adhesion to expanded polystyrene boards; pull-off adhesion values of 0.15–0.25 MPa with polystyrene substrate failure are commonly observed. However, published data for this specific high-flexibility VAc-acrylate grade in ETAG 004 configurations is limited, so formulation-specific testing remains necessary. The product is not used as the sole binder; cement provides early strength while the polymer contributes flexibility and adhesion.
For thin low-stress waterproofing membranes of 1.0–2.0 mm dry film thickness, the powder is formulated at 6.0–10.0 wt% with 0.5–1.0 mm aggregate and a water-to-powder ratio of 0.15–0.20. The cured membrane is flexible enough for crack-bridging over hairline cracks up to 0.2 mm when tested under ASTM C1305. Measured crack-bridging capacity depends on membrane thickness and polymer content; below 1.0 mm, the capacity is unreliable. The VAc-acrylate polymer is less water-resistant than pure acrylic RDP, so long-term water immersion exposure above 7 d is not recommended without a hydrophobic admixture.
