ELOTEX MP2070

A cementitious tile adhesive designed for porcelain and low-porosity ceramic tiles incorporates ELOTEX MP2070 as the sole redispersible vinyl acetate–ethylene copolymer powder at 2.5–4.0 wt% of total dry mortar mass. The starting formulation is based on CEM I 42.5 R at 35.0–40.0 wt%, silica sand 0.1–0.3 mm as balance, calcium carbonate filler at 5.0–15.0 wt%, methyl hydroxyethyl cellulose ether at 0.30–0.50 wt%, starch ether at 0.03–0.06 wt%, and a polycarboxylate-based accelerator at 0–0.30 wt%. The dry blend is produced in a ploughshare mixer at 20–30 rpm for 3–5 min; the powder bulk density of 450–650 g/L requires calibration of volumetric dosing augers on continuous filling lines. Water demand for a C2-class mix falls between 24 and 26 wt% of dry mix. Wet preparation uses a low-speed paddle mixer at 400–600 rpm for 3 min, followed by 2 min rest and 30 s remix. The redispersed dispersion remains compatible with Portland cement at pH 7–9.

With a supplier-listed minimum film formation temperature near 0°C, film coalescence proceeds under standard curing at 23°C after hydraulic setting removes free water. Compliance is verified under EN 12004 and EN 1348; tensile adhesion specimens are cured for 28 days at (23±2)°C and (50±5)% RH and conditioned for water immersion, heat ageing, and freeze-thaw cycles. A C2 classification requires adhesion of at least 1.0 N/mm² after each conditioning sequence. Loadings below 2.0 wt% commonly fail water-immersion adhesion on porcelain substrates, while loadings above 4.5 wt% entrain air and reduce early compressive strength. For large-format tiles, the upper dosage range is combined with a 10×10 mm notched trowel and back-buttering to keep void area below 5% of the tile surface.

Amine-based liquid accelerators should not be introduced into the dry mix without dispersion trials; localized charge reversal can destabilize the polyvinyl alcohol protective colloid before cement hydration. During application above 35°C substrate temperature, the open time measured by EN 1346 shortens, and paper-faced ceramic must be installed with a solid-bed technique to prevent skinning.

What Restricts Total Redispersible Polymer Content in Self-Leveling Underlayments Tested by EN 12706?

In calcium-aluminate-modified self-leveling underlayments, ELOTEX MP2070 is added at 1.0–2.5 wt% of total dry mortar to control surface dusting and improve flexural adhesion before installation of resilient floor coverings. The binder base typically combines ordinary Portland cement, calcium aluminate cement, and anhydrite or hemihydrate gypsum; the aggregate phase is 0.1–0.3 mm silica sand. Water-to-solids ratio is set at 22–28 wt%. Flow is evaluated with a flow ring having an internal diameter of 30 mm and height of 50 mm according to EN 12706; production formulations aim for an initial spread of 240–260 mm and a 20 min spread loss below 10 mm. Mixing is carried out in a continuous pin mixer at 500–700 rpm or a batch high-shear mixer, then pumped by eccentric screw pump at 6–12 L/min through a 10–15 mm hose. Entrained air is controlled with a mineral-oil or polyalkylene glycol defoamer; without defoaming, the upper polymer dose creates pinholes that appear only after moisture reaches the film phase.

The cured screed is classified under EN 13813, and flexural and compressive strengths are measured on 40×40×160 mm prisms by EN 13892-2. At 1.5 wt% MP2070, a typical formulation may retain CT-C20-F5 to CT-C25-F6 classification; raising the powder above 2.5 wt% increases air content above 3.0 vol% and creates a sharp compressive-strength reduction. Because the VAE film adsorbs onto hydrating cement grains and calcium aluminate phases, retardation is real and must be measured by Vicat needle under EN 196-3; published data for exact setting-time shifts with this specific powder across all binder ratios is limited, so plant-scale calibration is required.

The powder must be protected from ambient humidity above 60% RH. Bags exposed to a concrete floor can lump within 48 hours; silo discharge requires dry air at a dew point of −40°C to prevent arching and false flow. The finished underlayment is protected from draughts for the first 6 hours to avoid surface skinning before polymer film coalescence. A minimum substrate temperature of 10°C is required; below that, films remain brittle and the screed may not reach final hardness.

Polymer film coalescence in exterior base coats follows the same drying front that releases mixing water.

For exterior thermal insulation composite systems, ELOTEX MP2070 is incorporated into cementitious base coat mortar at 3.0–4.5 wt% of dry mortar to maintain adhesion to expanded polystyrene or mineral wool boards and to embed glass fiber reinforcement. The formulation uses CEM I 42.5 R, 0.1–0.5 mm limestone sand, cellulose ether, and a silane-based water repellent; water demand is held at 20–24 wt%. A first pass of 2–3 mm is applied to the insulation board, glass mesh of 145–160 g/m² is embedded by trowel pressure, and a second pass brings the total mesh-bearing layer to 4–5 mm. Mixing is performed in a forced-action paddle mixer at 400–600 rpm. Batch times longer than 5 min can shear the redispersed polymer and reduce crack-bridging capacity.

Crack-bridging and impact resistance are assessed under the relevant ETICS EAD; water vapour permeability is measured by EN 1015-19, and adhesion to insulation boards is assessed under the EAD pull-off method. Loadings below 3.0 wt% may produce brittle failure in crack-bridging specimens after freeze-thaw conditioning; loadings above 4.5 wt% increase trowel drag on EPS and reduce vapour permeability below the declared µ value. Continuous capillarity can soften the PVOH-stabilized film, so the base coat should be protected by a hydrophobic render or paint system. MP2070 is not recommended as the sole polymer for exposed base coats in permanently wet climates. The powder must be dry blended before water addition; direct addition to a high-speed mixer without aggregate dispersion causes agglomeration and mesh adhesion defects.

When MP2070 Is Placed in R2-Class Repair Mortar for Overhead and Vertical Profiles

When polymer-modified repair mortar is applied overhead at single-layer thickness between 10 and 40 mm, ELOTEX MP2070 is dry-blended at 1.5–3.5 wt% based on total dry mortar mass. The mix design uses CEM I 42.5 R or CEM I 52.5 N, 0.2–0.6 mm quartz sand, silica fume or metakaolin at 5.0–8.0 wt%, and a powdered polycarboxylate superplasticizer. The water-to-binder ratio is maintained between 0.12 and 0.15 to achieve thixotropy for overhead placement; the polymer redisperses and increases plastic viscosity, reducing sag without eliminating flow. Mixing is performed with a slow-speed mortar mixer at 300–500 rpm. Water is added in two stages to prevent balling of cellulose ether and MP2070.

Performance is specified under EN 1504-3 R2 class. Pull-off adhesion is measured by EN 1542 on concrete prepared by grit blasting to a minimum roughness of 50 µm; shrinkage is evaluated by EN 12617-4, and compressive strength by EN 12190. The polymer reduces shrinkage cracking and improves bond to low-porosity concrete but lowers compressive strength; compensation is achieved by lower water content rather than higher polymer dosage. Above 3.5 wt%, the mortar may retain excessive water and fail to achieve the early strength needed for overhead formless support. Continuous immersion is an operational boundary because the PVOH protective colloid can re-emulsify and soften the interfacial film; for permanent immersion, a styrene-acrylate or epoxy-modified system is normally evaluated. The powder should not be combined with aluminium-based expansion agents at high pH unless hydrogen gas evolution is quantified and controlled.

Tile Grout Viscosity Stability and Shrinkage Control at Low VAE Addition

Cementitious tile grouts compounded with ELOTEX MP2070 at 0.8–1.5 wt% are intended for joint widths from 2 to 8 mm. The powder is premixed with Portland cement, 0.1–0.3 mm quartz filler, iron oxide pigments, cellulose ether, and calcium carbonate extender; water demand is 22–25 wt%. The polymer phase stabilises the paste under repeated stirring in hot workplaces, but the dosage is deliberately low because polymer films in grout joints can lower microsurface hardness and make stain resistance dependent on film continuity.

Testing follows EN 13888, with abrasion resistance to EN 12808-2 and water absorption to EN 12808-5. At dosages above 2.0 wt%, the cured grout typically exhibits lower compressive strength and reduced abrasive wear resistance; water absorption may become film-continuity dependent. At 0.8 wt%, shrinkage cracking and colour wash-out are reduced without exceeding the water absorption limit. The powder must not come into contact with acidic cleaning residues or cationic pigment dispersions that can coagulate the PVOH-protected polymer. On ribbon-blender production lines, pigment and MP2070 are pre-blended for 90–120 s before cement is added to prevent colour streaking.

Gypsum-based joint fillers and skim coats accept ELOTEX MP2070 at 0.5–1.5 wt% of total dry formulation to reduce brittleness and bind calcium carbonate filler after the gypsum matrix has set. The powder is dry-blended with hemihydrate gypsum, limestone dust, methyl cellulose, and an organic retarder; water addition for joint filler is 38–45 wt% and for skim coat 30–38 wt%. Mixing uses a spiral or paddle mixer at 400–600 rpm for 2–3 min. Application is made in layers of 1–3 mm with a stainless steel trowel over plasterboard joints. Testing references EN 13963 for jointing materials and EN 13279-1 for gypsum plasters; adhesion to plasterboard is assessed after 7 days at (23±2)°C and (50±5)% RH.

The PVOH-stabilized VAE powder can delay final set in gypsum; retarder dosage is adjusted or calcium formate is added when the powder concentration exceeds 1.0 wt%. Because the film is water-sensitive, the filler is not suitable for continuously damp environments or as a substitute for cementitious waterproofing slurry. High ambient humidity above 70% RH during storage of dry mix can cause lumps and reduce redispersibility; opened bags should be re-sealed and used within 24 hours. Above 1.5 wt%, sanding dust adheres to screens and increases clogging in drywall sanding equipment with dust extraction air velocity below 20 m/s.