The Impact of Cellulose Ether’s Film-forming Property on Opening Time

In wet mortar, as water evaporates from the mortar, cellulose ethers become enriched on the surface, forming a film within 5 minutes that reduces the subsequent rate of evaporation. As more water migrates from thicker parts of the mortar to thinner layers, the initially formed film partially dissolves, bringing more cellulose ethers to the surface. Cellulose provides good water retention and workability for fresh mortar, especially playing a key role in the wetted area. To ensure the smooth progress of the hydration reaction, it prevents excessive water absorption by the substrate and water evaporation from the surface layer. Its air-entraining nature reduces the bulk density of the tile adhesive, saving material and lowering the elastic modulus of the hardened mortar body.