In the ready-mixed mechanical spraying mortar, the addition of hydroxypropyl methyl cellulose ether is very low, but can significantly improve the performance of wet mortar, mortar construction performance is a major additive. Reasonable selection of cellulose ether with different varieties, different viscosity, different particle size, different viscosity degree and addition amount has a positive effect on the improvement of dry mortar properties. At present, many masonry and plastering mortars have poor water retention performance, and water slurry separation will occur after a few minutes of standing. Water retention is an important performance of methyl cellulose ether, but also a lot of domestic dry mortar manufacturers, especially in the southern area of higher temperature manufacturers concerned about the performance. The factors affecting the water retention effect of dry mortar include the amount of MC, MC viscosity, particle fineness and ambient temperature. Cellulose ether is a synthetic polymer made of natural cellulose as raw material by chemical modification.
The important role of water-soluble cellulose ether in mortar mainly has three aspects, one is excellent water retention ability, the second is the influence of mortar consistency and thixotropy, and the third is the interaction with cement. Cellulose ether water retention, depends on the base of hydroscopicity, composition of mortar, mortar layer thickness, mortar water demand, condensation material condensation time. The water retention of cellulose ether comes from the solubility and dehydration of cellulose ether itself.
In the ready-mixed spraying mortar, hydroxypropyl methyl cellulose ether plays a role in water retention, thickening, delaying cement hydration power, improving construction performance. Good water retention ability makes cement hydration more complete, can improve wet mortar viscosity, improve mortar bond strength, can adjust the time. Mechanical spraying mortar adding hydroxypropyl methyl cellulose ether can improve the spraying or pumping performance of mortar, as well as the structural strength. Therefore, cellulose ether is widely used as an important additive in ready-mixed mortar.