The role of hydroxypropyl methylcellulose in wet mixed mortar

Hydroxypropyl methylcellulose is used as a water retaining agent and retarder in cement mortars to make the mortars pumpable. After mixing according to measurement at the mixing station, use a mixing truck to transport the mixture to the place of use and store it in a special container, and use the wet mix within the specified time. In the mortar used as a binder, in order to improve the spreadability and extend the operating time, the water retention of hydroxypropyl methylcellulose HPMC will not cause the slurry to break due to drying too fast after coating, and improves the strength. Water retention is an important property of hydroxypropyl methylcellulose HPMC and is also the performance of many wet mixed mortar manufacturers in China. Factors that affect the water retention effect of wet mixed mortar include the amount of HPMC added, the viscosity of HPMC, the fineness of the particles and the temperature of the use environment.

The important role of hydroxypropyl methylcellulose HPMC in wet-mixed mortar is mainly reflected in three aspects. One is its excellent water retention performance, the other is its interaction with cement, and the third is its influence on the consistency and thixotropy of wet-mixed mortar. Whether its water retention effect is good or not depends on the water absorption rate of the base layer, the composition of the mortar, the thickness of the mortar layer, the water demand of the mortar and the setting time of the solidifying material. The higher the transparency of hydroxypropyl methylcellulose, the better its water retention.

Generally speaking, the higher the viscosity, the better the water retention effect. However, the higher the viscosity, the higher the molecular weight of HPMC, and its solubility will decrease accordingly, which will have a negative impact on the strength and construction performance of the mortar. The higher the viscosity, the more obvious the thickening effect of the mortar, but this is not always the case. The higher the viscosity, the more viscous the wet mortar will be, and when applied it will exhibit stickiness and high adhesion to the substrate. The fineness of hydroxypropyl methylcellulose also affects its water retention. Generally speaking, for hydroxypropyl methylcellulose that has a viscosity phase and a different denier, the finer the denier, the smaller the denier. Better water retention effect.

In wet mixed mortar, the addition amount of HPMC is low, but it can significantly improve the construction performance of wet mixed mortar. This is the main additive that affects the construction performance of mortar. The correct selection of hydroxypropyl methylcellulose has a great influence on the performance of wet mix mortar.

The greater the amount of HPMC added to the wet-mix mortar, the better the water retention performance, and the higher the viscosity, the better the water retention performance. Fineness is also an important performance indicator of hydroxypropyl methylcellulose.

Factors that affect the water retention of wet-mix mortar include cellulose ether viscosity, addition amount, particle fineness and service temperature.