There are many factors affecting the application of hydroxypropyl methylcellulose HPMC in building materials, especially gypsum-based plaster, as follows:
1 water retention
Hydroxypropyl methylcellulose for construction prevents the excessive absorption of water by the substrate, and when the gypsum is completely set, the water should be kept in the plaster as much as possible. This characteristic is called water retention and is directly proportional to the viscosity of the construction-specific hydroxypropyl methylcellulose solution in the stucco. The higher the viscosity of the solution, the higher its water retention capacity. Once the water content is increased, the water retention capacity will decrease. This is because the increased water dilutes the solution of hydroxypropyl methylcellulose for construction, resulting in a decrease in viscosity.
2 anti-sagging
A plaster with anti-sag properties allows applicators to apply thicker coats without sagging, and also means that the plaster itself is not thixotropic, which would otherwise slide down during application.
3 Reduce viscosity, easy construction
Low-viscosity and easy-to-construct gypsum plaster can be obtained by adding various building-specific hydroxypropyl methylcellulose products. When using lower-viscosity grades of building-specific hydroxypropyl methylcellulose, the degree of viscosity is relatively reduced The construction becomes easier, but the water retention capacity of low-viscosity hydroxypropyl methylcellulose for construction is weak, and the addition amount needs to be increased.
4 Compatibility of stucco
For a fixed amount of dry mortar, it is more economical to produce a higher volume of wet mortar, which can be achieved by adding more water and air bubbles. But the amount of water and air bubbles is too much
Post time: Apr-20-2023