Low-viscosity hydroxypropyl methylcellulose is mainly used for self-leveling mortar. Its viscosity is low, although its water retention is poor. HPMC 's leveling property is good, and the mortar is dense. Medium and low-viscosity HPMC is mainly used in tile adhesives, joint fillers, anti-cracking mortars, and thermal insulation mortars. It has good constructability, a good water retention effect, and high mortar density. HPMC exists as a water-retaining agent in mortar. Its water-retaining properties prevent the paste from drying too quickly. And cracking after reapplying.

HPMC (Hydroxypropyl methyl cellulose) is a water-soluble polymer made from cellulose modified with hydroxypropyl groups. It is used as a thickener, emulsifier and stabilizer in foods, pharmaceuticals and cosmetics. HPMC is produced by treating methyl cellulose with propylene oxide. The end result is a white, odorless and tasteless powder. Hydroxypropyl methyl cellulose is very similar to methyl cellulose, but it is more soluble in water and has a higher viscosity. HPMC has many uses, such as a thickener (to replace cornstarch), a stabilizer (to prevent ingredients from separating or settling), a binder (to hold ingredients together), or an emulsifier (to mix two substances that do not dissolve well into each other).