Hydroxypropyl methylcellulose is generally used in putty powder with a viscosity of 100,000, while mortar has a relatively high viscosity requirement, so it should be used with a viscosity of 150,000. The most important function of hydroxypropyl methylcellulose is water retention, followed by thickening. Therefore, in the putty powder, as long as the water retention is achieved, the viscosity is lower. Generally speaking, the greater the viscosity, the better the water retention, but when the viscosity exceeds 100,000, the viscosity has little effect on the water retention.

According to the viscosity, hydroxypropyl methylcellulose is generally divided into the following types:

1. Low viscosity: 400 viscosity cellulose, mainly used for self-leveling mortar.
It has low viscosity and good fluidity. After adding, it will control the water retention of the surface, the bleeding is not obvious, the shrinkage is small, the cracking is reduced, and it can also resist sedimentation and enhance fluidity and pumpability.

2. Medium and low viscosity: 20,000-50,000 viscosity cellulose, mainly used in gypsum products and caulking agents.
Low viscosity, high water retention, good workability, less water added,

3. Medium viscosity: 75,000-100,000 viscosity cellulose, mainly used for interior and exterior wall putty.
Moderate viscosity, good water retention, good construction and drapability

4. High viscosity: 150,000-200,000, mainly used for polystyrene particle insulation mortar rubber powder, vitrified microbead insulation mortar
With high viscosity and high water retention, the mortar is not easy to drop ash and sag, which improves the construction.

Generally speaking, the higher the viscosity, the better the water retention, so many customers will choose to use medium-viscosity cellulose (75,000-100,000) instead of medium-low viscosity cellulose (20,000-50,000) to reduce the amount added, and then control cost