What is the most suitable viscosity of hydroxypropyl methylcellulose

Hydroxypropyl methyl cellulose is generally used in putty powder with a viscosity of 100,000, and the viscosity of the mortar is relatively high. It should be easy to use the viscosity of 150,000. The most important role of hydroxypropyl methyl cellulose is water retention, followed by thickening. Therefore, in putty powder, as long as the water retention is achieved, the viscosity is lower. Generally speaking, the higher the viscosity, the better the water retention, but when the viscosity exceeds 100,000, the viscosity has little effect on water retention.

Hydroxypropyl methyl cellulose is distinguished by viscosity, 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, it can also resist precipitation, enhance the fluidity and pumpability.

2. Low and medium viscosity: cellulose with a viscosity of 20,000 to 50,000, mainly used in gypsum products and joint fillers

The viscosity is low, the water retention is high, the workability is good, and the amount of water added is small.

3. Medium viscosity: 75,000-100,000 viscosity cellulose, mainly used for internal and external wall putty.

Moderate viscosity, good water retention, good construction drape

4. High viscosity: 150,000 to 200,000, mainly used for polyphenylene particle thermal insulation mortar powder, vitrified microbead thermal insulation mortar

High viscosity, high water retention, mortar is not easy to fall ash and sag, improving 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 low- and medium-viscosity cellulose (20,000-50,000) to reduce the amount of addition and control cost.