What is the most suitable viscosity of hydroxypropyl methylcellulose
Hydroxypropyl methylcellulose is generally used in putty powder with a viscosity of 100,000, while the mortar has a relatively high viscosity, and a viscosity of 150,000 should be selected. The most important role of hydroxypropyl methylcellulose is to retain water, followed by thickening. Therefore, in the 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 the water retention.
SLEOCHEM building materials grade hydroxypropyl methylcellulose is divided into the following categories according to the viscosity:
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 resist precipitation, and enhance the fluidity and pumpability.
2. Medium and low viscosity: 20,000-50,000 viscosity cellulose, mainly used for gypsum products and caulking agents.
Low viscosity, high water retention, good workability, less water addition,
3. Medium viscosity: 75,000-100,000 viscosity cellulose, mainly used for interior and exterior wall putty.
Moderate viscosity, good water retention, good construction hangability
4. High viscosity: 150,000-200,000, mainly used for polystyrene particle thermal insulation mortar glue powder, vitrified microbead thermal insulation mortar
High viscosity, high water retention, the mortar is not easy to drop ash, sag, and improve the construction.
Generally speaking, the higher the viscosity, the better the water retention. Therefore, many customers will choose to replace the medium and low viscosity cellulose (20,000-50,000) with medium-viscosity cellulose (75,000-100,000) to reduce the added amount, and then control cost.