The production process of hydroxypropyl methylcellulose is mainly a polysaccharide-based ether product produced by alkalinisation and etherification of cotton fibres (domestic). It is not charged in itself and does not react with charged ions in the gelling material and is stable. It is also less expensive than other types of cellulose ethers. Therefore it is mainly used in the construction industry: water-resistant putty powder, putty paste, tempering putty, paint glue and dry powder building materials such as masonry plastering mortar and dry powder insulation mortar.
The role of HPMC in mortar
1. HPMC has excellent water retention properties and is widely used in various mortars. Including masonry mortar, plastering mortar and floor levelling mortar, to improve the water retention of mortar.
2. HPMC has a significant thickening effect, improving the construction performance and compatibility of the mortar. It changes the fluidity of the product to achieve the desired appearance and improves the fullness and volume of the mortar.
3. HPMC overcomes the common problems of shelling and drumming of ordinary mortar because it improves the cohesiveness and workability of the mortar. Reduce the falling material, save material and reduce cost.
4. HPMC has a certain retarding effect, which can ensure the operability time of mortar. It improves the plasticity of the mortar and the construction effect.
5. HPMC can introduce the right amount of air bubbles, which can greatly improve the frost resistance of mortar and increase the durability of mortar.
6. Cellulose ether is a combination of physical and chemical effects to play a role in water retention and thickening. During the hydration process it can produce substances that cause micro-swelling properties, thus making the mortar have certain micro-swelling properties. This prevents the mortar from cracking due to shrinkage in the later hydration process and improves the service life of the building.