Views:3 Author:Site Editor Publish Time: 2021-12-27 Origin:Site
Industrial grade hydroxypropyl methylcellulose for mortar is distinguished by its viscosity, generally the following are commonly used
Low viscosity: 400 Mainly used in self-levelling mortars. Reason: low viscosity, good leveling, high compactness of mortar.
Mid-Low viscosity: 20000-40000
High viscosity:150000-200000 Mainly used for mortar Reason: high viscosity, mortar is not easy to fall, will hang, improve the construction.
--A: HPMC is widely used in construction materials, coatings, synthetic resins, ceramics, pharmaceuticals, food, textiles, agriculture, cosmetics, tobacco and other industries. At present, most of the domestic HPMCs are of construction grade. In the construction grade, the amount of putty powder is very large. About 90% is used as putty powder and the rest is used as cement mortar and glue.
--A: HPMC can be divided into quick-soluble and hot-soluble types.
The quick-soluble product is rapidly dispersed in cold water and disappears into the water. At this point the liquid has no viscosity because HPMC is only dispersed in the water, not really dissolved. After about 2 minutes, the viscosity of the liquid slowly increases, forming a transparent viscous gel.
The hot-soluble product, when encountered with cold water, holds a group, can be in hot water, quickly dispersed and disappears in hot water. When the temperature drops to a certain temperature, the viscosity slowly appears until it forms a transparent viscous gel.
The hot-soluble type can only be used in putty powder and mortar, in liquid glue and paint, the phenomenon of clumping will occur and cannot be used.
Instantly soluble, it has a wider range of applications. It can be used in putty powders and mortars, as well as in liquid glues and paints, without any contraindications.
--A: Hot water dissolution method: Since HPMC does not dissolve in hot water, initially HPMC can be dispersed evenly in hot water and then dissolved quickly when cooled. two typical methods are described as follows.
1) Put the required amount of hot water in a container and heat it to about 70. gradually add hydroxypropyl methylcellulose with slow stirring. At first the HPMC floats on the surface of the water and then gradually forms a slurry which is cooled with stirring.
2) Add 1/3 or 2/3 of the required amount of water to the vessel and heat to 70, disperse the HPMC as in 1) and prepare a hot water slurry. The remaining amount of cold water is then added to the hot water slurry and the mixture is cooled after stirring.
Powder mixing method: The HPMC powder is mixed with a large quantity of other powdery substances, mixed thoroughly in a mixer and then dissolved with water. The HPMC is then dissolved and does not clump together, as each tiny corner, with only a little HPMC powder, dissolves immediately when it meets water.
--This is exactly the method used by putty powder and mortar manufacturers. [Hydroxypropyl methylcellulose (HPMC) is used as a thickening agent and water retention agent in putty powder mortars].
Organic solvent wetting method: HPMC is pre-dispersed or wetted with organic solvents, such as ethanol or glycol oil, and then dissolved with water. The HPMC can then be dissolved smoothly.
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 itself and does not react with the charged ions in the gelling material, making it stable.The price is a
Hydroxypropyl methyl cellulose is a tasteless, odorless and non-toxic white powder that dissolves in water to form a transparent, viscous liquid. Hydroxypropyl methyl cellulose with adhesion, thickening, emulsification, dispersion, film forming, adsorption, gelling, surface moisture and protective c