Views:2 Author:Site Editor Publish Time: 2020-09-16 Origin:Site
Hydroxypropyl methyl cellulose ether-HPMC, as an auxiliary additive widely used in the field of building materials, is mainly used for water retention, thickening and improving the workability of the finish product.
Water retention rate is often one of the core indicators for selecting high-quality HPMC, so first of all, let's take a closer look at the factors that affect the water retention rate of HPMC:
1. First of all, the added amount of the HPMC, and its water retention performance is directly proportional to the added amount. The amount of HPMC used in building materials on the market varies depending on the quality. Taking the high-quality HPMC produced by Landcel as an example, it is generally added in such as bonding, plastering, anti-cracking mortar, etc. The general addition amount is 2~2.5 KG /MT, the adding amount of putty etc. is between 2~4.5 KG/MT, the tile glue is between 3.5~4 KG/MT, and the amount of tile grout is 0.3 ~1 KG/MT according to different construction methods, gap width and slurry fineness , the self-leveling mortar is between 0.2~0.6 KG/MT, and the ETICS is between 4~7 KG/MT. Within this range, the more HPMC is added, the water retention performance better.
2. The impact of construction environment. Air humidity, temperature, wind pressure, wind speed and other factors will affect the volatilization rate of water in cement mortar and gypsum-based products. In different seasons and different regions, the water retention rate of the same product will vary, but in general, Temperature has a great influence on the water retention rate, so there is a view on the market: HPMC with higher gel Tem. is a high-quality product with high water retention rate, and the high-quality HPMC produced by Landcel has a gel Tem. far exceeding the Similar products.
3. The production process and viscosity of the cellulose ether -HPMC. The high-quality HPMC produced by Landcel has very good uniformity. Its methoxy and hydroxypropoxy groups are evenly distributed along the cellulose molecular chain, which can increase the association of the oxygen atoms on the hydroxyl and ether bonds with water. The ability of hydrogen bonding makes free water become bound water, thereby effectively controlling the evaporation of water and achieving high water retention
When the viscosity of HPMC increases, the water retention rate also increases, the viscosity reaches a certain level, the water retention rate increases. It tends to be flat. Taking the high-quality HPMC produced by Landcel as an example, laboratory data show that within 100,000 cPs (NDJ), the viscosity is positively correlated with the water retention rate.
A simple overview. The water retention function of HPMC is affected by all aspects. The choice cannot be based on a single indicator. Due to its advanced technology, the high-quality HPMC produced by Landcel can achieve better water retention performance in the case of low viscosity. In a word, it is the right choice for HPMC to choose Landcel
Industrial-grade hydroxypropyl methyl cellulose used in mortar is distinguished by viscosity. Generally, the following types are commonly used Low viscosity: 400 is mainly used for self-leveling mortar. Reason: low viscosity, good leveling, high mortar density. Medium and low viscosity: 20000-400000
Hydroxypropyl methyl cellulose ether-HPMC, as an auxiliary additive widely used in the field of building materials, is mainly used for water retention, thickening and improving the workability of the finish product. Water retention rate is often one of the core indicators for selecting high-quality