Views:4 Author:Site Editor Publish Time: 2021-03-23 Origin:Site
At present, in most cities in the world, water-resistant, scrub-resistant and environmentally friendly putty has been basically valued by people.
A few years ago, because of putty made of polyvinyl alcohol and formaldehyde acetal reaction system gives off formaldehyde gas which is harmful to people's health, Therefore, this material is gradually eliminated, and it is replaced by cellulose ether series, which is the only material for developing environmentally friendly building materials.
There are two kinds of water-resistant putty, dry powder and putty paste, of which two kinds the cellulose ethers commonly uesd are modified methyl cellulose and hydroxypropyl methyl cellulose, with viscosity between 30000-60000cps.
As the formula of the putty is different from one manufacturer to another, such as calcium ash, light calcium, white cement, etc., or gypsum powder, calcium ash, light calcium, etc., the viscosity and amount of cellulose ethers are also different between the two formulations, and the usual amount is 2‰-5‰.
In the construction of wall coatings, because of the water absorption of the wall base (13% for brick wall, 3-5% for concrete) and the evaporation, the water loss is fast, it will lead to cracks or demineralization, thus weakening the strength of the putty, Anyway adding HPMC from Landcel will solve this problem.
However, the quality of the raw materials, especially the calcium ash, is also extremely important. The high viscosity of HPMC from Landcel enhances the buoyancy of the filler and avoids the phenomenon of sagging. HPMC from Landcel, which to be added to the powder putty, is convenient to opperate and use, the raw materials and additives can be mixed evenly in drymix powders, the construction is also convenient then.
Hydroxypropyl methyl cellulose is divided into two kinds of ordinary hot soluble cold water instantly soluble. Hydroxypropyl methyl cellulose uses are 1, Gypsum series In the gypsum series of products, cellulose ethers are mainly used to retain water and increase smoothness. Together they play a cer