1 cellulose water retention agent
The most widely used on the market today is hydroxypropyl methylcellulose, followed by methylcellulose, again carboxymethylcellulose. The overall performance of hydroxypropyl methylcellulose is better than that of methyl cellulose. The water retention of the two is much higher than that of carboxymethyl cellulose, but the thickening effect and bonding effect are worse than that of carboxymethyl cellulose. In gypsum dry-mixed building materials, the amount of hydroxypropyl and methylcellulose is generally 0.1%-0.3%, and the amount of carboxymethylcellulose is 0.5%-1.0%. .


2 starch water retention agent
Starch water retention agent is mainly used for gypsum putty and surface type plastering plaster, which can replace some or all of the cellulose water retention agent. Adding a starch-based water retaining agent to the gypsum dry powder building material can improve the workability, workability and consistency of the slurry. Commonly used starch water retaining agent products are tapioca starch, pregelatinized starch, carboxymethyl starch, carboxypropyl starch and the like. The dosage of starch water-retaining agent is generally 0.3% to 1%. If the dosage is too large, the gypsum product will be mildewed in a humid environment, which directly affects the quality of the project.


3 glue water retention agent
Some instant adhesives also provide better water retention aids. For example, 17-88, 24-88 polyvinyl alcohol powder, field green rubber and guar gum are used in gypsum dry-mixed building materials such as gypsum plaster, gypsum putty, gypsum heat-insulating rubber, etc., in a certain amount, It can reduce the amount of cellulose water retention agent. Especially in the fast-bonding gypsum, in some cases, the cellulose ether type water retaining agent can be completely replaced.


4 inorganic water retention materials
The application of composite water-retaining materials in gypsum dry-mixed building materials can reduce the amount of other water-retaining materials, reduce the cost of the product, and play a certain role in improving the workability and construction of the gypsum slurry. Commonly used inorganic water-retaining materials include bentonite, kaolin, diatomaceous earth, zeolite powder, perlite powder, and attapulgite clay. Type of division