Questions about You Should Know about HPMCMarch 23rd 2023
Cement-based tile glue is an adhesive used to bond tiles to various substrates. Cellulose ether is an indispensable ingredient in the formulation of tile glue, whether it is basic tile glue or high-quality tile glue, cellulose Ether plays a vital role.
1. Add water
The amount of water added to the tile glue refers to the amount of water added to the dry powder tile glue in order to meet certain requirements. In laboratory tests, the amount of water added is adjusted by testing the viscosity of the fresh mortar. Different cellulose ethers bring different water requirements for mortar.
European standards give the definition of slip, and the corresponding standard in China is JCT547. All modified cellulose ethers can provide a certain basic anti-slip property for tile adhesives. Highly modified cellulose ethers can significantly improve the resistance of tile adhesives. Slippage.
2. Open time
The moisture volatilization and hardening of the fresh mortar causes crusting, which can lead to insufficient effective wet adhesion area of the tiles. The time from fresh mortar application to skinning is defined as the open time. The modified cellulose ether can significantly delay the skinning, thereby increasing the effective wet adhesion area of the tile.
3. Adjust time and water retention rate
The water retention rate of tile adhesive is usually higher than 98%, so the water retention rate cannot be used to show the quality of tile adhesive. Adjusting time is introduced as another method to characterize the water retention rate. Cellulose ether has a very high shrinkage capacity. As long as there is water in the mortar system, the cement in the tile adhesive can continue to hydrate to produce mineral crystals, which is the basis for the cement-based tile adhesive to produce bonding strength. Secondly, the water retention capacity can also greatly reduce the occurrence of cracks and make the mortar easy to construct. The water retention rate is positively correlated with the viscosity of the cellulose ether and the added amount.
4. High temperature resistance
The viscosity of cellulose ether is related to temperature. When the cellulose ether solution is heated, its viscosity will gradually decrease until it suddenly loses viscosity when it reaches a certain temperature. This process is reversible, when the temperature drops, the solution will regenerate viscosity. The high temperature resistance is characterized by the viscosity loss during the heating process. The viscosity loss means that the water retention of cellulose ether is reduced and the adjustment time is shortened.