In putty, cement mortar and gypsum-based slurry, HPMC hydroxypropyl methylcellulose ether mainly plays the role of water retention and thickening, and can effectively improve the adhesion and sag resistance of the slurry. Factors such as air temperature, temperature and wind pressure speed will affect the volatilization rate of water in putty, cement mortar and gypsum-based products. Therefore, in different seasons, there are some differences in the water retention effect of products with the same amount of HPMC added. In the specific construction, the water retention effect of the slurry can be adjusted by increasing or decreasing the amount of HPMC added.
The water retention of methyl cellulose ether under high temperature conditions is an important indicator to distinguish the quality of methyl cellulose ether. Excellent HPMC series products can effectively solve the problem of water retention under high temperature. In high temperature seasons, especially in hot and dry areas and thin-layer construction on the sunny side, high-quality HPMC is required to improve the water retention of the slurry. High-quality HPMC can turn the free water in the mortar into bound water, thereby effectively controlling the evaporation of water caused by high temperature weather and achieving high water retention.
High-quality methyl cellulose can be evenly and effectively dispersed in cement mortar and gypsum-based products, and wrap all solid particles, and form a wetting film, and the water will be released gradually over a long period of time. A hydration reaction occurs, thereby ensuring the bond strength and compressive strength of the material. Therefore, in high-temperature summer construction, in order to achieve the water retention effect, it is necessary to add high-quality HPMC products in sufficient quantities according to the formula. If a compound HPMC is used, insufficient hydration, reduced strength, cracking, and voids will occur due to excessive drying. Quality problems such as drums and shedding also increase the difficulty of construction for workers. As the temperature drops, the amount of HPMC added can be gradually reduced, and the same water retention effect can be achieved.
The reaction process precisely controls the production of HPMC, and its substitution is complete and its uniformity is very good. Its aqueous solution is clear and transparent, with few free fibers. The compatibility with rubber powder, cement, lime and other main materials is particularly strong, which can make the main materials play the best performance. However, HPMC with poor reaction has many free fibers, uneven distribution of substituents, poor water retention and other properties, resulting in a large amount of water evaporation in high temperature weather. However, the so-called HPMC (compound type) with a large amount of impurities is difficult to coordinate with each other, so the water retention and other properties are even worse. When poor-quality HPMC is used, problems such as low slurry strength, short opening time, powdering, cracking, hollowing and shedding will be caused, which will increase the difficulty of construction and greatly reduce the quality of the building.
Post time: Apr-28-2024