D&J Chemicals was founded in 2013, the enterprise is located in Jinzhou Economic Development Zone, Hebei Province. It covers an area of more than 27,000 square meters and has an annual yield of 10,000 tons of methyl cellulose.
HPMC is used as a water-retaining agent for cement mortar and as a retarder for mortar pumping.
Wet-mixed Mortar r is a type of cement composed of cement, fine aggregate, additives, and water. According to the properties of various components, it is mixed in specified proportions at the mixing station, measured, transported to the location used by trucks, enters specialized storage containers, and is used as a finished wet mixture within a specified time.
When gypsum is used as a binder to improve spreading and extend working time, the water-retaining property of HPMC prevents the mixture from cracking too quickly after drying and enhances strength after hardening. Water retention is an important property of HPMC and a concern for many domestic wet-mixed mortar manufacturers. Factors affecting the water retention of wet-mixed mortar include the amount of HPMC added, the viscosity of HPMC, the fineness of particles, and the temperature of the environment. HPMC in wet-mixed mortar has three main functions: excellent water retention, influence on the consistency and thixotropy of wet-mixed mortar, and interaction with cement. The water-retaining effect of cellulose ether depends on the base’s water absorption rate, mortar composition, mortar layer thickness, mortar water requirement, and setting time. The higher the transparency of HPMC, the better the water retention.
Factors affecting the water retention of wet-mixed mortar include the viscosity, dosage, particle size, and temperature of cellulose ether. The higher the viscosity of cellulose ether, the better the water retention. Viscosity is an important parameter for HPMC performance. For the same product, using different methods to measure viscosity can yield significantly different results, sometimes even double the difference. Therefore, viscosity comparison must be conducted under the same testing methods, including temperature, rotor, etc.
Generally, higher viscosity corresponds to better water retention. However, higher viscosity implies higher molecular weight of HPMC, lower solubility, and negative impacts on mortar strength and construction performance. Higher viscosity results in more apparent thickening of mortar, but it is not a direct relationship. Higher viscosity makes wet mortar stickier, with good construction performance, high performance of sticky scrapers, and strong adhesion to the substrate. However, the improvement in the structural strength of wet mortar itself is not significant for both construction and performance, and anti-sag performance is not obvious. In comparison, some medium to low viscosity but modified HPMC exhibits excellent performance in improving the structural strength of wet mortar. The larger the amount of cellulose ether HPMC added to wet mortar, the better the water retention, and the higher the viscosity, the better the water retention. Fineness is also an important performance indicator of hydroxypropyl methylcellulose. The fineness of HPMC has a certain impact on its water retention. In general, under the same viscosity and different fineness, HPMC with smaller fineness has better water retention effects. In wet-mixed mortar, the addition of cellulose ether HPMC is very low but significantly improves the construction performance of wet mortar, making it a key additive affecting mortar performance. The rational selection of hydroxypropyl methylcellulose has a significant impact on the performance of wet mortar