Application of hydroxypropyl methylcellulose in gypsum mortar.

Features of hydroxypropyl methylcellulose in gypsum mortar:
1. Good construction performance: It is relatively easy and smooth to wear, and can be molded at one time, and it also has plasticity.
2. Strong compatibility: It is suitable for all kinds of gypsum bases, and at the same time, it can reduce the settling time of gypsum, reduce the drying shrinkage rate, and the wall is not easy to be hollowed out and cracked.
3. Good water retention rate: It can prolong the operation time of gypsum base, improve the thickness resistance of gypsum base, increase the bonding strength between gypsum base and base layer, have good wet bonding performance, and reduce problems such as falling ash.
4. Improve the coating rate of gypsum base: Compared with the same kind of hydroxypropyl methyl cellulose ether, the coating rate will increase significantly. Hydroxypropyl methylcellulose products can greatly improve the coating rate, can cover more area, can reduce labor intensity, save materials, and improve economic benefits.
5. Good sag resistance: when thick layers are draped, single-pass construction will not sag, more than two times, more than 3cm, will not sag when draped, and has good plasticity.
6. Application fields and addition amount: light bottom plastering gypsum, the recommended amount is 2.5-3.5 kg/ton.

2. Application experimental test of hydroxypropyl methylcellulose:
1. Strength test: After testing, gypsum-based hydroxypropyl methylcellulose has good tensile bonding strength and compressive strength.
2. Anti-sagging test: when the thick layer is draped, it will not sag in a single construction, and it will not sag when it is draped for more than two times (above 3cm), and the plasticity is good.
3. Wall hanging test: It is light and smooth when hanging, and can be formed at one time. The surface is delicate and soft, and it is bright.
4. Coating rate test: The coating rate of gypsum base refers to the result obtained by measuring the wet bulk density of gypsum base. One ton of gypsum-based products constructs a 10mm-thick wall area.
5. Water retention rate test: water retention rate reference standard GB/T28627-2012 “Plaster Gypsum”, the water retention rate of light bottom plastering gypsum is greater than or equal to 60%, gypsum-based hydroxypropyl methylcellulose is added 0.2% and 0.25% , has good water retention performance.