Application of Hydroxypropyl Methyl Cellulose in Gypsum Mortar

(1), the characteristics of hydroxypropyl methylcellulose in gypsum mortar:

1. Good construction performance: it is easy and smooth to hang, can be molded at one time, and has plasticity at the same time.

2. Strong compatibility: It is suitable for all kinds of gypsum bases, and can reduce the sinking time of gypsum, reduce the drying shrinkage rate, and the wall is not easy to hollow and crack.

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, good wet bonding performance, and reduce landing ash and other problems.

4. Improve the spread rate of gypsum base: Compared with similar hydroxypropyl methylcellulose ether, the spread rate will be significantly increased. Hydroxypropyl methylcellulose products can greatly increase the coating rate, can cover more areas, can reduce labor intensity, save materials, and improve economic benefits.

5. Good anti-sagging performance: when hanging thick layers, single-pass construction will not sag, and more than two passes, above 3cm, will not sag when hanging, and the plasticity is good.

6. Application fields and dosage: light bottom plastering gypsum, the recommended dosage is 2.5-3.5 kg/ton.

(2) Application experiment 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: No sag when one-pass construction is applied in thick layers, and no sag when applied for more than two passes (above 3cm), and the plasticity is good.

3. Wall hanging test: it is light and smooth when hanging, and can be molded at one time. The surface is delicate and soft, with brightness.

4. Spreading rate test: The spreading rate of gypsum base refers to the result obtained by measuring the wet bulk density of gypsum base. One ton of gypsum-based product for construction of a 10mm thick wall area.

5. Water retention rate test: Water retention rate reference standard GB/T28627-2012 “Plastering Gypsum”, the water retention rate of light bottom plastering gypsum is greater than or equal to 60%, and 0.2% and 0.25% of gypsum-based hydroxypropyl methylcellulose are added It has good water retention performance.