1.What is the primary use of hydroxypropyl methylcellulose (HPMC)?

Answer: HPMC is widely used in construction materials, coatings, synthetic resins, ceramics, medicine, food, textile, agriculture, cosmetics, tobacco and other industries. HPMC can be divided into construction grade, food grade and pharmaceutical grade according to its use. At present, most of the domestic production is in the construction level. In the construction level, the amount of putty powder is large, about 90% is used for putty powder, and the other is used for cement mortar and glue.

2.The application of HPMC in putty powder, what is the cause of foam in putty powder?

Answer : HPMC plays the role of thickening, water retention and construction in the putty powder. Do not participate in any reaction. 

The reason for the bubble: 1.The water is too much. 2. The bottom layer is not dry, just scrape a layer on the top, it is also easy to foam.　

HPMC 

3. There are several types of hydroxypropyl methylcellulose (HPMC). What is the difference between them?

Answer : HPMC can be divided into instant-soluble and hot-dissolved, instant-dissolved products, which dissipate quickly in cold water and disappear into the water. At this moment, the liquid has no viscosity, because HPMC just disperses in water and does not dissolve. About 2 minutes, the viscosity of the liquid gradually increased, forming a clear viscous colloid. Hot-melt products can quickly disperse in hot water and disappear in hot water when they clump in cold water. When the temperature drops to a certain temperature, the viscosity gradually appears until it forms a clear viscous colloid.

The hot melt type can only be used in putty powder and mortar. In liquid glue and coating, it will show clumping phenomenon and cannot be used. Instant type, with a wider range of applications, can be used in putty powder and mortar, as well as liquid glue and paint, there is no taboo.

4. How to simply and intuitively determine the quality of hydroxypropyl methyl cellulose (HPMC)?

(1) Specific gravity: specific gravity is bigger, heavier want to be better.

(2) Whiteness: Whiteness does not determine whether HPMC is easy to use, and if whitening agent is added in the production process, its quality will be affected.However, good products are mostly whiter.

(3) Fineness: The fineness of HPMC is generally 80 mesh and 100 mesh, with less 120 purposes. Most HPMC produced in Hebei is 80 mesh. The finer the fineness is, the better it is in general.

(4) Transmittance: Put HPMC for putty powder into water to form a transparent gel and observe its transmittance. The greater the transmittance, the better, indicating less insoluble matter.The transmittance of the vertical reactor is generally good, while that of the horizontal reactor is worse, but it does not mean that the quality produced by the vertical reactor is better than that produced by the horizontal reactor. There are many factors that determine the quality of the product.The content of hydroxypropyl inside is high, the content of hydroxypropyl is high, it is better to keep water.

The above information is provided by the wall putty manufacturer.