How to choose the right hydroxypropyl methyl cellulose

How to choose the right hydroxypropyl methyl cellulose

The relationship between water retention and viscosity of hydroxypropyl methylcellulose is not a proportional relationship within a certain viscosity range, but also depends on the practical application of the product. Relatively speaking, when hydroxypropyl methyl cellulose has a viscosity of more than 100,000, the difference in water retention between 100,000 viscosity and 200,000 viscosity is not large.

Analysis of the relationship between the viscosity of hydroxypropyl methyl cellulose and the water retention of cellulose: the viscosity of cellulose is generally between 50,000 and 200,000, and the production of discrete kettles In the production of the kettle, the viscosity of the vertical kettle production is relatively low, generally between 50,000 and 150,000, and there are also 200,000, but not too much. The annual production of the kettle is generally between 150,000 and 200,000, and there are also 100,000. Not rare.

Although the viscosity of the vertical kettle production is low, after 12 hours of reaction, there are still more raw materials to be added, so the water retention is better. The viscosity of the production of the kettle is high, but after 8 hours of reaction, The reaction time of the stand-up kettle is 4 hours less, and the added raw materials are relatively simple, so the water retention is less, and the corresponding cost will be lower.

Hydroxypropyl methylcellulose HPMC can be divided into fast-dissolving and hot-dissolving, fast-dissolving products, which are rapidly dispersed in cold water and disappear into water. At this time, the liquid has no viscosity because HPMC is only dispersed in water and has no real dissolution. About 2 minutes, the viscosity of the liquid gradually became larger, forming a transparent viscous colloid. The hot-melt type product, in the case of cold water, can be quickly dispersed in hot water and disappear in hot water. When the temperature drops to a certain temperature, the viscosity gradually appears until a transparent viscous colloid is formed. The hot-dissolved type can only be used in putty powder and mortar. In liquid glue and paint, there will be a phenomenon of clumping, which cannot be used. Instant type, wide range of applications, can be used in putty powder and mortar, as well as liquid glue and paint.

The mortar is required to be higher, and it is better to use HPMC with a viscosity of more than 150,000. Moreover, the most important role of HPMC is to retain water, followed by thickening.

In the putty powder, as long as the water retention is good, the HPMC with a viscosity of 70,000 to 80,000 can be used. Of course, the viscosity is larger, and the relative water retention is better. When the viscosity exceeds 100,000, the viscosity has little effect on the water retention. And the viscosity is large, it is better to use some in cement mortar.