Hydroxypropyl methylcellulose is widely used in the construction industry. Today, I will introduce the dissolution method of hydroxypropyl methylcellulose and how to judge the quality of hydroxypropyl methylcellulose.
The method of dissolving hydroxypropyl methylcellulose :
All models can be added to the material by dry mixing;
When it needs to be added directly to the normal temperature aqueous solution, it is best to use cold water dispersion type, and it can thicken within 10-90 minutes after adding;
After stirring and dispersing with hot water for common type, add cold water and stir to dissolve it;
If there is agglomeration and coating during dissolution, it is caused by insufficient stirring or direct addition of cold water to ordinary profiles. At this time, it should be stirred quickly;
If bubbles are generated during dissolution, they can be left to stand for 2-12 hours (determined according to the consistency of the solution) or removed by evacuation, pressurization, etc., and an appropriate amount of defoamer can also be added.
How to judge the quality of hydroxypropyl methylcellulose simply and intuitively
Whiteness: According to the whiteness, it is impossible to determine whether HPMC can be used normally, and if whitening agents are added in the production process, it will also affect its quality. However, products with good whiteness are mostly good.
Fineness: HPMC is generally 80 mesh, 100 mesh, 120 mesh, the finer the finer the better.
Transmittance: put HPMC into water to form a transparent colloid, and observe its transmittance. The greater the transmittance, the less insoluble substances in water. Generally, the transmittance is better in vertical reactors and horizontal reactors. It is worse in the vertical reactor, but it cannot explain that the quality of the product produced by the vertical reactor is better than that of the horizontal reactor.
Specific gravity: Generally speaking, because of the high hydroxypropyl content, the water retention effect is good.
Post time: Nov-17-2022