- June 24, 2021
- Posted by: admin
- Category: News
In the construction industry, HPMC has a very important impact. The use of inferior products will cause slurry strength to become lower, cracking, hollowing and shedding, which greatly delays the quality of the project.
Usually purchasing HPMC products is, how to distinguish the advantages and disadvantages of products? Here are some methods.
Pure HPMC has fluffy visual state and small bulk density, ranging from 0.3 to 0.4 g/ml.
The adulterated HPMC has better fluidity and feel, which is obviously different from the genuine appearance.
2. Aqueous solution:
Pure products aqueous solution has high clarification and transmittance, and water retention rate is more than 97%.
The adulterated products aqueous solution is turbid and its water retention rate is difficult to reach 80%.
Pure products could not smell ammonia, starch and alcohol.
Adulterated products can smell all kinds of flavors, even if tasteless, it will feel heavier.
Pure products powder is fibrous under a microscope or magnifying glass.
Granular solids or crystals can be observed in adulterated HPMC under a microscope or magnifying glass.
(1) Whiteness:Good products have high whiteness
Whiteness can not determine whether HPMC is good for use, and if whitening agent is added in the production process, it will affect its quality.
(2) Fineness: The finer the product, Therefore the better the quality in general.
Products usually has 80 meshes and 100 meshes in fineness, 120 meshes are relatively small, 120 meshes are very fine.
(3) Transparency: The greater the transmittance of HPMC in aqueous solution,Therefor the quantity is better.
Put it in water and form a transparent colloid. See its transmittance. The higher the transmittance, the better the quality. It shows that there are less insoluble substances in it.
(4) Proportion: The bigger the proportion, the quality is better.
It’s usually because of the hydroxypropyl group in it.The higher the content of hydroxypropyl, the better the water retention.