Simply judge the quality of hydroxypropyl methyl cellulose
Hydroxypropyl methyl cellulose has the characteristics of thickening, bonding, dispersing, emulsifying, film forming, suspending, adsorbing, gelling, surface active, retaining moisture and protecting colloids. The scope of application is very wide.
1.Fineness
Hydroxypropyl methyl cellulose generally has a fineness of 80 mesh and 100 mesh. The finer the fineness, the faster the dissolution, and generally better. Vertical reactors are usually thinner than those produced in horizontal reactors.
2.Transmittance
Dissolve hydroxypropyl methylcellulose (HPMC) in water to form a transparent liquid. See the transmittance, the better the transmittance, the less insoluble matter.
3.proportion
The specific gravity is moderate. If the proportion is too large or too small, it may be the result of the production process without control.
4.Exterior
Pure hydroxypropyl methyl cellulose has a fluffy visual state and a small bulk density, ranging from 0.3 to 0.4 g/ml; adulterated HPMC has better fluidity and a heavier hand feel, which is significantly different from the original appearance. Some special-purpose cellulose appearances and common specifications of cellulose are also very different, specific product specific analysis.
5.Aqueous solution
Since the pure HPMC aqueous solution is transparent, the light transmittance is high, and the water retention rate is ≥90%; therefore, the adulterated HPMC aqueous solution is more turbid, and the water retention rate is difficult to reach 70%.
6.White degree
Although whiteness does not determine whether HPMC is easy to use, and if it is added to the brightener during the production process, it will affect its quality. However, good products are mostly white.