How to Evaluate the Quality of HPMC (Hydroxypropyl Methylcellulose)

A simple way to distinguish the quality of HPMC(hydroxypropyl methyl cellulose):

(1) First look at the whiteness, the appearance color of hydroxypropyl methyl cellulose is white, uniform color, and there are no many black spots under the microscope; The poor color tends to be gray, with more black spots. Looking at the shape and fluidity of the particles, the particles using defatted cotton as the starting material are long and have poor fluidity, while the particles using lignocellulose as the starting material are close to cubes and have good fluidity.

(2) Secondly, look at the fineness and particle size distribution.The good  hydroxypropyl methyl cellulose has uniform particle size, small particle size, granular shape, and good fluidity; The bad one is just the opposite. The fineness of hydroxypropyl methyl cellulose is generally 80 mesh and 100 mesh, 120 mesh is less, The production of hydroxypropyl methyl cellulose is mostly 80 mesh, the finer the fineness, in general, the better.

(3) Transmittance: Put HPMC(hydroxypropyl methyl cellulose) into water to form a transparent colloid, observe its transmittance. The greater the transmittance, the better, indicating that there is less insoluble in it. The permeability of vertical reactors is generally good, and that of horizontal reactors is worse, but it does not mean that the quality of the vertical reactors production is better than that of the horizontal reactor production, and the product quality is determined by many factors.

(4) Proportion: the larger the proportion, the heavier the better. The ratio is generally because the content of hydroxypropyl is high, and the content of hydroxypropyl is high, so the water retention is better.