Hydroxypropyl methylcellulose process flow

Refined cotton a cotton one alkalization one etherification and a separation of a washing. A separation of a thousand dry, a crushing of a packaging of a finished product Open cotton: open the refined cotton, remove iron, and then crush. The crushed refine cotton is powdere, with the granularity of 80 mesh transmittance of 100%. Otherwise it is easy to gather together during the reaction process and reduce the etherification efficiency. Alkalinization: the powder refined cotton is add to the inert solvent, activated with alkali and soft water. So that the lattice swelling of the refined cotton is conducive to the penetration of etherification agent molecules. And improve the uniformity of etherification reaction.

The alkali used for alkalalization is metal hydroxide or organic alkali. The amount of alkali added (by quality, the same below) is 0.1-0.6 times of refined cotton, soft water add is 0.3-1.0 times of refined cotton. Inert solvent is a mixture of alcohol and hydrocarbon, inert solvent added | amount is 7-15 times of refined cotton. Inert solvent can also be 3-5 carbon atoms of alcohol (such as alcohol, propanol), acetone. It can also be fatty hydrocarbon, aromatic hydrocarbon; the alkali conversion temperature should be controlled within 0-35 ” C; the alkali conversion time is about 1hr.

Temperature and time can be adjusted according to the rear material and product requirements.

Etherification: after alkalization treatment, under vacuum conditions, add etherification agent, etherification agent is propylene oxide. In order to reduce the consumption of etherification agent, the etherification agent was add in two times. The first amount is 1-3.5 times that of refined cotton, and the total amount of two add | add is 1.5-4 times that of refine cotton. After adding the etherification agent for the first time, stir at 30 C temperature for 45min-90min, then heat up to 50-100C. Etherification was performe for 1 – 4h. When the refined cotton was reacte adequately with the etherification agent to generate H HPC. Smrush, bag. Assembly: the drying product is crushe and screene, and then the particle ularity of 40 mesh is 10096, or according to the user needs. Then package the factory.


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