The relationship between the viscosity and temperature of HPMC
(1) viscosity measurement: the weight concentration of aqueous solution prepared from the dried products was 2 ℃, and the ndj-1 rotary viscometer was used for measurement.
(2) the appearance of the product is powder-like, and the suffix of instant product is "s", and the suffix of pharmaceutical product is "y", such as me-4000s of instant product is me-4000.
Method of use of hydroxypropyl methyl cellulose
This method is the simplest and shortest method. The specific steps are as follows:
1.A certain amount of boiling water is added to the stirring vessel with high shear stress (cold water is soluble in hydroxyethyl cellulose products, so cold water can be added).
2.Start mixing at a low speed and slowly sieve the product into the mixing container.
3.Continue stirring until all particles are soaked.
4.Add enough cold water and continue stirring until all products are completely dissolved (the transparency of solution increases obviously);
5.Add other ingredients to the recipe.
Preparation of mother liquor: this method is to prepare the product into a higher concentration of mother liquor, and then add to the product.Its advantage is greater flexibility, can be directly added to the finished product.The steps are the same as those in the direct addition method (1-3). After the product is fully wetted, let it cool and dissolve naturally, and then stir it fully before use.It should be noted that: mildew agents must be added to the mother liquor as soon as possible.
Dry mixing: after dry mixing of powder products and powder materials (such as cement, gypsum powder, ceramic clay, etc.), add appropriate amount of water and knead and stir until the product is completely dissolved.
Dissolution of cold water soluble products: cold water soluble products can be directly added to the cold water to dissolve, add cold water after the product will sink quickly, wait for a certain period of time, open stir until completely dissolved.
Notes for preparation of solution
(1) products without surface treatment (except hydroxyethyl cellulose) shall not be dissolved directly in cold water.
(2) the product must be sifted into the mixing container slowly. Do not add large quantities or lumped products directly into the mixing container.
(3) there is a significant relationship between water temperature and ph value of the product, which requires special attention.
(4) do not add some alkaline substances to the mixture before the powder is soaked by water.Increasing the ph value after soaking will help dissolve.
(5) as far as possible, in advance to add mildew agent.
(6) for products with high viscosity model, the weight concentration of mother liquor should not be higher than 2.5-3%, otherwise the mother liquor is difficult to operate.
(7) the products that have been quick-dissolved shall not be used for food or medical products.
hpmc cellulose,hydroxypropyl methylcellulose
,china hpmc cellulose ether manufacturers