Improvements in or relating to the production of alkyl celluloses in a powdered form

A process for the production in powdered form of alkyl celluloses of the kind soluble in cold water and not in hot water comprises mixing a fibrous form of such alkyl cellulose and hot water, at a temperature above that at which it is soluble, in an amount at least sufficient to cause complete gelatinization at low temperatures, cooling the mixture to a temperature at which the alkyl cellulose forms a gelatinous solution, and heating this solution until the water present is driven off while continuously mixing with such intensity that the non-fibrous alkyl cellulose which is continuously precipitated is progressively converted into a substantially dry powder. The powder can be comminuted into a fine pulverulent form. The temperature at which the hot water and alkyl-cellulose are mixed may vary between the precipitation temperature and 100 DEG C. and the temperature to which the mixture is cooled is stated in examples to be 25 DEG C., 30 DEG C. and 35 DEG C. The alkyl cellulose may be a methyl-cellulose, methyl-ethyl-cellulose, ethyl-cellulose, ethyl-hydroxyethyl-cellulose or methyl-hydroxyethyl-cellulose. Specification 653,772 is referred to in the Provisional Specification.