Abstract: Cellulose fibres such as wood pulp are made more suitable for reinforcement of cement products by a treatment which reduces their swelling in aqueous and alkaline mediums. The fibres are dispersed in water, allowed to swell, and impregnated with a solution of a titanium and/or zirconium chelate compound. After drying, the fibres are heated to react the chelate compound(s) with the hydroxyl groups on the cellulose fibres, preferably to produce cross-linking between hydroxyl group residues.The treated fibres are more stable in cement media, and, despite their increased hydrophobicity, are dispersible in cement slurries to give good web formation in the manufacture of cement products such as sheet. They impart improved flexural strength and modulus to cement products compared with untreated cellulose reinforcing fibres.

Abstract: Cellulose ester fibres are dry-spun from a solution in an aliphatic carboxylic acid, which solution may comprise the product liquor of the carboxylation reaction used to form the cellulose ester. Spinnability is achieved by incorporating an organic fibre-forming carrier polymer such as poly(ethylene oxide) in the spinning dope. The process may be used to spin cellulose acetate fibres and is economical in avoiding the use of conventional acetate solvents and the various purification stages usually required after the acetate is formed by acetylation. Blow-spinning or centrifugal spinning may be used to spin fine fibres.