A method for making mixed polymer composite fibers containing cellulose fibers in which cellulose fibers are dispersed in an aqueous solution comprising a carboxyalkyl cellulose and a galactomannan polymer or a glucomannan polymer in water to provide an aqueous fiber dispersion; the aqueous dispersion treated with a first crosslinking agent to provide a gel; the gel mixed with a water-miscible solvent to provide composite fibers; and the composite fibers treated with a second crosslinking agent to provide crosslinked fibers.