CONTINUOUS PROCESS FOR MAKING FIBROUS CELLULOSE ACETATE FILTER MATERIAL

摘要

Fibrous cellulose acetate resembling asbestos in fibrous structure and liquid filtering properties which is useful for filtering potable liquids such as fruit juices, vegetable juices and wine is made continuously by introducing a stream of a 2-4% by weight solution of cellulose acetate of 25-45 secs. viscosity in acetone and a stream of water into a mixing T at velocities which create substantial turbulence and at a water:solution volume ratio of 4:1 to 20:1, continuously withdrawing the resulting cellulose acetate slurry from the mixing T and passing it through a mechanical shearer which shears the precipitate to a surface area in the range of 35-55 m2/g and thereafter depositing the slurry on a porous support to drain unabsorbed water/acetone from the precipitate and washing the precipitate with water until it is substantially acetone-free.