Patent GB-835502-A (GB)
Title: A method of scouring wool by means of solvents
Inventor: AGATSUMA TADAO
IPC: D01C3/00
Filed: 1958-01-28
Abstract: Lanolin is obtained in a process for cleansing greasy wool which comprises passing the wool through a plurality of cleansing stages, in each of which it is contacted with an organic solvent capable of dissolving the oils and fats contained in the wool, passing a proportion of the fat-containing solvent obtained from each but the first stage to the preceding stage, to constitute the solvent with which the wool is contacted in that preceding stage, said proportion being dependent on the oil and fat content of the wool, while supplying fresh solvent to the last cleansing stage, and pressing the wool after each cleansing stage before passing it to the next so as to leave a predetermined desired amount of residual fat in the wool, the lanolin being recovered from the solvent waste.  Specified solvents are trichloroethylene and perchloroethylene.  Solvent waste from the cleansing stages is preferably filtered, suitably with heating and with the addition of a peptizer, e.g. an organic acid, such as formic acid or acetic acid, or an alcohol, such as methanol or ethanol, to prevent impurities from assuming a colloidal state, and is then passed to a solvent recovery unit where it is distilled and the vaporized solvent condensed and recycled, the lanolin being recovered from the solvent waste as the residue of the distillation.ALSO:A process for cleansing greasy wool comprises passing the wool through a plurality of cleansing stages, in each of which it is contacted with an organic solvent capable of dissolving the oils and fats contained in the wool, passing a proportion of the fat-containing solvent obtained from each but the first stage to the preceding stage, to constitute the solvent with which the wool is contacted in that preceding stage, said proportion being dependent on the oil and fat content of the wool, while supplying fresh solvent to the last cleansing stage, pressing the wool after each cleansing stage before passing it to the next so as to leave a predetermined desired amount of residual fat in the wool, and recovering the lanolin from the solvent waste.  Fresh solvent may also be supplied to the first scouring stage.  Specified solvents are trichlorethylene and perchlorethylene.  After cleansing, the wool may be dried in a drying chamber and the vaporized solvent passed to a condenser, any unliquefied vapour which has passed through the condenser being re-heated and re-cycled to the drying chamber.  Alternatively, the treated wool may be dried by forcing air therethrough and the air containing vaporized solvent passed into a heavy oil capable of dissolving the solvent, the solvent being subsequently recovered from solution in the heavy oil. Solvent waste from the cleansing stages is preferably filtered, suitably with heating and with the addition of a peptizer, e.g. an organic acid, such as formic acid or acetic acid, or an alcohol, such as methanol or ethanol, to prevent impurities from assuming a colloidal state, and is then passed to a solvent recovery unit where it is distilled and the vaporized solvent condensed and recycled, the lanolin being recovered from the solvent waste as the residue of the distillation.