GB573180A - Improvements in and relating to dry carroting fur - Google Patents

Abstract

573,180. Carrotting fur. TRIGGS, W. W. (No- Mercury Felt Corporation). April 7. 1943, No. 5561. [Class 76] A process for "dry-carrotting" fur on the pelt comprises mixing a highly active concentrated liquid carrotting solution with pieces of substantially non-absorbent attrition material, which carry the solution without 'absorption thereof, to the exclusion of free-flowing liquid, tumbling the mixture with the pelts, and then separating the attrition material. The process is carried out in a rotating wooden drum, which may be glass lined and have an interior baffle, for a period not exceeding about 60 minutes (e.g. 15-30 minutes), the attrition material being then separated using a rotating cage, wherein the pelts may be treated with moving heated air. The attrition material has a specific gravity preferably less than 2, and in the examples consists of powdered flint, shredded rubber, wooden chips coated with paraffin wax, or pieces of synthetic resin, e.g., polystyrene. Pumice, carborundum, comminuted rubber, hard paraffin wax, natural or synthetic resins, e.g., Lucite, bituminous material, and asphalt (which may or not be hardened with sulphur) are also referred to. Carrotting reagents used in the examples are concentrated sulphuric and nitric acids, chloric acid, used either singly or in combination, to which may be added hydrogen peroxide and potassium permanganate as oxidising agents. Sulphamic acid, as a carrotting agent, and potassium or ammonium persulphate as an oxidiser, are also mentioned. A catalyst consisting of small quantities of zinc sulphate and chromium potassium alum may be used, the latter having a slight tanning action. The acidity of the carrotting solution may be reduced by adding an alkali such as ammonium or sodium carbonate or caustic soda to the contents of the tumbling drum. In the carrotting process it is preferable to protect the flesh side of the skin by coating with e.g., nitrocellulose lacquer, by securing two skins together, or by folding each skin.