GB360017A - Improvements in or relating to the making of sheet material from fibres produced from hides or skins - Google Patents

Abstract

360,017. Fibrous sheet materials. SOC. INVENZIONI BREVETTI ANON.- TORINO, 8, Corso Vittorio Emanuele, Turin, Italy.-(Assignees of Mackay, A. ; Asbury Park, New Jersey, U.S.A.) July 29, 1930, No. 22847. Convention date, Nov. 29, 1929. [Class 140.] In a process for making sheet material from. fibres obtained from hides or leather by depositing the fibres from a slurry or suspension thereof upon a reticulated support, a portion of the desired length of a formed sheet is wound on a reel, the formation of a second sheet is commenced and simultaneously the two sheets are superposed by connecting the rear end of the first sheet with the front end of the second sheet which is being formed, a layer of adhesive being interposed between the sheets. The material treated, which may be tanned or untanned hides or leather or scraps or cuttings therefrom, is first disintegrated and washed, and a slurry of the fibres in water is made. In the case of tanned fibres, the acidity of the fibres is neutralized, for example by the addition of an alkali such as sodium carbonate, and if the fibres are mineral tanned, by the addition of Rochelle salts to the slurry. A tanning solution such as sumach or quebracho, or mineral tanning agents or synthetic tannins, is then added, and an emulsifiable oil such as sulphonated cod oil or colloidal neat'sfoot oil. The slurry is then preferably neutralized with a mild alkali such as sodium carbonate. A binding material is then added, preferably a waterproof binder ; rubber, guttapercha, or balata latex may be used, or a synthetic latex. After complete incorporation of the binder, the slurry is treated with alum, tannic acid, an organic acid or other catalyst to precipitate the binder on the fibres. The slurry is then fed on to a travelling reticulated conveyer. 1, for example, of wire gauze, which passes over a roll 2, at which point the slurry is subjected to suction to extract the liquid. The forward end of the sheet is taken off the conveyer by a felt 3 and carried beneath a presser roll 4, and passes to a reel 5, which may be heated. After a length of material has been wound on the reel, the latter is shifted to the right, and the sheet cut. The cut end of the sheet is then superposed on the leading end of the new sheet being formed, the two sheets being passed together under the roll 4 and wound upon a second reel 5. Adhesive such as casein, latex, glue, rubber cement, or oil, is sprayed between the two sheets by means of a sprayer 8. The compound material is afterwards passed through pressure rollers and around drying rollers. The preliminary treatment of the fibres may be varied from that described; colouring material may be added to the slurry.