The Principles of Leather Manufacture

by H. R. Procter

The International Association of Leather Trades Chemists — The American Official Association of Agricultural Chemists — The sampling of material — Preparation of solution for analysis — Extraction of solid materials — Total soluble matter — Evaporations of solutions — The weighing of residues — The determination of non-tannins — The hide-powder filter method — The hide-powder shake method — Determination of moisture — Colour-measurement PAGE [300]

CHAPTER XXI.

THE GRINDING OF TANNING MATERIALS.

Primitive methods of grinding — The bell mill or coffee mill — Disc mills — Disintegrators — Carr’s disintegrator — Carter’s disintegrator — Adjustment of disintegrators — The Williams pulveriser — Myrobalans and Valonia crushers — Sawing mills — Shaving mills — Dyewood cutting machines — Screening of ground materials — Hatching of bark — Disintegrators and fire insurance — Dust from disintegrators — Chain conveyors — Belt conveyors — Vibrating conveyors PAGE [316]

CHAPTER XXII.

THE EXTRACTION OF TANNING MATERIALS, AND THE MAKING OF EXTRACTS.

Leaching — Early forms of leaches — The press-leach system — Handling of liquors — Distributing troughs and valves — Construction of leaches — Influence of temperature — Use of silent boiling jet — Closed extractors — Sprinkling leaches — Manufacture of extracts — Decolorisation of extracts — Soluble extracts — Concentration of extracts — Yaryan evaporator — Multiple effects — The use of extracts in the tannery — Effect of temperature on extraction and colour PAGE [328]

CHAPTER XXIII.

FATS, SOAPS, OILS AND WAXES.

Characteristics of fats and oils — Chemical constitution — Nature and production of soaps — Insoluble soaps — Distillation of fats — Solvents of oils — Drying oils — Saturated fatty acids — Non-drying liquid fatty acids — Less-saturated liquid fatty acids — Castor oil — Tallow — Neatsfoot oil — Wool fat — Holden fat — Distilled wool grease — Distilled stearine — Olive oil — Castor oil — Turkey-red oil — Linseed oil — Boiled oils — Japan for leather — Cottonseed oil — Sesame oil — Cod oil — Shark liver oil — Whale oil — Seal oil — Menhaden oil — Fish oils — Fish tallow — Dégras and Sod oil — Waxes — Sperm oil — Beeswax — Carnauba wax — Japan wax — Volatile or essential oils — Birch oil — Wintergreen oil — Mineral oils and waxes — Vaseline and vaseline oil — Paraffin wax — Ozokerit — Resin oils — Resin PAGE [350]