Abstract: The preparation of a pepsin extract from the stomach of pigs, sheep or cattle, which is suitable for the bating of hides, is presented. The process involves macerating the stomach mucous, sedimenting the material, reserving the middle layer for pharmaceutical preparation, combining the other two layers, drying them and adding salt for preservation. The resulting pepsin containing material is particularly suitable for acid enzymic bating of chrome tan hides after the pickle process with the main purpose of obtaining a higher surface yield and a softer leather.

Abstract: The present process yields superior leather materials from limed hides, without the use of chromium salts, by combining a series of essential method steps in a sequence which yields leather having a "chrome" character. The present chromium-free tanning process includes the method steps of pretanning a hide with a chromium-free tan until its shrinkage temperature is about 170.degree. to 185.degree. F., submerging the hide in an acidic brine, having a pH between 2.5 and 3.5, and adding (in sequence, and in amounts sufficient to yield specified concentrations of each) pretanning agents, syntans, vegetable extracts, neutralizing agents and retanning and finishing agents, all of which are free from chromium. This method of pretanning, tanning and retanning a hide with a specified sequence of particular concentrations of chromium-free reagents yields a leather product having the characteristics of chrome-tanned leather and which demonstrates superior shrink resistance, resilience and flexural strength.

Abstract: The present process yields superior leather materials from limed hides, without the use of chromium salts, by combining a series of essential method steps in a sequence which yields leather having a "chrome" character. The present chromium-free tanning process includes the method steps of pretanning a hide with a chromium-free tan until its shrinkage temperature is about 170.degree. to 185.degree. F., submerging the hide in an acidic brine, having a pH between 2.5 and 3.5, and adding (in sequence, and in amounts sufficient to yield specified concentrations of each) pretanning agents, syntans, vegetable extracts, neutralizing agents and retanning and finishing agents, all of which are free from chromium. This method of pretanning, tanning and retanning a hide with a specified sequence of particular concentrations of chromium-free reagents yields a leather product having the characteristics of chrome-tanned leather and which demonstrates superior shrink resistance, resilience and flexural strength.

Abstract: A surface active agent is comprised of lignin sulfonic acids, and optionally, an alkylaryl sulfonic free acid with at least 10 carbon atoms and a polypeptide having a molecular weight of about 2,500 to about 15,000. In addition, a disperse dye composition is provided which includes solid particles of a dye or pigment which have a particle size of less than 2 microns with the surface active agent disposed at the surface of the particles.

Abstract: A surface active agent is comprised of lignin sulfonic acids, and optionally, an alkylaryl sulfonic free acid with at least 10 carbon atoms and a polypeptide having a molecular weight of about 2,500 to about 15,000. In addition, a disperse dye composition is provided which includes solid particles of a dye or pigment which have a particle size of less than 2 microns with the surface active agent disposed at the surface of the particles.

Abstract: A method of forming soluble collagen fibers from raw animal hides is disclosed. Raw animal hides are treated with an aqueous solution of an alkali metal hydroxide and a dehydrating agent to remove the hair and fat therefrom to yield a substantially fat-free corium. The interfibular bonds of the collagen in the corium are stabilized with an aqueous solution of an alkali sulfate. The corium is neutralized and dissolved in an aqueous acid solution to yield a collagen solution. The pH of the aqueous collagen solution is adjusted to the isoelectric point of the collagen to precipitate the collagen fibers from the solution. The collagen fibers are dried. The collagen fibers so produced are useful in edible food, may be redissolved and further processed for a plurality of uses.

Abstract: A leather tanning composition comprises a sufficient amount of the reaction product of a polyaldehydic compound and a secondary amine to increase the shrinkage temperature of a hide.

Abstract: A method of preparing oligopeptides from collagen is disclosed. Collagen containing material is treated with an aqueous solution of a member selected from the group consisting of an alkali earth metal hydroxide, an alkali metal hydroxide and mixtures thereof in the presence of an agent which prevents overswelling of the collagen. The treatment removes substantially all of the hair and fat from the collagen. The remaining non-collagenous material is removed by treating the dehaired and defatted collagen with an aqueous solution which acts as a solvent for the non-collagenous material. The collagen is neutralized and residual salts are removed therefrom. The collagen is heated under pressure in the presence of water to hydrolyze polypeptide chains to form oligopeptides having a molecular weight of between about 5,000 and 20,000. The recovered oligopeptides are particularly useful as a trophic agent for feeding animals.

Abstract: Manufacture of grain and split leather is simplified by pre-tanning hide with a chromium-free tan until its shrinkage temperature is about 170.degree. to about 185.degree. F, splitting the pre-tanned hide to provide a grain intermediate and a split intermediate, shaving at least one of these intermediates, and chrome-tanning the shaved intermediate. Shavings contain no chromium and can be disposed of by dumping, without significant environmental impact. Before splitting, the hide can also be pickled to improve the splitting and shaving and make the unfinished hide better suited for shipping to remote geographical areas. Entire hide treatment sequence can be effected with two stages in which batches of hides are loaded in a container such as tumbling drum; unhairing, bating and pre-tanning with or without a pickle, all in one stage, and final tanning, coloring and fat-liquoring in another stage.