Enzymes are macromolecular biological catalysts. Like all catalysts, enzymes increase the rate of a reaction by lowering its activation energy. Some enzymes can make their conversion of substrate to product occur many millions of times faster. Chemically, enzymes are like any catalyst and are not consumed in chemical reactions, nor do they alter the equilibrium of a reaction. Enzymes differ from most other catalysts by being much more specific.
Surfactants are compounds that lower the surface tension (or interfacial tension) between two liquids or between a liquid and a solid. Surfactants may act as detergents, wetting agents, emulsifiers, foaming agents, and dispersants. Surfactants are usually organic compounds that are amphiphilic, meaning they contain both hydrophobic groups and hydrophilic groups. Therefore, a surfactant contains both a water-insoluble (or oil-soluble) component and a water-soluble component. Surfactants will diffuse in water and adsorb at interfaces between air and water or at the interface between oil and water, in the case where water is mixed with oil.
Tanning or retanning agents are used during the wet end operations of leather processing for retanning of chrome tanned wet blue leather. Use of tanning or retanning agents in retanning of wet blue leather help to modify the physical properties of leather with respect to its strength, softness, fullness, weather resistance, dye penetration, levelness and brilliance of dye shades, grain characteristics etc. Retanning of chrome tanned leather with tanning or retanning agents produces crust leather which is then subjected to finishing operations using leather chemicals that include acrylic binders, lacquer emulsions and wax emulsions etc. to produce finished leathers.
Fatliquoring agents based on synthetic and natural oils and waxes, with especially designed products for any process step of leather and fur production. The fatliquoring agents are roughly classified in an emulsion type and a non-emulsion type. The emulsion type fatliquoring agents include anionic type ones such as sulfated oil, sulfited oil, sulfonated oil, soap, phosphated oil and aliphatic acid condensate base oil; cationic ones such as aliphatic acid amine base oil; amphoteric ones such as aminocarboxylic acid base oil and betaine compounds; and nonionic ones such as polyethylene oxide derivatives. The non-emulsion type fatliquoring agents include natural oils such as fish oil, beef tallow oil, vegetable oil (olive oil), animal oil (beef tallow, lard and mutton tallow), wool grease, mineral oil, wax, paraffin wax and the like.
Leather dyes have an affinity for leather, used for changing the color of all smooth leather items. Leather dyes require a good resistance to light, washing and rubbing fastness, good leveling property, non-toxic, non-polluting and safe to use. Leather dyes mainly include acid dyes, direct dyes, basic dyes, metal complex dyes and reactive dyes.
Finishing play a vital role in the process of in the leather making process.It can enhance the quality and the grades of leather. The finishing agents include nitrocellulose luster emulsions mo dified with polyurethane, acrylate emulsions, aqueous polyurethane dispersions, acrylate -polyurethane latex interpenetrating polymer networks ( LIPN ), acylate emulsions modified with polysiloxane, aqueous polyurethane dispersions modified with polysiloxane, etal.