The present invention provides a method of manufacturing leather, which not only significantly suppresses the occurrence of adhesive wrinkling and boarding/alighting wrinkling when used for an automobile seat, for example, but also exhibits appropriate flexibility.

The present invention is a method of manufacturing leather including a pretreatment step, a tanning step, a retanning step, and a drying and finishing step in this order, the retanning process including, in the following order, subjecting a shaving leather obtained from the tanning process to a stage of performing treatment using a predetermined retanning agent and a predetermined resin, a stage of performing treatment using a predetermined retanning agent, a predetermined resin, and a predetermined fatliquoring agent, and a stage of performing treatment using a predetermined resin and a predetermined fatliquoring agent, and the drying in the drying and finishing process including, in the following order, subjecting a leather obtained from the retanning process to a stage of drying under reduced pressure under predetermined conditions and a step of drying at atmospheric pressure under predetermined conditions.

A method for tanning a hide wherein said method comprises treating a tannable hide with a tanning composition comprising from 25 to 75% by weight (wt. %) of at least one chromium(III) salt; from 5 to 70% by weight (wt. %) of at least one zeolite having the general formula (1): Mx/n [(AlO.sub.2)x(SiO.sub.2)y] wH.sub.2O, wherein M is an alkali metal cation, a bivalent cation, a trivalent cation or a mixture thereof, n is the valence of the cation, w is the number of water molecules per unit cell, y is a number from 0.8 to 50 and the ratio y to x is ranging from 0.7 to 100, treated with at least one acid selected from the group consisting of a monocarboxylic acid and a polycarboxyic acid; and from 1 to 70 wt. % of at least one aluminium(III) salt; wherein all wt. % are relative to the total weight of the composition (T).

A method for tanning a hide wherein said method comprises treating a tannable hide with a tanning composition comprising from 25 to 75% by weight (wt. %) of at least one chromium(III) salt; from 5 to 70% by weight (wt. %) of at least one zeolite having the general formula (1): Mx/n [(AlO.sub.2)x(SiO.sub.2)y] wH.sub.2O, wherein M is an alkali metal cation, a bivalent cation, a trivalent cation or a mixture thereof, n is the valence of the cation, w is the number of water molecules per unit cell, y is a number from 0.8 to 50 and the ratio y to x is ranging from 0.7 to 100, treated with at least one acid selected from the group consisting of a monocarboxylic acid and a polycarboxyic acid; and from 1 to 70 wt. % of at least one aluminium(III) salt; wherein all wt. % are relative to the total weight of the composition (T).

A process for tanning animal hides comprising the steps of: providing a container comprising a pickled hide, a tanning agent and optionally an aqueous solution, where the total amount of water in the container is no more than 110% of the total water that can be retained by the pickled animal hide, and where the total amount of tanning agent in the container is no more than 110% of the total tanning agent that can be retained by the pickled animal hide, and basifying the animal hide to bind the tanning agent in the animal hide.

A process for tanning animal hides comprising the steps of: providing a container comprising a pickled hide, a tanning agent and optionally an aqueous solution, where the total amount of water in the container is no more than 110% of the total water that can be retained by the pickled animal hide, and where the total amount of tanning agent in the container is no more than 110% of the total tanning agent that can be retained by the pickled animal hide, and basifying the animal hide to bind the tanning agent in the animal hide.

Methods and systems for sorting hides are provided. In particular, one or more embodiments comprise a tanning control system that enhances the traceability of hides by capturing and utilizing data related to the unloading, tanning, sorting, and packaging of hides. Furthermore, one or more embodiments enable the tanning control system to improve efficiency by sorting hides based, at least in part, on data generated during prior tanning processes. Additionally, one or more embodiments facilitate the tanning control system in customizing the sorting and packaging of hides based, at least in part, on one or more hide characteristics and/or customer specifications.

Methods and systems for sorting hides are provided. In particular, one or more embodiments comprise a tanning control system that enhances the traceability of hides by capturing and utilizing data related to the unloading, tanning, sorting, and packaging of hides. Furthermore, one or more embodiments enable the tanning control system to improve efficiency by sorting hides based, at least in part, on data generated during prior tanning processes. Additionally, one or more embodiments facilitate the tanning control system in customizing the sorting and packaging of hides based, at least in part, on one or more hide characteristics and/or customer specifications.

A recycling process for achieving near-zero emissions of tannery effluent is characterized in that effluent recycling is carried out independently in soaking, liming, re-liming, de-liming bating, pickling chrome tanning, re-tanning, neutralizing, and dyeing procedures. The effluents in the above procedures can be recycled in each step. This process greatly reduces effluent discharge and helps solve the problem of tanning pollution. The process also improves the quality of the finished leather, effectively decreases loose grain rate and increases compactness and fullness of the finished product. The project can reduce chemical material consumption by 15%-55%. For example, the consumption of chromium powder can be reduced up to 65%. Consumption of other chemical materials can be reduced by more than 90%, while certain chemical materials can be essentially completely conserved.

A recycling process for achieving near-zero emissions of tannery effluent is characterized in that effluent recycling is carried out independently in soaking, liming, re-liming, de-liming bating, pickling chrome tanning, re-tanning, neutralizing, and dyeing procedures. The effluents in the above procedures can be recycled in each step. This process greatly reduces effluent discharge and helps solve the problem of tanning pollution. The process also improves the quality of the finished leather, effectively decreases loose grain rate and increases compactness and fullness of the finished product. The project can reduce chemical material consumption by 15%-55%. For example, the consumption of chromium powder can be reduced up to 65%. Consumption of other chemical materials can be reduced by more than 90%, while certain chemical materials can be essentially completely conserved.

In a method of producing leather comprising a plurality of steps, methanesulfonic acid is used in at least one step.