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.

Provided are a leather improving agent which exhibits the effect of suppressing contraction of hide to enlarge the area; and a method for treating leather using the leather improving agent. The leather improving agent comprises an M23A subfamily protease as an active ingredient.

Provided are a leather improving agent which exhibits the effect of suppressing contraction of hide to enlarge the area; and a method for treating leather using the leather improving agent. The leather improving agent comprises an M23A subfamily protease as an active ingredient.

The present invention relates to a process for producing leather in which methanesulfonic acid (MSA) is used in the pickling step at a high pH value, and the use of MSA is to improve the quality of the final leather product as well as to improve the environmental impact of the waste liquor.

The present invention relates to a process for producing leather in which methanesulfonic acid (MSA) is used in the pickling step at a high pH value, and the use of MSA is to improve the quality of the final leather product as well as to improve the environmental impact of the waste liquor.

A process for leather production from a raw animal hide includes the steps of pre-soaking, soaking, unhairing and liming, re-liming, deliming and bating, pickling and tanning, degreasing, re-tanning, neutralizing, dyeing and fatliquoring, and washing the processed hide. Waste liquid is collected from at least one of the foregoing steps is recycled to at least one of the foregoing steps. The collected waste liquid can be recycled to the same step, to a different step, or to two of more steps in the process.

A process for leather production from a raw animal hide includes the steps of pre-soaking, soaking, unhairing and liming, re-liming, deliming and bating, pickling and tanning, degreasing, re-tanning, neutralizing, dyeing and fatliquoring, and washing the processed hide. Waste liquid is collected from at least one of the foregoing steps is recycled to at least one of the foregoing steps. The collected waste liquid can be recycled to the same step, to a different step, or to two of more steps in the process.

A method for preserving hides, skins and pelts prior to tanning, without salt-curing. The hides are fatliquored, pickled and dried, all prior to tanning. The method may include the preliminary steps of washing, fleshing, liming and unhairing followed by the steps of fatliquoring, deliming, bating, pickling and drying. The method avoids the environmental damage caused by salt-curing. The treated hides are dry, flexible and readily rehydrated for further processing.

A method for preserving hides, skins and pelts prior to tanning, without salt-curing. The hides are fatliquored, pickled and dried, all prior to tanning. The method may include the preliminary steps of washing, fleshing, liming and unhairing followed by the steps of fatliquoring, deliming, bating, pickling and drying. The method avoids the environmental damage caused by salt-curing. The treated hides are dry, flexible and readily rehydrated for further processing.

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.