Leather Processing

Leather Processing Technology

Less salt curing system
The technology provides an option to replace a substantial amount of salt with other agents like boric acid, biocide for the purpose of curing of raw hides and skins. Whereas the enormous amount of salt ( about 40% on raw weight) used in conventional method of curing contributes to a large extent for the environmental pollution relating to Total Dissolved Solids (TDS), this technology does not employ more than 5% salt, thereby providing an eco-benign method for curing of raw hides and skins. The process has been investigated using goatskins. It has been found effective in field testing, carried out in one of the tanneries at Ambur, having linkages with primary raw skin collection centers in Mumbai.

Sludge Free Liming Process
It is an eco-friendly, sludge free liming process resulting in improved quality of leather. The process involves liming the well-soaked raw hides and skins wherein, unlike the conventional process, no lime sludge is formed in the lime bath, thereby reducing the load of beam house effluent. The unique feature of the process is to carry out liming, avoiding completely the use of lime.

Total lime and sulfide free enzymatic dehairing
It is essentially an enzymatic process to completely eliminate lime/sulfide, conventionally used for dehairing of hides/skins, thereby providing an eco-friendly option for dehairing in tanning industry. The enzymes are extracted from both animal as well as plant sources. The unique feature of the process lies in providing an eco-friendly option to produce dehaired pelt without adding to effluent load. The technology has been transferred.

Lime free fibre opening
The technology relates to the use of bio-product in order to avoid lime, which is conventionally used for the purpose of fibre opening of pelts. When coupled with lime free unhairing, this technology offers possibilities of direct pickling without resorting to deliming after fleshing. The technology has been found to be effective for all the substrates – cow, buffalo, goat, sheep. Finished leathers processed through such fibre opening technique were found to be comparable with conventionally processed leathers in all aspects.

Ammonia free deliming of skins/hides
The process is an eco-friendly option for deliming of hides/skins which involves passing carbon-di-oxide while agitating the deliming bath, at a temp. of 30-34 o C. The process has enormous potential, especially in view of the emerging stringent regulation in certain countries against the use of ammonium salt, which is conventionally used for the purpose of deliming.

High Exhaust Chrome Tanning
While the conventional chrome tanning ensures a maximum of 60-70% exhaustion of chrome resulting in wastage as well as adding to pollution load, this process technology provides a process, whereby more than 90% exhaustion of chrome has been possible. Sectional streams of chrome tanning solutions may contain about 1500-3000 ppm of chrome depending on the absorption level, causing a serious environmental concern. An approach based on closed pickle-tan loop and ALUTAN-BCS has been successfully found to ensure near total utilization of chromium. The process has been shown to offer an overall reduction of Rs. 2000/- per ton of leather processed in chemical costs in addition to the significant environmental benefits. In other words, the recycling method leads to the reduction of BOD, COD and TDS in the effluent. The unique feature of the process lies in providing an economical as well as eco-friendly approach to produce wet blue leather of improved quality.

Eco-friendly leather processing
This relates to a package of different technologies, which are environmentally friendly. Hexavalent chromium formation poses serious problem in leather production. Suitable treatment methodologies have been evolved using reducing agents to avoid formation of Cr(VI) in leather. The process technologies have been standardized for the production of cow upper and sheep nappa garment leathers. Moreover, lime and sulfide free enzymatic-processing options also form part of this package.

Finishing of Split Leather By Transfer Coating Technology This is a novel finishing technique for ensuring value addition while finishing split/low grade leathers. The process involves casting film of the finishing 'season', prepared by conventional method, on release paper, followed by subsequent transfer of the same to the split / low grade leather, to be upgraded while finishing. Varieties of grain patterns such as goat, cow, ostrich, emu, etc can be imparted on to the splits by using release papers of the respective designs.
The unique feature of the process is that it ensures natural leather-look and adds substantial value to split/low grade leathers thereby ensuring their economical utilisation.

Buffalo Automotive Upholstery Leather
The process for the manufacture of upholstery leather from buffalo hides involves green fleshing, enzymatic unhairing, lime splitting, ammonia free deliming, followed by use of polymer fatliquor and subsequent aqueous finishing. The uniqueness of the product is that it is manufactured from buffalo hides using appropriate chemicals to impart fog as well as flame resistant properties on leather. These leathers are very much suitable as seat covers for car and aircraft.