Council of Scientific and Industrial Research

Jonnalagadda Raghava Rao

Balachandran Unni Nair

Thirumalachari Ramasami

Palanisamy Thanikaivelan

Mookandi Kanthimathi

Subramani Saravanabhavan

Ramasami Thirumalachari

Kalarical Janardhanan Sreeram

Thanikaivelan Palanisamy

Murugan Chandrabose

Bangaru Chandrasekaran

Nishtar Nishad Fathima

Saravanabhavan Subramani

Palanivel Saravanan

Rathinam Aravindhan

Gladstone Christopher Jayakumar

Balaraman Madhan

Conventionally skins/hides are tanned with metal-ions and vegetable tannins. Environmental constraints on the discharge of toxic metal-ions and poor biodegradable vegetable tannins in the wastewater have become a serious issue. In this invention, the pelts are tanned using eco-benign bio-molecules other than vegetable tannins to reduce the pollution loads. Performance of the leathers is on par with conventionally processed leathers.

Bio-tanning process for leather making

A process of combination tannage is disclosed whereby Zirconium salt is complexed with THP salt to produce wet pink leather without using any conventional dye. The resulting leathers exhibit a shrinkage temperature of more than 100&#xb0; C., and other properties comparable to those of conventionally processed leathers.

Process for making wet-pink leather

A novel synthetic aluminium tanning agent as an alternative for chromium based tanning salts without using formaldehyde was prepared by using aromatic polymeric matrix and aluminium (III) salts as raw materials with suitable masking agents. The preparation of the syntan consists of sulphonation of aromatic molecule, which is incorporated with a polymeric network along with ligands specially designed for the complexation of aluminium (III) salts. The complex can be used as a self-tanning agent in leather industry with fairly good filling behavior. The tanned leathers exhibit shrinkage temperature about 85&#xb0; C. Due to the higher precipitation point of the product, it can be used for tanning directly after deliming thus eliminating the pickling process. This product, unlike the conventional phenol based products, does not undergo photo-oxidation thereby preventing the discoloration of the tanned leathers.

Process for preparing a synthetic aluminium tanning agent

A process for the preparation of a synthetic tanning agent is disclosed whereby multi functional polymer is polymerized with sulfonated aromatic compound, pretreated with organic ligand to form an organo-polymeric matrix, which is essentially formaldehyde-free. The product has potential application in leather industry as an eco-friendly approach to chrome tanning by eliminating the conventional pickling process and the related problem of total dissolved solids (TDS) associated with the effluent. The present invention also provides for an exhaust aid for chrome due to its multiple carboxyl groups.

Process for the preparation of a formaldehyde-free synthetic tanning agent

The present invention relates to a novel leather making process whereby the post-tanning wet operations are done prior to tanning stage itself to make leather in eco-friendly manner in substantially shorter duration. The present process reduces the number of required steps for leather processing and the pollution load generated in comparison to conventional leather processing.

Transposed process for making leather

The use of lime and sodium sulfide in leather making creates a lot of environmental concern. However, there is no commercial beam house process that could totally eliminate the use of lime and sodium sulfide. In this invention, a novel bio-chemical process has been standardized employing specific enzymes and non-toxic chemical that could totally eliminate the use of lime and sodium sulfide in leather processing. It has been found that the extent of hair removal and opening up of fiber bundles is comparable to that of the conventional limed leathers. Performance of the leathers is shown to be on par with conventionally leathers. The process also enjoys reduction in chemical oxygen demand and total solids load compared to conventional process.

Dehairing and fiber opening process for complete elimination of lime and sodium sulfide

The present invention relates to an eco-friendly beam house process for de-hairing of leather using commercially available enzymes that obviates the use of lime and other alkalis. The present invention also provides an alternate process for opening the fibers of leather using commercially available enzymes. The present invention further provides a three-step process for tanning hide or skin in a narrow pH range of from about 7.5 to about 8.5.

Growing community of inventors

Chennai, India

Jonnalagadda Raghava Rao