College duo comes up with eco-friendly tanning process
leather has always been in vogue. This time round, it will be eco-friendly leather that will dominate the markets if the two final-year students of the Government College of Engineering and Leather Technology, Kolkata, get a patent for their product -- eco-friendly leather made out of fish skin.
Sandip Das and Risin Dey, the two young leather technologists, claim the leather from fish skin is soft to touch and is as sturdy and utilitarian as cow or buffalo skin leather. But the technology behind the novelty is still under wraps as the duo has applied for an Indian patent and were not letting out the green method they used for tanning yards of fish leather in their college laboratory.
Study results, certified by the college, have cleared their claim of the absence of the usual toxic tannery effluents like sulphides and hexavalent chromium in the process of making leather out of fish skin. The chemical treatment protocol developed by Das and Dey comprises the usual steps of salting, liming, deliming with, what they call, "harmless chemicals" and then tanning. And thus eco-friendly.
While fish leather has a tensile strength (weight carrying capacity) ranging between 175 and 220 kg/cm2, the tensile strength of other leather varieties like cow, buffalo and goat skin is in the range of 150 to 250 kg/cm2. This makes fish leather almost as sturdy as any other leather. Also, it is quite cost effective. The production cost of conventional leather varies between Rs 70 and Rs 90 per square feet but the technologists have shown through their small-scale production that fish skin leather would cost less than Rs 4 per metre square.
They are also in the process of experimenting with an array of lifestyle accessories and are collaborating with Bradish Anilene Soda Fabriquin, a German multinational. "After the news of our new leather material spread, we have been flooded with queries from many leather companies interested in this highly profitable venture," says Dey. Profitable because the raw material is obtained from locally available fish skin, generally discarded by vendors. According to Dey, Kolkata alone produces over 80 tonnes of fish skin per day. The potential can be tapped to create a vibrant cottage leather industry for unemployed youth, who do not have to worry about the initial investments. But the only problem with fish skin is its size. Unlike cow or buffalo skin, the length and width of fish skin is smaller in size.
"If we have to make a pair of shoes or a bigger bag, we need bigger pieces of fish skin and for that we need to get the fish specially skinned so that there are no cuts and nicks in between. We also need to take care that we get exactly the same leather patterns for both pairs of shoes," says Dey.
To overcome the problem, the duo suggested in their report to the government that it would be a good idea to genetically breed large fish varieties at the West Bengal University of Animal and Fisheries Sciences to procure bigger and stronger skin spreads. They have also submitted a report to the West Bengal fisheries ministry to create infrastructure for a downstream industry near fish markets consisting of a skin collection and processing chain unit.
Fish skin leather may be an inviting option but the promise of an ecofriendly formula for tanning is what is intriguing. The young scientists are looking forward to a large-scale commercial launch of their fish leather products by the end of this year. Meanwhile, the patent acceptance is awaited.
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