India develops new tanning technology25 February 2008
According to a recent edition of the journal Chemistry & Industry, scientists at the CLRI in India report that they have developed a new tanning technology that makes the process substantially more eco-friendly. Tanning as we know can produce high levels of water pollution.
Raghava Rao and his team at the Central Leather Research Institute in Adyar, have modified the process to make it into an eco-friendly, more cost-efficient technology. The researchers found that by simply reversing the order of the tanning and post-tanning steps and promoting non-chemical-based pre-tanning methods they were able to reduce the amount of chemicals released by 82% and achieve an energy saving of nearly 40%. Rao said: ‘The significance is tremendous in the context of environmental challenges being faced by the leather industry. Most importantly, no loss of the leather quality was observed when compared with conventional tanning methods.' Our technical editor Graham Lampard writes: ‘Back in the 60s Otto in Germany suggested that complexing chromium and adding it after the deliming step would ensure a 100% uptake, good distribution and high shrinkage temperatures. ‘Another ecologically friendly process could be: Split raw hides straight into hair save process eg Sirolime, CO2 delime, to pH 8.5. Add 0.5% formic acid, followed 10 minutes later by 50% basic chromium. Run overnight. ‘If done correctly, it will come out perfectly tanned (Wades of Nottingham did the tanning bit back in the 50s on elephant hides!). Given the improvements in drum control and technology it would be far more controllable these days. ‘But the question is: is it cost-effective, easy to use and can the tanners be bothered to change?