It feels like we have been trying to replace water as the vital fluid in tanning fir decades. Dyeing with the Swiss Multimac machine was just a typical example of many ideas intended to avoid leather having to processed in an aqueous bath. The patent for this was applied for in 1986. I last saw one lying rusting away in a field outside Oporto in Portugal. At the end of the day water remains a key material and the effective work being done today in tanneries is a reduction in its use, using it better and cleaning it more effectively.
Yet at the 117th edition of the SLTC conference on Saturday we heard the first moves in an approach from the University of Leicester. Professor Andrew Abbott gave the Procter Memorial Lecture on “Ion-age Leather Processing – a Step Change in Technology”. Part of the concept is to design new materials specifically to carry chosen chemicals into leather, but not on the basis of the material just being a solvent that carries the material in and then needs cleaning up after.
If I understood it correctly using eutectic solvents which can be cheap, non flammable and biodegradable we can include active ingredients such as chromium and dyestuffs into the liquid rather than dissolving it as a solvent. Mimosa was also tested. All these are still at small stage testing for feasibility but in each case penetration was quick and the early indications are first of viability but then of both greater process speed and decreased effluent. The system has been bulked up to work commercially in immersion coating, electroplating and electro polishing so taking it further in leather processing looks to have some realistic potential. It is good to see that an SLTC conference can still come up with creative new ideas that put it at the leading edge of thinking.
A few years ago it looked like the SLTC would quietly wind down suffering from disinterest from the much reduced UK trade and wind down using up its reducing funds having an annual party for retirees and publishing the journal. Yet, perhaps linked to the return to Northampton, now the SLTC is back amongst the living and really moving forward. There is a real dynamic in the organisation and the conference clearly has regained the support of the industry and of Corium students at Northampton. Hopefully this means that all students will be persuaded to join the Society and stay members for their entire careers, just as so many of our older colleagues have done. Being a Corium club member and an SLTC member should be two strong outcomes of time in Northampton.
Mike Redwood
July 27th 2014
First published in ILM magazine