Mike Redwood


International Leather Maker

At the recent American Leather Chemists Association (ALCA) Annual Convention, I answered a question about why so many tanneries stopped making use of items like fleshing, hair and shavings in the 1960s and 1970s and instead threw them away. My answer was the ruthless pursuit of “efficiency”.

As I sat in Chicago’s O’Hare International Airport, waiting for my flight back to Europe and reflecting on the meeting, it felt like a poor answer. A definition of efficiency I found points to it meaning “the ability to achieve an end goal with little to no waste, effort or energy”, but what I was talking about was ruthlessly trying to improve the bottom line.

Changing industries

During the last century, the leather industry has changed a lot. The mass production of automobiles lost leather its equine volumes, rubber and plastic substitutes hit the leather soling market and its aftercare business, advancing fashion and technical textiles upended the clothing and gloving business and the introduction of sneakers impacted almost all sectors of footwear.

During this period, chemical companies, meatpackers and brands adjusted their structures and approaches to secure good margins while tanners, mostly quite small family-owned SMEs, were squeezed.

In the 1960s, up popped low-cost production in Korea and Taiwan, followed in the 1970s by a determined push towards finished leather and products by India. Suddenly we had sizeable global overcapacity in tanning, squeezing margins and making lower grades a tough sell. Exactly at a time when new regulations meant most tanners in more advanced markets had to spend hefty sums on environmental matters.

Many old and famous tanneries closed and everywhere efficiency became the byword. Where could money be saved and margins increased? For most tanneries, the “efficiencies” were about removing marginal or loss-making activities in a fight for survival.

At the same time, for many tanneries in emerging economies, the infrastructure to deal with byproducts was not built – gelatine factories were rare or did not exist at all. Complaints were made about these new tanneries not treating their effluent, although most significant new plants did in fact have well-equipped waste treatment plants.

As we discovered later, the problem lay in enforcing their use, particularly in older tanning zones where no provision had ever been made. Regardless, no-one initially gave a thought to byproducts and, when the question was asked, “sent away” was the most common answer. That is, carried off to be legally or illegally dumped.

At the other end, the traditional end uses for such byproducts changed or became more competitive. Leatherboard lost its place to synthetic materials for use in footwear and, in the same way, hair lost its market as a carpet underlay as the flowing market changed.

Even that most historic material, gelatine, saw a changing market. Post-war tanners were sending gelatine for photographic purposes, and we were told photographic gelatine was the highest quality with food relegated to second. A more basic gelatine formed a historic type of glue that was still quite popular.

A different way of doing things

While the digital revolution in photography is the most dramatic example of the transformation, it only highlights what had been happening over many years. Gelatine’s role in food, pharmaceuticals, cosmetics and all manner of technical uses started to grow even faster, but the closure of so many Western tanneries, some with their own gelatine plants, left a lot of gelatine factories in the wrong place and they closed.

As new uses increased in importance and old ones declined, gelatine plants have transformed into highly advanced chemical plants where staff have to cover their hair and wear white overalls. They may still be hydrolysing limed splits and raw pigskins with strong alkalis and acids, but their markets started to demand a level of quality control and hygiene unheard of earlier in the century. Much of the leather trade struggled to follow.

So, while chasing “efficiency” might have been a fair answer in the time constraints of a symposium, it is one of those weasel words that are probably inappropriate at a scientific event.

Increasingly, the dumping of organic wastes into landfill has become expensive or prohibited altogether, so this subject has re-opened. Traditional ideas are returning as society regains its understanding of natural materials and, for items like hair and wool, new end uses such as insulation, stabilising concrete mixes and biochar are being considered. For example, fleshings have increasingly been used to produce biodiesel.

Most exciting is probably gelatine, as it is such an indispensable material for which demand will only grow, offering tanners new opportunities for trimmings, splits and lower grade material. Grasping these opportunities will perhaps give us a new, more positive, way to look at efficiency.


Follow Dr Mike Redwood on Twitter: @michaelredwood

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