September 25, 2024

Biomaterials could be allies against plastics

A highlight of my career was being invited to the U.S. last year to give the John Arthur Wilson Lecture. I returned to Leeds University to discover Wilson had started there exactly 50 years before I did. His work there with Procter was about understanding the science to help leather renew itself for the modern age of electricity and the combustion engine.

I made three points in my lecture that relate to driving the leather industry forward, which all overlap. We need to recover our ability to do fundamental research. We must stop trying to defend chrome tanning. Its time is over, and work is required on perfecting alternates to truly replace wet-blue. And tanners must embrace the better of the new biobased materials to work alongside leather to replace plastic.

All this would clear the decks, look forward rather than merely justifying the past, bring in new partners and ideas and create an opportunity for future growth beyond the 1% per annum available from being a byproduct of the meat and dairy industry.

Last week, I tried to deflect leather from aggressive self-righteous defence towards promoting its beauty, built on its sustainable truths with its natural and aesthetic qualities – those that create the emotion involved in most purchases. Leather lives in a material world and it is only the natural materials such as wool, silk and leather which offer this promise. Vinyl, Corfam, Generation Phoenix (ELeather), Baycast and the like have never stirred a positive consumer emotion, with a trigger based only on cost and some form of efficiency.

PU-coated materials and microfibres

The newer PU-coated materials and microfibres of the 1990s are still getting better but the concepts of longevity, patina and beauty remain distant for them. The newer biomaterials offered more but chose 10 years ago to surf on a heavily financed tide against leather at a time when the elastic raw material price of hides and skins was being stretched beyond sensible limits. It’s a waste material after all, is it not?

We needed to look beyond these ridiculous claims of being leather substitutes, of leather killing cows and that anything with the label of “biomaterial” that was not leather was inherently sustainable. The careless use of the term leather and the lack of detail about the manufacturing and actual chemical content of these materials has left a cloud of suspicion. Nevertheless, for a number of our most respected tanners, including some in Italy, Germany, Spain and the Netherlands, along with a major part of our supply chain, these materials were seen and remain as partners for the fight against the pure plastics and as a meaningful extension to the leather business.

My own thought was that the cellulosic materials initially offered the best solution, and I particularly involved myself with Piñatex where I was introduced to the owner and her work. Manufacturer Ananas Anam subsequently became a B Corporation with full transparency and Piñatex remains one of the few such materials to have commercially entered a multitude of sectors.

However, the cellulosic materials have not managed to advance as expected and thus walked into the FILK-researched trap when its study showed a high level of dependence on polyurethanes to achieve acceptable specifications. While they resolve their positions, mycelium and Bio-VERA are out in the lead.

Without question, mycelium is unbelievably powerful and clever, but whether it makes commercial sense in this material space is unclear with some companies pausing – giving up – and others pushing forward very strongly. Bio-VERA, showed at Lineapelle, and the suede we first saw at the Lake Geneva ALCA convention in 2023 had been advanced in every aspect in part through the addition of protein and work with tannery partners in Asia and Italy.

A detailed performance sheet is not yet available but anyone who handled the material at Lineapelle, ALCA or anywhere in between knows that it is exceptionally strong, feels good and will certainly be durable and long lasting. Modern Meadow thinks it will be repairable and makes it clear that, in any colour, it will be possible to continuously recycle it, not just one time and in one colour like so many plastics.

Its rapid advancement has been helped because it comes to the tanner as a raw material to be tanned, further processed and marketed by the tanner. Under their control, it is an adjacent, additive material rather than a competitor. While Modern Meadow might still cling to “leather hide material”, tanners marketing it will be more cautious in their wording. For them, it widens their palette and their offer and is in no way a direct substitute for leather. Illegal and inappropriate terminology will not be used.

Leather does not need a “leather solution” from biofabricated or plastic materials but the solution for leather’s future does involve tanners overcoming their romance of leather and looking hard at the role tanneries must play in the future. Getting every hide and skin back into the tannery to make leather, partnering with sustainable biofabricators and increasing their overall material market share at the expense of partners.

More than likely, many of the materials we will see will be hybrids, as the tanners input their processing, their creativity and their own byproducts such as shavings and trimmings into the mix. Are tanners so determined on purity that they are unwilling to get involved in new hybrid concepts or the more natural finishes sought by biomaterials? These could well benefit splits or even some grain leathers.

We should remember that the FILK report measured only a moment in time, for materials that are mostly determined to keep improving. While some cellulosics are little more than a polyurethane soup with a bit of added green matter, many do have the opportunity to tighten their fibre structure and make a stronger, better feeling network free of PU. Time will tell.

Too much in the world has become binary and the antagonism in some quarters towards new ideas from some tanners feels like a move to entrap leathermaking in a narrow world of absolute product orientation. As I see it, for those following this route, the industry will shrink by half to about 10 or 12 billion square feet, and the remaining raw material will eventually end up in gelatine or be shredded for rendering. Quite a lot could end up in novel bioplastics of one sort or another, but tanneries would not be involved.

I’m trying to stay involved in this partnership as I truly think that it will bring new creativity, new research funds, new business growth and real excitement back to our sector. We will be growing and leading with new friends, not sliding into small scale obscurity.

Michael Redwood

Leather chemist, writer, and advisor on responsible leather manufacturing and material strategy. This article was originally written for ILM.