The significance of plastics

Redwood Comment
Published:  08 August, 2018
Dr Mike Redwood

I first began to understand the significance of plastic in 1966. Three of us, one each from the three British Leather Schools in London, Leeds and Northampton, had won a Kids Tanner prize for a three-week trip visiting the leather industry in the Netherlands and Germany.

While at Rohm and Haas, we were introduced to their polymethyl methacrylate or Plexiglas. They had first brought this material to market in 1933, often since called Perspex or Lucite, but it seemed especially relevant in the 1960s, hence, time was spent showing to us, alongside talk of bating products and low temperature fatliquors.

What we were not then aware of was that leather was going to find competition from different types of plastics. Coincidental to our visit, DuPont was pushing Corfam into a head-to-head challenge against leather in conventional full leather upper men’s and ladies footwear. Corfam had a structure comprising a microporous polyurethane top layer, an interlayer of woven Dacron (PET or PETP) fibre, and a substrate of polyester non-woven fibres with a suitable binder. Other poromerics around that time skipped the interlayer which increases the modulus of elasticity and thereby reduces the degree of conformity to foot shape. When we did enter the industry a few years later, Corfam was being classed as a failure since consumers never made a second purchase because the shoes were so uncomfortable.

The idea that shoes should be cleaned and repaired has become a historical one

Nowadays, modern synthetics and designs that build foot comfort into the structure with a variety of materials mean that the two big problems, breathability and fit, have been overcome. What is even more of an issue is that as shoemaking relocated to developing countries the unit price dropped and consumers began to consider many types of footwear as readily disposable. The idea that shoes could be looked after, carefully dried when wet, cleaned, polished and repaired as appropriate became very much a historical one. 

This fits synthetics as they cannot be repaired and do not, anyway, last very long. Here lies the modern issue with plastic when used to replace leather. It takes an oil based material, uses it once in a mix of materials that is difficult to separate out after use, and disposes it into landfill or worse. There it takes hundreds of years to decompose, and what it breaks down into is not very good for the planet. Anything which peels or rubs off in use will end up in landfill or washed into rainwater drains mostly destined direct to rivers and the sea. Had we realised all this fifty years ago, we would have fought these synthetics much harder, but society’s belief in “plastic” as promoted in the film such as “The Graduate” was very strong and not to be deflected.

While right at this moment it is footwear that is being challenged by alternate materials on the basis of cost, ease of automation, and the lack of trained workers, we have seen these plastics spread through all sectors including clothing, automobiles, leather goods and even gloves. As tanners we can have no objection to consumer choice, but we can respond when plastic is ignorantly preferred to leather on sustainability grounds.

Published data notes that since we began consuming plastics last century, 8,300 million tonnes have been produced of which 75% has been disposed of, 80% of which has ended in landfill or “drifted into the environment”. (New Scientist, May 19, 2018). In the U.S. today, over 75% still ends up in landfill or lying about, while in the EU only 27% does. In Europe though, a lot of recycled plastic goes overseas for recycling and Japanese experience sending plastic waste overseas indicates most ends up with careless handling and uncontrolled burning. China’s recent ban on importing such waste has also made this aspect of the market chaotic.

On top of this, a minimum of eight million tonnes a year go into the sea, via streams and rivers or directly; a humanitarian and environmental disaster. For sustainability, use leather every time; and polish those shoes.

Dr Mike Redwood

August 8, 2018

mike@internationalleathermaker.com

Follow Dr Mike Redwood on twitter: @michaelredwood

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