Innovative footwear upper materials26 June 2006
With customers increasingly looking for chrome-free alternatives, BLC set themselves the challenge of coming up with a new tanning method which will emulate chrome-tanned leather characteristics without actually using chrome. The results are a novel epoxide tannage which should be available on the market in 12-18 months. Dr Vikki Addy said that historically within the footwear industry there had been no real drive from brands to introduce chromium-free leather but this is now beginning to change. Many of the major brands are looking to offer the consumer environmentally preferred materials. This should not necessarily involve the exclusion of chromium but is a route taken by some (Daisy Roots and Ecopell for example). The alternatives to chromium tanning are: * Vegetable tanning * Aldehyde (wet-white) * Novel tannages (Epoxytan) Aldehydes will react with the amino groups of collagen (the same groups that react with dyes and fatliquors) to result in a cross-link, whereas chromium reacts with the carboxyl groups. As a result there are differences observed in the properties of the leather. In order to avoid some of the problems related with aldehyde tanning, BLC has been working with the University of Loughborough on developing a novel tanning material. This is based on epoxy technology with the aim of combining the benefits of a non-mineral tannage with the properties typical of chrome-tanned leather. An added benefit of this technology is the potential to add further reactive sites to improve fixation of post-tanning chemicals. Preliminary trials have evaluated commercially available epoxy resins and curing agents and a process has been developed that combines an epoxy resin with a vegetable tanning agent. In laboratory trials shrinkage temperatures in excess of 100°C were obtained. Research is continuing to enlarge this project to a practical tannery scale. The latest trials have proved to be highly promising and further development work is ongoing. Leather on a roll Dr Andrew Hudson then introduced E-Leather as a new material for footwear construction. It is a leather byproduct whereby tanned waste is fiberised and processed into a form of leather on a roll. Unlike traditional leatherboard, the fibres are interlinked without adhesives, giving a new material that is very strong, good to touch and which can be engineered to meet a variety of requirements. It is a composition of 75-80% leather fibre with a man-made fibre reinforcement and is lighter in weight than the real thing. Their novel marketing strategem is to offer a leather byproduct which is better than leather! The benefits are: * Retains the appearance, feel and comfort of natural leather * Can be thin and 'foot forming' with no loss of strength * Strength and stretch can be accurately engineered to sport requirements * Material weight is about half that of natural leather * Supply in rolls allows multiple parts cutting and saves 20% wastage The versatility of engineered E-Leather stems from its internal reinforcing mesh. Strength and stretch can be varied by the choice of reinforcing fibres, ranging from conventional polyesters and nylons to ultra high strength Kevlar. Choice of mesh construction further widens the performance range. The high content of natural leather fibres in E-Leather provides the high perspiration absorption and expiration that make traditional leather shoes so comfortable. The man-made reinforcement provides support for the foot and can be engineered to provide a wide range of options, from high shape retention for fashion shoes, to high stretch with full return for women's leisure shoes. E-Stretchleather is a competitive new product for comfortable, form fitting shoe uppers. The low force extension of 10N/cm at 30% elongation closely matches the load/extension characteristic of Lycra backed calf skin and provides an easy stretch across the width of the shoe while retaining normal support along the length. The company behind E-Leather was formerly known as B&H Research Ltd but they changed their name to E-Leather Ltd in February to reflect the product and the change from research to full scale manufacturing. B&H's research into 'engineered leather' took ten years and $26 million to establish production. The patented process combines the most modern leather and textile technologies and will produce rolls 1.5m wide and up to 1km in length. Smaller rolls can be supplied if required. Production will come on stream in September from their new premises in Peterborough UK. Terra Plana Completing the novel footwear materials trio was Galahad Clark with his presentation on the challenges of design and sustainability in footwear. Clark, 7th generation of the famous footwear family, said that the aims of Terra Plana International are to be the most innovative and ecologically friendly designer shoe brand in the world. 'The goal is to create sustainable products and be a sustainable company in all dimensions: people, process, product, place and profits by the end of 2010. It is a process we started two years ago and we still have a long way to go. 'For many people, sustainability translates into being 'environmentally friendly', but it is broader than that. It represents much more than reducing waste, protecting wildlife and recycling. Understanding and adopting sustainable business practices requires a new awareness of the whole world, its natural systems and all of its species. It requires a deeper understanding of how the earth works and how man's processes affect nature's delicate balance. 'Each choice we make has a 'cost'. Some would argue that sustainability is not economically based or economically feasible. Sustainability makes perfect business sense and it will continue to be a defining characteristic of successful businesses of the future. Financial success is key to achieving sustainability. Bankrupt businesses are not sustainable.' Clark sees the shoe industry as traditionally one of the most polluting and energy intensive industries in the world. 'A lot of modern shoe making uses oil based toxic products such as pvc materials to make shoes - these types of products have to be removed. 'Most shoes in the world are cemented together - the glues used to cement shoes are toxic and dangerous to the people who make the shoes, the people that wear them and the environment after they are disposed of. Nearly all shoes have in excess of 60 components and the strange shape of feet make most production very energy inefficient. 'Cheap fashion shoes are bought and used with reckless abandon. It is unsustainable to make shoes that fall apart or people will not treasure for the entire product life cycle. What happens to shoes when they are thrown away is another massive problem. Nike have instituted a take-back system and we provide take-back solutions in our retail outlets. 'Terra Plana uses stitched artisan constructions as a basis for all its products. A lot of these stitched constructions have been innovated - but the principle is that by using stitched constructions, we minimise the necessity for glue and hence toxins in the products. We are working with our suppliers to install water-based glues in all our products - but this is someway off being complete. 'Repairability, lightness, anatomic design (healthy for feet), and durability are all important factors for eco-friendly design that Terra Plana also concentrate on. The majority of our leathers use a special chrome-free tanning system called White Line, a revolutionary new system developed by TFL to meet with leading eco-labels around the world. 'We also use vegetable-tanned leathers for our more deluxe products and some special item leathers.' Until two and a half years ago, Terra Plana still produced their footwear designs in Europe but they have now moved manufacturing to Asia for cost effectiveness. The move to Asia seems to be inescapable. Their Worn Again project uses 98% of recycled materials (he mentioned parachutes, offcuts from the automotive and airline industries, quilts, coffee bags, tweed jackets, jeans etc). They have taken this project to Africa where moccasins are being made and the money is going to local AIDS orphans. They also have a worn again project running in Northampton which avoids toxic finishes and materials and uses local and recycled materials. Clark believes they have all the angles covered: global, local and social and said that they were also working on a project with IKEA for an IKEA shoe. At the conference, Hudson was asked if a non-chrome version of E-Leather was possible. Since E-Leather is a byproduct of leather it is merely a question of getting enough waste material from a non-chrome source. This was done and the resulting non-chrome version of E-Leather was given to Galahad Clark for incorporation into a Terra Plana designed shoe. The first design is shown opposite. The conference was organised by Leather International together with BLC Leather Technology and sponsored by APLF and LANXESS.