Sustainability is now driving a whole new approach to the business of fashion. The movement toward using more natural, organic and ethically-made fabric is pushing the apparel and footwear industry to re-invent materials and re-imagine fashion.
As we seek means to turn fashion into a sustainable business, we look to source sustainable raw and smart materials. On our shopping list are raw materials like responsibly-sourced down, recycled fiber, organic cotton and conflict-free minerals. However, what has generally been missing is regard for the polyurethane (PU) coated materials that are used as leather substitutes in shoe upper materials, garments, belts, fashion bags and sports shoes. These materials also deserve their place on the responsible sourcing agenda.
The reason is simple. Coated textiles are everywhere in today’s world. PU coatings are effectively the “skin of fashion,” used to replicate natural leather and create special effects on bags, shoes, clothes and accessories. PU plays a crucial role in preserving our natural resources, as durable PU coatings ensure, in an economic manner, that the lifetime of many products is extended well beyond what it would be otherwise. Each year, more than 4 billion square meters of PU coated fabrics are produced, enough to wrap around the Earth 100 times. The demand for these textiles is only going to grow as the demand for fashionable purchases also increases.
Many brand owners have concerns about the manufacturing process of PU synthetics as it normally requires the use of the solvent dimethylformamide (DMF). As a so called “Substance of Very High Concern,” its use must be carefullt controlled to avoid worker exposure and environmental pollution risks, but it many cases, such controls are missing. An estimated 5 billion tonnes of DMF is used per year—equivalent to 2 million swimming pools—and often in high exposure environments. The traditional process also requires large amounts of water during the washing stage, and high levels of heat to dry the substrate and recover the DMF. It is an energy- and resource-intensive process.
Some manufacturing solution providers are coming up with answers to these environmental and health concerns. INSQIN from Covestro offers brands the opportunity to source waterborne PU synthetics with a wide range of effects, and the same hand-feel and durability, and the same hand feel and durability as today’s materials. Waterborne PU coating does not require DMF or other solvents. PU synthetics based on INSQIN technology can be manufactured with less than half of the energy consumption and 95 percent lower water consumption compared to the traditional process.
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What’s more, new legislative restrictions on the use of hazardous materials and their chemical by-products pose formidable obstacles to conventional polyurethane textile manufacturers. In China, where the vast majority of PU synthetic material is produced, policies are also developing in favor of waterborne PU coating.
In July, China’s Ministry of Industry and Information Technology and Ministry of Finance announced an Action Plan to Reduce VOCs in key industries, including footwear and synthetic leather manufacturing. Under the plan, industries are expected to reduce the use of benzene, toluene, xylene, DMF and other solvents by 20 percent by 2018, down from 2015 levels.
At the industry level, the Zero Discharge of Hazardous Chemicals (ZDHC) program has established a partnership with the China Plastics Processing Industry Association (CPPIA) to improve chemical management in synthetic leather manufacturing. The partnership, known as the Synthetic Leather Sustainable Supply Chain Industry Innovation Coalition, will conduct a baseline investigation of hazardous chemical control in the synthetic leather industry in China, and use ZDHC tools to implement best practice.
As waterborne PU technology becomes commercially viable, the policy environment and institutional support for responsible coating is also maturing. This is good news as the goal to turn sustainable coating into the new normal is finally within reach. What is needed now is collective effort across the industry to create the economies of scale and economies of experience needed to lower material cost. Conversion comes with a cost and manufacturers need scale to justify the upfront capital investment.
Then comes the question: who would want to be the first mover to replace all their synthetic materials with waterborne PU coated materials? To aim for full-scale change overnight would be foolish, but replacement by small amounts can go a long way. Small orders by many individual brands and retailers will be able to catalyse innovation, and create the economy of scale and experience to lower material cost.
If brands and retailers join together and standardize requirements for PU coating incrementally, then the norm can be built. This is what regulators are increasingly demanding, and it is the right thing to do for consumers, workers and the long-term health of the industry.
By Nick Smith, global head of textile coatings, Covestro