The waste generated by the fashion and clothing industry is massive, and not just because of the items that are worn a few times before being discarded in favor of the latest trends. Recycling clothing made from cotton is tricky business, meaning pieces like jeans and shirts often become rags rather than being broken down and repurposed as high-quality garments. A new breakthrough could overcome this problem, however, with scientists demonstrating a new technique that returns cotton to a fiber form suitable for mass manufacturing.
The reason recycling clothing items like pants, trousers and shirts is so difficult, at least in a way that reproduces items of the same quality, is because they are typically made from a mix of fibers. For example. the cotton fabric in one garment can also include polyester, elastane (spandex) or other chemical fibers, and untangling the right ingredients from this mish-mash of materials is no mean feat.
In the team’s sights was a type of manufactured fiber known as a viscose rayon fiber. These are typically made from wood-based cellulose, which acts as a “pulp” starter material that is dissolved in a solution and then spun into the regenerated cellulosic fibers. But a team of scientists at Fraunhofer Institute for Applied Polymer Research has been working with Swedish company re:newcell to investigate more eco-friendly starter materials.
“Re:newcell sent us cellulose sheets made of recycled cotton and asked us to find out if they could be converted into viscose rayon fibers,” says Fraunhofer’s André Lehmann. “We were able to extract the foreign fibers from the pulp by setting the right parameters for both the dissolving and spinning processes, for example, with effective filtration stages.”
From the cellulose sheets of recycled cotton, the team was able to produce a yarn measuring several kilometers long made of 100-percent cellulose and with comparable quality to those made from wood-based cellulose. Critically, the team says the technique is compatible with standard procedures for producing viscose rayon, suggesting that it could be integrated into these processes as a way of giving discarded cotton clothing a new lease on life.
“Cotton clothing is usually incinerated or it ends up in the landfill,” says Lehmann. “Now it can be recycled several times to contribute to greater sustainability in fashion. This will also broaden the base of raw source materials for pulp production in the textile industry. The starter material for viscose rayon fibers has been wood-based cellulose. By optimizing the separating processes and intensifying the filtration of foreign fibers in the spinning process, we will eventually be able to establish recycled natural cotton fiber as a serious alternative source of cellulose and base raw material.”
Clothing recycling breakthrough takes aim at fashion and textile waste [New Atlas]