The LYCRA Company is hosting a series of global panel discussions with 28 apparel industry experts on critical sustainability issues facing the sector. For the second topic, panelists discussed the pros and cons of creating recycled fibers using mechanical versus chemical methods and what is needed to make garment recycling a commercial reality.

In mechanical recycling, the input can include materials from outside the textile industry such as PET water bottles in the case of polyester, or fabrics from within the industry that get shredded and turned into new fibers. These recycled fibers usually have lower tensile strength than virgin fibers, meaning they generally cannot be recycled at end-of-life unless they are mixed with virgin materials.

In chemical recycling, a series of chemical processes are used to separate and recycle blended fabrics. The resulting recycled fibers have the same strength and performance characteristics as virgin fibers, enabling them to be recycled multiple times.

The limitations of mechanical recycling

“Mechanical recycling is a good option for homogeneous fabric types. But when it comes to many heterogeneous fabric types such as blends of nylon, cotton, polyester with spandex, mechanical recycling is not a viable option,” remarked Thiwanka De Fonseka, senior executive, environmental sustainability at textile manufacturer MAS Holdings.

Since the majority of pre- and post-consumer textile waste is from heterogeneous compositions, the panelists agreed that mechanical recycling is not the best option for blended fabrics.

The promise of chemical recycling

On the other hand, chemical recycling can fill this role admirably.

“Chemical recycling allows for greater flexibility in quality, color and performance in the final product,” acknowledged Anushka Darshana, technology entrepreneur and chemist, Open Innovation. “Chemically recycled polyester using a glycolysis process, for example, reduces CO₂ emissions by more than 40 percent compared to virgin polyester. While chemical recycling is more energy-intensive than a mechanical process, there are still environmental impact savings.”

Kshanika Goonesekera, manager, sustainability at MAS Intimates, agreed. “Though mechanical recycling is important, the way forward is definitely through chemical recycling,” she said. “Research is progressing at a rapid rate where now chemical recycling uses less energy, less water and close to 99 percent recycling of the chemicals used.”

According to Goonesekera, other advantages of chemical recycling include recycled synthetic fibers being basically identical to virgin fibers, and “re-recycling” up to five to seven times or more before needing to mix in virgin fibers.

“Some even say they can be recycled an infinite number of times, but this is yet to be seen,” she concluded.

De Fonseka also believes chemical recycling is the best option, but shares that there are still three key points to consider when formulating chemical recycling processes. The first is making the process sustainable when disposing the chemical waste generated. Secondly, recyclers must consider whether the chemicals used are aligned with sustainable chemical standards. And finally, they must account for the environmental footprint of the process compared to virgin fiber manufacturing.

The need for infrastructure

Because chemical recycling is still at a relatively early stage, participants acknowledged the need for infrastructure to support the tech’s expansion. Laura Kincaid, head of sales and product development at sustainable manufacturing company 4tify, commented that “the infrastructure is not up to scale for fabric recycling yet, this is why we need to dedicate funds and resources to companies that are building fabric recycling facilities.”

“In an ideal world, there would be many industrial closed-loops producing garments and then eventually receiving them back for recycling. However, we live in a messy world, and the reality will require organizations to be set up just to gather materials for recycling,” said David Cottrell, managing director of business development consultancy Gradient Limited. “It’s no good setting up garment manufacture capable of using x percentage of recycled fibers if they can’t be sourced easily. We have to ‘feed the beast’ and this requires investment to gather and sort waste streams.”

Overall, the panelists agreed that chemical recycling is an exciting and promising technology that offers unique performance benefits; however, many expressed that more innovation is needed to scale up capabilities and ensure all aspects of the process are truly sustainable.

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