In the past, good clothing would last forever. Not anymore. This is the age of “fast fashion,” where the norm is trendy, affordable garments that wear out quickly and can be thrown away.

Disposable apparel, however, has created a serious environmental problem. Poor-quality clothes that are tossed out often end up in landfills, where they degrade and release carbon dioxide, the leading greenhouse gas.

There are a few efforts underway to recycle worn clothes, and other programs that shred old clothing and use the fibers as cleaning rags, or in carpets and other products. But many of these also often end up in landfills.

Several Finnish scientists believe that a better option would be to “upcycle” disposable garments — make new fibers from the old, and turn them into new clothes. They have developed a chemical process they hope will be able to do just that.

“I’m pretty sure that we will have to live with the fast fashion phenomenon,” said Herbert Sixta, professor and head of the chemical pulping technology department at Aalto University in Espoo, Finland. But “with all the rubbish piling up, it is in everyone’s best interest to find a solution.”

The scientists’ goal was to find a way to process old cotton-polyester blends by dissolving the cellulose in the cotton —cellulose is a main component of plant cell walls and vegetable fibers — without affecting the polyester, and then spin the cellulose solution into new fibers.

Earlier research found many ionic liquids (salt in a liquid state) are capable of dissolving cellulose, but the resulting material couldn’t be used to make new fibers. About five years ago, however, Sixta and his colleagues found an ionic liquid that could dissolve cellulose from wood pulp, producing a material that could be spun into fibers.

The scientists tested it to see if it also could work on cotton-polyester blends — and discovered that it could. The different properties of polyester and cellulose worked in their favor, says Simone Haslinger, a doctoral candidate at the university and Sixta’s collaborator. The researchers were able to dissolve the cotton without affecting the polyester.

“I could filter the polyester out after the cotton had dissolved,” Haslinger said. “Then it was possible, without any more processing steps, to spin fibers out of the cellulose solution, which could then be used to make clothes.”

To move their method closer to commercialization, Sixta and his colleagues are testing whether the recovered polyester also can be spun back into usable fibers. They also are exploring ways to scale up the process, and looking at ways to reuse dyes from discarded clothing.

A bow tie and handkerchief from fibers made from dissolved cellulose from birch. Source: Eeva Suorlahti, Aalto University

This advance, however, likely will do little to satisfy environmental groups fighting textile industry pollution. They believe manufacturers should focus on creating clothes made of pure materials right from the start, rather than separating them in a complicated process afterwards.

“True innovation to make the fast fashion industry more sustainable lies not in more high-tech and chemical-intensive recycling solutions, but in a radical mindset change,” said Kirsten Brodde, project lead of the “Detox my Fashion” campaign at Greenpeace, which has released several publications critical of fashion industry practices.

“We need to massively slow down the current system of wasteful overproduction and replace cheap, disposable fashion with long-lasting garments that can be truly valued — and let’s care for, share and repair them,” Brodde said.

Sixta doesn’t believe the industry will reverse itself anytime soon, and insists the technology he and his colleagues developed will result in “high quality” products. “We want to not only recycle garments, but we want to really produce the best possible textiles, so that recycled fibers are even better than native fibers,” he said.

But he admits they face many challenges before the process can work on a large-scale basis.

Increase in global fiber demand in millions of metric tons. Source: Greenpeace

For example, the industry needs to establish an efficient way to collect old garments for processing and upcycling, a mechanism that does not now exist. “The key problem in the recycling of textiles is lacking logistics,” Sixta said.

Also, before applying the technology, manufacturers will need to find out exactly what materials were in the original clothes. Without that information, it will be difficult, if not impossible, to upcycle them. “We can handle the science, but we might not know what dye was used, for example, because it’s not labeled,” Sixta said. “You can’t just feed all the material into the same process.”

The scientists agree that the system only will work if the textile industry develops a system that can track and record the materials and chemicals used during their original production so they can be sorted properly for upcycling.

“There are no proper systems or strategies to sort textile waste,” Haslinger said. “Once fabrics are disposed, we usually do not know anymore what they were made of. People might have cut off the tags describing the composition of the textile. Sometimes the descriptions are also no precise enough in order to apply adequate process conditions.”

Fabrics from Sixta’s lab. Source: Eeva Suorlahti, Aalto University

Moreover, “almost every fabric is dyed with chemically different dyes, even if you just examine denim clothing,” she added. “Currently, we are also planning to maintain the original color of dyed fabrics throughout our recycling process, but we do not know yet how different dyes might impact on the process.”

The team, which will present its findings at the national meeting of the American Chemical Society, is collaborating with a local Finnish design company and researchers from the university’s school of arts and design, to craft samples of new textiles from their process. “We are producing fabrics, garments, table cloths, scarves, etc.,” Sixta said. “Two dresses have been presented at different fashion shows, and more are coming.”

The researchers say that eco-toxicity tests performed thus far show the ionic liquid to be safe, although “more work is needed,” Sixta said.

For now, the process only works on pure cotton or cotton-polyester blends “because these are the most abundant ones on the market.” Sixta said. “The process would also work for any other cellulose-polyester blended fabric, such as viscose-polyester, or rayon-polyester, tencel-polyester, lyocell-polyester, etc. I can also imagine that it could perhaps also be employed on other synthetic fibers, but this still needs to be tested.”

They haven’t tried it on wool, he said, adding: “Our next target is silk.”

Marlene Cimons writes for Nexus Media, a syndicated newswire covering climate, energy, policy, art and culture.