New Low Cost and Efficient Denim Recycling Process Devised by ACS Chemical Researchers

Researchers at the American Chemical Society (ACS) have come up with a low-cost method that can efficiently convert discarded denims into viscose-like fibers, to be woven as new fabric.

Their newly devised textile recycling process can lessen the large contributions of discarded denim, and other kinds of cotton-based apparels to the wastes that go yearly into landfills. At the same time, it can lessen the demand for cotton, which requires substantial use of land and resources.

Now more than ever, with the growing population and the quickness by which changing fashion turns clothing items into wastes, an efficient and inexpensive method of textile recycling is of utmost importance. Although the current advocacy is for the promotion of circular economy, where wastes can be recycled as new products, the cost it takes to recycle wastes is now an emerging issue.

The ACS Fiber to Fiber Wet Spun Process for Recycling Denim into Cotton

Nolene Byrne and colleagues Beini Zeng, Yibo Ma, and Xungai Wang, ground into powder three types of textile samples: a multi-colored T-shirt, a blue denim fabric and a pair of red denim pants. They then dissolved the powdered cloths in a mixture of ionic liquid, methylimidazolium acetate and dimethyl sulfoxide (DMSO) to produce cellulose.

The cellulose will then be spun into fibers that will subsequently be woven into new fabrics. In a previous experiment, they found out that ionic liquid or salt in liquid form, was not as effective. The high viscosity of the solution made the cellulose more difficult to work on. In addition, ionic liquid is more expensive. .

In another experiment, the researchers used DMSO as co-solvent. Reducing the salt solution or ionic liquid, while using DMSO as co-solvent proved more efficient. Since viscosity was reduced, the process of spinning the resulting cellulose into new fibers became easier. In this process, the recycled waste fabric was able to retain its original color.

Furthering their experiment, the ACS researchers pre-treated the powdered textiles with a solution of sodium hydroxide. The resulting cellulose attained a white color, which means this particular process, can also produce white viscose fibers that can be spun into white textile.

Although other methods of recycling denim to produce new textile have been introduced, the processes involved are not as cost efficient.

Application of this newfound textile recycling process therefore, will allow textile manufacturers to use discarded denim and other cotton-based garments as raw materials. Aside from greatly reducing the volume of wastes contributed by discarded clothes, the new method can also reduce the amount of land and resources needed to grow cotton.