Re-cycled Cotton Becomes New and Emerging Fabric 

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Cotton that has been recycled is transformed into new fabric

In the textile industry, sustainability is still at the forefront of product decisions, brand initiatives, and strategic planning. The use of recycled materials, including recycled cotton, is becoming increasingly popular under the sustainability umbrella. 

How cotton can be recycled into new fiber? 

Cotton can be converted into sugar, which can then be turned into spandex, nylon, or ethanol, according to researchers. 

Many of us try to recycle our old textiles but realize that they are difficult to reuse and they frequently end up in landfills. Scientists at Sweden’s Lund University have developed a method for converting cotton into sugar, which can then be processed into valuable products such as spandex, nylon, and ethanol. 

The Youtube video explains the full process. 

An estimated 25 million tons of cotton textiles are thrown away globally each year. 100 million tons of textiles are wasted overall when the various sorts are added up. In Sweden, the majority of the material is burned directly to produce district heating. It is considerably worse in other places because used clothing is frequently disposed of in landfills. 

 
“Considering that cotton is a renewable resource, this is not particularly energy-efficient,” says Edvin Ruuth, a researcher in chemical engineering at Lund University. 

‘Some fabrics still have such strong fibers that they can be re-used. This is done today and could be done even more in the future. But a lot of the fabric that is discarded has fibers that are too short for re-use, and sooner or later all cotton fibers become too short for the process known as fiber regeneration’, adds further. 

There is a wealth of information about employing microorganisms and enzymes, among other things, to convert the “tougher” carbohydrates in biomass into simpler molecules where Edvin Ruuth works, at the Department of Chemical Engineering in Lund. This implies that anything can be converted into bioethanol, biogas, and chemicals, including biological waste, booze, straw, and wood chips. 

Now, scientists have also been successful in dissolving cellulose, the plant fiber found in cotton, into smaller parts. Instead of using microbes or enzymes this time, the procedure calls for soaking the cloth in sulphuric acid. A crystal-clear, deep amber-colored sugar solution is the result. 

“The secret is to find the right combination of temperature and sulphuric acid concentration,” explains Ruuth, who fine-tuned the ‘recipe’ together with doctoral student Miguel Sanchis-Sebastiá and professor Ola Wallberg. 

Glucose is a very flexible molecule and has many potential uses, according to Ruuth. 

“We plan to produce chemicals which in turn can become various types of textiles, including spandex and nylon. An alternative use could be to produce ethanol.” 

They extract five liters of sugar solution from a normal sheet, with each liter containing the equivalent of 33 sugar cubes. However, due to the presence of corrosive sulphuric acid, the liquid could not be turned into a soft drink. 

One of the difficulties in overcoming the complex structure of cotton cellulose. 

What makes cotton unique to be recycled? 

“What makes cotton unique is that its cellulose has high crystallinity. This makes it difficult to break down the chemicals and reuse their components. In addition, there are a lot of surface treatment substances, dyes, and other pollutants which must be removed. And structurally, a terrycloth towel and an old pair of jeans are very different,” says Ruuth. 

“Thus, it is a very delicate process to find the right concentration of acid, the right number of treatment stages, and temperature,” adds further

According to Ruuth, the concept of hydrolyzing pure cotton is not new; it was discovered in the 1800s. The challenge has been to make the process efficient, economically viable, and appealing. 

“Many people who tried ended up not utilizing much of the cotton, while others did better but at an unsustainable cost and environmental impact,” says Ruuth. 

When he started making glucose out of fabrics a year ago, the return was a paltry three to four percent. Now he and his colleagues have reached as much as 90 percent. 

When the recipe is finished, it will be both simple and inexpensive to use. 

However, for the process to become a reality, logistics must function properly. There is currently no established method for managing and sorting various textiles that are not sent to traditional clothing donation locations. 

Fortunately, a recycling center, unlike any other in the world, is being built in Malmö, where clothing is automatically sorted using a sensor. Some clothing will be donated, rags will be used in industry, and textiles with coarse enough fibers will be transformed into new fabrics. The remainder will be used for district heating. 

Hopefully, once Lund’s technology is in place, the proportion of fabrics going to district heating will be significantly lower. 

Also read: Ralph Lauren Announces ‘LIVE ON’ Promise: A Pledge to Extend the Life of Products