A team at the US North Carolina State University (NC State) has discovered a way to separate blended cotton and polyester fabric using enzymes. The discovery will lead to a more efficient way to recycle the fabric's component materials, thereby reducing textile waste, they hope.
However, the process needs more steps if the blended fabric was dyed or treated with chemicals that increase wrinkle resistance.
The polyester will not degrade in a landfill, and the cotton might take several months or more to break down. Using the new method, the cotton can be separated from polyester in less than 48 hours, said the study's corresponding author Sonja Salmon, associate professor of textile engineering, chemistry and science at NC State.
A ‘cocktail’ of enzymes was used in a mildly acidic solution to chop up cellulose in cotton. The idea is to chop up the cellulose so that it falls out of the blended woven structure, leaving behind some tiny cotton fibre fragments and glucose, a release from the university said. Glucose is the biodegradable byproduct of degraded cellulose.
The process then involves washing away the glucose and filtering out the cotton fibre fragments, leaving clean polyester behind.
"We still have some more work to do to characterize the polyester's properties, but we think they will be very good because the conditions are so mild. We're just adding enzymes that ignore the polyester," Salmon added.
The study was published in the peer-reviewed journal ‘Resources, Environment and Sustainability’.