Wool and cotton textiles have been mechanically recycled for many years, long before we started talking about the circular economy.
Mechanical recycling, unlike chemical recycling takes waste and recycles it into a secondary material without changing its basic structure. Common mechanical techniques for textile recycling include shredding and carding for natural fabrics, and shredding, melting and extruding for plastic fibers. Recycled nylon, such as Econyl is a combination of mechanical and chemical recycling, but this depends on the type of nylon that is created.
Recycled cotton
Textile cotton waste can be mechanically processed into recycled cotton.
- Fabric is sorted and separated by color
- Machines are used to cut and shred the fabric into small pieces, which are pulled apart into fibers
- Carding is used to align the fibers
- The recycled cotton is usually spun with another fiber, such as virgin cotton or polyester, to improve the quality of the yarn. Recycled cotton by itself has short fiber lengths, is weak and may not meet brand quality requirements.
Many mills have developed fabrics using different recycled fibers, including denim scraps. Some denim brands are using a percentage of recycled cotton in their product offering. All Mud Jeans, for example, contain a percentage of recycled cotto.
Recycled wool
The Prato region of Italy has been recovering and recycling wool since the early 20th century. Bales of woolen textiles are sent from all over the world, and Prato is known as the “go-to” location for recycling wool. Technical expertise and processes are in place to create a product that is cost effective, meets quality requirements, and is commercially available. The wool is recycled using the process outlined below.
- Bales of discarded clothing are sorted by quality and fiber content
- Clothing is pulled apart into fibers and then sorted into different colors
- Color mixing occurs to create an acceptable shade. Sometimes, the wool is overdyed to create darker, richer shades.
- The fibers are carded to align them in one direction, spun into yarns, and then either woven or knitted into fabrics.
Recycled polyester
Almost all recycled polyester is made from plastic bottles, and not polyester textile waste, even though both originate from polyethylene terephthalate (PET).
The benefits of using plastic bottles as a waste source are clear. There is an abundant supply and a “collection infrastructure”. Plastic bottles are fairly clean, are often clear and contain relatively few chemical additives.
- Bottles are separated by plastic type and sorted by color
- A machine shreds the PET into flakes
- Washing and drying removes dirt, contaminants and excess water
- PET pellets are then formed by chopping and pelletizing the flakes.
- The pellets are then melted and extruded into a recycled polyester fiber.
Textile waste may contain hazardous chemicals, and more research is needed to determine if this is the case. If so, these chemicals must be removed prior or during recycling.
A benefit of using textile waste is that the dyeing process could be eliminated if textiles were sorted by color. What an advantage that would be!
Do you need help with your circular strategy?
For help with sustainability, circularity and chemicals, contact Amanda Cattermole at (415) 412 8406 or Amanda@cattermoleconsulting.com. We can help you develop powerful solutions to protect your company and brand reputation.
Tips and Insights contains information to help you make informed sustainability decisions. Each post highlights a particular topic and includes questions you may want to consider for your business.