Although growing environmental awareness has prompted the textile industry to seek increasingly sustainable production methods, recycling and reusing textile materials is not new within the textile industry. The regenerated yarns produced by the rotor spinning process (Open end) are a clear example of the reuse of resources that has been carried out in the textile industry for more than 50 years.
The introduction of rotor spinning in industrial production took place in 1967 and was a great revolution since, for the first time, spinning and winding processes could be carried out on a single machine from a card or ribbon. draw frame. This made rotor spinning a more straightforward process, eliminating the need for the roving frame and winder used in conventional or ring spinning. This fact, together with its higher productivity, led to the rapid spread of this new technology that allowed the manufacture of yarns at a lower cost.
Although systems for spinning both short and long fibers were developed, only short fiber rotor spinning has been able to establish itself on the market. The rotor system allows the processing of fibers up to 60mm, thus covering the classic range of short cotton fiber.
Currently most of the yarns manufactured by rotor spinning are in the range of counts between Ne 6 and Ne 40. For finer counts, conventional or ring spinning remains the most used and recommended option by machine manufacturers. . Regarding the composition, cotton is the most used fiber in this type of spinning (55% of the total volume) followed by polyester and to a lesser extent by other fibers such as viscose, modal, or polyacrylic. Fashionable applications for open end yarns include: denim, trousers and work or sports underwear. Its applications within home textiles are mainly terry cloth and upholstery.
Another advantage of rotor spinning is that it allows the use of textile waste produced during the manufacture and reuse of garments that have already reached the end of their useful life. The threads made with this type of material are called regenerated threads.
By shredding textile waste it is possible to separate the fibers again so that they can be reprocessed in the spinning process.
Since recycled fibers are normally short in length, it is necessary to mix them with virgin (longer) fibers so that the resulting yarn has the correct strength, elasticity, hairiness and uniformity values. In any case, continuous innovation in technology, together with the experience acquired by yarn manufacturers, have allowed the proportion of recycled material in regenerated yarns to increase every day. The regenerated yarns currently produced are of a high quality and more than meet the needs of all the applications for which they are intended.
Fortunately, large fashion manufacturers are increasingly involved in textile recycling. In Spain, the Inditex group, with a worldwide presence, is strongly committed to recycling and has installed garment collection containers in more than 2,000 of its stores in 46 countries. Part of these garments are repaired and resold for social purposes and part are recycled. Sorting garments according to their color and composition and eliminating non-recyclable parts such as buttons and zippers is a challenge when it comes to recycling these garments. The development of new systems to automate these processes will be of great importance in textile recycling.
In the same way, future innovations in spinning machines can help increase the proportion of recycled material that can be used to make regenerated yarns. In this sense, the continuous innovation and research of Spanish companies will continue to play a very important role in making the textile industry more and more sustainable.