The efficient use of natural resources and the utilization of recoverable wastes are getting more and more important day by day since recovering wastes have both economic and environmental benefits. As the source material costs constitute the majority of the yarn production costs, decreasing raw material costs provide considerable advantages for spinners.
Textile wastes can be divided into two main groups: production wastes and post-production wastes. Production wastes are raw materials of each production step which cannot be put into end product due to different reasons.
For yarn spinners, these wastes can occur during the cleaning of the fibers or combing out short-staple fibers from the long ones in the combing machine, etc.
These clean/unclean wastes in fiber form or not can be reused. After the spinning mill, there are wastes in yarn and fabric forms, and they need recycling to be put again in production.
Postproduction wastes are generally worn out cloths, which can be recycled and may be used again in textiles or utilized in other products.
Sources of textile waste
Mainly textile waste comes from household sources. The average lifetime of any clothing is deemed to be for about 3 years, after which, they are thrown away like old clothes. Sometimes even ‘not so worn garments’ are also discarded as they become unfashionable, or undesirable.
These are post-consumer waste that goes to jumble sales and charitable organizations. Most recovered household textiles coming to these organizations are sold or donated. The remaining ones go to either a textile recovery facility or a landfill.
Textile wastes also arise during yarns and fabric manufacturing, apparel-making processes and from the retail industry. They are the post-industrial waste. Apart from these textile wastes other wastes such as PET bottles etc. are also used for recycling polyester fiber.
Textiles for recycling are generated from two primary sources. These sources include:
1. Post-consumer, including garments, vehicle upholstery, household items and others.
2. Pre-consumer, including scrap created as a by-product from yarn and fabric manufacture, as well as the post-industrial scrap textiles from other industries.
Textile waste recycling
Textile recycling is good for both, environmental and economic benefits. It avoids many polluting and energy-intensive processes that are used to make textiles from fresh materials.
The requirement of landfill space is reduced. Textiles lead to many problems in a landfill. Synthetic fiber doesn’t decompose. Woolen garments do decompose but also produce methane, which contributes to global warming.
Pressure on fresh resources too is reduced. This leads to the balance of payments as we buy fewer materials for our requirements.
As fibers get locally available, they don’t have to be transported from abroad thus reducing pollution and saving energy. Lesser energy is consumed while processing, as items, does not need to be re-dyed or scoured. Wastewater reduces as it does not have to be thoroughly washed with large volumes of water as it is done for, say, raw wool. Demand is reduced for textile chemicals like dyes and fixing agents.
Cotton wastes in spinning mill
cotton fibers used in short-staple spinning as virgin fiber (from ginning mill), clean waste, comber waste, recycled fibers from dirty waste, and fibers torn out of hard waste (roving, yarn, and twisted threads).
Broken ends of sliver, lap, web, and filter strippings from draw frame, roving frame, ring-spinning frame, and rotor spinning frame are known as clean waste, having more than 95% of good fiber. Comber and roving wastes’ good fiber ratio is around 95–97%.
Wastes generated in blowroom machines, and cards are dirty wastes with 35–55% good fiber ratio. Besides, another dirty waste, flat and filter stripping waste, has a higher amount of good fiber (65–80%). As the waste fibers are processed in different numbers of machines and therefore stressed fibers, their good fiber content is less than virgin fibers.
For this reason, spinners prefer to feed the waste fibers into the normal spinning process, in a controlled manner, with a constant percentage to avoid quality variations. Generally, wastes arising in the mills can be returned to the same blend from which they arose; comber wastes are mostly used in rotor spinning.
In carded ring-spun yarn and fine rotor-spun yarn production, waste fibers can be used, up to 5%, but for combed yarns, waste fiber ratio can be lower, up to 2.5%. Higher waste fiber amounts can be used for medium and coarser rotor yarns, about 10 and 20%, respectively.
The textile industry is among the most essential consumer goods industry. However; the textile industry is also accused of being one of the most polluting industries. Not only production but consumption of textiles also produces waste. Commercially, textile waste generation is influenced by the production of textile goods. Higher the production is, the greater the amount of waste. This is, in turn, a function of consumer demand, which is influenced by the state of the economy.
While this may have a limited impact on waste production in the manufacturing sector; it can have a much greater influence on the production of household textile waste.
To counter the problem, the textile industry has taken many measures for reducing its negative contribution to the environment.
One of such measures is textile recycling- the reuse as well as the reproduction of fibers from textile waste. The generation of waste was such that it got naturally recycled, being mostly biodegradable.
Conversely, after the advent of industrial revolution different types of wastes came into existence which are often both non-biodegradable and highly hazardous. Production is always associated with some form of pollution and in specific cotton cultivation, production and processing release various types of waste, of which more than half is reused.
In Physical Recycling Manufacturing waste and post-consumer products are reprocessed into new products using reclamations process or commingled plastics waste processing. Due to its simpler, cheaper and more environmentally friendly process, physical recycling is more favorable than chemical recycling.
Chemical recycling is to convert high molecular weight polymers into low molecular weight substances. The obtained substances can be used as the reactants for preparations of other chemicals and polymers. Recycling of textile waste can serve as a means of providing solutions to many economic, environmental and social issues.
Though textile recycling has an old history, in recent years it has assumed prime importance due to Fast Fashion culture in the western world which has resulted in over consumption of textiles and corresponding waste generation. The least expensive and adverse effect on the environment is when a component can be recycled into its original product, i.e. called ‘closed-loop’ recycling.
The second best is when it can be used in another article which usually requires fewer demanding properties, for example, faces car seat fabric being recycled into a backing material.
Types of recycling technologies
Thermal Recycling Technology
Chemical Recycling Technology
Thermal recycling technology: Thermal recycling is intended to recover heat energy generated from the incineration of fiber wastes as thermal or electrical energy. Material Recycling Technology: Material recycling recovers polymers from fibers and at present, the idea of transforming polyethylene terephthalate (PET) into fibers is most economical and widely used for practical purposes.
Chemical recycling technology: Chemical recycling recovers monomers from waste fibers by polymer decomposition. Impurities can be easily removed from recovered monomers, so their quality will be made exactly equal to virgin monomers.
Benefits of textile recycling
Textile and clothing recycling can give old clothes, linens, and other textiles a second life. The recovery of textiles and clothing for recycling provides both environmental and economic benefits. It avoids many polluting and energy-intensive processes that are used to make textiles from fresh materials. ~ 166 ~ International Journal of Home Science Clothing and textile recycling reduces the need for:
- Landfill space: Synthetic fiber products will not decompose in the landfill. Woolen garments do decompose but they also produce methane which contributes to global warming. Clothing and textile recycling reduces pressure on
- Virgin resources: Recycled clothing does not require the use of new textile resources such as cotton or wool. Clothing and textile recycling encourages the
- Development of additional markets: Raw materials created from recycled content generally cost less, making their use attractive and desirable to manufacturers. This, in turn, leads to the development of more markets for reclaimed fibers. Clothing and textile recycling saves Energy
- Reduces pollution: Recycling saves on energy consumption when processing. Unlike raw wool, reclaimed fibers do not have to be thoroughly washed using large volumes of water. Clothing and textile recycling reduces the demand for
- Dyes and fixing agents: This, in turn, reduces the problems caused by their use and manufacture.
Textile recycling- the reuse, as well as reproduction of fibers from textile waste, can bring a sustainable future for the textile and apparel industry.