Textile Recycling - Different Mechanism of Collection and Sorting Textile Waste

This article is written by Sweta Singh. 

The textile business may be impacted by the rise in living standards brought on by economic progress. The environmental concerns facing the textile sector are significant.

In 2018, 105 million metric tonnes of textiles were produced worldwide. Up to 64% of all textile fibre production comes from the petrochemical sector. Cotton, 24%, cellulosic fibres, 6%, wool, and natural fibres account for the remaining 36% of all fibres. The clothes sector has significantly contributed to the volume and rate of waste generation with its current fast fashion business model, which is characterized by mass manufacturing, variety, agility, and affordability.

Due to the complicated structure of textile polymers, sorting and identifying textile components presents a challenge for textile recycling. In addition, the bulk of textile materials are made of fibre, and because textiles have a sophisticated weave, sorting and recycling them provide the most obstacles. The excess fabric is frequently combined with other materials, including buttons, zippers, or other embellishments. 

There are a number of techniques for identifying textile materials, such as ISO-standardized quantification methods based on distinctive dissolution behaviour (such as ISO 1833-1) and morphological variances discovered using microscopy. 

In this article, I would be discussing the key stakeholders in the textile recycling process which are the collectors and the sorters.

The Textile Exchange's research on the 2020 Preferred Fiber and Materials Market examined the breakdown of fibres by composition and compared it to information from waste mapping studies conducted by Reverse Resources in 20 countries and 1200+ companies. Based on that, a general idea of waste types and fibre compositions is available in the global market for textile recycling. This amount of waste is produced annually. It exceeds the expectations of the industry, which has been concentrating on the difficulties associated with managing post-consumer waste. Additionally, manually collecting and sorting textile waste is not possible.

Fig: 1- Recyclable Textile Waste Globally (Image Source: Reverse Resources)


Pre, as well as post-industrial waste, is a low-hanging fruit for scaling up the production of recycled yarns and fabrics, which could start replacing raw materials for fashion and close the loop of circulation in light of new emerging recycling technologies searching for a good fit with the feedstock they could use. But the major hurdle in achieving this milestone is the lack of players in the collection and sorting mechanism.

In the following illustration in Fig: 2 you will see that the pre and post-consumer wastes are first collected and then sorting is being done based on different parameters such as colour, size, composition, and other different parameters.

The sorted wastes or what I would like to call ‘Degenerated Raw Material’ are then sent for chemical recycling, mechanical recycling, or for reuse depending on the condition of the material.

Fig: 2- Possible Textile waste recycling routes

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Related article: Why is it difficult to recycle your clothes?

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1. Different collection mechanisms (of textile waste):

Let us look into current mechanisms available for sorting of textile waste for textile recycling.

1. 1 NGOs and Charitable Trusts:

Giving used clothing to non-profit organizations is the most often utilized technique for collecting them separately. Typically, textile recycling containers found in public spaces, corporate buildings, or second-hand shops are used for collecting. The textiles collected can be transported after the containers have been emptied by the municipality or the non-profit organization. Charitable organizations (like the Salvation Army and others in the United Kingdom) use the money generated from the trade and collection of used textiles to support their activities and further their objectives.

A variety of private businesses may also purchase or receive worn textiles. A range of methods, including kerbside collection, textile container collection, and in-store collection, are used by the performers to collect worn clothing. Examples of these actors include:

1. Commercial collectors (such as private garbage management organizations and recycling businesses).
2. Second-hand shop (not operated by governments or non-profit organizations).
3. Collect partners with clothing companies like H&M and Jack & Jones to collect textiles for recycling or reuse.
4. Clothing retailers collect unwanted fabrics for campaigns and resale (such as WRAP).
5. Clothing donation centers like the Salvation Army
6. These artists might only be hired for commercial endeavors or they might work for non-profit organizations (i.e. passing on the collected textiles).

1. 2 Municipal waste:

Municipal waste management agencies can pick up discarded clothing off the side of the road, in textile bins, or in recycling facilities. As an alternative method of collection, municipalities can also use (private) waste haulers to gather textile waste and used apparel.

Municipalities can collaborate with non-profit organizations by, for example, allowing them to place collecting bins in public spaces like recycling centers. In these circumstances, either the municipalities (like Fretex in Norway) or the charitable organizations (on their own) may be responsible for emptying the containers (e.g. UFF in Norway). Municipal garbage providers gather the garments that have been dumped in the residual waste.

2. Different sorting mechanisms of textile waste

Several techniques can be used to detect textiles as they pass through a recycling facility. There are businesses that produce cutting-edge textile sorting technology, such as Fibersort by Valvan Bailing Systems. All textiles can be sorted based on colour, weave type (woven vs. knitted), and fibre content (100% PET, 70% PET, 30% Cotton, etc.). The following paragraphs outline the available methods;

2.1. Manual Technique: 

This method is widely employed. Only features that people can see and touch can be used in this way to differentiate between materials. Color, fabric type (leather, wool, cotton, denim, etc.), quality (if the textile is torn or filthy), style, etc. are factors that are taken into account during manual sorting.

2.2. Fourier transform infrared spectroscopy (FTIR): 

FTIR can analyze a textile's colour and fibre composition, but it hasn't yet developed to the point where it can separate things much more successfully than a skilled human sorter. When this technological possibility is realised, FTIR could improve particular stages of sorting by fibre type and colour and raise the value of specific output streams. When this technical potential is realised, it may be preferable to think of FTIR as an advantageous supplement to manual methods.

2.3. RFID: 

Consider RFID tags as a "wireless USB memory stick" that can store and read data at a distance. The tag contains the exact description of the cloth, which could include information about its complex manufacturing process. The tag is read when the textile is delivered to the re-processor, enabling it to be sorted into the appropriate bin.

2.4. Bar code: 

It is necessary to choose the optimum bar code data format and guarantee that labels will continue to be machine readable after the textile's use phase. The label's black and white design was scanned and decoded by a camera and computer.

India is a very old player in textile recycling, especially in mechanical recycling. Now with the emerging technology in Chemical Recycling a huge quantity of feedstock is required so, it is very important to have a proper and well-organized collecting and sorting mechanism. Globally many organizations are trying to compete for the same.

References

1. Damayanti, D., Wulandari, L. A., Bagaskoro, A., Rianjanu, A., & Wu, H. S. (2021). Possibility routes for textile recycling technology. Polymers, 13(21), 3834.
2. News: Reverse Resources. (n.d.). Retrieved from Reverse Resources: https://reverseresources.net/news/how-much-does-garment-industry-actually-waste
3. Palm, D., Elander, M., Watson, D., Kiørboe, N., Salmenperä, H., Dahlbo, H. & Nystad, Ø. (2015). A Nordic textile strategy: Part II: A proposal for increased collection, sorting, reuse and recycling of textiles. Nordic Council of Ministers.
4. Palme, A. (2016). Recycling of cotton textiles: Characterization, pretreatment, and purification. Chalmers Tekniska Hogskola (Sweden).

About the Author: Sweta Singh is currently pursuing a Master in Fashion Technology from NIFT, New Delhi, with an experience of 7 months in SGS India Pvt. Ltd. as Asst. Quality Coordinator. She has done her B. Tech in Apparel Production and Management from the Government College of Engineering and Textile Technology, Serampore.