11. February 2022
from Thomas Schäfer, bluesign® ACADEMY
Sustainable fibers as well as sustainable textile chemicals are required to achieve sustainability in the textile value chain. All parties involved are responsible for socially and environmentally responsible production of textiles. What does this mean in concrete terms? What must be done?
Clean Clothes Campaign reports that three out of five of the 100 billion garment textiles produced in 2018 ended up in landfill after just one year. Social issues in production companies in Asia, particularly in clothing firms, are an ongoing issue. According to a Mc-Kinsey study, production of clothing textiles doubled between 2000 and 2014. This is just a random selection of examples that quickly highlight the importance of this topic.
What does sustainability mean?
The German word "nachhaltend", meaning "sustainable", can be traced back as early as the 18th century. In 1713, Carlo von Carlowitz addressed the principle of forestry sustainability for the first time in his work Sylvicultura oeconomica: "The greatest art, science, diligence and institution of these countries will rely on the manner in which such conservation and growing of wood is to be undertaken in order to have a continuing, stable and sustained use, as this is an indispensable cause, without which the country in its essence cannot remain." The publication of the Brundtland report in 1987 is considered a milestone in the global discourse on sustainability. The principle of sustainability (continuous development) is clearly outlined and it's remarkable that the statement by Carlowitz, which is more than 300 years old and relates only to forestry, is basically reproduced: "Continuous development is development that meets the needs of the present without the risk of future generations not being able to meet their own needs."
There are three main pillars for sustainable development:
■ social justice
■ economic performance
■ environmental sustainability
The main focus of this paper should be on the ecological aspects in the textile value chain.
The textile value chain
The textile chain is considered one of the most complex industrial value chains due to the many processing stages and processing methods. If we also take into account the chemical suppliers, we must really talk about a supply network, a supply matrix rather than a supply chain (Fig. 1).
Looking at the network, the challenges faced by a brand company quickly become clear. On the one hand, the supply chain is globally positioned, on the other hand, it is possible to differentiate between different tiers. Often, the brand company only has contact with an agent or so-called converter. It may sound astonishing, but naming all players in the supply chain (including the correct address details and potential subcontractors) is a huge challenge for many brand companies – especially those in the fast fashion sector – and can rarely be accomplished completely.
And even if the contacts go deeper, they often only go to tier 1 – the finished good assemblers. At this level, with the often large sewing rooms, social aspects clearly dominate over environmental issues. Attempts are made to meet set standards with environmental and social audits. Because audits and standards are usually not mutually recognized, too many audits are currently being carried out. Social and environmental audits also often do not result in real improvements to the situation on site, but merely in a global "audit business".
And this business usually relies on so-called "compliance audits" rather than audits that aim to continuously/sustainably improve working conditions and environmental performance (so-called "capacity audits").
However, when it comes to improving environmental performance, resource efficiency and chemical management along the textile chain, tier 2 stands out. Here, large quantities of fresh water, chemicals and energy are required in the textile processing plants. This in turn leads to significant CO2 emissions and large amounts of wastewater.
Textile Exchange published a detailed report on "Preferred Fiber & Materials" in 2021.
First, a few facts:
■ 109 million tonnes of fibers were produced in 2020
■ Production volume is expected to increase by 34% by 2030
■ Polyester accounts for 52% of this volume, cotton 24%; cellulosic synthetic fibers such as viscose, lyocell or cellulose acetate, account for 6%
■ The market share of recycled fibers is approx. 8% (94% PET)
It makes limited sense to compare different types of fibers, such as polyester and cotton or cotton and viscose, in terms of their sustainability and to give preference to a specific fiber type. You are comparing apples with pears here, as the different types of fibers have very different properties. Or, to put it simply: Polyester underwear does not offer the same comfort as cotton products.
But what are sustainable fibers?
Fibers made from recycled raw materials and fibers from bio-based raw materials are the main candidates here.
Cotton and other plant-based natural fibers, such as linen or jute, as well as man made cellulose fibers (MMCF), are biobased and are therefore manufactured from renewable raw materials without crude oil as the starting point. Polyester is also already available, where one of the two monomers required to form the polymer, ethylene glycol, is generated from biomass. But we have to delve into this group of bio-based fibers in even more detail.
For example, cellulose is extracted from wood and global forest management is not always sustainable.
We can therefore summarize that bio-based fibers can be considered sustainable if:
■ (put simply) "organic cotton" is used (e.g. with the labels Fairtrade or Cotton Made in Africa)
■ the cellulose source in MMCF comes from sustainable forest management (proven via FSC or PEFC label, for example)
Animal welfare must be taken into account for sustainable wool fibers and down fillings.
The second group of sustainable fibers are recycled fibers, particularly recycled polyester. PET drinking bottles are usually mechanically crushed and then processed into fibers by melt spinning. The advantage is that no crude oil, a finite resource, is used for chemical synthesis. Unfortunately, however, we cannot refer to a closed cycle here; downcycling is actually more accurate, since most of the textiles end up in incineration/landfill, frequently after just a short period of use and are thus removed from the cycle. MMCF can also be made from recycled material. One example is Lenzing’s RefibraTM, a lyocell fiber that is commercially available and made with 30% preconsumer cotton waste (which is production waste).
In general, the biggest problem with post-consumer textile recycling is the variety of materials used (just think of the ingredients of an outdoor jacket) and the fiber mixtures used. Elastane, for example, is currently present in quantities of up to 5% in a large number of textiles.
Consumption [kg/t textile]
Table 1: Average specific consumption of chemicals in textile finishing.
It is therefore hardly surprising that the proportion of textile to textile recycling worldwide is less than 1%.
Another example of sustainable fibers is dope-dyed fibers. In the melt spinning process (usually with PES), small quantities of color pigments are added to the spinning mass. This saves the entire aqueous dyeing process in the textile dyeing department. The resource savings are significant. The reduced flexibility of this process (only larger batches are worthwhile; quick implementation of color shades is not possible) is the obstacle to increasing the market share of spun-dyed fibers.
Sustainable textile chemicals
Textile finishing companies use large quantities of textile additives, dyes and basic chemicals (such as caustic soda or acetic acid). Table 1 provides an overview.
In recent years, the focus in chemical management has been on banning certain chemical substances (via so-called Restricted Substances Lists (RSL) or MRSL (Manufacturing Restricted Substances List)) and reducing contamination of chemical products to a minimum for ecolabels and also for brand-name companies. This prevents employees from handling harmful chemicals in the company and these chemicals from being released into the environment. This also enables consumer protection requirements to be met. This approach is correct and important; it is usually backed up by analytical tests on textile semi-finished and finished products. Some organizations, such as Bluesign, create so-called positive lists of textile chemicals, which are optimized in this regard.
More and more attention is being paid to the actual consumption of chemicals in the finishing plant; the creation of so-called "chemicals inventory lists" - introduced a while ago as part of the waste water register for German textile companies – allows textile companies to manage chemicals appropriately.
However, the focus is increasingly also on sustainability aspects in the manufacture of chemicals and in the use of additives and dyes. Topics here include
■ the use of bio-based raw materials or use of recycled raw materials in the production of chemicals. An Italian chemical company developed a leveling agent for the dyeing plant and uses recycled restaurant olive oil as a raw material for the chemical synthesis; a Swiss company manufactures auxiliary agents based on certified palm oil; a German company manufactures a hydrophilising agent made from chemically recycled PET.
■ Development of auxiliaries and dyes that save water, energy, time and usually also financial resources in textile operations. Typically, the process temperature can be lowered or bath change or rinsing baths can be reduced during pretreatment, dyeing or finishing.
It is much more difficult to quantify the use of resources in chemical production and to make a statement about green house gas emissions, for example. There is currently a lack of structured data collection and evaluation in the chemical companies and, above all, their global suppliers.
The specific water consumption of a textile finishing company can range from 50 l per kg textile to over 250 l/kg textile. The specific energy consumption ranges between 5 kWh/kg textile and over 25 kWh/kg textile. However, it is rarely possible to really compare Plant A and Plant B without further analysis. For example, a cotton processing company that refines woven fabric requires more water than a polyester processing company due to the processes involved.
Nevertheless, we can say in very simplified terms that all textile companies with a specific water consumption of more than 150 l/kg textile have significant potential for saving resources in places. On the one hand, a modern machine fleet is advantageous here (with correct use and operation). On the other hand, there are countless examples of so-called "low hanging fruits", which enable significant savings to be made in terms of water, energy and chemicals without a major investment. Good housekeeping is a must to detect these low hanging fruits (such as boiler feedwater recuperation, correct insulation of steam lines, no uncontrolled overflow rinsing, correct dosing of chemicals, leaks in the compressed air system) and to initiate the necessary measures.
And even though is may seem too simple: textile companies often lack knowledge of the specific use of water and energy (particularly at process level), which is the basic prerequisite for targeted and effective optimization measures.
A sustainable textile finishing company has the knowledge and awareness that resource efficiency, chemical management, environmental performance and working conditions (especially when handling chemicals) must be continuously optimized. This is a 24/7 job. And – not to forget – new approaches, such as inkjet printing, which in many cases has now replaced screen printing, can also increase a textile company’s resource efficiency and environmental performance.
A basic requirement for a sustainable textile product is that it is manufactured taking into account the points already mentioned above. The following example highlights how – even if everything appears to be "ok" - argumentation difficulties may well arise.
A fleece jacket usually consists of a dyed, finished polyester fabric, where the pleasant "fleece property" is achieved by subsequent shearing and raising of the fabric. In these mechanical processes, approx. 15% of the textile already produced is removed and pressed into fiber waste. This means that 15% of the polyester, which has already been spun into the fibers and processed into knitted fabrics, dyed and finished using a significant amount of resources, becomes a waste product just before use. Our goal isn't to paint fleece fabrics in a negative light here, but the example shows how difficult it is to define a sustainable product. The same applies to the denim industry, which basically intentionally "damages" jeans before use.
Put simply, a sustainable item of clothing is characterized by the following features:
■ The garment is placed on the market by a company that exercises its corporate due diligence throughout the supply chain
■ Production takes place under socially responsible conditions and using sustainable fibers and chemicals in production facilities optimized for resource efficiency and the lowest possible environmental impact as far as possible
■ The garment is durable
■ The garment or backpack can be repaired (example zip) and will be repaired
It must be said that there is still a very long way to go to achieve recyclability of used textiles on an economically significant scale.
Durability focuses on the materials used and their processing. However, a fashionable item of clothing is per se not durable, as it loses its appeal with the next season change.
And a recyclable product should consist of only a few parts. While it may be possible to simplify the components used for a T-shirt, there are limits to how far the list of materials can be reduced for an outdoor jacket designed for performance. In the end, you have to ask yourself, can fashion textiles, can fast fashion be sustainable at all? The honest answer is: when selecting the fibers and chemicals used and when selecting the production facilities, one can and should take into account the sustainability aspects outlined above. This is a first step. Changing consumer behavior with the aim of reducing textile consumption – this is also referred to as ethics of abstention – is a mammoth social task that is certainly not made easier by the dogma of the constant growth of a capitalist economic form.
Who is responsible for sustainability in the textile value chain?
The answer is simple:
■ all players in the network (Fig. 1)
■ the consumer himself/herself
■ state and supranational institutions, regulations
■ NGOs (Non Governmental Organizations)
■ ecolabels and social labels that must clearly distinguish themselves from "greenwashing"
Prompted not least by NGOs such as Greenpeace with their textile chain-oriented detox campaign or the campaigns of Changing Markets (Dirty Fashion Campaign) focused on cellulose-based synthetic fibers, sustainability has become part of the corporate policy of many brand companies, chemical companies and processing companies. Many companies make voluntary commitments and set targets to reduce GHG emissions, for example. Let us hope that the objectives set, supported by legislation and the eco/social label, as well as demands from environmentally/socially conscious consumers, will be achieved quickly and sustainably. So-called flagship projects must be avoided, which serve only for marketing purposes (in the worst case even amount to greenwashing) and do little to make the textile value chain more sustainable.
First published in TEXTILplus (translated from German language into English)