Natural, artificial and synthetic fabrics: how do they differ?

The textile fibers used on an industrial level for the production of clothing are numerous and technological progress causes their number to increase year after year. The multitude of information available about their characteristics and the speed of technical evolution can make it difficult to understand the differences, not only for consumers, but also for companies that are faced with sustainable production choices.

This article aims to analyze the classic distinction between natural fibers and synthetic fibers, illustrating their pros and cons and debunking false myths and is addressed to all those companies which, embarking on a path of sustainability for the first time, want to carry out a analysis of the materials used in its collections, making informed choices.

The characteristics of natural, artificial and synthetic fibers

Textile fibers are divided into natural, artificial and synthetic fibers.

• Natural fibers: they are obtained entirely from products of vegetable origin (e.g. cotton, linen, hemp and jute) or animal origin (e.g. wool and silk) which, following purely mechanical processes, are suitable for the production of yarn. They are the oldest fibres, which have always been used and appreciated for their flexibility and ease of spinning.
• Artificial fibers: like natural fibers, artificial ones also derive from material of natural origin, cellulose or proteins of vegetable origin. In this case, however, the production of yarn takes place through chemical transformation (e.g. viscose, acetate, rayon). This category is the one that has had the greatest development in the last decade, in which the growing demand for sustainable fashion and vegan clothing has led to the constant search for new ecological fibers. We have thus witnessed the birth of numerous artificial fibers derived from citrus fruits, milk, corn, marc and from trees such as eucalyptus and beech.
• Synthetic fibers: unlike the previous ones, synthetic fibers are produced by chemical synthesis (so-called polymerization), using petroleum by-products and materials of mineral origin (e.g. nylon, polyester, polyamide, acrylic).

Synthetic fabrics: pros and cons

Since the 1960s, synthetic fibres have developed enormously and, to date, it is estimated that they represent more than two thirds (69%) of all fibres used in the textile sector.

Numerous environmental and industry associations have denounced the negative environmental impacts caused by the excessive use of these materials in the fashion industry. Here are the main issues to take into account:

• Fossil Fuel Based: as previously mentioned, synthetic fibres derive from the processing of petroleum by-products and the indiscriminate use of synthetic fibres is one of the main causes of the environmental impacts for which the fashion industry is held responsible. It is estimated that the production of synthetic fibres requires in fact 1.35% of world oil consumption (more than the annual consumption of Spain), and that in 2015 the production of polyester was responsible for the emission of more than 700 million tons of carbon dioxide. Many are the Call to Action addressed by environmental and industry associations to the main fashion houses to align themselves with the objectives of decarbonisation defined by international institutions. The main measures proposed include the reduction of synthetic fibres from non-recycled sources.
• Waste: it is estimated that in the last 15 years the number of garments purchased by consumers has increased on average by 60%, growth indirectly proportional to the number of times each garment is worn. In fact, clothing items are thrown away on average after seven/eight uses, and then end up in landfills, incinerators or dispersed into the environment. This high production of waste is particularly harmful when it comes to clothing made of synthetic fibers: they are in fact made with non-biodegradable plastic, which can survive in landfills for over 200 years, releasing chemicals such as methane and microfibers.
• Microplastics: during washing and use, synthetic fibers break up into small particles (so-called microplastics), invisible to the naked eye, which are dispersed in the environment. It has been estimated that about half a million tons of plastic microfibres, released from synthetic fabrics, end up in the ocean every year, with serious consequences for marine ecosystems.
• Toxicity for human health: The Istituto Superiore di Sanità warns that microplastics can also pose a serious danger to human health. In fact, they can come into contact with the human body through the inhalation of air or the ingestion of contaminated food, causing serious problems to the respiratory and digestive systems

The negative effects caused by the extensive and indiscriminate use of synthetic fibers in the fashion industry have long been the subject of heated debate. However, it is also important to consider the positive aspects:

• Versatility and industrial development: as anticipated, synthetic fibers are produced by chemical synthesis, i.e. by the creation in the laboratory of monomers that have petroleum or materials of mineral origin as a starting point. In the production process, the monomer can be provided with any characteristic, depending on the specific textile application for which it is intended. For example, synthetic fibers are very suitable for the production of technical fabrics for sportswear, as they are resistant, breathable and elastic.
• Chemical recycling: if various doubts have been raised about the effectiveness of the mechanical PET recycling process and its effective sustainability (to which we dedicate an in-depth paragraph in this article below), the same objections do not apply to chemical recycling of nylon. This process, the so-called "depolymerization", allows to decompose the plastic material into its original monomers, indistinguishable from virgin polyester, keeping all the qualities unchanged. This process can be repeated countless times on the same material, using textile fibers as a starting point. In this regard, the Italian company Econyl deserves a mention, holder of the process patent for the chemical recycling of nylon, which allows the regeneration of numerous wastes including fishing nets, used carpets, as well as industrial plastics.

Recycled synthetic fibers: are they really more sustainable?

The recycling of plastic materials deserves a separate mention, above all for the massive use it has been making in fashion in recent years. Indeed, the market share of recycled polyester reached 14% in 2019 and is increasing.

Conflicting opinions have been expressed on the use of rPET for the production of garments.

On the one hand, recycled polyester (so-called rPET) requires fewer resources to be produced than virgin polyester, despite having comparable qualities to it: according to a 2017 study by the Federal Office of the Environment, energy savings are around 59% and the Waste and Resources Action Program estimates that manufacturing rPET reduces carbon dioxide emissions by 32% compared to regular polyester.

On the other hand, however, the rPET currently used in the textile sector comes from mechanical recycling processes, through which virgin PET is transformed into shavings which are then reintroduced into the traditional fiber production process. During the process, however, the quality of the fiber is reduced: this implies that rPET must be mixed with virgin fibers to achieve sufficient quality standards and furthermore that the recycling process on the same material cannot be repeated indefinitely. A garment in rPET tends to end up in landfills.

It should also be taken into account that recycled PET comes from bottles and not from disused textile fibers, with the consequence that the amount of textile waste that ends up in landfills remains extremely high. Companies like Patagonia are studying recycling solutions starting from used garments.

Are natural fabrics always preferable to synthetic ones?

If there are numerous critical issues highlighted regarding the use of synthetic fibers, it is however incorrect to assume that the production of natural fibers does not also have significant environmental impacts.

Natural fibers, due to the etymology of the word itself, are often associated with the concept of sustainability, but the analysis to be carried out is much more complex: it must take into account multiple factors relating to the production chain which, especially in the case of natural fibers is long and complex.

The Sustainable Apparel Coalition's (SAC) Higg Materials Sustainability Index (Higg MSI), one of the most trusted tools for measuring and evaluating the environmental impact of materials, confirms the importance of conducting a comprehensive sustainability assessment that considers how of management of the production process; for example, if the potential global warming index of virgin polyester fabric is 9.62 (compared to 8.87 of conventional virgin cotton fabric), mechanically recycled polyester fabric has an index of 7.12, 19.7% less compared to cotton fabric. (Source: Global Warming Potential Impact Scores, based on Higg MSI 3.2 data at Higg.org.) Attention: this does not mean that recycled polyester should be preferred to conventional cotton (the data from the Higg MSI are, among other things, rather debated and must therefore be used with due precautions); it is rather an indication of the fact that each type of material can have a very different impact depending on its supply chain, and it is therefore possible and desirable for each company to minimize the environmental impact of the materials it uses by making considered choices.

Using natural fabrics to produce an item of clothing is not always the most sustainable choice. Among the negative aspects of the production of natural fibers should be mentioned:

• Agricultural exploitation: to ensure maximum yield of land, chemical fertilizers and insecticides are often used in the cultivation process. For example, it is estimated that around 16% of the world's insecticides and 7% of pesticides are used to grow conventional cotton. These substances lead to a reduction in soil fertility and seriously compromise biodiversity, as well as causing serious health problems for farmers. Even farming for the production of cashmere wool involves intensive exploitation of the land: according to recent data from the Mongolian government, which together with China produces 90% of the cashmere used throughout the world, around 60% of the pastures have dried up, with large areas turned into desert.
• High water footprint: the water consumption of cotton cultivation is much discussed, but it must be remembered that the situation is completely different if artificial irrigation or rainwater is used; to have control over this element, it would therefore be necessary to know one's supply chain to ensure correct management of water resources, especially if the cotton comes, as often happens, from countries affected by severe water stress.
• Animal Cruelty: in sheep farms destined for the production of Merino wool, the Mulesing technique is often applied. It consists in the removal of part of the posterior tissues, very often including the tail, to ensure that the new tissues that are formed are smoother and that there are no folds and inlets where infections can settle. If it is true that infections, such as myiasis, very common in sheep, can lead to the death of the animal, it is also true that Mulesing involves deep wounds and that blood loss can sometimes be fatal and often become infected, returning among other things, to the starting problem. The practice of Mulesing has been made illegal in many countries, but unfortunately it is still allowed in Australia, where according to the PETA association, People for Ethical Treatment of Animals, 25% of the world's production of Merino wool is concentrated.

Even from a social point of view, the cultivation and livestock intended for the production of natural fibers is not without criticism. Manufacturers face significant social and economic challenges, for which the textile and fashion industry as a whole must be held accountable. They include:

• Forced labor and child exploitation: the lack of legislation and the weakness of protection systems in various producing countries lead to violations of workers' rights and the exploitation of child labour. One example among many is the one denounced in 2021 by the BBC, according to which hundreds of thousands of Uyghur Muslims and other ethnic minorities were forced into unpaid manual work in the Chinese region of Xinjiang, from which 20% of world cotton production comes.
• Financial problems: insufficient access to institutional credit in producing countries leads farmers and stockbreeders to get into debt, with interest rates reaching 120% per annum, for the purchase of tools and resources necessary to carry out the activity (in particular for the purchase of genetically modified seeds, often sold at high prices). Furthermore, the greater risks due to the impact of climate change are further increasing the economic burden of producers, together with price fluctuations and the absence of international supply-demand management policies.

Finally, the advantages of using natural fibers should be highlighted, which lead many companies to prefer them to synthetic ones:

• Biodegradability: coming from raw materials of vegetable or animal origin, natural fibers are biodegradable, remaining in the environment for very short periods of time compared to synthetic fibers. Wool, for example, biodegrades in three or four months if buried and kept in ideal thermal and humidity conditions. Furthermore, during the degradation process, it releases essential elements such as nitrogen, sulfur and magnesium into the soil, which can be absorbed by plants and contribute to soil fertility. It should be noted that the biodegradation process can be influenced by treatments such as dyeing and anti-crease, which cause an increase in the initial resistance of the fabric.
• Recyclability: once subjected to the spinning process, natural fibers can be reintroduced into the production process and recycled with procedures that often minimally compromise the quality of the original fiber. For example, the recycling of wool is a tradition of the Prato district. If the recycling of wool is a tradition, it is more difficult to find other recycled materials such as cotton.

Conclusions

The brief examination of the negative and positive aspects of synthetic and natural fibers demonstrates that sustainability choices are not unique and do not have a single solution.

If on the one hand, in fact, conventional cotton is the object of harsh criticism due to the numerous environmental impacts that its production entails, it is also true that the negative effects described can be tempered by preferring other vegetable fibers (such as, for example, hemp and jute , which need much lower quantities of water and are naturally resistant to parasites and insects), or recycled cotton, coming from regenerative or certified organic agriculture (on the subject, in particular, see the article by Cikis GOTS Certification: what is and why choose it).

Equally, if the thoughtless use of synthetic fibers in the fashion industry leads to serious problems from an environmental point of view, it is also important to consider that they are recyclable and that the use of the depolymerization technique can effectively contribute to the reduction of the amount of waste polluting marine and terrestrial resources.

Cikis can help companies identify the best choice, through a careful selection of materials and the proposal of strategies tailored to company needs. In this way, the company will be able to achieve high levels of sustainability, will benefit to the maximum from the investment made and will avoid incurring reputational risks.