Strong, elastic, and easy to dye, nylon has the distinction of being the first commercially viable textile ever fully created in a laboratory. While other synthetic fibres, like polyester and acrylic, might now have more of the market share, nylon remains popular for clothes that need to be stretchy and durable, such as swimsuits, activewear, and hosiery.
When it comes to sustainability though, nylon is unlikely to win any prizes. From its raw materials to its manufacturing process to its life as clothing, nylon raises some serious issues for any eco-conscious consumer.
Let’s take a closer look at this synthetic fabric and what manufacturers are doing to try to address its environmental impact.
What is nylon?
Nylon is a type of plastic, usually derived from crude oil. It was first formulated by American scientists working for the chemical manufacturing corporation, DuPont Company, shortly before World War II. The team was led by Wallace Carrothers, who is usually credited with the invention of nylon.
The DuPont Company had already found commercial success by taking an early share of the American market for rayon. They were keen to capitalise on this achievement by developing a synthetic fibre that could replace expensive silk and brittle rayon.
Their scientists used the growing research into polymerisation to develop synthetic fibres that could be pulled and then spun into yarn. Unlike the other polymer fibres they had tried in the past, nylon had a high enough melting point to survive ironing and didn’t dissolve in water. The DuPont Company had found a winner.
Early nylon was used almost exclusively to make stockings, which were a staple of women’s wardrobes in the 1930s and 1940s. But the advent of World War II meant that much of the supply was soon diverted to the war effort, where it was used to make parachutes, ropes, shoelaces, hammocks, and even aircraft fuel tanks.
Nowadays, nylon’s durability, stretchiness, and ability to take dye well make it a favourite in clothing such as swimsuits and exercise gear. It can be static and itchy when used alone though, so you will usually find it blended with other fibres, such as cotton or polyester.
As well as activewear, nylon is used to make everyday items such as toothbrush bristles, rope, and umbrellas. And it is still commonly used to make stockings, as well as tights, socks, and underwear.
You’ll even find nylon mesh used to make teabags – its high melting point prevents the bags falling apart as you steep your tea.
How is nylon made?
Nylon is made in a complex process that starts with crude oil.
There are a couple of different nylon polymers, but the most common is PA 6.6, which is made from two of the chemicals that can be derived from crude oil by-products – the monomers hexamethylenediamine (diamine acid, for short) and adipic acid, which both come from benzene.
The diamine acid and adipic acid molecules are combined to create long polymer molecules in a chemical process known as condensation polymerisation.
This forms a crystalline substance called nylon salt, which is then heated and extruded through a spinneret, transforming it into fibres.
The fibres are stretched to increase their strength and elasticity. Then they are wound onto a spool in a process called drawing. Finally, the stretched fibres are spun into a yarn, which can be used to make clothes.
The other frequently used form of nylon is PA 6. This only uses one molecule, caprolactam, but the process is otherwise similar.
Is nylon sustainable?
Synthetic fibres like nylon are less water-hungry than cotton. And nylon’s durability can mean that clothes last longer.
But, as you may have guessed from the description of how it is manufactured, traditional nylon isn’t a sustainable fabric. Being based on chemicals derived from crude oil means it is associated with the fossil fuel industry, with all of the environmental devastation that implies.
Oil refineries are a major cause of both air and water pollution, impacting the health of humans, animals, and aquatic life. And crude oil itself is a finite resource, making it an inherently unsustainable raw material, even before we consider its environmental impact.
The production of the nylon itself does little to improve the picture. The manufacture of the adipic acid that is one of its main ingredients produces nitrous oxide. You may know this best as laughing gas, but nitrous oxide is a greenhouse gas that has 300 times the warming potential of carbon dioxide.
While most of this harmful greenhouse gas comes from agriculture, scientists believe that around 10% of nitrous oxide emissions may come from the production of nylon.
Nitrous oxide is also given off when waste nylon is burnt. And it is emitted during the production of caprolactam too, so nylon 6 and nylon 6.6 both produce the gas, contributing to climate change.
That’s a big environmental impact. But the issues with nylon don’t stop there…
Nylon isn’t biodegradable
Like other plastics, nylon isn’t biodegradable, which means your discarded swimsuits and tights will sit in landfill for years before breaking down into microplastics which can contaminate the soil and the water system.
Nylon sheds microplastics
Even before nylon gets as far as landfill, tiny plastic fibres are lost when you wash your clothes. And again, these microscopic bits of plastic can cause big problems when they end up in our oceans.
Nylon requires a lot of energy
There are a lot of steps involved in creating nylon and then spinning it into a yarn suitable for making clothes. And these processes require a lot of energy.
What are the alternatives to nylon?
The fashion industry is well aware of the issues involved with using synthetic and non-biodegradable textiles like nylon. And concern from brands and consumers alike is driving an appetite for more sustainable fabrics. Two major options have emerged as an alternative to traditional nylon.
1. Recycled nylon
One potential alternative for nylon is the growing use of recycled nylon, like ECONYL, which is manufactured by Italian company, Aquafil.
Recycled nylon aims to close the loop, taking waste nylon and using it to create new fabric.
Not only does this reduce the amount of nylon that is sent to landfill, but it also removes some of the reliance on crude oil and its derivatives to create our clothes.
Much of the waste nylon used to make ECONYL comes from fishing nets, which are causing a huge problem for our oceans. Abandoned fishing nets are thought to make up around 10% of the plastic waste in our waters.
These nets can entangle marine animals and fish, injuring or killing them. In a report by Greenpeace, they outline one incident in 2018 that led to around 300 sea turtles being found dead after becoming entangled in a net off the coast of Mexico. And because they don’t biodegrade, the nets can cause issues for years after being discarded.
Recycled nylon aims to address the issue of abandoned fishing nets by reclaiming them from the sea and giving them a second life as clothing.
Aquafil partnered with sock manufacturers Star Sock and NGO Ghost Diving to launch the Healthy Seas initiative in 2013. They work with volunteer divers to remove nets from the water and recycle them using the ECONYL process.
ECONYL also uses fabric scraps, industrial plastics, and nylon carpets. The waste is sorted and cleansed to reclaim as much nylon as possible, which is then regenerated to make fresh nylon for the manufacture of carpets and clothes.
According to ECONYL themselves, every 10,000 tonnes of recycled nylon prevents 65,100 tonnes of carbon dioxide emissions and saves 70,000 barrels of crude oil.
Best of all, the nylon is indefinitely recyclable. So, the new clothes made with recycled nylon can, in their turn, become another new item at the end of their lifecycle.
So, is recycled nylon an environmentally friendly option then?
Well… yes and no. Recycled nylon is a far better choice than virgin nylon. It requires fewer resources to manufacture, diverts waste from landfill, and can help to tackle the urgent issue of abandoned fishing nets in our oceans.
But the problem of microplastics still remains. At the end of the day, the recycled nylon has the same chemical makeup as the original nylon – in other words, it is still made of plastic. And that means it will still shed microplastics.
Even if you send your clothes back to be recycled at the end of their life, preventing them from going to landfill, those tiny fibres can still escape when you wash them.
That said, there are some items, like swimsuits and stockings, where it is very difficult to avoid nylon altogether. Choosing an item made from recycled nylon instead of virgin nylon will vastly reduce the environmental impact of your clothing.
And it will provide a commercial incentive for the fishing industry to send its waste nets to be made into new fabrics, rather than abandoning them in the oceans.
As public concern over plastic waste and the use of fossil fuels increases, many manufacturers are seeking new ways to make their plastic. And to do that they are turning to alternatives like corn starch or sugarcane. Bioplastics can even be made by microorganisms.
It was only a matter of time before interest turned to making a renewably sourced alternative to nylon. Sure enough, in 2020, biotech specialist Genomatica announced they had perfected a process that creates 100% renewably sourced nylon.
Their method uses a fermentation process similar to beer-making. A specially engineered microorganism ferments the sugars found in plants. But instead of making alcohol, the microorganism used by Genomatica creates the chemical caprolactam – which can be used to make nylon 6.
It is early days yet for this technology, but Genomatica are partnering with Aquafil and hope to bring a fully renewably sourced nylon to the market in the near future. They are aiming for the first bio-nylons to be available to manufacturers by the end of 2021.
Genomatica’s process is exciting for the textile industry because it can make an existing product, nylon 6, which is one of the most used nylons in the world. But other companies have been championing the use of alternative nylons, such as nylon 11, which is made from castor beans.
More commonly used to make resins, nylon 11 is also being used as a renewable alternative to nylon 6 and 6.6 for making clothes. Fulgar’s EVO is an example, marketed as an alternative to traditional nylon for high performance activewear.
Are bio-nylons an environmentally friendly option?
Like other bioplastics, bio-nylons avoid the use of crude oil and come from a sustainable source. But this doesn’t necessarily mean that they are better for the environment.
Manufacturing bioplastics can be resource intensive, so some bioplastics have been found to have a greater environmental impact than traditional hydrocarbon-based plastics, when the full lifecycle is taken into account.
Also, just because a plastic is made from a biological source, doesn’t necessarily mean it will biodegrade, especially under normal conditions. And some bioplastics may cause issues for marine life too.
Ultimately, bio-nylons still use virgin materials to make new fabrics, which means they don’t tackle the issue of clothing waste. Until a full lifecycle analysis is available of these new alternatives, it is difficult to see them as an environmentally friendly option.
Synthetic fabrics like nylon caused a revolution in how we dress and were quickly adopted by fashion-conscious shoppers when first launched.
But our growing understanding of the environmental impact of fabrics made from crude oil means that traditional nylon is one to avoid for most ethically minded modern consumers.
Where no other alternative is available, choosing clothes made from a recycled nylon like ECONYL is one option that can lessen the impact of this manmade textile.
Swimwear made from recycled fishing nets feels like a satisfying way to support efforts to tackle plastic waste in our oceans, as well as being a more environmentally friendly fabric than traditional nylon.
Just be sure to minimise the shedding of microplastics via your washing machine as much as you can. Using a bag can prevent some microplastics from entering our waterways. And simply washing your clothes less often is an easy way to reduce microplastic pollution from items you already own.
It is too early to say whether bio-nylons are an environmentally friendly alternative to traditional nylon. But on the eco-scale of reduce, reuse, recycle, bio-nylons don’t fit the bill – no matter their raw materials, they are a new product that is unlikely to stack up against recycled options.
Nylon isn’t a sustainable choice, but there are options out there that can help you to reduce your clothes’ impact when you can’t avoid it altogether.