What is Nylon?
If you’ve ever shopped for sock yarn, you’ve probably noticed that most of the commercially produced ones on the market contain some amount of nylon (normally between ten and thirty-five percent). It is generally accepted that sock yarns need some amount of nylon to add strength and durability, and many knitters wouldn't consider making socks out of a yarn that didn’t contain it. When I started researching sock yarns, I felt instinctively that I didn’t want to use yarn that contained any synthetic materials, but I also realised that I didn’t know anything about where nylon came from or how it was made, so I decided to do a bit of research on nylon and its production. Here’s what I found out.
History
Nylon was the very first fibre to be made entirely synthetically. The first example was synthesised in 1935 by DuPont. In 1940 around 1300 tons of nylon was produced, and 64 million pairs of stockings were sold, marking the dawn of a new age of synthetic fabrics.
During the Second World War production of nylon was diverted away from stockings to military use, for items such as rope, fuel tanks, mosquito nets, hammocks and parachutes. Once the war was over, a shortage of silk and other traditional dress fabrics meant these nylon parachutes were widely repurposed to make clothing. However, as nylon clothing became more commonplace, it became clear that pure nylon isn’t actually great for clothes. It’s fragile and lacks absorbency (it doesn’t ‘wick’ moisture away from the skin). The solution was to blend pure nylon with a wide variety of other natural and synthetic fibres, including wool, cotton and polyester. In this way the desirable characteristics of nylon could be retained, and many of the undesirable ones eliminated.
Although nylon gradually became less fashionable from the 1970s onwards, worldwide production was estimated to be 8.9 million tonnes in 2020. The largest producers of virgin nylon are China, India and Pakistan.
Production
Nylon is made from petroleum or crude oil. Carbon based chemicals from these substances are reacted in a high pressure environment and heated. This chemical reaction is called condensation polymerisation, and the result is a sheet of nylon which is then chipped, melted down and drawn through a mechanical spinneret to produce the nylon fibres. These fibres are then cooled and stretched, causing the molecules to form parallel lines and giving nylon its strength and elasticity.
Why is Nylon Used in Socks?
Many of the properties of nylon make it perfect for socks. Socks are subject to a huge amount of wear and nylon is incredibly durable and resistant to abrasion. It’s also very elastic and not weakened by sweat or other chemicals. Adding nylon fibres to wool also means that it can be spun very finely without breaking. However due to its lack of absorbency, socks with a high nylon content will feel sticky.
Environmental Impact
The production of nylon has a negative environmental impact for a number of reasons. Most processes use crude oil, a non-renewable fossil fuel whose acquisition and use is harmful to the environment. The production process also uses a lot of energy and produces a lot of waste. It requires a large quantity of water to cool the nylon fibres, and it produces nitrous oxide - a greenhouse gas. And it’s not just the production of nylon that is detrimental to the environment: as a synthetic fibre, nylon sheds microplastics each time it is washed, and it is not biodegradable in any form. While discarded nylon will eventually break down, it could take up to two hundred years to do so.
So is there anything we can do with the nylon that already exists? Well, nylon is a plastic, and as such it can be recycled. There are a number of companies that produce recycled nylon, so it’s worth searching these out if you want to use nylon in your socks (The Fibre Company’s Amble Sock Yarn, for example, contains recycled nylon). If you already own nylon socks or sock yarn, don’t throw them away - use them, but try to minimise how often you wash them. .
Alternatives
Nylon has been around for just under a century, but humans have been knitting and wearing socks for hundreds of years, so it must be possible to make good, hardwearing socks without the addition of nylon. Although it is the case that non-nylon socks will probably require darning before their nylon counterparts, that seems like a small price to pay for having handmade socks that won’t take hundreds of years to break down, and there are a number of ways to prolong their lives.
The type of fibre, the way that it’s been spun and whether it’s been blended with anything to add strength will all affect how hard wearing your socks are, as will the stitch patterns and design elements that you choose. I’ve written more about all of that here.
Sources:
https://sewport.com/fabrics-directory/nylon-fabric
https://goodonyou.eco/material-guide-nylon/
https://sciencing.com/nylon-8618074.html
https://tortoiseandladygrey.com/2016/02/01/environmental-impacts-nylon/
https://www.close-the-loop.be/en/phase/3/end-of-life