What Is Acrylic and Synthetic Yarn and What Is It Made Of?
If you walk into - or log into - a yarn shop, you’ll have a vast choice of yarns from different manufacturers. The main types of yarn are acrylic yarn and natural yarn. But what’s the real difference between yarn made from natural fibers and those made from acrylic fibers? Keep reading to find out!
What is an acrylic yarn?
Acrylic yarns, as opposed to yarns made from natural fibers like wool and cotton, are created from man-made or semi man-made fibers. These fibers are created in various different ways and are also used for different types of projects and to give specific characteristics to yarn, usually to mimic natural fibers like wool, cotton, linen, etc.
Acrylic yarns are used widely because they are usually cheaper than natural yarns - sometimes by quite a lot. This makes it a more budget-friendly choice, especially with the new acrylic yarns that are a lot softer than the first acrylic yarns that were produced.
How is acrylic yarn made?
Acrylic yarn is made from coal-based and petroleum chemicals, making them a fossil fuel-based fiber. The petroleum chemicals are treated with certain monomers (a type of molecule) that leads to the formation of polymers. Acrylic fiber and yarn are made from a synthetic polymer called acrylonitrile.
This polymer is then dissolved and the resulting gel is spun into thin fibers using an extraction method and spinnerets. These fibers are then spun (wet or dry) before being washed and stretched. It’s these fibers that can then be spun into yarn.
Other types of man-made and semi man-made fibers used for knitting and crochet
These acrylic fibers made from acrylonitrile are not the only man-made fibers that can be used for knitting and crochet. Nylon, rayon, lyocell, and viscose are also created and used for different types of yarns and projects.
Probably the most well-known synthetic fiber after acrylic, nylon is often used in sock yarn, where the nylon content is usually about 25%.
Nylon is made in much the same way as acrylic, and is also a type of plastic that is manufactured out of crude oil. An intensive chemical process is required to produce the strong and stretchy nylon fibers.
When the nylon is first created, it’s in the form of a sheet, which is then broken into smaller pieces, melted, and extracted into fibers using spinnerets. These individual fibers can be used in yarn and fabric.
What are the main characteristics of nylon?
- Has a certain amount of stretchiness
- Can be moulded into a specific shape
Why is sock yarn so often blended with nylon?
Nylon’s stretchiness is what makes it so great for using in sock yarn, as it helps the sock to fit your foot snugly, while also returning to its original form once you take the sock off. It’s also often used in conjunction with superwash merino or other types of wool. This means that the socks can be washed in a washing machine - on the delicate setting - and don't need to be hand washed.
What is bio-nylon?
Genomatica has engineered microorganisms to ferment sugars found in plants to form the chemical caprolactam; which is what nylon is made of. This “bio-nylon” is, therefore, made without the need for crude oil and can be manufactured in a renewable way.
Rayon is a semi man-made fiber that is made from the cellulose that is found in wood, soybeans, cotton, and bamboo. The cellulose is first dissolved using chemicals before it’s converted back into insoluble fibrous cellulose using other chemicals, including sulfuric acid and zinc sulfate.
This converted cellulose forms fibers almost like that of silk and rayon is often used to mimic silk, cotton, and linen.
Lyocell is a type of rayon and is also made from plant cellulose. However, the chemicals used to make lyocell are different from those used to make rayon. Also, while the process used to make rayon uses carbon disulfide (which is toxic to workers and the environment), the process to produce lyocell uses the N-methyl morpholine-N-oxide (NMMO) dissolution method that is far more environmentally friendly if more expensive.
Another type of rayon, viscose is used as a silk substitute as it has a similar drape and feel to silk. In fact, when viscose was first produced in 1883, it was used as a cheaper artificial silk.
What is a yarn blend?
A blend, as the name suggests, is a yarn that is made by using more than one type of fiber, for example sock yarn that’s a blend of merino wool and nylon or a synthetic yarn that is a mixture of acrylic and nylon.
Why use synthetic or acrylic yarns instead of yarns made from natural fiber?
There are a number of reasons to use acrylic or synthetic yarns rather than natural fibers like wool:
- Knitting or crocheting an item for someone with a wool allergy if you don’t want to use or can’t use yarn made from plant fibers like cotton and bamboo.
- It’s a very large project and cost is an issue; acrylic yarns are much cheaper than those made from natural fibers.
- You’re on a strict budget and can only afford acrylic yarn.
- Items made from acrylic yarn can be warmer than those made from natural fibers, as it is less breathable overall.
- Acrylic yarns - with their extra “grip” on knitting needles and crochet hooks - make it the perfect type of yarn for beginners.
What is most eco-friendly synthetic yarn to use?
Because so many chemicals are used to make acrylic yarn - which is in itself a type of plastic - it’s not biodegradable and not good for the environment. But, if you need to use acrylic yarn for a project, there are some choices that are more eco-friendly than others.
The semi-synthetic lyocell yarn (also sold as tencell) is the most eco-friendly of the synthetic yarns. This is because it is made from plant fiber and not crude oil and also uses less chemicals and water to produce than other types of rayon. Lyocell are also available blended with natural fibers like cotton and bamboo.
In the end, you have to weigh up the pros and cons of the different synthetic and natural yarns to decide which you’ll use.