Educational Checkpoint #1 Clothing Fibres

Welcome everyone to Educational Checkpoint #1 of the 2021 Soil your Undies challenge.

In this checkpoint we’re thinking less about the soil and more about what we’ve buried in it – cotton undies. We are also going to be taking a closer look at our wardrobes to see what our other clothes are made of and how to be a little more thoughtful around our clothing choices. Join Kieran as he explores the fabric of his wardrobe.

Why Cotton?

Cotton is a natural fibre as it is grown on a cotton plant. The cotton fibres grow as a little bundle that protect the cotton seeds after the cotton flower has been pollinated. The flower buds are harvested and the cotton is separated to produce cotton threads and fabric. The cotton fibres are made of a plant product called cellulose, which is composed of a plant sugar. When the cellulose is buried in the soil, the micro organisms that inhabit the soil treat the undies just like they would dead leaves or compost – as food. When our undies break down it is because the micro organisms are using enzymes to break down the cellulose fibres and release the sugars for food. In very healthy soil, all the cotton will be broken down in just a few weeks.


What other clothing fibres are there?

This is why we sent you a pair of 100% cotton undies. Many undies are made of a polyester-cotton (polycotton) blend. Burying a pair of polycotton undies will result in the cotton being eaten away, but the polyester fibres will be essentially untouched. You would dig up a pair of undies that still look a lot like undies, the fabric will just be a lot thinner.


Are synthetic fibres a problem?

The clothing fibres that we choose are important as the clothes that we throw out most often end up in landfill. Clothes made of natural fibres are able to break down very quickly, however synthetic fibres can take hundreds of years to break down. Some examples of fibre decomposition times are:

  • Cotton: 2-4 months
  • Wool: 1-2 years
  • Linen: 4-6 weeks
  • Bamboo: 12 months
  • Polyester: 200 – 400 years
  • Elastic: 50-100 years
  • Spandex: up to 200 years
  • Nylon: 30-40 years

Clothing made of synthetic fibres is often much cheaper to produce than their natural counterparts largely due to the time and resource cost of producing natural fibres. It’s much easier and cheaper to make a kilo of polyester from petroleum by products than it is to spend months growing and cultivating a cotton crop or flock of sheep. Because of this, many cheaper clothes are made from polyester and other synthetic fibres, which results in these being the products the consumer will most likely buy.

In 2019-2020, Australians threw out over 780,000 Kg of textile waste. This includes all fabrics (curtains, upholstery, etc) but the majority of this waste comes from clothing. By simply thinking more about the clothes we buy and how often we replace them, we can have a dramatic effect on the environment. By preferencing natural fibres over synthetic the amount of plastic waste ending up in landfill could be reduced.

When synthetic fibres break down, they first disintegrate into microplastic before they chemically degrade. Microplastic is becoming an increasingly serious problem as it is making its way into the food web and the human food chain.


See you soon for Checkpoint #2

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