Sustainability In Denim

Even the average jeans customer knows already that denim belongs to the bad guys concerning sustainable issues. Our industry consumes lots of water, uses hazardous chemicals and with all the super stretch types of denim, we contribute to microplastic pollution.

But the awareness is raising, new possibilities were developed over the past years and there are many ecological materials and treatments available already today.

In this series, we take a look at the impact of denim and jeans, but we put focus on the progress of sustainable alternatives.
The time when sustainable decisions came with limited possibilities in design and outcome is a thing of the past!

No.2: Recycling in denim, how we could minimize the impact of farming

In the last episode, we talked about hemp and why it makes sense to replace some cotton with hemp fibers to create a more sustainable denim fabric. In case you have missed this first article, read it here.

Today we take a look at an even more sustainable material: recycled cotton.

The cultivation of cotton is quite impactful. Besides lots of water and the use of chemicals, cotton needs much land to grow. Let’s do some math to understand how much area is used to cultivate the cotton fibers we need for one jean:

An average jean consumes around 1,8m² of denim fabric (1,3m length x 1,4m width). For that piece of fabric, 920 grams of raw cotton is needed. The average lint outcome of 1m² of cotton harvesting is 220g long fibers, suitable for spinning (varies a lot by region and climate). That means an area of 4,2m² for half a year is required to cultivate the cotton, we need for one jean.

Wouldn’t it make more sense, to use that land to grow food to feed the world, instead of “growing clothes”? Additionally, we read about mountains of clothes in landfill enlarging every day, because humans buy more and more clothes just to wear them a few times and then dispose them. The cotton fibers in these wasted jeans are mostly still in a good condition, even if the garment itself is not.

mud jeans

Images of the recycling process by Mud Jeans.

How Recycle Worn Jeans Into New Jeans

Wouldn’t it be great if we could make use of them again? Here comes the good news: You can recycle worn jeans to become new jeans, but there are a few requirements:

Recycling of cotton fibers is done mechanically, which means the fabric is shredded into smaller and smaller pieces to finally reach the single cotton fiber. This is only possible if all the trims like buttons, rivets, and zippers are removed manually.

This recycling process requires a high percentage of cotton in the garment. Although most systems tolerate up to 5% of different fibers, a mono-material is most suitable. That makes super-stretch denim unusable for recycling because fossil-based materials like elastane and polyester cannot be separated during the process. (You should consider that when you buy your next new jean.)
Because shredded cotton fibers get shorter, so lower in quality, those recycled materials need to be mixed with virgin cotton to achieve a high-quality denim fabric for durable jeans.

To reach the best results possible, quality-wise and sustainable-wise, 30-40% of recycled cotton turned out to be the limit so far. But, coming back to math, replacing 40% of virgin cotton with recycled material in just one jean, saves around 1,7m² of land, which could be used to grow 1,3kg of wheat instead.

Also, lots of fertilizers, pesticides,­­­­ irrigation water, and energy can be saved by switching to recycled cotton.
What a big step towards closing the loop in the denim industry and using our planet’s resources for something more important than clothes.

Further Solutions For Higher Recycling Content

According to the Dutch Denim Deal, signed by 30 members of the industry, 3 million jeans entering the market in 2023 should contain a minimum of 20% post-consumer recycled cotton. And the industry is working on further solutions for higher recycling content, by using chemical recycling for example.

In a collaboration with Saxion University and Tech For Future, Mud Jeans just reached the first sample made from 100% post-consumer recycled jeans and now plans to scale that up for production and sale. (Read more about the 100% post-consumer Mud Jeans here.)

Today, cotton fibers need to be seen like a Lego-building block: Don’t throw it away after you don’t like your construction anymore, disassemble it and create something new instead!­­­­­

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Images of the recycling process by Mud Jeans.

Read also the first episode: Sustainable Fibers For Denim, Why Hemp Attracts More And More Attention here.

Stay tuned for more sustainable alternatives in the denim world!

Written by Sina Steidinger
Sina Steidinger is a self-employed denim designer and sustainability manager based in Amsterdam. After working for several brands in Germany for the past decade, she recently moved to the Netherlands to be in the heart of the European denim capital and to contribute to the latest developments in sustainable fashion. She is currently designing for Mud Jeans, a Dutch brand, and pioneers in circular denim. As a consultant, she gives workshops and speeches and advices brands on their way to a sustainable future.