Wool, Wool Felt & Sustainability

Growing up in the Lake District, UK, I was always in awe of the majestic landscape. My job took me away from this beautiful place many years ago, but my love for the area has never diminished. The Herdwick sheep, dotted across the fells, were a familiar sight and this centuries-old breed has played an important role in the Lake District, keeping the landscape in good shape. Growing up here definitely inspired my love of nature.

Being as sustainable as possible was a key decision for me when starting Fern Green Designs. I had a very pre-defined idea of what that meant for me, and as time has passed, I’ve done a lot more research into understanding more about the impact that certain materials and processes have on our environment. At first, I was looking mainly at where a product comes from and how it can be recycled or whether it biodegrades, but there are so many more factors involved in assessing the impact.

As I’m creating art and craft kits, my focus is on fabrics and other components used in making these, along with the packaging used. I’ve learnt so much already, and my head is full, so I thought it would be good to get some of the information into a blog.

It is such a huge topic so I’ve started with looking at the fabrics I use in the craft kits, and wool and wool felt are first on the list.

Important Factors in Assessing Environmental Impact

So first, in general terms, what are some of the most important factors to consider? It’s all about assessing the life cycle of a product in its entirety.

The image below contains some of the questions to ask as a product moves through its own process.

Going back to basics, what is wool, where does it come from and is there anything special about it?

Does ‘Natural’ mean ‘Sustainable’?

‘Natural’,‘renewable’ and ‘sustainable’ are some of the hottest terms that have been used to market products. However, in recent years, there has been a shift from automatically equating the term‘natural’ with ‘sustainable’,[1] and with increasing attention being paid to environmental impact, fibre and textile industries are under more scrutiny than ever.

Two major concerns have been raised in connection with wool as a product; 1) the levels of methane, a by-product of sheep’s digestion, and its impact on the environment;[2] 2) the welfare of sheep.

A study of the Australian wool supply chain found that the methane produced by sheep, was the biggest contributor to the carbon footprint of the entire cycle, but that the Australian wool industry was actively engaged in developing ways to deal with this issue.[3]

Recent research has shown that changes to cattle feed supplements can reduce methane emissions, whilst increasing animal productivity and without having any adverse effects on the animal’s health.[4]

Similarly, when it comes to the welfare of sheep, companies that use wool in their products are demanding better welfare conditions and practices. Take Fjällräven, for example, who have established a traceable wool supply from farms which are accredited to ensure animal welfare, and environmental and economic sustainability.’[5] Fjällräven expect all of their wool products to be fully traceable by the end of 2021. For more information on their goals go to: https://foxtrail.fjallraven.com/articles/making-traceable-wool-a-reality

These are however, both areas which require further investigation and development to improve.

Wool Felt: How is it made?

Take a look at this short video https://vimeo.com/79350076 (2.05 minutes), created by ‘fitzfelt’, which gives an overview of the entire process, from start to finish.

Washing

Whether the product is a wooly jumper, or a piece of wool felt, all raw wool must be cleaned. Sheep’s wool contains high levels of impurities, such as dirt and grease (lanolin),[6] [7] and in the case of Merino wool, approximately 50% is dirt and grease.

Traditionally, cleaning has been done through the process of hot aqueous scouring which inevitably involves the use of water, chemicals, and electricity. As a result, the waste water becomes polluted and requires further treatment before disposal.[8]

It is estimated that using this method to make 1 tonne of wool fibre for clothing, uses 2,200m3 of water, produces 46 tCO2e[9] and 1.6tonnes of waste.[10]

However, new processes, such as ‘dry scouring’ have been developed which aim to reduce water and energy consumption as well as reducing chemicals used and therefore polluted waste. In addition, these new methods aim to recover all by-products, such as wool grease and dust, for use in other products.[11] Wool grease, for example, can be used in pharmaceutical products and cosmetics,[12] while wool dust can be used in fertilisers.

A study[13] into the benefits of this technology concluded that:
Wool was whiter, cleaner, smoother, fibre entanglement free, with a lower grease content.
95% wool grease recovery.
100% wool dust recovery.
70% less water consumption.
30% less energy consumption.
70% less waste water effluents;
70% less detergents and chemicals used.

The infographic below shows how cleaned wool is made into rolls of felt.

The dyeing process, in particular, is one which can potentially have a negative impact on the environment.

Fabric dyes can be extremely damaging for the environment due to the harmful chemicals they contain, and the high level of energy consumption and waste water.

Choosing wool felt that uses dyes free from toxic chemicals, can help to reduce this damage.

Certification standards such as the Oeko-Tex 100 indicates that every component of the fabric has been tested for harmful substances, including toxic chemicals.[14]

'End of Life' Cycle

When an item is no longer wanted by its user, it reaches its 'end of life'. What happens to the wool or wool felt at this point, is just as important as how it is produced, when it comes to impact on the environment.

Some of the factors to consider are:

How long does the item last?
Can it be reused or recycled?
Does it biodegrade or does it sit in landfill?

When a product comes to the end of its life-cycle, there are three main options available:
reuse, recycling or disposal.

Reuse

As you’ve seen, wool and wool felt are very durable, which means that the products will last for a long time. In the case of wool garments, they can be re-used time and again and are highly valued items in the second hand / reuse market. The life span of woollen garments has been shown to be between 20 to 30 years and that within that time, has the potential to have a minimum of two cycles of use.[15]

Wool felt has the same durability as other woollen items. The sale of offcuts & remnants by felt manufacturers can be used by crafters for their own projects.

These scraps and remnants can often be at substantially discounted prices.[16]

Closed-loop Recycling

The original product is used, and at the end of its cycle, is recycled to make a new product which is exactly the same as the original product. For example, wool fibres are made into yarn which is used to make a woollen garment. At the end of its life cycle, the garment is shredded and returned back to fibre, which is in turn made into yarn ready to make new woollen garments.[17]

Open-loop Recycling

The original product is used, and at the end of its life-cycle, is recycled and made into entirely new products from the original material. In the case of wool, new materials such as insulation or mattress padding are two new products that can be manufactured.

Disposal

The final option available is disposal, which could include incineration or landfill. This is where one of wool’s special properties comes into its own: wool is 100% biodegradable and will completely biodegrade within 3 months to two years!

The Future...

Traditionally, the process of making wool felt involves the use of electricity, water and the application of dyes and the pollution of waste water.

Improvements have already been made to many areas of the processing, such as:
increasing water and energy efficiency during wool processing.
reducing waste production during wool processing.
the use of plant based textile dyes that can be disposed of in waste water.
not using harsh chemicals e.g. bleach in the cleaning process.[18]

Reducing energy consumption

Reducing energy consumption has been achieved by some companies generating their own electricity, for example by using solar panels. In one example, Ideal Felt has stated that the solar panels they have installed, generate more green energy than it takes to make the felt, and without emitting any CO2.[19]

Reducing greenhouse gas (GHG) emissions

Further reductions to GHG emissions can be made by changing to renewable energy sources during wool processing, for example, using the organic waste from the scouring process to generate renewable energy which would reduce the use of fossil fuels in the process.[20]

New Uses

A relatively new concept has been proposed, for biodegrading wool fibres to be used in compost as a replacement for peat. Studies have shown that as wool breaks down, it slowly releases nutrients, including sulphur, nitrogen, phosphorous and potassium into the soil. Other studies have shown that container-grown plants can be grown directly on wool fibres, with the fibres providing the nutrients for the plants.[21]

Final Note

This is only my first exploration into researching a bit more deeply about the kind of things I’m using to make my artwork and craft kits.

Based on my research so far, I’m happy to keep using wool and wool felt in the things that I make and wear.

Declaration: I don't have any connection, paid, unpaid or any other capacity, with the companies, manufacturers, or organisations, that I've referred to in this blog.

References

[1] https://www.sciencedirect.com/science/book/9781845694531
I.M. Russell, 3 - Sustainable wool production and processing, Editor(s): R.S. Blackburn, In Woodhead Publishing Series in Textiles, Sustainable Textiles, Woodhead Publishing, 2009, Pages 63-87,
ISBN 9781845694531, https://doi.org/10.1533/9781845696948.1.63.
(https://www.sciencedirect.com/science/article/pii/B9781845694531500036)

[2] Black, J.L.; Davison, T.M.; Box, I. Methane Emissions from Ruminants in Australia: Mitigation Potential and Applicability of Mitigation Strategies. Animals 2021,11, 951. https://doi.org/10.3390/ ani11040951 published 29 March 2021

[3] I.M. Russell, 3 - Sustainable wool production and processing, Editor(s): R.S. Blackburn, In Woodhead Publishing Series in Textiles, Sustainable Textiles, Woodhead Publishing, 2009, Pages 63-87,
ISBN 9781845694531, https://doi.org/10.1533/9781845696948.1.63.

[4] Black, J.L.; Davison, T.M.; Box, I. Methane Emissions from Ruminants in Australia: Mitigation Potential and Applicability of Mitigation Strategies. Animals 2021,11, 951. https://doi.org/10.3390/ ani11040951 published 29 March 2021

[5] https://foxtrail.fjallraven.com/en/articles/allwool

[6] https://webgate.ec.europa.eu/life/publicWebsite/index.cfm?fuseaction=search.dspPage&n_proj_id=4254

[7] https://webgate.ec.europa.eu/7eb84637-80ad-45f7-807d-0c7fd6d8f238

[8] https://webgate.ec.europa.eu/life/publicWebsite/index.cfm?fuseaction=search.dspPage&n_proj_id=4254

[9] tCO2e is tonnes of carbon dioxide equivalent. ‘Carbon dioxide equivalent’ is a measure greenhouse gas emissions, whether they are from carbon disoixde, methane or another gas.

[10] WRAP ‘Introduction to Sustainable Fibres’ video https://youtu.be/P2LAAScu6W8

[11] https://webgate.ec.europa.eu/life/publicWebsite/index.cfm?fuseaction=search.dspPage&n_proj_id=4254

[12] Wiedemann, Stephen & Biggs, Leo & Nebel, Barbara & Bauch, K. & Laitala, Kirsi & Klepp, Ingun & Swan, P.G. & Watson, K.. (2020). Environmental impacts associated with the production, use, and end-of-life of a woollen garment. The International Journal of Life Cycle Assessment. 25. 10.1007/s11367-020-01766-0.

[13] https://webgate.ec.europa.eu/7eb84637-80ad-45f7-807d-0c7fd6d8f238

[14] https://www.oeko-tex.com/en/our-standards/standard-100-by-oeko-tex

[15] Russell S., Swan P., Trebowicz M., Ireland A. (2016) Review of Wool Recycling and Reuse. In: Fangueiro R., Rana S. (eds) Natural Fibres: Advances in Science and Technology Towards Industrial Applications. RILEM Bookseries, vol 12. Springer, Dordrecht https://doi.org/10.1007/978-94-017-7515-1_33

[16] https://www.filzfelt.com/images/uploads/downloads/FF_Environmental_Statement.pdf

[17] https://lampoonmagazine.com/manteco-recycled-wool-system/

[18] https://www.filzfelt.com/images/uploads/downloads/FF_Environmental_Statement.pdf

[19] https://www.idealfelt.com/en/technical-textiles-felt-sustainability

[20] Wiedemann, Stephen & Biggs, Leo & Nebel, Barbara & Bauch, K. & Laitala, Kirsi & Klepp, Ingun & Swan, P.G. & Watson, K.. (2020). Environmental impacts associated with the production, use, and end-of-life of a woollen garment. The International Journal of Life Cycle Assessment. 25. 10.1007/s11367-020-01766-0.

[21] https://businesswales.gov.wales/farmingconnect/news-and-events/technical-articles/use-wool-compost-and-other-alternative-applications