Finding new uses for wool at AgResearch
AgResearch is partnering local and international businesses in helping to develop new uses for wool including air filters, combat sportswear and woollen shoes.
Wool has a complex biological, chemical and physical structure with a range of attributes - many that are reasonably well understood. Among wool’s attributes is its high UV protection and flame retardant properties. Wool is also biodegradable, breathable, non-allergenic, durable, elastic, easy care, machine-washable and naturally insulating.
Wool promotional campaigns have traditionally promoted the “naturalness” of the fibre but there is a long list of other attributes that play a part in making it highly versatile.
In 2007 the WRONZ (Wool Research Organisation of New Zealand) was bought by AgResearch. The object was to start developing new applications particularly for strong wool. At the same time they wanted to enhance the characteristics of wool to make them even better.
Technically most other respiratory filters are measured by their particle capture efficiency and the energy required to pass gas through it. New Zealand based company Lanaco (formerly Texus Fibre) came to AgResearch for help in developing a filter using wool. https://www.ruraldelivery.net.nz/stories/Texus-Fibre
Stewart says technically the filters are tested by their particle capture efficiency and ‘pressure drop’ i.e. how much does the air pressure drop from one side of the filter to the other. A low pressure drop measure is a good indicator, as it means less effort is required to pull air through the filter, either by the human who is wearing a respirator or mask, or by a machine.
He says the Lanaco filter has really good efficiency (traps lots of particulate material) and low pressure drop (easy breathing).
Wool is processed to produce a continuous textile roll, – made using a non-woven production line, which is then made into filters.
Stewart Collie says there is a lot in the technology that is protected IP, but the end result is a highly breathable structure that has excellent efficiency in removing particles plus has some additional key characteristics. “The other thing you get when you use wool in a filter is absorption for moisture - which is a big advantage over other filter materials. So along with the things you need in a filter you get a comfort advantage.”
The original concept of wool-based shoes was that you could translate the comfort of wool that was well known in “base layers” as used in the outdoor industries and put that into shoes.
Traditionally wool has been regarded as too “prickly” to be worn next to the skin but developments in wool technology have seen the emergence of machine washable wool clothes that can comfortably sit next to skin.
A business partner – Allbirds – now sells shoes that are advertised as being extremely comfortable. The shoe uppers incorporate wool and are advertised as having three key characteristics of wool as a strong selling point: minimising foot odour, regulating temperature and wicking moisture.
Stewart says probably one of the most important aspects of wool in this application is its ability to resist odour. He says that while there’s been anecdotal evidence of wool’s ability to prevent odour build up in garments, science is now trying to understand why wool can resist odour so effectively and what particular conditions have to exist when it does that.
He says the next step is to find out what could be done to enhance that ability and make it even better.
“There’s a growing sector in the apparel space, the so-called athleisure sector, which is a kind of cross over from athletic wear and casual wear, where odour is managed and minimized.” He sees a real opportunity for wool in these “crossover areas”.
Another aspect of the challenges around developing a wool-based shoe upper was that it needed to be really strong, given the mechanical forces that are used in that environment. Stewart says that footwear application is far more severe in terms of stresses and strains than with garments worn elsewhere on the body. Given that tough environment Stewart says it is common to incorporate other fibre types to enhance the wool so that it is able to be durable. “So you get all the benefits of wool but you end up with something that is resilient enough to perform in that footwear application.”
Another example of wool being used in new ways is its use in combat sportswear. Stewart says this sector is a good example of combing the natural qualities of wool with other fibres to produce a fabric that has the best of both worlds.
Robes for use in sports like karate and judo are called ‘gi’. Traditionally they have been made from heavy cotton canvas. He says that the disadvantages of that material are that when it absorbs sweat it becomes heavy and uncomfortable.
The idea was to incorporate wool in a new fabric that has the breathability and comfort of wool combined with superior moisture management.
“When we were working with the people who came up with this concept, to help them develop this fabric, we needed to combine wool with another material to create a textile that has a robust structure but also has all the comfort benefits of wool.”
The GiMono apparel makers worked with AgResearch over three years to develop the fabric that combines wool and polyester. The wool sits next to the skin for thermal regulation and comfort, while the polyester layer is on the outside. The makers are also looking at other sectors where the fabric would be suitable, such as military and equestrian applications.
Stewart says the filters, shoes and sportswear have the potential to start making a dent in the amount of wool fibre being produced in New Zealand and add real value to the sector. He says while some of the products are niche they could grow to be significant consumers of wool longer term. He says the rise of textiles like these three examples have been bubbling under the surface for years. “They’ll take time to mature but there are opportunities for more products that we haven’t conceived of yet that will utilize wool fibre in these new areas.”