Awarded method makes textile fibre from waste cotton

Last Wednesday was a great moment in the careers of many members of the Aalto Community: the Ioncell-F method that makes it possible to recycle cotton was granted the Global Change Award by the Conscious Foundation of the clothing giant H&M in a ceremony held in the Stockholm City Hall.

‘It is a great honour and a huge source of motivation for our entire team,’ says Herbert Sixta, Professor of the Department of Forest Products Technology at Aalto University, and smiles. He received the award from Victoria, Crown Princess of Sweden.

Sixta and his team have been developing the non-toxic and environmentally friendly Ioncell method for years now. It has previously been used to make textile fibre from Finnish birch cellulose and recycled cardboard, but now it has been proved that Ioncell-F also works with waste cotton.

‘It is this possibility to utilise other materials in addition to cellulose that makes our method different from other similar methods,’ Sixta explains.

‘Thanks to the ionic solvent developed at the University of Helsinki, the process is not sensitive to impurities, which is why it is suitable for treating recycled materials,’ he specifies.   

An inspiring material

In the Ioncell-F method, the raw material – whether cellulose, recycled cardboard or cotton – is first dissolved using an ionic solvent, i.e. liquid salt. Dry-jet wet spinning, a method in which thin fibres are created by forcing the solution through spinnerets, is used to produce new textile fibres from the solution.

‘The properties of the fibre are equal to other cellulose fibres, but from the point of view of sustainable development, this is a far better alternative than, for example, organic cotton.  It is an extremely inspiring and wonderful material for a designer,’ says Pirjo Kääriäinen, Designer in Residence at Aalto University, and stresses how important it is that experts from different fields are involved in the development.

‘The technology has been developed by top experts in materials science and chemistry, but making prototypes, in other words turning fibres into thread and further into textiles as well as presenting ideas to stakeholder groups requires design and textile design professionals.’

New textile fibers produced from recycled cotton garment with Ioncell -process. Design project by students Eugenia Smirnova (Aalto University School of Arts, Design and Architecture) and Zhen Zeng (Aalto University School of Chemical Technology). Photo by Eeva Suorlahti / Aalto University.

According to Herbert Sixta, collaboration between the experts from different fields at Aalto University has been smooth from the beginning. However, there are plans to extend it even further in future.

‘Textile manufacturing is a truly multidisciplinary business. It requires real expertise in chemistry, business, engineering science as well as design. We want to involve all schools of Aalto University in this.’

From laboratory to large scale operation

The demand for textile fibres is growing globally at a rate of more than three per cent per year. Cultivated land is needed for food crops, so it is not really possible to increase cotton production, and manufacturing viscose, on the other hand, requires toxic chemicals. Therefore, there is a huge gap in the market for functioning and environmentally friendly cellulose fibres; however, it will take some time before there are any Ioncell-F clothes on sale in shops.

‘At the moment we can only manage laboratory-scale production of good-quality fibre,’ Sixta reminds us.

‘‘The method must be scaled up next. It is challenging as manufacturing industry has been fading in Finland in the past few decades, which means that some of the expertise has also disappeared – and now we have to build it up again. Making the recycling of ionic solvent efficient is also a big challenge.

We have active discussions with large companies in cellulose industry and our group also works in close collaboration with Marimekko, Ikea and H&M. The group will soon travel to Shanghai for innovation training provided by H&M Conscious Foundation, Accenture and KTH to the five finalists in the competition as part of the Global Change Award.’

‘We will visit large textile companies in order to find out what kind of needs there really are in the field,’ Sixta says.

‘To make waste cotton a truly profitable and ecological raw material of textile fibres, a much more polished recycling process is required. One of the Global Change Award finalists was an Estonian team that had been developing a global system for optimal collection, sorting and sales of leftover pieces of fabric from the textile industry. The idea is excellent as for example leftover pieces of a certain shade of red could be used to manufacture red textile fibre without any unnecessary removal of colour or dyeing – or chemicals required in those processes.

More information:

Professor Herbert Sixta
Tel. +358 50 3841764
[email protected]

Designer in Residence Pirjo Kääriäinen
Tel. +358 50 3810 217
[email protected]

Read also:

A process revolutionising cotton recycling wins the H&M Global Change Award (aalto.fi/en)