Finland based VTT Technical Research Centre, Aalto University and Tampere University of Technology are together developing novel recycled textile fibres in the Design World of Cellulose project, a major technological scheme of Tekes - the Finnish Funding Agency for Technology and Innovation.
VTT is developing methods for restoring worn-out textile fibres to good-as-new condition and its research scientists are currently working on methods for separating the cellulose molecules contained in textile waste, such as cotton, using efficient and environmentally friendly solvents.
"Even the molecules of old and worn fibre qualify for reuse. The fibrous components of worn fabric can be separated and returned to textile production as raw material and end result can be a product of equivalent quality to the original, or even better", says VTT.
The dissolving of textile waste offers the opportunity to return large volumes of waste to textile production. Novel and efficient methods will be able to recover cellulose molecules, providing one way of resolving the limitations soon to be placed on the use of landfill sites.
Several methods exist for dissolving cellulose, and these have seen notable development over the past decade. One example of such a method is Aalto University's Ioncell-F, which uses ionised solvents developed together with the University of Helsinki.
VTT's role in the project covers cleaning the textile mass and preparing the cellulose in a suitable form for solvent application, while Aalto University develops the spinning processes.
VTT is developing methods for the recycling, decolouring, bleaching and dissolving of textiles. Textiles are fed into the process both intact and as loose scraps. Colour is then removed and the solubility of the cellulose increased.
After the application of solvents and removal in solution, the recovered cellulose is then spun into fibre. The remaining fibrous material is normally polyester, which can be melted down and used in the preparation of fibres and composites.
Such methods will also serve to promote the efficient use of materials. Finland, as with other countries in the EU, must make decisions on the future treatment of textile waste.
The EU Directive in 1999 contains quantitative restrictions for phasing in with regard to biodegradable waste deposited at landfill sites. The practice of taking textile waste to landfill sites will be brought to an end by regulations entering into force in Finland on 1 January 2016.
"Although reuse of textiles and mechanised recycling methods ease the burden on the environment, the textile mass also includes material in poor condition or heavily soiled, limiting the opportunities for recycling. The new methods multiply the utilisation possibilities," says Ali Harlin of VTT.
"Textile recycling saves virgin raw materials for products with higher production value. The prerequisite for functional recycling is a system that recovers textiles efficiently with regard to environmental considerations", says Anna-Kaisa Auvinen, MD at Finatex – the Federation of Finnish Textile and Clothing Industries.
