Recycled Textiles Get New Life

Sept. 25, 2014
Finnish researchers plan to revive worn textiles to better-than-new condition

Novel processing techniques being developed in Finland raise the prospect of returning large quantities of waste textile material back into production and helping the country meet its regulatory commitments.
Finland consumes around 70,000 tons of clothing and household textiles each year. Government figures suggest that about 30% of this is eventually reused and about 14% sent for recycling. The rest goes to landfill. At the same time, the amount of textile waste is rising. According to the Helsinki Region Environmental Services Authority Sorting Study 2012, the capital’s metropolitan area alone generated 14% more waste between 2007 and 2012 — rising from 8.9 to 10.2 kg/inhabitant/year.

However, Finland, like other countries in the European Union (EU), has to make decisions on the future treatment of its textile waste. The EU Waste Framework Directive contains quantitative restrictions for biodegradable waste deposited at landfill sites. Finland is set to ban sending textile waste to landfills starting January 1, 2016.

Large-scale solutions to the problem already are being devised. Researchers at Valtion Teknillinen Tutkimuskeskus (VTT) Technical Research Centre, Espoo, Finland, are developing methods for restoring worn-out fiber to good-as-new condition. Scientists are currently working on methods for separating the cellulose molecules contained in textile waste, such as cotton, using efficient and environmentally friendly solvents. This provides one way of resolving the limitations soon to be placed on the use of landfill sites.

Even the molecules of old and worn fiber qualify for reuse. The fibrous components of worn fabric can be separated and returned to textile production as raw material. The end result can be a product of equivalent quality to the original, or even better, say the researchers.

“Although reuse of textiles and mechanized 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 utilization possibilities,” says research professor Ali Harlin of VTT.

VTT is one of the biggest multi-technological applied research organizations in Northern Europe and is focused on providing high-end technology solutions and innovation services.

“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. It is important to incorporate recycling early, at least at the planning stage. The best result will be achieved when the textile and clothing industry, consumers and other stakeholders work together to build a voluntary and practical recycling system. We have gathered the key actors around the same table with the intent of developing the solution to Finland’s textile recycling,” says Anna-Kaisa Auvinen, managing director of Finatex — the Federation of Finnish Textile and Clothing Industries.

VTT, Aalto University, Espoo, and Tampere University of Technology, Tampere, together are developing novel recycled textile fibers for the Design World of Cellulose project, a major technological focus of Tekes — the Finnish Funding Agency for Technology and Innovation.

Several methods exist for dissolving cellulose, and these have seen notable development over the past decade. For example, Aalto University’s Ioncell-F uses ionized 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 is developing the spinning processes.

VTT also is working on methods for the recycling, decoloring, bleaching and dissolving of textiles, which are then fed into the process both intact and as loose scraps. Next, color is removed and the solubility of the cellulose increased. After the application of solvents and removal in solution, the recovered cellulose is then spun into fiber. The remaining fibrous material normally is polyester, which can be melted down and used in the preparation of fibers and composites.

“The manufacture of hygiene products and technical textiles will be possible in the very near future and the solvent, after decoloring, can also be used in the recycling of pulp, for example from waste packaging,” adds Harlin.

Seán Ottewell is Chemical Processing's Editor at Large. You can e-mail him at [email protected]