Functional fibres

Manfred Heuberger (Empa), Paul Keller (Avery Dennison Materials Europe) and Urs Mäder (SATW)

Present situation worldwide and in Switzerland

Functional fibres are already being used for a wide range of practical applications, especially for the production of functional sports and leisure wear, and as an insulation, composite and reinforcement material in the construction sector and paper industry. Other applications that are still being tested or are already being implemented in practice include the following:

  • Fibres with antimicrobial properties (through absorption or the release of antibacterial substances)
  • Superabsorbent fibres with high water absorbency for medical and cosmetic products
  • Fibres with controlled water absorption and release for food packaging
  • Fibres for the selective removal of heavy metals from wastewater

For many technical applications, additives are mixed in with the fibres during the spinning process to achieve new properties, or a finish is applied. During the production process, it is also possible to change the fibres’ structure, producing conventional round fibres or hollow, flat or other fibres.

Combining new production methods and new materials such as nanoparticles could enable the development of functional fibres with hitherto unattainable properties. Such possibilities should be explored more precisely to assess their potential and encourage them as necessary. Promising applications include:

  • Composite fibres made from a combination of different materials with specific surface properties, e.g. bi-component fibres with a sheath that melts at lower temperatures than the core and dissolves into the surrounding material (matrix)
  • Fibres with nanoparticles such as silver for new textiles with a protective effect against mechanical or electromagnetic impacts such as electricity, radiation or heat
  • Fibres with microencapsulated liquid agents or with a liquid core
  • Biodegradable fibres as a substitute for synthetic nonwovens e.g. in the household, in cosmetics or in agriculture
  • High-tolerance fibres for medical applications, e.g. as vascular substitutes, for wound healing in case of extensive burns, or for the measured release of medication via the skin or inside the body

A major technological trend is the development of a new generation of flame-retardant fibres with high-grade mechanical properties such as tensile strength. Both in the US and in the EU, efforts are being undertaken to ban brominated and halogenated flame retardants from various products, especially plastics and textiles. The past ten years of research have yielded new phosphorous organic compounds, which are environmentally sound yet highly potent. They can be used in such small quantities that the fibres’ mechanical properties remain largely intact. In the next five years, this trend is expected to produce new fibres made of various polymers with improved flame retardant properties.

Implications for Switzerland

Switzerland is at the forefront of research on flame retardants: the country’s industry is therefore in pole position to secure intellectual property rights and to develop markets with high added value. In addition, these developments are likely to have a stimulating effect on other polymer processing sectors (compounding, films, injection moulding).