Nanotechnology and technical textiles: An unbeatable duo!?
Over the last decade, nanotechnology has found its way into almost all sectors – one of them being the textile industry. The possible range of applications is as large as that of the textiles themselves. Be it in medical technology, filter technology, functional apparel or automotive construction, well-known exhibitors at Techtextil will be showcasing the many and varied areas of application for this innovative technology.
Apparel textiles, with dirt- and water-resistant nano finishes, are already widespread, especially in sports and outdoor wear. Textiles with anti-bacterial qualities, based on the use of silver nanoparticles, have also found their way onto the market. Moreover, rapidly advancing research is opening new horizons all the time.
The anti-bacterial textiles we are talking about are optimised for use in the healthcare sector – as a weapon in the fight against the spread of antibiotic-resistant germs. Other possibilities for medical applications of nano textiles include surgical bandages that can be removed without leaving any residual traces.
These can be made from a nonwoven fabric of bio-compatible nanofibre or in the form of sticking plasters that imitate the well-known technique that a gecko’s foot uses to cling on. At the Institute for Textile Machinery and High-Performance Materials Technology at the Technical University of Dresden, (Institut für Textilmaschinen und Textile Hochleistungswerkstofftechnik,TU Dresden) nanofibres made of biopolymers are formed into nonwoven fabric, which are due to come into use in regenerative medicine as so-called ‘scaffolds’. These form a structural basis for the cultivation of cells with the aim of creating artificial tissue that can be used for implant purposes.
Doctors are agreed that clothing with a high level of UV protection can significantly reduce the risk of skin cancer. Here, too, nanotechnology offers a variety of approaches to solutions. Textile coatings containing nanoparticles of titanium oxide or zinc oxide have, thanks to their huge total surface area, an enormous ability to absorb ultraviolet radiation. At the North West German Textile Research Centre (Deutsches Textilforschungszentrum Nord-West) sol-gel coatings, based on nano-sized zinc oxide particles, have been developed and can be applied using conventional methods such as dipping and spraying. The completely wash-resistant layer not only significantly improves UV protection, it also improves resistance to abrasion, whilst having virtually no effect on the degree of whiteness of the fabric.
Nanoparticles can also be used to improve the dimensional stability and wear-resistance of man-made fibres, which are subject to high levels of mechanical stress or direct sunlight, as, for instance, in car seats. This topic is the subject of a research project at the Denkendorf Institute for Textile Chemistry and Chemical Fibres (Institut für Textilchemie und Chemiefasern Denkendorf) in collaboration with various partners, including the proudly traditional company, ETTLIN Textiles, and the textile-processing company, Lindenfarb Textilveredlung Julius Probst.
The polyamide-fibre products which have been optimised using nano-sized additives will be capable in future of being processed on traditional machines without any major technical changes.
Textiles in polyester have only limited moisture-absorbing and water-retaining capabilities, which make them more difficult to wash and limit their range of applications from a technical point of view. Working with a number of other partners, research and development staff from the German Institute for Wool Research at Aachen University (Deutsches Institut für Wollforschung, RWTH Aachen) and from the companies, Wirth Fulda and Märkische Faser, have achieved significant improvements in the hydrophilic properties of polyester fabrics. Using a nanometre-thin polyamine coating, it has proved possible to increase the water absorbency of PET microfibre fabrics by up to 40 per cent by weight, compared to the original material. Washability and wash-resistance have also been significantly improved, with simultaneous cost reductions as against traditional solutions. Suppliers for the motor vehicle industry should benefit from this improvement as much as apparel manufacturers.
There are many other examples that could be included here, for example nonwovens made with nanofibres that can also be used in filter technology or carbon nanotubes that can be embedded in antistatic clothing and packaging fabrics, as in protective suits for cleanrooms or for blast protection, for example. We will look around at Techtextil for textile innovations based on nanotechnology.
Background picture: Deutscher Verband Nanotechnologie