Different levels of these particles were integrated into the fibre’s core, thereby preserving the fibre’s inherent properties, rather than being added as a topical finish using additives based on titanium oxide or other metal-based compounds. The effects of the new method are permanent and cannot be washed out, the company reports.

Testing results

The trials showed that the new fibre delivers a level of IR-activity that could be proven in measurements of the Total Solar Reflectance Value (TSR).

Visible light is reflected by 90 to 95%, while in the near infrared range, a reflectance of up to 90% is reached, depending on the wavelength spectrum. This proves a clear benefit in the reflectance of direct sunlight, where the fibre is capable of providing a cooling effect, for example by protecting the human body from outside radiation, according to the manufacturer.

Warming applications

At the same time, the fibre may also be used in warming applications, where the thermal radiation emitted from the body is reflected by these particles back to the body, reducing the cooling effect and keeping the person warm. In the mid IR-range an increase of reflectance of about 20% of m-IR radiation was achieved in tests compared to normal viscose.

The fibre can be used for both textile and nonwoven processes, where the fabric can either protect against outside influences or reflect the IR-radiation back to the inside source.

“Comfortable feel-good clothes and functional special clothing are just two obvious applications for our new IR fibre,” said Dr Daniela Bauer of Kelheim Fibres’ R&D team. “The level of loading can be adapted according to the requirements of the final product, which provides high versatility. As a next step, the fibre will be tested for its effectiveness in various end-applications in cooperation with our partners.”

Kelheim Fibres

Kelheim Fibres is the leading producer of viscose speciality fibres and the most important supplier of viscose fibres for the tampon industry.

Approximately 90,000 tons of viscose fibres are produced and tested every year at Kelheim in South Germany. These are used in most diverse applications – from fashion, hygiene and medical products to nonwovens and speciality papers.

www.kelheim-fibres.com