BOENNIGHEIM (im) Soil-repellent textiles that optimally utilize what is known as the “lotus effect” seen in nature have been developed under the auspices of a joint research project of the BMWi [Federal Ministry of Economics and Technology] carried out by the Hohenstein Institute in Boennigheim and ITCF Denkendorf. By means of new fibre structuring, the soil-repellent effect has for the first time been realised through fibre immanent surface structuring. Particles that have been incorporated during manufacturing have shown only negligible effects on the behaviour of dyes and the dye absorbency of the polymer.
Up to now, conventional, subsequent finishing was the means used to apply hydrophobic micro and nano-structures to surfaces. The functional layer produced in this way demonstrated good soil repellent effects but was nevertheless not always durable under conditions of intensive use. Now a new approach to the manufacturing of surface structures has significantly reduced this deficit and optimised the soil-repellent effect of surfaces.
An additional, nano-structured surface is generated with the help of super paramagnetic nano-particles directly during the melt spinning process of manmade fibres. This so-called ferromagnetic fibre structuring with high energy magnetic field coil takes place directly after the spinneret, when the spin-melt is still in a thermoplastic state, which ultimately allows for subsequent filament stretching as usual.
Yarns and knitted sample swatches were manufactured in lab scale from the mono-filaments for the purpose of characterising the newly developed surface properties. These samples could then be assessed for their hydrophobic and soil-repellent characteristics as well as their durability during use. For an industrial production of these ferromagnetic structured fibres further research together with a fibre manufacturer is necessary to scale up the spinning process.