TU Müenchen develops steel ‘Velcro’

Hook-and-loop fasteners made of spring steel have been developed at the Institute of Metal Forming and Casting at the Technische Universitäet Müenchen.

Josef Mair, a scientist from the Institute of Metal Forming and Casting at the TU Müenchen, said: 'The advantage of a hook-and-loop fastener (such as Velcro) is that it is easy to close and open again.'

Because of this, hook-and-loop fasteners have found a range of uses, as an alternative to shoe laces, to secure medical bandages and prostheses, and for the cable boots used in automotive and aviation electronics.

Unfortunately, standard synthetic hook-and-loop fasteners are not very resistant to heat and aggressive chemicals, explained Mair.

To solve those issues, the researchers at TU Müenchen, led by Prof Hartmut Hoffmann, developed a steel version of the hook-and-loop fastener, which they have named Metaklett.

Temperatures in excess of 800°C and aggressive chemical solutions do not pose any problem for Metaklett, which also offers adhesive strength of up to 35 tonnes per square metre when tensile force is applied parallel to the fastener surface.

When it is applied perpendicular to the fastener surface, Metaklett can still withstand a force of seven tonnes per square metre. Moreover, like a standard Velcro fastener on a child's shoe, it can be opened and closed again without the help of any tools.

The researchers say that the Metaklett product is suitable for use in all applications that require easily opened but stable fasteners, such as in ventilation systems in buildings, in automotive applications and in the construction industry.