Global Fastener News

9/18/2009
FEATURE
Steel “Velcro” Takes 35 Ton Load

Metaklett developed at the Institute of Metal Forming and Casting of the Technische Universitaet Muenchen, Germany (courtesy Munich Technical University).

Hook and loop fasteners made from spring steel have been developed at the Institute of Metal Forming and Casting of the Technische Universitaet Muenchen, Germany.

The fasteners are resistant to chemicals and can withstand a tensile load of up to 35 tonnes per square metre at temperatures as high as 800°C. ‘Metaklett’ won a German Stahl-Innovationspreis (Steel Innovation Award) in June this year, overcoming more than 100 competing projects. The jury noted, “Metaklett is suitable for a wide variety of applications, in which the combination of simple production and a high level of resilience in the fastener is crucial.”

Researchers at the Munich Technical University opted to use spring steel, which combines high ductility with high strength, to make the fasteners. They created 3-D models to come up with a variety of interlocking mechanisms and then took the most promising on as prototypes.

Two tested models ultimately made the grade. One, a spring lock mechanism, is known as the Flamingo. The other, a hook and loop system, is the Entenknopf or duck’s head. Both consist of 0.2mm thick hook tape and loop or perforated tape of the same thickness.

The duck’s head system is based on the traditional synthetic hook and loop concept, in which numerous delicate steel hooks attach at any angle to the loops in the perforated metal tape.

The Flamingo variant, the researchers say, is even more stable. Wider hook elements snap into opening in the perforated tape. They are bent in such a way that they deform elastically under light pressure and glide into the holes, similar to the mechanism of a backpack strap buckle. Once inserted their sprung splaying arms revert to form and resist back pull like an expanding rivet. ©2009 GlobalFastenerNews.com and Fastener+Fixing Magazine

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• Institute of Metal Forming and Casting