Lightweight material for tough applications


PHOTO: Schwalbe's new Evo Tube uses thermoplastic polyurethane from BASF

HOW to provide the same strength yet be ultra-low weight – the new inner tube for mountain bikes from Schwalbe takes on this challenge. The company, the market leader in Europe for bicycle tyres and inner tubes, has worked with BASF to develop a new thermoplastic material.

It is based on the thermoplastic polyurethane (TPU) Elastollan® by BASF. The excellent mechanical properties of this material mean that the wall thickness could be considerably reduced. This gives the eye-catching blue Evo Tube an important advantage over butyl-based inner tubes: the weight has been reduced by as much as 65% compared with a standard 29-inch tube; depending on the size of the tyre, the Evo Tube weighs between 68 and 76 grams. According to Schwalbe, the tube will be in stores from December 2015.

The thermoplastic polyurethane from BASF is remarkable for its many useful material characteristics. It is particularly resistant to abrasion and wear and therefore really long-lasting. Furthermore, an inner tube made from this plastic can withstand a very high level of continuous load and – despite its greatly reduced wall thickness – maintain a constant air pressure over long periods. An interesting feature of the solution that was developed with Schwalbe is that the tube, valve base and valve stem are all made from materials based on Elastollan. This simplifies the production process and also allows the product to be easily recycled. "Thanks to our extensive portfolio of suitable types of Elastollan, we were able to find the perfect combination of materials to make the new Evo Tube," explains Sascha Mattfeld, from TPU Sales at BASF.

The thermoplastic polyurethane from BASF also has a wide range of possible applications in other industries and sectors, for example in the automotive industry or in mechanical engineering and medical engineering. The synthetic material can also be processed in various different ways: among other things, Elastollan can be injection moulded, extruded or blow moulded.