New material for crash components promises to make cars safer

WASHINGTON - In a bid to make vehicles ‘crash’ safe, researchers have now found a way for the automotive industry to mass-produce a particularly safe class of materials known as thermoplastic fibre composite components.

Highly stressed load-bearing structures and crash components that are designed to buckle on impact help to reinforce the body in order to protect the vehicle’s occupants in the event of a collision.

Automakers have previously constructed these parts from composites using a thermoset (i.e. infusible) matrix.

But this approach has a number of disadvantages: as well as being difficult to implement efficiently in a mass production environment, it can also be potentially hazardous since this material tends to “delaminate” into sharp-edged splinters in a collision.

A further problem is the fact that thermosets cannot be recycled.

Researchers from the Fraunhofer Institute for Chemical Technology ICT in Pfinztal have now found a solution to this problem by developing a new class of materials designed for large-scale use in vehicle construction: thermoplastic fibre composite materials.

Once they have reached the end of their useful life, they can be shredded, melted down and reused to produce high-quality parts.

And they also perform significantly better in crash tests- thermoplastic components reinforced with textile structures absorb the enormous forces generated in a collision through viscoelastic deformation of the matrix material - without splintering.

ICT engineers have developed a process suitable for mass production, which makes it possible to manufacture up to 100,000 parts a year.

“Our method offers comparatively short production times. The cycle time to produce thermoplastic components is only around five minutes. Comparable thermoset components frequently require more than 20 minutes,” said Dieter Gittel, a project manager at ICT.

The Fraunhofer researchers have named their technique thermoplastic RTM (T-RTM). It is derived from the conventional RTM (Resin Transfer Molding) technique for thermoset fibre composites.

The composite is formed in a single step.

A demonstration part has confirmed the benefits of this new class of material- the trunk liner for the Porsche “Carrera 4″ weighs up to 50 percent less than the original aluminum part.

To improve the crash behaviour of the vehicle’s overall structure, the ICT engineers also calculated the optimum fibre placement. (ANI)