by Simon Robinson - Urethanes Technology International, courtesy http://www.plasticsnews.com/

Düsseldorf, Germany — How many companies does it take to reduce the part weight of a component by almost two-thirds?

The answer, if it is a license-plate holder for a high-performance motorbike, is eight, including two machinery companies and a major polyurethane supplier.

The motorbike in question is the KTM 1290 Super Duke R. Its 1300cc 170 horsepower engine can accelerate the bike from 0 to 100 kilometers per hour (60 miles per hour) in about 3 seconds, thanks, in part to a consortium of companies involved in all the stages of the plate holder manufacture.

The part may sound fairly insubstantial, but it is subject to great stresses and strains in everyday use, said Jens Winiarz, head of sales for composites and advanced applications at Hennecke GmbH.

German polyurethane machinery maker Hennecke has industrialized Cavus technology from Germany’s KTM Technologies — part of KTM Group, which also makes the motorcycle — which enables hollow fiber composites to be made using high-pressure resin transfer molding (RTM) technology in series production.

The standard production method for the part involves riveting together two pieces of steel and over molding in a polymer, a total of around 30 parts, said Winiarz.

The composite solution involves just one part, Winiarz said as he outlined the process. In this, a sand core from H2K minerals is used, which can withstand 500 bar mold pressure. This contains a water-soluble binder that can be flushed out after molding.

This core is then braided in carbon fiber by the Institute of Aircraft Design, in Stuttgart, Germany.

The part is then inserted into a mold, supplied, by Persico of Italy and housed in an Engel Elast 400 machine. The mold closes, a vacuum is applied and the Huntsman Victrox polyurethane is metered and injected from a Hennecke Streamline machine.

The Victrox grade has been “tuned to give a snap cure five or six seconds after mold filling,” said Winiarz, giving an overall cycle time of around 140 seconds for the part.

Winiarz added that the Hennecke machine is designed with “pressure control, sensors in the mix head outlet, hydraulically controlled back pressure function and mold filling monitoring.

“This,” he continued, “is to compensate for any variations in the weight of the preform.

“Because the liquid polyurethane system has a low viscosity before it cures, a reuseable mold seal material was developed,” Winiarz said.

This is designated Murlock from Murtfeld. It is “resistant to high-cavity pressures of 100 bar and resistant to damage from material and carbon fibers,” Winiarz said.