Lanxess Develops New Metal Plastic Hybrid technology Process Metallic Hollow Profiles

Lightweighting has become increasingly important in the automotive industry. One method that has gained increasing acceptance for the manufacture of lightweight structural components is plastic metal hybrid technology developed by the specialty chemicals company Lanxess. This technology makes it possible to combine the benefits of both plastic and metal and has been used in past years for the manufacture of parts like front ends, pedal boxes and brake pedals. This hybrid technology involves use of glass fiber reinforced polyamide (PA) 6 for injection molding in tandem with a steel or aluminum sheet as the metal component.

Lanxess has now extended the use of this hybrid technology to cover metallic hollow profiles with round or rectangular cross sections.

Lukas Schröer, project manager for lightweight structures in the High Performance Materials (HPM) business unit said that when compared to sheet metal, hollow profiles exhibit significantly higher dimensional stability and higher torsional strength and stiffness. He said that the new ‘Hollow Profile Hybrid Technology’ would make it possible to manufacture components like cross car beams. Till now, this was not considered possible with the use of classic metal hybrid technology as the cross bars were not resilient enough.

Lanxess came up with cost-effective one-step process for its hollow profile hybrid technology and had to face several challenges during the development of this process.

Boris Koch, hybrid technology specialist in the HPM business unit’s technical application development said that it was necessary to have a process that would make it possible to smoothly and fully automatically place the metal inserts into the injection molding tool. Normally, metal inserts demonstrate dimensional tolerances, which can damage the tool. If the inserts are undersized, the result could be leaks in the tool system. The metal insert also has to be supported as the melt pressure during the injection molding process is high and the profile could collapse. Another challenge was to create a long-lasting, form fitting bond between the plastic and the metal in all directions.

Koch said that Lanxess’s new process is a simple one that is suitable for large scale production, requires minimum investment for standard injection molds and machines, and makes short cycle times.
This technology could potentially be used not just for cross car beams, but also for other structural components with high mechanical demands like front ends, seat structures, tail gates, and mirror brackets in trucks.

Lanxess offers customized polyamide compounds as injection molding materials for its hollow profile hybrid technology. “This includes particularly easy-flowing material varieties for complex ribbed structures and shapes as well as highly filled types of PA 6 that, thanks to their outstanding mechanical properties, take the structural performance of hybrid components to a higher level,” explained Koch.

Lanxess is now working on expanding hybrid technology to simple and competitive die-cast or extrusion molding inserts. Koch said that even hollow profile inserts made of fiber-reinforced composite can be used in the new hybrid technology and this would allow manufacturers to achieve further weight reductions in the mass production of structural components.