Lightweight construction through evolution of hybrid technology

“Lightweight construction through evolution of hybrid technology” is the motto chosen by LANXESS for its stand at this year’s VDI conference on “Plastics in Automotive Engineering” in Mannheim. As the inventor of hybrid technology, the company has more than 20 years’ experience in this method of construction, which combines the strengths of sheet steel and polyamide. “In Mannheim we will be showcasing further developments in classical hybrid technology and new lightweight, intelligent material composites. All of them open up significant potential for weight savings and cost reduction in automotive engineering,” explained Ralf Zimnol, Head of Applications Development in the Semi-Crystalline Products Business Unit. 

Front end produced by hybrid technology with organic plastic sheet 

One highlight of the LANXESS stand is the first hybrid front end to be reinforced with organic plastic sheet alongside aluminum sheet. The organic light weight material forms part of the lower beam. This component proves that organic sheet meets all the requirements relating for instance to torsional and flexural strength. It is an excellent alternative to steel and aluminum sheet in hybrid technology. LANXESS sees the component as an intermediate step to all-plastic hybrid front ends that are series manufactured using only inserts of organic sheet in combination with polyamide 6. It is fitted in the luxury-class limousine of a German motor manufacturer. LANXESS supplies tailor-made polyamide 6 grades from its Durethan range not only for producing the organic sheet but also for injection molding the hybrid front end.

Spare wheel recess in highly filled polyamide 6

Another highlight on the LANXESS stand is a large spare wheel recess for the new Audi A8 made of highly filled Durethan DP BKV 60 H2.0 EF with 60 % glass fibers. “This part is representative of the great potential offered by this exceptionally stiff polyamide 6 in the design of large, complex structural components using all-plastic or hybrid technology,” said Zimnol. Polyamide 6 enables precise injection molding of the part’s complex geometry. It would be very difficult to make the component from sheet metal due to the limited space available and the high draw ratios. The spare wheel recess is bonded and bolted to the body framework, and fulfils the additional function of reinforcing the rear end of the car. The component is strengthened by integrating two reinforcing channels, each around two meters long, using gas injection technology (GIT). 

Full-surface hybrid bonding is more than twice as strong

Another topic on the LANXESS stand is a new form of hybrid technology which is currently being developed with a number of partners in the industry. It is based on sheet steel coated with adhesion promoters which is first formed and then provided with a polyamide rib structure in the injection mold. This results in a full-surface hybrid bond between the metal and the plastic as opposed to a number of separate anchoring points. “The quasi-static simulation of 3-point bending on the Erlangen beam showed that a bond of this sort can withstand forces twice as high as a bond produced by standard hybrid technology, and is also much more flexurally and torsionally stiff,” explained Zimnol. 

New polyamide for hollow parts in the engine compartment

The LANXESS presentation also focuses on grades of polyamide 6 and 66 for piping and tubing used in the engine compartment for air management, oil and coolant circulation and fuel supply. Examples include new materials for producing such parts by blow molding and water injection technology, and also foor fuel lines – particularly for AdBlue supply.