The TecPart Innovation Award, which recognizes innovative plastic parts, was held during the K show taking place in Düsseldorf in October 2022.
The composite structural component was developed by BBP Kunststoffwerk Marbach Baier, Lanxess and a German commercial vehicle manufacturer. It can be used in multiple truck models and takes the form of a trough with a cover which is fastened to a truck’s ladder frame, the companies say.
In this position, it can hold two batteries weighing 75 kg each, as well as three compressed-air tanks at around 7 kg. The structural component is exposed to acceleration forces over a vehicle service life of approximately 1.2 million km. This, plus the weight of the entire assembly and the small number of fastening points mean that it is subject to significant mechanical loads, Lanxess said.
As an alternative to metal reinforcement, BBP and Lanxess designed a purely injection-molded component that would be capable of withstanding the high dynamic loads and simulated its manufacture. One challenge was fastening the component to just a few points on the ladder frame and designing these fastenings to be capable of bearing the necessary loads, the company said. “[W]e used a process simulation to determine how the short glass fibers orient themselves locally during injection molding, which leads to direction-dependent mechanical component properties,” said Frank Lutter, computer-aided engineering (CAE) specialist at Lanxess. “We then fed the data from that into the structural simulation, which helped to make precise predictions about the mechanical behavior of the component.
Using injection molding makes it easier to reproduce fiber orientation, wall thickness and warpage., according to the company. Production also lends itself better to automation, and cycle times can be shorter and more efficient. The material used was Lanxess’ Durethan BKV35H2.0 901510 polyamide 6 compound, reinforced with 35% weight short glass fibers.
“Our material and our comprehensive process and structural simulations have helped to ensure that the carrier does not have to be reinforced with heavy and expensive metal inserts, in contrast to a DLFT [direct long fiber thermoplastic] composite design variant based on polypropylene,” said Dr Matthias Theunissen, head of plastics application development at Lanxess. “As a result, the component is around 35% lighter and much cheaper to manufacture.”