Polyamides 6 and 66 are very similar in their characteristics. Therefore, polyamide 66 can be replaced by polyamide 6 in many applications. One example is a steering column switch housing for various models of the Ford Fiesta, Ford Focus and Ford Eco Plus. The component is produced by Leopold Kostal GmbH & Co. KG. This family-owned company is headquartered in Lüdenscheid, Germany and is one of the world's leading suppliers and developers of control components, sensors and control unit systems. It originally used glass-fiber-reinforced polyamide 66 as the shell, and recently switched to Durethan BKV30H3.0, a polyamide 6 compound from LANXESS, with a 30% glass-fiber-reinforced material.
"Changes in materials occur directly in the standard tools originally developed for polyamide 66. No changes are needed. Our materials are advantageous because they enable cost-effective component solutions and also meet stringent dimensional accuracy requirements "" Said Dr. Bernhard Helbich, Technical Marketing Specialist, LANXESS Performance Materials (HPM) Business Unit.
Advantages of foaming
The shell is injection molded from foamed polyamide 6. This foaming process has several advantages. Compared to solid components, it saves material and weight-with a reasonable balance in mechanical properties. "Using our materials for foam injection molding reduced weight by almost 10%," Helbich said. In addition, the occurrence of warpage and shrinkage caused by foaming is significantly reduced. This facilitates the dimensional accuracy of the components, which adapts to many steering wheel functions, such as switches for turn signals and windshield wipers, and therefore has a highly complex geometry. As Helbich said, "High dimensional accuracy ensures that the switch works reliably and runs smoothly throughout the entire life cycle of the car." Another benefit of the foaming process is the significant reduction in cavity pressure. As a result, the part can be produced on smaller injection molding machines with lower clamping forces. This also reduces cycle times compared to solid molded parts, ultimately paving the way for cost advantages.