Performance Evaluation of PU Over-molded Thermoplastic Steering Wheel 2010-01-0916
Automotive steering wheel (SW) is generally manufactured with metal armature and polyurethane / polypropylene (PU / PP) overmolding. The metal armature is used to provide structural stiffness and strength while PU / PP foam gives shape, touch and feel. Developed market use cast Magnesium or Aluminum as armature material, however emerging markets use steel for armature construction. With additional requirements (airbag integration, functional integration, aesthetics, compact and light weigh) being added to steering wheel, the steering wheel design is becoming more and more complex in nature.
Thermoplastic SW offers competitive stiffness, impact, ductility and chemical resistance characteristics needed for the global automotive markets. A thermoplastic SW had been developed from a unique recyclable polycarbonate. Subsequently, for the emerging markets, an injection molded SW with over-molded foam, is designed and developed with further optimized mass, processing complexity and performance.
This paper focuses upon the design, analysis, physical testing, and correlation studies of single piece PU over-molded thermoplastic steering wheel. Different testing details for an original equipment manufacturer (OEM) and performances of thermoplastic wheel against different requirements are presented.