Development of Plastic Rear Seat Cushion Frame Using PP-LFT

Rear seat cushion frame of passenger car using PP-LFT (Long Fiber Thermoplastic) has developed for the purpose of weight reduction as well as tooling cost saving. At the design stage, dynamic structural analysis by LS-Dyna and flow analysis using MoldFlow were performed to check both validity of the cushion frame design and optimization of the injection conditions respectively. To check the degradation propensity of the candidate material, heat cycle, heat aging and fatigue tests were performed. The warpage and shrinkage characteristics of the cushion frame were also investigated through 3D-scanner. The fabricated proto cushion frame shows ∼45% weight reduction as well as ∼10% tooling cost down than conventional steel frame, which is made by steel spot welding.