Optimization of process variables for improvement of seat-backboard peel strength using response surface design method

With an increased demand for comfortable and aesthetically pleasing automobile interiors, fabric seat covers are being used more widely. Previously, covers were manufactured using adhesives attached to a molding and covered with a skin layer. However, this process releases Volatile organic compounds (VOC), pollutes the air inside the automobile, and leads to peel-strength-related problems. This study examines a multi-component injection molding process that uses residual heat during injection molding to glue the skin layer to the molding, employed in seat-backboard manufacturing. Hence, the VOC emission problem is overcome as adhesives are not employed. To obtain enhanced peel strength the optimal skin material is selected using surface-adhesion length and material peel-strength measurements. The response surface design method is utilized with a design-of-experiments method to determine the process variables that maximize the peel strength for the selected materials. The process variable selection is then confirmed via additional experiments. It is expected that the problems related to VOC emissions and peel strength, which limit current seat-backboard manufacturing techniques, can be resolved through application of the optimal conditions identified in this study to a multi-component injection molding process.