A parametric optimization approach for radial shaft seal production processes for rubber waste reduction

While engineered rubber products (ERP) offer excellent mechanical and thermal properties suited for demanding industrial applications, the diversity of materials, equipment and processes involved in their processing poses challenges to their cleaner production. Existing literature canvasses recycling and reusing of products at the end-of-life (EOL) stage of the ERP life cycle to control their environmental impact. This research is focused on modes of reducing waste generated in the ERP production processes to minimize the environmental impact at the production stage of the life cycle. A novel experimental procedure grounded on the Shainin System (SS) principles is developed for parametric optimization in complex batch process settings. Unlike the established design of experiment (DoE) approaches based on statistical models, the proposed experimental procedure is based on sequential observational plans to reduce the search space while identifying the dominant family(ies) of causes (called Red X) of niggling defects. The application of the proposed experimental procedure is illustrated at an auto-ancillary cluster in India for reducing the rejection of radial shaft seals (RSS) due to rubber moulding defects. The case study's findings showed a reduction in the cluster's carbon footprint (i.e. 11,715 kg CO2-eq across the cluster), and overall production cost (saving of USD 1.20 million/annum) due to process improvements in the RSS moulding and assembly process. •A novel experimental approach grounded on the Shainin System is developed.•The approach facilitates parametric optimization in complex batch process settings.•A case study of the auto-ancillary cluster in India is illustrated.•Results on reduced cluster-level eco-cost and carbon footprint presented.