Analysis of the viability of additive manufacturing for rapid tooling: A case study for the plastic industry

Abstract

The current environment of changing market trends that include mass customization, sustainability, environmental impact and localized production drives the manufacturing industry to strive for additive manufacturing because of the versatility of the technology. Injection Moulding Company (IMC) is using traditional manufacturing approaches which compromise its competitiveness resulting in decreased production rate and high operational costs due to lengthy changeover times. The aim of the study was to investigate the viability of additive manufacturing technology for the manufacture of moulds to reduce operational costs. ABC mould demand classification analysis conducted for the top 16 moulds revealed that the moulds for the switch cover ranked highest in terms of the demand of moulds that were fabricated by IMC. The value stream map revealed that there was room for improvement in terms of push to pull and frequent lot transfer, standardising work, reducing cutting time and process scrap, as well as introducing poka yokes and cellular manufacturing, and it was proposed to reduce material movements and setup times. Through the deployment of group technology and rank clustering algorithm, three mould families and three machine cells were derived. As a result, the mould fabrication process was improved by reducing material movements and reducing setup times. Analytic hierarchical process was deployed as criteria for comparison and selection of the best 3D printing technology from among the recent additive manufacturing (AM) technologies that would meet surface finish, dimensional accuracy, cost, and manufacturing lead time requirements. Four AM options included Multilevel Concurrent Printing, MELD technology, Metal Jet 3D printer, and VELO3D. The final results indicated that the VELO3D is better than other additive manufacturing technologies for rapid tooling for the manufacture of moulds. The switch cover mould was then assessed for viability of fabrication through AM. The research proposed a process for evaluation of investment in VELO3D machine. A final decision was made through the comparison of AM technology, VELO3D versus traditional manufacturing capabilities in tool production. The traditional manufacturing was found to be characterised by a huge mould cost which was absent when additive manufacturing technology is adopted. The results demonstrated that VELO3D outperformed the traditional approach from a cost perspective leading to an 80% overall cost savings from the adoption of AM.