Additive manufacturing, rapid manufacturing, operational performance, lean manufacturing, lean practices, seven production wastes, automotive industry, rapid prototyping, rapid tooling, and direct manufacturing
Additive manufacturing is an industrial process, developed in the early 1980s and currently used in several industries such as the medical, aircraft and automotive industries. In the first place,additive manufacturing was mostly usedby manufacturing industries to produce prototypes, models and patterns. Nowadays, this technology can be used at any point in the lifecycle of a product from pre-production(rapid prototyping and rapid tooling) to production (direct manufacturing). This technology is especially adapted for the production of limited series of small and geometrically complex components.The purpose of this study is to identify howadditive manufacturing affects operational performance during the development and production phases, specifically in the case of the automotive industry.With this purpose in mind, I have collected primary and secondary data through a qualitative study using both in-depth semi-structured interviewsand archival records found on automotive companies’ websites. The objective of collecting multiple sources datawas to gain a reliable and comprehensive perception of the situation and understand the effects of additive manufacturing on operational performance, and more precisely on the seven production wastesdefined on lean practices, to be able to answer my research question. The data are analyzed using an inductive thematic analysis approach and testthe presupposition that emerged from the empirical findings. Through the analysis of the data collected, I came to the conclusion that additive manufacturing is mostly used during the prototyping phase and sometimes also used for rapid tooling. But it appears that this technology is only used for direct manufacturing in some specific niche markets such as luxury carmakers. Another interesting finding concerns the use of additive manufacturing for marketing purpose. Concerning operational performance, the impacts of additivemanufacturing remainlimited, and contrary to what some authors said, the use of this technology is still marginal in the automotive industry compared to traditional manufacturing.
Tooling design is a critical step when designing an injection molding op-eration for a new product. Conventional molds used in injection moldingare costly, thus, a considerable amount of detail and time is spent ensuringthe tooling will be correct the rst time. In the last three decades rapidprototyping technologies (RP) have become more useful in the productdesign phase of mold manufacturing. Prototyping components in similarmaterials and geometries as the nal molded part have seen the lion'sshare of RP involvement in mold design. Indirect and soft tooling havealso beneted from RP master molds which are manufactured exceedinglyfaster than traditional physical prototypes. Manufacturing of rapid tool-ing (RT) is expected to be the next signicant industrial application ofRP. Where a traditional mold may take several weeks or even months tomachine, a RT mold could be made in hours or days at a fraction of thecost. Signicantly decreasing the time and cost needed to mold proto-types and or decreasing the cost where only a limited number of parts isrequired.The objective of this research is to implement a simulation based proce-dure for the validation and analysis of a rapidly prototyped tooling beforeproduction. Creating a predictive model will aid in exploring the eld ofRT with new materials and various scales of tooling not yet investigatedby giving a simple pass/fail critique on designs. To carry out such a modelMoldex3D and Dassault's Abaqus were used to simulate the molding pro-cess and internal loading on a RT mold cavity design. By comparing twosimilar models each with a dierent pass/fail result the simulation resultswere comparing to experimental results. The comparison of the simula-tion and experimental results demonstrate the validity of the model basedapproach to establish guidelines to begin the standardization of RT molddesigns.
Additive manufacturing, 3D printing, Rapid prototyping, Biomaterials, Tissue engineering, Scaffolds, Constructs, Bone, and Cartilage
Bone and cartilage constructs are often plagued with mechanical failure, poor nutrient transport, poor tissue ingrowth, and necrosis of embedded cells. However, advances in computer aided design (CAD) and computational modeling enable the design of scaffolds with complex internal michroarchitectures and the a priori prediction of their transport and mechanical properties, such that the design of constructs satisfying the needs of the tissue environment can be optimized. The goal of this research is to investigate the capability of additive manufacturing technologies to create designed microarchitectured tissue engineering scaffolds for bone and cartilage regeneration. This goal will be achieved by pursuing the following two objectives: (1) the manufacture of bioresorbable thermoplastic scaffolds by selective laser sintering (SLS) (2) and the manufacture of hydrogel scaffolds by large area maskless photopolymerization (LAMP). SLS is a laser based additive manufacturing method in which an object is built layer-by-layer by fusing powdered material using a computer-controlled scanning laser. LAMP is a massively parallel ultraviolet curing-based process that can be used to create hydrogels from a photomonomer on a large-scale (558x558mm) while maintaining extremely high feature resolution (20µm). In this research, SLS is used to process polycaprolactone (PCL) and composites of PCL with hydroxyapatite (HA) for bone tissue engineering applications while LAMP is used to process polyethylene glycol diacrylate (PEGDA) which can be used for hard and soft tissue applications.