Subtractive SLS Fabrication

Research and development of Additive Manufacturing technologies, specifically 3D printing, is increasingly focused on improving printing resolution for increased feature accuracy and smoothness. This approach however is generally time consuming and expensive when it comes to large-scale fabrication, making product scale printers rare. Challenged by these limitations, we propose the use of plastic pellets as the material for selective laser sintering (SLS) 3D printing. Plastic pellets are the raw form of plastics; they are typically used for feeding injection-molding machines and are thus relatively cheap. In this research we use a conventional laser cutter to sinter the pellets in successive layers utilizing the heat dissipating from the Laser Cutter in order to ‘glue’ the layers together. Various types of thermoplastic plastics were tested, and both rigid and flexible objects were printed using this process. The layer height is determined by the pellet diameter (~3mm). The relatively large layer height allows for the integration of other materials within the printing process such that the pellets are sintered around them. The integration of wood, metals, acrylic as well as PCB s for creating ready-to-use products with embedded electronic functionality are demonstrated. This technology can potentially lead to the creation of large-scale additive manufactured products including full-scale furniture 3D printing. Furthermore, this research proposes an integrated approach for fabrication using subtractive machines for additive processes.