Explanatory notes
… source, e.g., lasers, resistors, electron beams or UV light, to produce a 3-dimensional object out of materials … machines layer plastics, such as Polypropylene (PP), High-density polyethylene (HDPE), Polystyrene (PS), … material drips out of a nozzle and is then hardened by a UV light. (4) Material extrusion machines heat filaments inside …