The additive manufacturing process, also called 3D printing, is a process that builds a three-dimensional object based on a Computer-Aided Design (CAD) model, usually by successively adding material layer-by-layer. The term “3D Printing” covers a variety of processes in which material is joined or solidified under computer control to create a three-dimensional object, with material being added together (such as liquid molecules or powder grains being fused together). In today’s world, precision, repeatability, and material range have increased to the point that some 3D printing processes are considered viable as an industrial-production technology, whereby the term additive manufacturing can be used synonymously with “3D Printing”. One of the key advantages of 3D printing is the ability to produce very complex shapes or geometries, where the prerequisite for producing any 3D printed part is a digital 3D model or a CAD file, which could be produced using reverse engineering or forward engineering methods.
There is a plethora of additive manufacturing technologies, where the most-commonly used 3D-Printing process is a material extrusion technique called Fused Deposition Modeling (FDM). While FDM technology was invented after the other two most popular technologies; Stereolithography (SLA) and Selective Laser Sintering (SLS), FDM is typically the most inexpensive of the three by a large margin, which lends to the popularity of the process.
Although thermoplastics drew the most attention in the early days of 3D Printing (plastic), material options continue to grow. Additive manufacturing now uses metals, ceramics, glass, composites, graphene-embedded plastics, paper, concrete, food, yarn, and bio-inks, used to create artificial organs and soft tissues, among others. Research continues to provide advances in 3D Printing, addressing challenges that define which materials can be used, including high melting points, layer thickness, print speed, and production capacity.