How Do 3D Printers Work?

3D printing is a process that consists of layering two-dimensional cross-sections sequentially to build a three-dimensional object. The process is similar to how a traditional printer applies ink to paper; however, a 3D printer solidifies or binds a liquid or powder material at specific points to create solid structures. The layering process is repeated numerous times until the desired object is fully formed in its vertical dimension.

Objects can be 3D-printed using materials such as plastic, metal, or even biological substances, depending on the desired application. The starting material is often a fine powder, which is dispensed in small amounts and spread in thin layers over the build area. The materials are solidified using various techniques, such as by spraying a binding agent or using lasers to sinter or melt the powder so that it fuses together. Selective laser sintering (SLS) uses lasers to heat and fuse powder particles, while direct metal laser sintering (DMLS) employs a high-power laser to create solid metal parts without binder material.

Computer-aided design allows engineers to create a digital model of the object to be printed. The model is then sliced into two-dimensional layers, and instructions are generated to guide the printer on where to solidify the material for each layer. 3D printing allows users to customize their creations and to rapidly prototype designs, making it possible to produce unique and complex parts quickly and efficiently. However, there are limitations to the size and quality of parts created by 3D printers. Designs that are prototyped using a 3D printer are typically mass-produced using traditional manufacturing processes.