3D printing

A 3D-printing workflow begins with a digital model, commonly made in computer-aided design software or derived from a scan. Software divides the model into cross-sections and creates instructions for the machine. The printer then deposits or solidifies material in successive layers until the shape is complete. This additive approach differs from subtractive machining, which removes material from a larger piece, and from methods such as molding that form an object in a different way. The terms “3D printing” and “additive manufacturing” are often used interchangeably, although standards and technical fields use carefully defined terminology.

There is no single 3D-printing process. Some machines heat and extrude thermoplastic filament through a nozzle; others selectively fuse or bind material in a powder bed, or use light to harden a liquid photopolymer resin. Each method has different equipment, material requirements and part characteristics. Common feedstocks include plastics and metals, while some industrial processes use ceramics and other specialized materials. A finished part may also need support removal, cleaning, heat treatment or other post-processing, depending on its material and intended use.

A major use is rapid prototyping: designers can produce and revise a physical model without first making dedicated tooling. Additive manufacturing can also make low-volume or customized parts, including geometries that are difficult to produce with some conventional methods. It is used for manufacturing aids, molds and components in fields such as aerospace and automotive production. In health care, examples include dental restorations, surgical instruments, external prostheses and certain implants. Patient-specific design is possible, but a medical product still has to meet relevant safety, performance and regulatory requirements; the printing method alone does not establish that a device is suitable for use.

Because material is added where needed, some additive processes can reduce waste compared with cutting a part from stock. Avoiding dedicated molds or tooling may also make prototypes, design iterations and some short production runs more economical. Complex shapes and customization can be valuable where conventional processes would require several components or extensive tooling. These advantages are not universal. Printers may take a long time to produce parts, have limits on build size and usable materials, or require substantial finishing. Strength, dimensional accuracy and surface quality depend on the process, material and production settings. For consistent industrial and medical use, measurement, inspection and standards are important; additive manufacturing complements rather than replaces other manufacturing methods in every setting.