3D printing (3DP) is a kind of rapid prototyping technology, also known as additive manufacturing [1], it is a 3D model file based on the use of powder metal or plastic and other adhesive materials, through layer by layer printing to construct the object technology.


3D printing is usually achieved using digital technology material printers. Often used in mold manufacturing, industrial design and other fields to manufacture models, and gradually used in the direct manufacturing of some products, there are already parts printed using this technology. The technology is used in jewelry, footwear, industrial design, architecture, engineering and construction (AEC), automotive, aerospace, dental and medical industries, education, geographic information systems, civil engineering, firearms and other fields.

Ordinary printers used in daily life can print flat items designed by computers, and the so-called 3D printers work basically the same principle as ordinary printers, but the printing materials are somewhat different, the printing materials of ordinary printers are ink and paper, and the 3D printers are equipped with different "printing materials" such as metal, ceramics, plastics, sand, etc., which are real raw materials. After the printer is connected to the computer, the "printing material" can be stacked layer by layer through the computer control, and finally the blueprint on the computer is turned into a physical object. In layman's terms, a 3D printer is a device that can "print" a real 3D object, such as printing a robot, printing a toy car, printing a variety of models, and even food. The reason why it is commonly called "printer" is based on the technical principle of ordinary printers, because the process of layered processing is very similar to inkjet printing. This printing technology is called 3D stereoscopic printing. 

There are many different techniques for 3D printing. They differ in the way the materials are available and are built in different layers to create the parts. [14] Common 3D printing materials include nylon glass fiber, durable nylon material, gypsum material, aluminum material, titanium alloy, stainless steel, silver plated, gold plated, rubber materials.