Many people have heard of 3D printing, but what exactly is it, and what are its mainstream technologies?
3D printing, professionally known as additive manufacturing, differs from traditional cutting, grinding, and forging methods. It doesn't require molds or cutting away excess material. You simply draw a 3D model on your computer, and the machine slices the model into extremely thin slices, like slicing bread, and then gradually builds up the material. From precision jewelry and dental models to automotive and even aircraft engine parts, it can do it all.
Currently, the mainstream 3D printing technologies are mainly divided into four categories, each with different applications.
The first category is stereolithography, which emphasizes high precision and smooth surfaces, making it the first choice for small, intricate parts. SLA stereolithography relies on lasers to cure resin point by point, achieving extremely high precision and is often used for dental molds and precision industrial parts. DLP and LCD stereolithography, on the other hand, expose and form the entire surface, resulting in faster printing speeds and lower equipment costs, making them the most commonly used technologies for printing everyday figurines and crafts.
The second category is FDM (Fused Deposition Modeling), which is the most widespread and cost-effective technology. Its principle is simple: it melts plastic filaments such as PLA and ABS through high-temperature heating, then extrudes and stacks them layer by layer to form the final product. It's widely used for home printing, school teaching, and the production of simple non-standard parts. The only minor drawback is that the finished product may have slight layering, resulting in relatively average precision.
The third category is industrial-grade powder molding technology, the mainstay of high-end industrial manufacturing. SLS (Single Laser Sintering) technology can sinter powders such as nylon and glass fiber without requiring a support structure, making it suitable for mass production of industrial plastic parts. SLM (Single Laser Melting) technology focuses on metal printing, melting metal powders such as stainless steel, titanium alloys, and aluminum alloys, and is commonly used in high-precision fields such as aerospace, automotive engines, and orthopedic implants. In addition, there are multi-jet melting and powder bonding technologies, mainly used for mass production of nylon parts and casting sand molds.
The fourth category is jet molding and special processes. PolyJet inkjet curing can simultaneously print multiple colors and materials with a combination of hard and soft materials, and is widely used in medical devices and tooling fixtures. Emerging technologies such as WAAM electric arc additive manufacturing and bio-3D printing are respectively adapted to special scenarios such as large steel structure printing, artificial organ scaffolds, and biomedicine.
