3D printing technology continues to develop at a startling pace. From SLA and FDM to SLS and Metal printing, these technologies offer new ways to fabricate incredible products. Below is a list of the latest developments.
SLA (Stereolithography)
Stereolithography consists of an additive production technique that incorporates UV lasers as illumination for curing polymer resins selectively. It has become a popular vat photopolymerization technology and can be used to generate objects through polymer resin curing layer after layer. The materials utilized for this printing technique are thermoset polymers which are photosensitive and appear in liquid form. This 3D printing method was first patented around 1986 and is considered the earliest technology of its kind. It is highly affordable and achieves more accurate and smoother surface finishes.
FDM (Fused Deposition Modeling)
Fused deposition modeling uses material layers fused together within specific patterns to produce objects. The material will often be melted slightly beyond the glass transition point. It will then be extruded inside a pattern that is on or next to the previous extrusion. This technology was developed in 1991 and has become popular because multiple 3D printing material types can be used (e.g., thermoplastics, paste, chocolate, metal, and wood).
SLS (Selective Laser Sintering)
Selective Laser Sintering is also an additive process that can be used for manufacturing. It works by using a laser to selectively sinter polymer powder particles, fuse them as one, and construct parts layer after layer. The materials applied within SLS consist of thermoplastic polymers in granular form. This form of 3D printing is versatile and can be applied to both functional components and prototypes for smaller production runs. SLS was also developed during the 1980s around the same time as Stereolithography.
Metal 3D Printing
First developed in 1994, this is one of the newest three-dimensional printing methods. It consists of a build chamber filled with an inert gas such as argon. This gas reduces the oxidation of metallic powder after which it will be heated to an ideal temperature. Next, the thin layer of metallic powder will be spread onto a build platform. A powerful laser then scans the component cross-section and fuses the particles to generate a layer.
The whole area will be scanned, which allows each portion to be fully constructed as a solid. Once the scanning is complete, a build platform will travel downwards by each layer thickness. A recoater will then spread another thin metallic powder layer. This process repeats until the entire part is finalized. Although this 3D printing method costs more than others, it minimizes warping and the metal components have greater hardness and strength. Another benefit is that the metallic powder can be recycled with a wastage of less than five percent. After each print is complete, unused powder can be collected and sieved.
