Three-dimensional (3D) printing is an additive manufacturing process that creates a physical object from a digital design. The process works by layering thin sheets of material, such as liquid or powdered plastic, metal, or cement, and then fusing them together. Stereolithography (SLA) is the original industrial 3D printing process and is renowned for its ability to produce parts with high levels of detail, smooth surface finishes, and tight tolerances. SLA parts are often used in the medical industry for anatomical and microfluidic models.
We use 3D Systems' Vipers, ProJets, and iPros for SLA printing. Selective Laser Sintering (SLS) is another 3D printing process that melts nylon-based powders into solid plastic. SLS parts are stronger than SLA parts and have rougher surface finishes. Additionally, SLS requires no support structures, so multiple parts can be nested in a single construction. This makes it suitable for larger part quantities than other 3D printing processes.
Many SLS parts are used to prototype designs that will one day be injection molded. We use 3D Systems' Pro140 machines for SLS printing. Fused deposition modeling (FDM) is a common desktop 3D printing technology for plastic parts. An FDM printer works by extruding a plastic filament layer by layer onto the build platform. It is a fast and cost-effective method for producing physical models, but the parts have relatively rough surface finishes and lack strength.
Liquid additive manufacturing (LAM) is another 3D printing technique that deposits a liquid or high viscous material onto the build platform. DLP uses lamps to produce prints at higher speeds than SLA printing because the layers dry in seconds. In stereolithography based on mask imaging, a 3D digital model is divided into a set of horizontal planes. The cutting sequence is completed before the 3D printer deposits the next layer of adhesive, and so on until the part is complete. In recent years, gold and silver have been added to the range of metallic materials that can be printed directly in 3D, with obvious applications in the jewelry sector. The starting point for any 3D printing process is a 3D digital model, which can be created using a variety of 3D software programs in the industry, such as 3D CAD.
For manufacturers and consumers there are simpler and more accessible programs available or scanned with a 3D scanner. Some other early food experiments include 3D printing of “meat” at the cellular protein level. As 3D printing processes have improved in terms of resolution and more flexible materials, an industry renowned for experimentation and outrageous statements has come to the fore. Today, precious metals can be 3D printed in a variety of patterns and designs quickly and cost-effectively. In addition, machines and devices wear out over time and may need quick repair, for which 3D printing produces an optimized solution. Material blasting is one of the most expensive 3D printing methods, and parts tend to be brittle and degrade over time.
In healthcare, customization is critical: most hearing aids made in the U. S. are manufactured almost exclusively with 3D printing.
