Via: @Engineezy
What is 3D Printing?
About the 3D Printing Process
3D Printing, or additive manufacturing, is a process that utilizes a CAD file (typically an STL) to produce a 3-dimensional part. Objects are produced layer by layer using a variety of different materials and layer adhesion technologies.
Types of 3D Printing
3D printing has evolved significantly over the decades and over time many different technologies have been developed:
Fused deposition modeling (FDM) is a 3D printing technology (also known as additive manufacturing) commonly used for modeling, prototyping, and production applications. Each layer is created by extruding material from a nozzle to produce 3D objects.
FDM processes require support material, either breakaway or soluble, so it’s important to keep this in mind when choosing this process as it can affect the final part.
Selective Laser Sintering uses high-powered lasers to sinter powdered material, binding it together to create a solid structure. It is often confused with another similar process called Selective Laser Melting (SLM), the difference being that it only sinters the powders together as opposed to achieving a full melt.
Parts are supported by unsintered powder in each layer, which remain spread across the build volume until each layer is fused together. Once complete, the part is removed from the remaining powder and cleaned by hand and using water/air jets.
While parts created using this technology can contain some metal, they are usually plastic composites that present a good strength to weight ratio and can be acquired relatively cheaply. For parts that must be structurally as sound as forged solid metal, DMLS is required. Still, the high level of accuracy, relatively cheap feedstock, and high temperatures achievable with SLS printing make it an incredibly useful technology with a broad range of applications ranging from architectural models to control surfaces of aircraft and surgical tools.
Stereolithography (SLA) is known for achieving highly detailed and functionally accurate parts. The technology utilizes a mirror that is programmed to direct an ultraviolet laser to draw and cure a part's cross-section onto a vat of photopolymer resin.
Multi Jet Fusion, or MJF, is a cutting edge 3D printing technology from HP that helps companies accelerate time to market with production-grade 3D printing.
The technology works by spreading out a fine layer of powder, depositing a fluid in the desired locations, and then fusing those areas. The raw powder acts as support for the parts within the build bed. Once the parts are complete, they are cooled, cleaned, and media blasted for a smoother surface finish.
MJF is ideal for bridge production quantities in the hundreds, given that the daily output is comparatively higher than other 3D printing technologies. It’s also great for functional testing and form/fit validation because of its high resolution and excellent tensile strength and heat deflection. It can even produce end-use parts and is a great transition into injection molding, since MJF parts have homogenous mechanical properties.
MJF is a versatile process leveraged by a broad range of industries including healthcare, automotive, and consumer electronics. Some common applications include prosthetics, aerospace camera enclosures, dental molds, and automotive component molds.
PolyJet is a 3D printing technology similar to inkjet document printing, but instead of jetting drops of ink onto paper, PolyJet 3D printers jet layers of liquid photopolymer onto a build tray and instantly cure them with UV light. The layers build up to create a precise 3D model or prototype.
Along with the selected model materials, the PolyJet 3D printer also jets a gel-like support material specially designed to uphold overhangs and complicated geometries. It is easily removed by hand or water.
Other technologies include: Direct Metal Laser Sintering (DMLS), Digital Light Processing (DLP), Electronic Beam Melting (EBM), Laminated Object Manufacturing (LOM), and others.
Advantages of 3D Printing
Additive manufacturing can provide more flexibility in geometry compared to subtractive manufacturing methods (CNC). Thus, a higher level of complexity can be more easily achieved through 3D printing. Compared with injection molding, 3D printed parts do not require costly tooling, thus technologies like Multi Jet Fusion can be a great option for production parts at lower volumes.
#engineering #mechanicalengineering #3dprinting
