A 3D model is created with CAD software or a 3D digital scanning technology. Next Additive Manufacturing professionals examine the 3D model file to determine the best process and layout for manufacturing the part. The digital file is then “sliced” into layers that provide instructions to the machine on how the materials will be printed, fused, deposited, or joined.

Some Additive Manufacturing processes for polymer materials include:

• Material Extrusion: With Fused Filament Fabrication, aka FDM (Fused Deposition Modeling), the part is produced by extruding small beads or streams of material from a nozzle that harden immediately to form layers on a build table. An industry standard, fused filament fabrication 3D printing is a process that provides engineers and designers with numerous material options with the open-source machine platform. Durable, rigid, single-color parts with moderate detail are suitable for check fixtures, specialized tools, functional prototypes, and end-use parts.

• Material Jetting / Binder Jetting: An ultraviolet-sensitive gel is deposited by a printhead and immediately cured by a UV lamp. The machine can use rigid and rubber-like materials and has an excellent surface finish. Material jetting 3D printing is a solution for designers who want excellent visual models with an end-product feel. This technology can incorporate multiple materials and colors into one print. It is suitable for complex, flexible models.

• Powder Bed Fusion: These processes use selective fusing of materials in a granular powder bed. Material can be fused by laser sintering or laser melting. SLS (selective laser sintering) uses powdered thermoplastics (typically nylon) precisely fused by a high-powered laser. With automated vapor smoothing, SLS production parts are water-tight, air-tight, heat-resistant, strong, and easy to reproduce. Nylon also can produce living hinges and flexible end-use parts and can be easily dyed in various colors.

• Stereolithography (SLA):  Uses ultraviolet-sensitive liquid resins (photopolymers) that are instantly cured when activated by a UV laser. Then the parts are post-processed with additional UV and thermal treatments when necessary. Stereolithography is a speedy and highly accurate process used most commonly for form and fit prototypes, master patterns, and large concept models. The combination of speed and design freedom offered by Stereolithography enables rapid iteration for new product development.

• Digital Light Processing (DLP): Uses UV-sensitive liquid resin cured by a digital light projector. Ideal for projects requiring high detail and finishing in various production-grade materials. From flexible silicone to rigid high-temp cyanate ester Digital Light Processing can make parts with different durometers and characteristics. It’s an excellent technology for small end-use components, light metal part substitutions, functional, high-detail prototypes, jigs, and fixtures.

• Hybrid PhotoSynthesis: This process blends stereolithography and digital light processing to create highly accurate and efficient 3D prints. It is remarkably fast while maintaining incredibly smooth surface areas similar to injection molding. Hybrid PhotoSynthesis can be used for prototypes and end-use parts such as handles, cranks, knobs, fasteners, snap-fits, and cases.

• Multi Jet Fusion: HP’s proprietary Multi Jet Fusion (MJF) printer uses infrared energy to precisely fuse a powdered thermoplastic and a liquid agent. This technology can create functional nylon prototypes and end-use parts. A few ideal applications are brackets, connectors, hinges, housings, and thin-wall ductwork. Multi Jet Fusion is also great for producing accurate parts in higher volumes.