3D Printing and Additive Manufacturing Services Information
Additive manufacturing service providers have equipment and knowledge to produce three dimensional parts using 3D printers. Parts can be almost any shape and are produced by sequentially depositing or curing layers of material into a desired geometry. Other than the functionality to quickly create custom parts, a key feature of this technology is the ability to create single parts that could not be created using traditional manufacturing processes. Once considered for form and fit prototyping applications alone, 3D printing has evolved the ability to create functional prototypes, one-off replacement parts, and limited low-production parts.
3D printers have the ability to create parts that would not have been possible using other processes, often eliminating the assembly step in a production process. This allows for designs with fewer parts, less weight, smaller overall size, and a potentially stronger and less expensive overall design. In terms of materials, 3D printing has grown to include many plastic and metal material options.
Additive manufacturing services are capable of fabricating a wide range of part sizes from microscale and nanoscale to large parts that are multiple feet in height. Size is dependent on the technology and machine capacities.
There are a variety of 3D printing technologies utilized in additive manufacturing services to fabricate parts, including:
Fused deposition modeling (FDM) is an extrusion technique involving heating a material and dispensing it from a nozzle to form layers of the final object. The material hardens immediately after extrusion. FDM techniques can be quiet and reliable, although the process is often quite slow for some object geometries. The process is best used with materials such as thermoplastics, edible materials, elastomers, and clays.
Robocasting or direct ink writing (DIW) is similar to FDM in that a material is dispensed from a nozzle to form layers, but distinct in that the "ink" is often a ceramic slurry that requires the final object to undergo a sintering process to achieve mechanical strength. DIW is typically employed for ceramics and metals.
Stereolithography (SLA) involves building object layers by focusing an ultraviolet laser on to a volume of photopolymer resin in the desired pattern, solidifying the resin due to its photosensitivity. SLA provides high accuracy and great surface finish in the finished product.
Digital light processing (DLP) differs from SLA in that the source of light is a more conventional lamp as opposed to a laser. The light is reflected off of a deformable mirror device (DMD) or through a liquid crystal panel to expose the photopolymer from below. DLP requires a smaller volume of photopolymer than SLA, and has the potential for faster production because an entire layer is exposed at once.
Powder bed techniques include powder bed and inkjet head 3D printing (3DP), electron-beam melting (EBM), selective laser melting (SLM), selective heat sintering (SHS), selective laser sintering (SLS), and direct metal laser sintering (DMLS). Powder bed processes are ideal for most metals and some polymers and thermoplastics.
Laser sintering is a powder bed technique similar in concept to stereolithography methods. A laser is focused on a bed of powder material, fusing the powder in the desired pattern one layer at a time. Laser sintering is ideal for thermoplastics and powdered materials, and the equipment required is typically complex and costly.
Selective laser sintering.
Image credit: Materialgeeza / CC BY-SA 3.0
Laminated object manufacturing (LOM) involves cutting cross sections of the desired object out of a web material such as paper and layering each section with a plastic coating in between acting as a bonding agent.
Selective deposition lamination (SDL) is similar to the LOM method, but involves carefully depositing adhesive in higher densities in the areas that will become the part, and much lower densities in areas that will only serve as support, allowing rapid removal of supporting material when the part is complete.
Electron beam freeform fabrication (EBF) utilizes an electron beam to melt a metal wire and deposit the material on a metallic substrate, which then solidifies immediately. The technique reduces the need for surface finishing by creating objects that are very close to the final desired shape.
Jonathan Juursema / CC BY-SA 3.0