Support structures are an important feature of the 3D printing process. It helps in creating unsupported shapes/designs and complex geometries. Without support structures, it is impossible to realize the full potential of 3D printing and the freedom to design unconventional shapes. The support structure can be removed later during the post-processing of the 3D-printed part. Support structures can be created for plastic and metal parts according to the requirements. Also, there are various strategies to minimize or eliminate the need for support structures entirely by applying DfAM principles. Support is important to prevent deformation and other defects of the part during the printing process. Unique support materials are available which can be easily detached from the part without much effort leaving behind a smooth surface.
When are support structures needed?
3D printing is the process of creating the object layer-by-layer cross-section-wise. However, overhang or cantilever-type shapes need scaffolding-type support to enable their formation. Without the support structures, the cantilever-type shape will simply collapse within the part or deform making the physical non-usable. In metal 3D printing where high heat application is involved, support structures act as fins dissipating heat from the part to the environment preventing the part from accumulating residual stresses which leads to various quality issues.
Support structures in various AM technologies
Supporting structures are applied in almost every 3D printing process. Let's discuss structures in various 3D printing processes.
FDM (Fused deposition molding)
The FFF/FDM process works by extruding the filament out of the nozzle and deposition it on the build plate. Part builds layer by layer in the vertical direction as per the CAD data. The overhang or bridge-type features generally need support to hold them into the desired position. Without support, the overhanging feature will simply deform or collapse. Support material could be the same as the printing filament or secondary material extruded thru the second nozzle only where support structures are needed. Later the support structures are removed manually using pliers etc. or immersed into a liquid(water) to dissolve the supports in case of water-soluble support material.
FDM/FFF support structures. Photo credits: Ultimaker
SLA (Selective layer sintering)
SLA process forms part by solidification of photo-sensitive liquid resin by the application of laser light. Each time the laser beam strikes a thin film of resin, it solidified and gets deposited on the build plate. In complex geometries, overhang structures needed support structures to hold the shape in the desired place.