Depending on the specific 3D printing technology and the complexity of the 3D model, your 3D print might require a support structure. Upon completion of the print, this support structure needs to be post-processed.
When printing with FDM or SLA, the support structure is usually printed in the same material as the part. This requires the support structure to be removed manually.
Other printing techniques can involve support that is printed with a material that is different from the primary print material. This support material is often weaker, soluble or can be melted at lower temperatures.
Sometimes not all the support material can effectively be removed with the support removal techniques mentioned above.
Does my print require support removal?
- Support for FDM is needed for printing overhangs. Support removal can be done by the hub.
- Support for SLA or DLP is always needed. Support removal can be done by the hub.
- Support for Polyjet is always required. Support material removal is often easy because a secondary material is used that is weaker or water soluble.
- Metal printing always requires support. For metal printing alloys that have a lower melting temperature and/or are mechanically dissolvable are commonly used as secondary support.
- SLS doesn’t require support. Only the unfused powder around the print needs to be removed.
- Binder jetting doesn’t require support. Only the unfused powder around the print needs to be removed.
Common undesirable surface texture characteristics of 3D prints:
Stair-stepping: Since 3D printing is an additive process - objects are created by laying down successive layers of material - layers are often clearly visible to the naked eye.
Powder adhesion: A fundamental problem with binder jetting and powder bed fusion (PBF) processes. For these technologies, post-processes are integral for manufacturing dense parts and to ensure good mechanical properties.
The most common methods of post-processing 3D printed components are:
- Wet / dry sanding and sandblasting
- Water jetting
- Filling (priming)
Painting: For the smoothest finish, parts are usually painted before sanding. Painting the surface will seal porosity and smooth out the stair-step effect, making sanding more effective.
Property enhancements using non-thermal techniques
Property enhancements using thermal techniques
Matte finishes can be achieved by bead blasting of the surface. This will even the surface texture and remove sharp corners from stair-stepping. Alternatively, a tumbling machine can be used to automate this process.
Glossy finishes can be achieved by vapor treatments (e.g. Acetone and XTC-3D). Note that vapor treatments will have a negative impact on small feature resolution, sharp corner retention and part accuracy.
- Coloring: Depending on the material, your part can be colored by dipping it into a dye of the appropriate color. This is particularly effective for parts created from powdered beds as the the porosity in these parts leads to effective absorption.
- Chrome finishing: Chrome finishing generally refers to a mirror-like chrome finish. The more affordable option for this type of finish is to use a spray, such as Cosmichrome. Chrome plating (a technique of electroplating a thin layer of chromium onto a metal or plastic object) is a more expensive option and will give a more robust coating.