Knowledge base Post-processing for 3D Printing

Post-processing & finishing 3D Printed parts

Written by
Ken Giang
Find out if your 3D print requires finishing and what post processing options are available per technology for improving aesthetics, form, properties or fit.

1. Cleanup

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.

  • Support removal

    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.

    3D printed part (SLA) with support structure

    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.

  • Support leftovers

    Sometimes not all the support material can effectively be removed with the support removal techniques mentioned above.

    Additional post-processing is needed to remove the support marks from this SLA print.

Does my print require support removal?

2. Process

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.

    The stair-stepping pattern is clearly visible in this 100 microns ABS print.
  • 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.

    For better powder adhesion, a glue or epoxy is added to this binder jetted print.

The most common methods of post-processing 3D printed components are:

  • Tumbling
  • 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

3. Finish

  • 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.

    FDM bronzefill print non tumbled (left) vs. tumbled (right).
  • 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.

    A 100 micron ABS print with Acetone treatment (left), a 100 micron ABS print (middle) and a 200 micron ABS print (right).
  • 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.
Written by
Ken's picture
Ken Giang

Ken's Hub (Industrial) Designer working with 3D printers; mainly focussed on making prototypes and proof of concepts.

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