Vapour smoothing, or vapour polishing, involves a heat and chemical treatment that smooths out minute cracks and blemishes in the surface of 3D printed parts. Following production of the parts using selective laser sintering (SLS) or multi jet fusion (MJF), Protolabs transfers the parts into a smoothing chamber which heats them and introduces a finishing agent. This agent then evaporates, with the vapour spreading across all surfaces of the part, melting and redistributing surface material to even out microscopic peaks and troughs, seal tiny cavities, and leave a polished, sleek finish.
“Whilst 3D printing allows an engineer to design and produce complex parts and is ideal for low production runs when compared to injection moulding, the surface finish of the latter is far smoother,” explained Andrea Landoni, Protolabs EMEA’s 3D Printing product manager. “Now, using vapour smoothing, we can bridge that gap for additive manufactured parts to smooth and seal even the smallest cavities on the surface.
“This allows parts in these materials to be used for a wider range of applications that demand a very fine smooth finish for aesthetic and functional reasons.”
According to Protolabs, the process also improves a part’s mechanical properties due to increased elongation at break and impact strength, with the resulting surfaces both water and air tight and easier to clean. The sleeker surface finish and improved sealing opens up new applications in industrial and medical sectors, including parts such as fluid bearing pipes and ducts, valve covers and oil sumps.
The post-processing automated technology is currently available for the commonly used nylon material PA-12, plus the elastic material TPU-01, with Protolabs looking to extend the technique to a broader range of polymers.
“Currently this process is available for PA-12 and TPU-01, which covers many potential applications.,” said Landoni. “However, we are also currently testing the process for more materials so watch this space for additions.”
