The Fused Deposition Modeling (FDM) 3D printing process of layering extruded material makes FDM parts porous. This can be a benefit for some applications such as Thermoforming that requires air to be drawn through a tool. However, sealing a part to hold an airtight vacuum may be necessary for other applications.
In 2016 I wrote a blog, FDM Build Parameters to Create a Vacuum, using software parameters to create a denser filled part. This method requires using advanced Insight software to modify build parameters. But, what if your Stratasys equipment such as the Stratasys F120, F170, F270 or legacy machine does not support the advanced Insight software?
Vapor smoothing can be used to achieve a sealed airtight vacuum also. I built the simple bottle shown on the right with ASA material using standard GrabCAD Print parameters of .010-inch layers and the Solid build style. With this design, the tube can be used to draw and measure a vacuum with a simple automotive vacuum hand pump, shown below.
As you can see from the picture on the left, the Stradivarius Vapor Smoother does a great job of smoothing the surface as well as sealing it. The part was suspended in the acetone vapors for only 10 seconds, making it a very quick operation with little labor. The FDM part on the bottom was not vapor smoothed and is shown for a visual comparison of the surface finish.
The Stradivarius Vapor Smoother utilizes acetone vapors to ‘melt’ the surface of ABS, ASA or PC-ABS materials. As shown in the picture on the right, the Stradivarius Vapor Smoother heats acetone to create a vapor and employs cooling condenser coils to reclaim the vapors back to a liquid. This creates a ‘vapor range’ or reservoir that the FDM part can be suspended within.
For more information on the technical operation of the Stradivarius Vapor Smoother please see the blog, Industrial Grade Vapor Smoothing with Stradivarius, from my colleague Cullen Williams.
More complex parts could be aided in sealing with multiple borders from the advanced Insight software and/or a layer of an Acrylic spray clearcoat to ensure non-porosity.
For more information on purchasing a Stratovarius Vapor Smoother please contact your CATI representative.
Sr. Application Engineer, Additive Manufacturing
Computer Aided Technology, LLC