Post Processing For Polymer Additive Manufacturing
Post-processing of solid-state powder sintering often presents challenges related to the removal of support materials, which can be labor-intensive and time-consuming. This limitation can restrict design complexity, as support structures in small or intricate features are difficult to eliminate with existing equipment. Similar issues are observed with liquid-phase beds, albeit to a lesser degree. A novel vacuum-based process has been developed to circumvent these removal obstacles, as demonstrated by the results presented below.
Powder Bed Fusion Material Removal
Liquid Phase Bed Fusion Material Removal
Originally Printed Gear
Gear After One Hour
Gear After Three Hours
The component depicted above underwent chemical treatment in a 3% sodium hydroxide solution, with a pulsed vacuum cycle to generate vapor within the internal cavities every 15 seconds. The VCN vacuum system facilitates the removal of spent solution from the internal passages of the component and introduces fresh sodium hydroxide solution to sustain the dissolution process. After a duration of 3 hours, the component was thoroughly cleaned, with all moving parts exhibiting free rotation. Typically, this cleaning process requires approximately 48 hours in a circulation bath containing 10% sodium hydroxide to achieve complete material removal.
The internal support material of the FDM (Fused Deposition Modeling) parts, shown on the left, requires a processing time of 1 to 2 days in an agitated bath for removal. The part displayed on the right has undergone 20 minutes in the VCN (Vapor CHamber Nucleation) process, with an additional 20 minutes sufficing to extract all internal support material. Refer to the video below to observe this process operational in real time.