At the session, we mainly spoke about three things:
HP’s multi jet fusion (MJF) technology which uses PA 11, PA 12, and PP, among other materials, to print strong, robust, plastic parts ready for prototyping as well as production use cases
DyeMansion’s PolyShot C and how it is used to automatically clean parts that are additively manufactured using HP MJF
DyeMansion’s PolyShot S is used after running parts through PolyShot C to equalize the peaks and lows on the surface of 3D printed parts, maximizing coloring results, and delivering a unique semi-gloss look & pleasant haptics.
However, some participants looked at the photos of parts that were shown and asked us if the parts printed using HP MJF can be painted in the post-processing phase to deliver different colors. The answer? A loud, resounding yes!
At our 80,000+ sq. ft. facility in Windsor, Ontario, recently, we additively manufactured a batch of parts printed using HP MJF. A small number of the raw parts, after having been moved through the PolyShot C and the PolyShot S, are in a bucket and ready to be painted in figure 1 below.
Figure 1: Raw HP MJF printed parts.
The spray-painting process isn’t challenging – it just requires a decent amount of space to be allocated to it, proper ventilation and face masks to ensure workers are safe, and the right paint to match the color codes specified by the customer.
Painting, in itself, is a process Advantage Engineering is very familiar with. First, a primer is applied to the parts. Next, it is painted with the right colors, adding a clear coat to lock in the paint. Finally, it is finished with a bake cycle that meets the paint specifications. We have the ability to either ‘low bake’ or ‘high bake’ depending on the needs of the project, thanks to our monitoring system.
In image 2 below, a batch of the customer’s HP MJF printed parts have been spray painted by a paint technician at Advantage Engineering and our VP of Operations Mark Rauth is running through the process and reviewing the final product.
Figure 2: HP MJF parts being spray painted.
When spray-painting a part, the last stage is often most important and is often the one that takes the most time. When we undertake a paint job for additively manufactured parts, we recommend that customers allow us to allocate 12 to 15 hours to cure the paint. Doing so allows for the paint to off-gas properly and dry sufficiently to ensures that when packed, it doesn’t emit any ghosting or other defects related to not curing long enough.
Figure 3: Painted parts being cured.
Once cured, the parts are ready to ship.
While the paint job done above was for a batch comprising of small-sized parts, we can paint any number of parts, of any size.
Clients that need their HP MJF parts painted often find that while the task adds a day or two to their lead time, it is incredibly efficient, and results in high-quality parts that are ready for end-use.