Spengler unveils steam dyeing machines for MJF and SLS parts

French AM post-processing specialist Spengler, part of the IntegrAM group, has unveiled a new solution for coloring Multi Jet Fusion (MJF) and selective laser sintering (SLS) parts. Spengler’s new range of SurfPro SD machines use a process of “steam dyeing” to color parts, using a fraction of the water and colorant required by immersion coloring techniques.

On the whole, MJF and SLS parts can be easily and effectively colored due to their porosity. The tiny gaps in a part’s surface allow dye to be absorbed, resulting in a consistent and long-lasting finish that does not peel or chip like spray paint—a method more suited to smooth-surfaced parts made using other AM technologies. Moreover, batch coloring of MJF and SLS parts is made possible by simply adding multiple parts to a larger dye bath.

However, one disadvantage of immersion dying is the excess amount of dye and water required. Enough colorant must be used to fill the entire immersion container, making the process less efficient than painting, where only enough colorant is required to coat a part’s surface. Spengler’s new post-processing systems aim to combat the inherent wastage of the dyeing process via a process of vapor or steam dyeing. Rather than submerge AM parts in liquid, the SurfPro SD machines release high-temperature steam via a vibrating vat to apply color consistently across batches of parts without total immersion.

According to Spengler, the process uses 1/10 the amount of water and 1/20 the amount of dye as an immersion process. This results in less waste and lower operating costs while still achieving consistent coloration across part surfaces. Furthermore, the machines have a recycling and recovery tank with a three-way control valve and electric pump to further minimize wastage.

The Spengler SurfPro SD machines are available in 25, 50 or 120 liters and are designed to be used for high-throughput post-processing of parts made on machines like the HP Jet Fusion 5200 and EOS P3 NEXT. The post-processing systems also feature a hot air blower for part drying and HMI touch screen for program and recipe management.

Spengler’s first colorant for use on the SurfPro SD is Extra-Black, but a complete range of colors will follow. Spengler’s other post-processing solutions include depowdering, sieving and microfluidic surface finishing systems. The team behind Spengler also heads Verne Additive Manufacturing Labs, whose STROM SLS 3D printer—designed to process high-performance materials like PEKK—debuted at Formnext 2024.