In the second of our ‘We Like to Work With Innovators’ posts we look at our first work with AMT and its PostPro3D(r) technology, initially developed at Sheffield University.

AMT are a rare company in 3D printing because rather than working within the construction phase of 3D printed forms they specialise in post-processing. Post-processing includes the physical unloading, cleaning, surface treatment, colouring and sealing of 3D printed parts after they have been constructed.

Post-Processing Tech – An Underdeveloped Element

Print farm development and automation has been making strides over the last few of years but post-processing tech has yet to really catch up, especially in the polymer world.

With the entry of the big chemical companies to the 3DP polymer field making a wider range of materials available, and the declining cost of hardware that is able to access those materials, the door is opening to developing a suite of tech that adds 3rd party colour, texture, functionality (e.g. electrical conductivity, anti-microbial action or water repulsion) or engineering function such as impermeability or surface strength. The skills and materials to manually impart all of these properties already exist on their own or in combination, but few companies can afford to retain the range of staff needed to support their full commercial application.

Enter specialised automated post-processing tech.

Additive Manufacturing Technologies – AMT

AMT demo pieces

AMT demo pieces

AMT Hardware Products

AMT Hardware Products

Post-processing of polymer powder-based additive manufacturing is where AMT started and seems to be best developed, but its technology takes things past simple powder removal. It uses a chemical process to melt the outer layers of a finished form, providing both smoothing and sealing of the surface. Other elements within its developing eco-system offer colouring and unloading automation.

Our tests

We took up AMT’s kind offer to test our material against their tech and found the following;

GIGO applies

Print quality impacts how well AMT’s process works. It is a chemical process and the chemical will infiltrate porosity in the model potentially increasing the ‘speed’ of melt in volumes where a higher surface area is exposed.

Geometry is a limiting factor

AMT’s PostPro3D(r) technology can give a really fine, smooth surface but it can only work with what is there already and there is a balence between how much processing a model can undergo and its whole model geometry.

For FDM that means layers can be smoothed out to a degree but the thickness of the wall, rather than the layer height, will define how effective that can possibly be. AMT has developed a set of design recommendations that will impact many applications, our feeling is that aesthetic applications, such as small model making where fine detail is the aim, might be less suited to this approach. However at the same time mechanical componentry designed with PostPro3D(r) in mind could easily leap out in terms of raw strength and engineering performance.

Material agnostic but not necessarily a consistent result across varied materials in a single model

It might sound obvious but if a finished part has multiple materials then AMT’s tech can’t differentiate between them in post-processing. Its all or nothing, though hypothetically there may be the potential to coat specific areas of a model to protect them, in an analogy of acid etching.

Final comments

We submitted two models to AMT and selected them to challenge its process, not to give it an easy ride. We’re only showing one here because the other print was an extreme challenge and really not a very good print to start with.

PostPro3D(r) definitely worked on both so we know that our material is compatible with the technology but desktop scale FDM is probably not the best additive manufacturing method to couple with it. Its certainly not a way to salvage a bad print. An industrial quality FDM printer is probably a better starting point than a lower-end Prosumer machine from 3 years ago 😉

In a business (and this is never going to be a hobbyist solution) you’d optimise the print phase against the post-processing phase to get the best overall performance. That could be something as simple as changing the layer height or as far as switching tech entirely to enable full automation in mass customisation.

It is a nylon friendly process so we fully expect future developments from Fishy Filaments to be compatible in the longer term.

Conclusion

The big take home for us is that our material is fully compatible with this technology leader’s process and that the results do enhance even relatively low quality prints. We’re probably going to to go back with a better demo piece when we have one and now that we’re sure that it will work and we look forward to exploring AMT’s growing product range.