Vapour Treating 3d prints

2015-01-08 19.42.15

The main objective here is to take what are quite brutalist objects, as a result of the printer resolution and layer height, and soften them into something that as consumers we are more used to. Rapid prototyping has a bad rep from a consumer perspective with regard to the finish. My intention is to explore ways of making the objects more acceptable to a person interacting with them who had not overcome the natural “nuances” of printer resolution.

Vapour treatment is not the only option with regard to this… it would be possible to fill/sand objects provided they were strong enough. Also different processes give different layer heights. The SLA resin based technique used by FormLabs Form1 gives a layer height of 200 microns, compared to 500+ microns from home FDM techniques.

In industry, Stratasys Connex range are achieving layer thicknesses of 16 microns, so ultimately these vapour smoothing techniques will become redundant as technology moves on from where it is today. Currently our home rep-rap/makerbot etc machines are printing to 100.

I have decided to look into vapour treating my 3D printed pieces. I’ve found a couple of great links for this here and here. The gist is, while handling extremely unsafe chemicals, to suspend the 3d printed objects in the vapours for a short period (less than 10 minutes). This should melt the ABS or PLA enough that the ridges disappear and we are left with a smoothed model.

The first thing of note in all this is that the process for both is dangerous…

Both chemicals (acetone for ABS and Tetrahydrofuran (THF) for PLA) are highly flammable, carcinogenic, and give off toxic fumes. The process itself involves heating the solvent to create the vapours. In theory however it should produce an amazing finish. The setup used on Sink Hacks uses an electric hob/saucepan combo, but I plan on using a slow cooker for safety reasons…

There is a process described on Airwolf’s website that does not use a heated technique so I plan on experimenting with that too. They note there that smoothing single shel parts doesn’t work as they go floppy so I may need to experiment with my single shell/spiral vase print but there were a couple of drafts prints so I can play about.

The initial process will involve designing appropriate apparatus do carry out vapour smoothing and manage the risks: fire/fumes/ventilation. There is an added variable of changing the piece drastically beyond it’s original STL form (therefore it no longer an accurate representation of what was intended) but these are things that will need to be explored, seeing as I have no previous experience as to how the materials will react to these solvents.

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