Heat treatment of printed parts

Hello all, I find that the printed parts are not very resistant to shear and bending when forces are applied 90º to the direction of the print (or the Z-axis). In other words, if you print a cylinder standing vertically, and you bend it, it will break quite easily. This, of course, has to do with the bonding between the layers. I was thinking it might be useful to heat treat the parts to fuse the layers. Has anyone tried this? To avoid deformation due to it's own weight, the parts most be supported in a media that wont stick to the hot (and soft ABS) and be easy to remove if some particles stick. 

Sand will support well, is inexpensive but I think it will stick to the ABS and will be hard to remove. Perhaps some silicone granules or powder, or perhaps leave the parts floating in hot wax near the "annealing" temperature of the ABS. There are water soluble waxes available that melts at quite high temperatures that would make  the post processing of the parts easy.

When I find time, I will do some tests and see how it turns out. Need to look into what temperature is optimal.

Has anyone tried this or given it any thought? 

Thanks!

John Tangerås

I found that acetone baths smooth the layers but adds strength to the parts. Of course there is info out there that suggests acetone application weakens parts but I hadn't found that to be true. So I don't know if I am just nuts (up for review) or the info circulating is faulty.--(maybe they were referring to PLA and not ABS, unsure)

This link investigates heat treatment of 3D printed ABS

http://koikonomopoulos.com/?portfolio=the-effect-of-heat-treatment-on-the-tensile-and-feature-properties-of-3d-printed-acrylonitrile-butadiene-styrene-abs

I do not think that heat is a good idea to increase layers cohesion mainly because with heat you create also deformation of part.

I agree with previous post. Solvent is a better way.

In my experience ,  abs parts broken because of load on Z axis ,  a longer spool holder for my M200,  have been glue together with just solvent  and then resist to the load that broke them previously.

It is very important to wait enough time to allow solvent to completely evaporate, usually 24 h are enough.

Heating the part moderately to completely dry it could help.