Can A 3D Printer Print Better Filament For Itself?

3D printed parts are generally no way near the strength of an equivalent injection moulded part and techniques such as a sustained heat treatment, though effective usually distort the part beyond use.

[CNC Kitchen] was investigating the results (video, embedded below) of a recent paper, that described a novel ABS filament reinforced by a “star” shaped Polycarbonate core, an arrangement the authors claim is resilient to deformation during the annealing process often necessary to increase part strength. While the researchers had access to specialised equipment needed to manufacture such a composite material, [CNC Kitchen’s] solution of simply using his dual extruder setup to directly print the required hybrid filament is something we feel, strongly resonates with the now old school, RepRap “print your printer” sentiment.

The printed filament seems to have reasonable dimensional accuracy and passing the printed spool through a heater block without the nozzle attached, ensured there would be no obvious clogs. The rest of the video focuses on a very thorough comparison of strength and deformation between the garden variety Polycarbonate, ABS and this new hybrid filament after the annealing process. Although he concludes with mixed results, just being able to combine and print your own hybrid filament is super cool and a success in its own right!

Interested in multi-material filaments? Check out our article on a more conventional approach which does not involve printing it yourself!

21 thoughts on “Can A 3D Printer Print Better Filament For Itself?

  1. It would be interesting to see the cross section of the extruded material. It could be that when the printed filament is extruded through the nozzle that it prevents ABS inter-layer contact. If you have some left try extruding a single line and check it.

      1. I could be wrong but it looks like it was just extruded from the nozzle. I was thinking more of printing a normal line on the plate. Better yet do a 2×2 lines and look at cross section. But like I said I could be wrong.

    1. “Worse” is sort of subjective but you do often get a shift in critical stress, elastic modulus and viscoelastic coefficients because of chain scission and there are other oxidation effects as well. If you’re looking for a “softer” material or one that is easily broken (shear pin, for instance) this kind of thing might be desirable.

  2. The “experiment setup” is wrong. He invested a lot of time and money in “it doesn’t help at precisely THESE parameters”. So apparently the parameters still need some tuning. So instead of immediately going for the “and statistically prove that it works” sample size, the way-to-go should have been to test different annealing temperatures and lengths. Consider “when it starts sagging” as “too hot, not an option” and discard that track of the experiments.

    If his parameters would have been “good” then this experiment setup would’ve been much more useful. Sadly that isn’t the case.

    1. You expect him to basically redo the already completed research? What’s the point of that?
      This was useful, it showed that if you print your own filament and use the parameters from that experiment you won’t necessarily get the same results.

  3. I’ve wondered for a while if you can take a 3D printed part, pack it in sand or clay, heat it to the softening point, then dust off the sand.

    Obviously it’s strong enough to hold liquid metal, so it should hold kinda-melty plastic in place, right?

    Another interesting things would be to have a filament that was able to slightly absorb microwaves(Like soy wax) and heat it while cooling the outside, to not affect the surface finish.

    Or potentially, do the opposite, and heat only the surface shell with lasers.

    1. I really don’t think any method of support and heat cycling will really change the nature of 3d printed parts.. Even if you stuffed it full and then took it just past melting point I expect you would find a mess coming back out with all the gas pockets expanding (and be sure its 100% infill or it will just slump into the bottom). And just plain annealing as shown here doesn’t change the mechanical properties much – though I’ve seen evidence it works well for heat resistance in some filaments at least.

      Maybe if you put enough work into it and use a filament that outgasses more for infill than the outer layers you could melt the outside and have pressure inside forcing it into the tightly packed sand.. There is certainly scope for some tweaking and maybe you can get certain benefits with this concept but no test on printing I’ve seen shows much change in properties.

      The irradiate inside/outside selectively idea might just work sometimes – but much of the strength is in the perimeters so melting the insides together better won’t have much impact especially on low infill %. And melting the outside with a laser without burning (so protective atmosphere or relatively low power?) I think would just warp the parts – you are spot heating an area so it expands only there – with enough testing maybe you can compute dwell and scatter to keep that to a minimum but its going to be very hard and need a 5 axis or greater CNC arm with laser to manage focusing on the contours of anything but simple prints – Seems to me the better approach is to cool/provide a large thermal mass for the interior of the print (an inserted stone rod/fill with ice water etc) and then throw into a very very hot box so the entire outside is heated evenly (relatively) and rapidly – followed by a rapid cool and you might get a prince Ruperts drop effect in the outershell while not warping or melting the print too badly (though again I doubt it – to really melt the outside together you will need to be over the melting point so smaller details are going to be lost or sag)

      If you really need 3d printed geometry and more solid parts the only choice I can see for a hobbyist is lost-wax style casting – can even pour in a two part resin if you still want a plastic part.

  4. You aren’t choosing the right to test ,there are technologies that can print parts for end use , subjected to mechanical testing as well as heat treatment

    If you keep using FDM only 3d printing will never be a good solution

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