Annealing Conducting Filament


#1

With the idea that eventually the photon could be connected with 3D printed parts especially conductive filament. Could someone, ( @peekay123 @ScruffR ) have a look at this issue on the raise3D forum…

http://forum.raise3d.com/viewtopic.php?f=3&t=1715&p=14618#p14618

Basically we are trying to anneal conductive filament to reduce it’s resistance. So far a small 1 cm strip embedded in regular PLA has a resistance of about 2000 ohms.

By heating the PLA to about 110 Degrees Celcius and slowly cooling it, I managed to reduce the resistance by 600 ohms. Just wondering if we could use electricity to heat the conductive filament. Any suggestions?

I am thinking 30 V DC but not really sure for how long to heat about 3 grams of Conductive PLA (0.13 W / m K Thermal Conductivity). Any ideas or safety concerns?


#2

Very cool experiment. I played with Protopasta also for the purposes of making touch sensitive buttons for which one does not need too low of a resistance. Found that Protopasta makes a nasty mess with your printer nozzle but thats another story.

If heating up with a current going through works, you will have to be able to control that current quite well. What I am thinking will happen is that you’ll get into a walk-away situation whereby the current heats up the PLA, the PLA conducts a bit better, which causes a bit more current to go through which causes the PLA to become hotter, which increases the conductivity and… well you’ll see where that is going. I suspect that you will find that there is a critical current level at which things start to work all of a sudden which will need to be controlled quite well.

Just my 2ct


#3

Yes, took about a meter of regular PLA filament to clear out the black of the conducting filament.

I was wondering about the current changing as it heats up. I have a current meter for the Photon, might be something a photon could monitor and auto adjust.

All of this might be mute. Just got an email from Protopasta saying that the conductive PLA does not anneal.