Glass + filament adventure (Page 1 of 2)

Darn wish I had my Filastruder, I'd certainly be willing to try.

That really sounds intriguing, what would PLA suitable for surgery be. Could one autoclave regular PLA to sterilize it?

Ralph

does it have to be in PLA?

Also I'm not sure about using the autoclave on print PLA, but it's a great idea.  I'll suggest it to him.  If he has some extra time, maybe he can run some samples and I can get back to you on how well it works.

He's been pretty ecstatic lately because nobody in the lab knew anything about 3D printing or that PLA had become widely available in cheap printing filaments.  They've been doing all of their experiments with medical grade PLA.  Turns out their results with print PLA are pretty indicative of what they'll be with the medical grade stuff, so he's been able to do tests lately that would have previously been wildly out of budget.

I am tooling up for graphene as a reinforcement test and would be happy to extrude some glass filled PLA. I would also need to know the fill percentage that is needed to get a stable structure after disolving of the PLA. It could be too high to get a workable filament(too stiff) Let us know..

What is going to keep the glass together once the PLA dissolves?  Does the PLA gradually get replaced by tissue which then holds the glass?

Awesome!  I'll send over some contact information!

I was thinking maybe the PLA could be heated and mixed with the glass, then perhaps blended or something to bring it back down into pellet form.  This should ensure reasonably even distribution.  The glass particles will be no larger than .02 millimeters, so it should be of a powder consistency.

Yep.  It's downright fascinating.

There are so many possibilities for things you could embed in the stuff.

They're tiny grids with lines about 200 microns wide at most.  My account is too new to post a picture, I think, but here's a shortened, mangled url to a picture of a few:  h ttp://goo.gl/m2YYE

As you can see, they're just begging to be 3D printed.

That's a good point.  The materials used in the final extruder, if filament can be made, may need to be pretty unusual or at least coated.  Same would go for the printer parts in this case.  This really is turning into quite the adventure.

Thanks for bringing that up.  I'll look into it.

Worst case scenario some of the parts could be made in ceramic.  I'm reading now about ceramic augers, so apparently there is some precedent to work from, and I could probably get access to a shop that works with it.

Sounds like an interesting project you've got going.  Can't wait to see what you come up with!

the end result is the bridge would have to be sterile to be used in the body and any kind of oxidation be it iron or galvanize would be a foreign body and cause problems with infection.  I think the auger, Barrel & nozzle would need to be a high grade stainless.

That's correct for this stage.  In fact, the glass we're intending to use for this test batch of filament is just your standard, run of the mill stuff you'd find in any bottle.  This is mostly to show that 3D printing is capable of making a scaffold at a tiny fraction of the current cost and piquing a bit of curiosity in it.  The lab spends a ton making and researching these things, and we're thinking the people who write the checks might be as fascinated as we are.  At that point, getting the right machines built becomes a little easier, as then this wouldn't just be out-of-pocket, on-the-side inquiry anymore.

Based on my experiments mixing plastic beads with powder directly in the filastruder hopper, the mix ratio will not be precise at all. As the first amount of plastic pushes through, it will have a tiny portion of powder on it - and all of that will be on the outside. As more plastic pushes through, more of the powder will be embedded in it, but again, it will mainly coat the outside, with solid globs of unmixed plastic inside of the filament. Not all of the powder will be used up in that initial run - it will contaminate the filastruder for a long time.

It's going to work better to mix the PLA and the glass chemically, and then to run the resulting plastic through the filastruder. This will create a more uniform mixture. An example of a process to mix plastic with a filler is described in the paper, "A Simple, Low-Cost Conductive Composite Material for 3D Printing of Electronic Sensors."  Google for it, it's available online. This silly forum won't let me link it.

In that paper they dissolve PCL (polycaprolactone) in DCM (dichloromethane.) PLA is also soluble in DCM, although using DCM on something that is supposed to dissolve inside of someone's body would probably cause the FDA some consternation. But we're talking proof of concept here, right?

One thing to consider if you're going to stick with a thermal based mixing approach would be to use ecorene, which is a powdered form of PLA. Using that as an input should help get a more even distribution of filler/plastic.