viscous/fluid materials

Hi folks,

For a project at university we need a 3D printer that can print a fluid material, it will harden once out of the printer. If possible we don't wont to spend 200k for a bioprinter. And as far as I can see printers like MakerBots couldn't handle something liquid, right?


Note: I now look around some more, and the problem with resin printers like Form2 is that what I want to print is not a photopolymer...I kinda want a printer that works like a filament extruder but instad of the filament has some kind of "bag" with my liquid in it, that it can compress and print out of the nozzle.

Best regards and thanks for your help,
Soia

You mean something like this

http://www.keep-art.co.uk/Self_build.html

A ceramic paste extruder

Yes, but I'd need high resolution so I'd rather have something commercial. Maybe we can buy the Inkredible Bioprinter, if this really works for 5k (university price) that seems to be quite fair.
But I'll also have a look if I find something interesting googeling for ceramic paste extruder :)
Thanks alot

cheers,
Soia

Sounds like another XY problem to me.

Quote:

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Originally Posted by Marm

Sounds like another XY problem to me.

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Hm, since I am at the very start of 3D printing this did not occur to me, but you might be right. So let me rephrase it.
I intend to squeez a material with the viscosity of honey through a nozzle. This I would like to do with Z stacks of approx. 100um (The object will have a final height of 1-2mm). And of course I would like this to be an automated process, where I can make a CAD file to be read and printed. The material will solidify once its on the building platform.
Is there a cheap (up to circa 3000$) 3D Printer that can do this?

Best,
Soia

I think you're still in XY territory, but much better. Props for understanding that too.

Why a viscous liquid? In order for a liquid to stay where you want it to, it will either need a catalyst to harden, or go through a phase change, which complicates the whole process. What is preventing this hardening in the tank/extruder?

Does the end product require this particular material? Are there other materials, that while maybe not as ideally suited as your the liquid, that will simplify the production process, lower costs, and work almost as well by staying within tolerances/specs? If so, then you might want to look in that direction.

If not, well, we should be able to help you figure out what you need. But I'm thinking we'll need some more info on exactly this material is, and the conditions it must endure for production.

Thanks, okey so the problem is that my liquid is bio-compatible but not biodegradable, and so far I haven't found much else that has these properties (+possibility of hardening).
I think I will be able to change the viscosity to that of toothpaste so that it stays put until I apply the catalyst for it to harden (it needs two components to harden and in the tank is only one). But you are of course right that for initial experiments I could use some kind of Bioink, to test things out.
To whole print process should take place at room temperature or not higher than 35°C.

Best,
Soia

At Hyrel, we have equipment which performs to your specifications.

See:

https://www.youtube.com/watch?v=vmw0LS_f9V0

and

https://www.youtube.com/watch?v=XREWb_Md5o0

and

https://www.youtube.com/watch?v=aR4d-2BZj_Y

PM me if you would like a live demonstration via skype.

It sounds like you need to develop a material that will either stay in place when deposited and slowly harden, or harden immediately upon deposition. FDM printing works because certain thermoplastics harden so quickly after being melted and extruded. A clay-like material would be an example of the former. But there's only so much weight that an unhardened "toothpaste" material will support before it starts sagging - you can try it yourself next time you're brushing your teeth.

If the material you have in mind needs a catalyst to harden, you might think about extruding both the resin and catalyst through a mixing nozzle, like the ones used to dispense epoxy: http://www.techni-tool.com/512AC441?...170411205942:s

Yes, awerby. Hyrel has heads which accept static blending baffled nozzles like that with fixed or programmable ratios. UV crosslinking photoinitiation can also be used when appropriate.

For mixing heads with programmable ratios, see https://www.youtube.com/watch?v=DQj6oLfrbLo

For UV photoinitiation, see https://www.youtube.com/watch?v=h95IurET7UM

Sorry I thought I closed this thread but it seems I never posted my last response. Thanks a lot for all your input. @awerby I know that the material will ned quite a lot of work. But the toothpast material hardens immediately when I add a second component to it, so what I intend is to have one layer "toothpaste" then with a second print head add a layer of hardening component then repeat. Since it hardens really within seconds I'm afraid that I would just clogg any mixing nozzles...
Thanks again for all your help, I do see now that this project is gonna be quite a bit trickier than I thought at the start :)

We have the ability to print alternate layers from alternate heads if you wish.