UV curing photopolymer for rapid prototyping

Hi,

Do you have an alternative photopolymer for projet 3dsystems

Hello Rob,

My resins are designed to be very versatile, but they have not been tested on a Pojet before yet.

Correct me if I am wrong, the projet is based around an ink-jet head, am I right?
[www.youtube.com]
It looks like the resin jets ink-jetted slided to a UV curing stage and hardened, to come back to the ink-jet area.

This means that the viscosity, surface tension and cure speed has to be just right.

Just to add to spota's response, I'm very familiar with the ProJet systems, and I cannot stress enough that you should not be trying to make custom formulations for it. The machine relies on a phase change from solid (cartridge) to liquid (printhead) to solid again (once a droplet hits the surface of the part). This is an extremely finely tuned process, and not something for the tinkerer to be playing with. You're likely to destroy an $8k printhead if you try to do this. DO NOT DO IT.

spota Wrote:
-------------------------------------------------------
> As for resins, you may want to have a look at
> this: [www.suscomp.com]
> These work at 359nm mostly, so you 355nm should
> hit close enough to the maximum absorption peak to
> work fairly well. Plus the excess power will help.
> But no kidding, vaporisation of whatever the laser
> touches may be your major concern.

I've tried this UV-L Resin (96% linseed oil epoxy), since I've targeted to use a sustainable and harmless resin, but was very dissappointed. First I ordered a sample of 1kg (the prices are quite cheap compared to other sources, and I need at least 25kg for a huge project of a dozen large scale objects), but then found out (by reading the attached datasheet) that the resin cures at a wavelength about 359nm (as spota mentioned above). It's very expensive to get a reliable light source emitting with a peak at this wavelength and ended up using a face tanner with 150Watts and an area of approx. 35x30cm (as a test light source to find out the curing speed of a layer with 0.1mm thickness). My goal was to use a DLP Projector and replace the light bulb with one of those "face burner" (500W)...
So, my tests where very frustrating: I can't get the resin cuing faster than 30 seconds (the face tanner was placed at a distance of approx 10cm, layer thickness was 0.1mm), which is an unacceptable/unusable result for 3D stereolithography printing. Now my questions are:

- Is there a way to speed up the curing by adding an additional PI (the resin is already mixed with one, no clue whatever this is, but maybe it's too less with 4%, and I felt that this is the reason for the cheap price anyhow). I wondered about this:

> As for photoinitiators, you would be interested in
> the following:
> 4,4'-Bis(diethylamino)benzophenone
> Diphenyl(2,4,6 trimethylbenzoyl)phosphine oxide
> Methybenzoylformate
> Thioxanthen-9-one
>
> Good hunting!


- Is there a way to move the photo inition peak at 359nm from UV-A towards the Near Visible Light with an additional PI? (which would decrease the costs for the light source)

- Is there someone on this forum (I really admire you guys!) who knows which light curing nature based sustainable resins might be an alternative?

Sounds very interesting. Could you guys send the detailed information to me jack.lee@uidearp.com [www.uidearp.com]

Hi mo,

I know this is fairly late. To increase cure in a UV curable resin normally you can achieve that by slightly modying to resin it self with faster curing monomers. Dpha is an example. Using PI closer to the visible spectrum will lead to an increased cost .Generally phosphine oxides will have some cure around there. So tpo bapo mapo, but bapo tends to be the more reactive. But as with everything it will take some experimentation to get it to where you want.

I have not worked with 3d printers before. But I do work for a UV curable ink company. Let me know if this was of any use to you.

Fungis

Edited 1 time(s). Last edit at 11/25/2013 01:02AM by fungis.

Hey Fungis,

My start up 'Blue One' is working on photopolymers for 3d printing. It would be great if you could help us develop them. Can we converse more privately over email?

Thanks,
Vineet

hello,Rod. I don't know what 3D Systems uses. Here is what we use for your reference - DSM Somos 14120. wavelength: 355nm.

Thank you,

Quote
fungis
Hi mo,

I know this is fairly late. To increase cure in a UV curable resin normally you can achieve that by slightly modying to resin it self with faster curing monomers. Dpha is an example. Using PI closer to the visible spectrum will lead to an increased cost .Generally phosphine oxides will have some cure around there. So tpo bapo mapo, but bapo tends to be the more reactive. But as with everything it will take some experimentation to get it to where you want.

I have not worked with 3d printers before. But I do work for a UV curable ink company. Let me know if this was of any use to you.

Fungis

Fungis, could you use non-functional resins dissolved into the UV monomer to help reduce PI requirements, by reducing the amount of monomer you need to react? Something like an acrylic bead/pellet resin?

UV curing epoxies takes quite a long time to cure, i.e. 15 30 minutes in sunlight at least. it's not compatible with printing. Careful with your eyes... uv's in dilated eyes = cataracts later.