The Latest on Resins?

[Dave Cowden]

Hey, everyone:

I've just spent a couple of hours reading about resin formulations ( Fang, etc)-- unfortunately it is hard to get an idea of what the current 'state' of the resin situation is. Things have moved so fast in the last 4 months of posts!

What is the current situation?  I see a lot of references to bucktown -- are they making resins at a reasonable price that work ?  And, are there any vendors who will make the Fang composition yet? 

Sorry, not trying to be lazy, but its hard to get an idea of just what the 'latest news' is coming to the part late...

thanks!

[Hradec]

Me and TJ have being focusing mostly on hardware and software lately, and not much on resin composition. 

Our first manual test was done using the original recipe from here: https://nano-cemms.illinois.edu/materials/3d_printing_full

TJ did the mixing and testing, so he can give you better details on the final recipe he used. 

I want to try the solarez UV epoxy as soon as I can, since they sell a liter for just $25 bucks!! it's the cheapest one! 

I have being following bucktown, but I didn't see anyone test with it. 

3DLPrint did some suscessfull tests and played a lot with resin and dye recipes... check it out on his website!

Not sure what you mean with "Fang composition"... Didn't see that yet... could you point me out to it?

my 2 cents...
-H
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[Dave Cowden]

Hi there:

sorry the 'Fang composition' is the same as the link you sent-- referencing  Professor Nicholas Fang who heads that project. I have an email into bucktown to understand their pricing but no word back yet.

Does the one you linked to work pretty well? i have to assume it is less than ideal if you are trying another one?

[Shane Graber]

I was under the understanding that the general public were not able to obtain the required chemicals. Has Cytec and others begun selling to the individual?

--
Shane 

[Dave Cowden]

I have a buddy who is a chemical engineer-- he is connected into how to get the various chemicals. 

If you guys would be interested, i will contact him, give him the recipe, and see if he could advise on if it is feasible to mix. I'll also ask him whether he could help us experiment with different recipes to find what works best for this machine. Would that be helpful and of interest?

Dave

[Hradec]

sorry the 'Fang composition' is the same as the link you sent-- referencing  Professor Nicholas Fang who heads that project.

Hooo.. ok then!! LOL

[Hradec]

On Tue, Apr 10, 2012 at 6:07 AM, Shane Graber <sgr...@gmail.com> wrote:

I was under the understanding that the general public were not able to obtain the required chemicals. Has Cytec and others begun selling to the individual?

If you own a company, even being a small non-chemical company you can buy then.

Also, you can contact some Chinese chemical companies... they will send you samples for free! ;)

-H
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[Hradec]

On Tue, Apr 10, 2012 at 8:57 AM, Dave Cowden <dave....@gmail.com> wrote:

I have a buddy who is a chemical engineer-- he is connected into how to get the various chemicals. 

If you guys would be interested, i will contact him, give him the recipe, and see if he could advise on if it is feasible to mix. I'll also ask him whether he could help us experiment with different recipes to find what works best for this machine. Would that be helpful and of interest?

That would be great, Dave.. thanks for the offer!!

-H

[Shane Graber]

I worked as a UV chemist for ~15 yrs, which is why I ask.  ;)

Based on the simplicity of the recipe, it's completely feasible to mix. All of the components are miscible in one another. I am a bit surprised by the high level of Irgacure 819 as typical concentrations are more around 0.5% as a starting point.  Sudan 1 is not all that expensive and neither is the acrylate monomer they recommended. The photoinitiator (in this case Irgacure 819) is expensive so optimizing its concentration is of utmost importance from a costing aspect.

I will caution that these are "chemicals" and as such require proper PPE (glove, goggles, etc). While the acrylates that are being used to formulate these mixes aren't toxic per-se, they can and will cause one to be sensitized (contact dermatitis, etc) if you keep it on your skin too long. In this case, hydrocortizone creams are your friend.  Also if you get samples in you are required to dispose of them properly.

In regards to free Chinese samples:  obtaining the acrylates probably won't be an issue. Obtaining Irgacure 819, however, will be as I believe it is still on patent by Ciba meaning you won't find it from other sources.  A potential replacement would be TPO or TPO-L which are both off patent and everyone has their own version of it now.

Shane

--
Shane 

[Dave Cowden]

Sure i will get on it.  I am fairly new to the DLP area-- can confirm that I have the following correct:

  * we want a resin that is as tough as possible, generally speaking. do we prefer polyester, epoxy, or other formulations specfiically?
  * we need curing to occur between about 350 and 400 nm-- ideally about 385 ( what type of bulb does the viewsonic projector u guys are using have? )
  * tintability is ideal, so that we can choose colors
  * lower viscosity is better.  Do we need the ability to modify viscosity, or do we plan to heat the vat when we'd like to reduce viscosity? Do we know what viscosity we want? ( in cps i mean )?
  * curing time must be low as possible, but must be able to sit in indoor light for at least 4 hours without curing

Can you help me with the specs-- the more information i have the better. 

On Tuesday, April 10, 2012 12:16:35 PM UTC-4, Hradec wrote: