[Johnm]

Greetings to everyone who decided to click on my topic.

First I'd like to state what I'm trying to achieve with my experiment. Right now I'm developing a selective laser sintering (SLS) 3d printer. As far as hardware goes, I know how i'm going to use the laser to sinter the ABS plastic. The problem that I'm running into right now is access to a finely ground ABS powder. The benefit of having a fine ABS powder is the higher resolutions prints your capable of producing. The finer the material, the higher the resolution...

So I've addressed the problem, producing a powder form of ABS. But how does one go about doing this? I thought about grinding it down with the use of ball mills but it wouldn't produce a fine enough mixture. I read online that you could dissolve ABS in acetone, because they are both polar. Then with the ABS/Acetone solution, extract the ABS by mixing it with water and boiling away the acetone. Would this method work? Would I disrupt or break apart the polymer's in the ABS?

If this method is complete garbage, could someone please shed some light on my with possible solutions?

Thank You
Anthony G

[billnotgatez]

I assume ABS is
Acrylonitrile Butadiene Styrene ABS
http://www.dynalabcorp.com/technical_info_abs.asp
http://en.wikipedia.org/wiki/Acrylonitrile_butadiene_styrene

Is this link the source for your idea

http://www.3dreplicators.com/cgi-bin/cblog/index.php?/archives/488-Chemically-grinding-ABS-scrap.html

[Johnm]

Yes. Actually, its not my idea, but that's where I found the idea.

[Johnm]

I've decided to try some experiments my self and gather some data from it. I'll post my information and maybe some pictures within a week. Hopefully then you guys can tell me exactly what I've produced from my experiment. Unless someone already knows exactly what will happen...

[billnotgatez]

Thank you

[fledarmus]

I read the link Billnotgatez posted, and it certainly looks like it worked for him. It would be nice to do some testing to see whether the undissolved material he reports is different from the dissolved material or from the bulk polymer. Polymers are not single chemical compounds - they are complex mixtures of extremely large molecules with molecular weights that usually range between 10,000 and 1,000,000. Different processes for making the compounds can give different mixtures of molecular weights and different properties to the finished material.

If your source ABS material is acetone soluble, you may be able to get a nice fine powder without using water by simply spray-drying it: spraying a solution of ABS in acetone through a hot atmosphere. On a large enough scale, you can collect the exhaust gases and condense and reuse your acetone.

[Johnm]

Thanks for the reply fledarmus.

Have you ever heard of anyone building a spray dryer for small experiments? I did some research on spray drying and I couldn't find anyone who made their own spray dryer. I guess it wouldn't be to complicated to make... I just have to get my hands on a nozzle to spray the liquid.

[fledarmus]

We did some types of spray drying just with an air-compressor, a paint sprayer, and one of those electric space heaters that worked like a blow dryer. We built a duct for the hot air with a big collection box at one end and sprayed the solution down the duct. The dry powder settled out in the collection box. If you're using something highly flammable and volatile like acetone, however, I would recommend just using a powerful fan rather than a heater unless you have really good techniques for isolating the heating coils from the solvent vapors.

I don't know how this would work for ABS - we did spend a lot of time cleaning up the paint sprayer nozzles.

[billnotgatez]

If you do something like fledarmus suggested -
Do it outside
far away from buildings and flammable stuff
have safety gear on hand like a fire extinguisher
stay as far away from the process as possible


be safe as you can

On the other hand the water method in the link I provided may be the safer way to go as long as you not breathing fumes. Again a hood or outside far away so as not to effect others is probably called for

[Johnm]

So I just did some tests and I am extremely pleased with the results. This sample was produced using the spray drying method, not the water extraction method.

[billnotgatez]

Did you expect it to be this dark a color