Thursday 19 April 2012

More trifurcated PLA

I repeated the PLA in acetone experiment with red PLA and pure acetone. Same result, trifurcation after a few minutes:


Here is what happens to an object:


These were identical PLA clothes-pegs, one was dipped in acetone for a few minutes.  It fell apart when I tried to pick it out with tongs.

A bit of Googling reveals acetone causes PLA (which is normally amorphous) to become crystalline. That explains why it loses its transparency I think. It also becomes rubbery and crumbly.

Not a very useful result, but it does show that acetone would not be any good for cleaning out a hot end filled with PLA. Also I think people have suggested you could use ABS as support for PLA and dissolve it out with acetone but that plainly will not work either. The opposite works, dissolving the PLA with an alkali.

3 comments:

  1. I've got to laugh because I had just tried dissolving some PLA filament in acetone, with the same results.
    I'd be interested in any solvents you come across that can dissolve PLA.
    I did have some sucess with Plastruct Plastic Weld, but I'm not sure what the active solvent is.
    I'd like to try MEK, but it's no longer for sale in California. The local big-box hardware stores have a MEK substitute, but it appears to have no affect on PLA.

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  2. I have some MEK so I will try that next.

    I heard a rumour that isopropyl dissolves PLA slowly, so I can try that as well.

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  3. This may explain why I had so much difficulty when I tried using acetone to clean out a nozzle a few months back, which I had been changing between ABS and PLA on. :$ I really ought to scrape some money together for a second nozzle.

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