Jamie Hascall 11/11/16

I received a query from a fellow mountmaker as to whether the plastic PLA (Polylactic Acid) has ever been Oddy tested? PLA is one of the various plastics that are used in 3D printing, but is probably better known to most people as the plastic that biodegradable tableware is made of. https://en.wikipedia.org/wiki/Polylactic_acid Any information would be appreciated. Thanks, Jamie  Jamie Hascall Craftsman, Trainer, Consultant Mountmakingfocus.com jamie@mountmakingfocus.com Seattle, WA 206-954-4141

Philip Brutz 11/11/16

Is it going to biodegrade in our cases?  What is life expectancy before it degrades? Philip Brutz Mount Maker Cleveland Museum of Art

Ralph Walter

11/14/16

Here is a link to a short article that may be helpful.  Apparently the biodegrading process doesn’t begin until certain conditions are met.  I’d say that whilst in the museum environment it isn’t likely to progress very far if at all. 

Ralph Walter

Preparator – Mountmaker

EMP Museum

Seattle

empmuseum.org

Jamie Hascall 11/14/16

If you've got "bio" in your cases, I think you may have other problems... Jamie

Pamela Gaible 11/15/16

Hi Jamie, This is from one of the conservators here at the Field Museum. PLA is biodegradable in an industrial hot compost (90°C or higher), but as a practical matter it doesn't biodegrade below 55°C. 

We Oddy tested PLA. I can't find a record of the color tested, but it was probably white or natural since those are the only colors we've bought. It failed pretty hard, but this might be because the test is conducted at 60°C (i.e., at the temperature where it starts to decompose). Best, Pam

Jamie Hascall 11/15/16

Hi Pam,  Thanks for sharing your results. It looks like this material may need to be tested in a more “real world” manner to get a more unambiguous result. Sadly, that won’t provide answers quickly and by the time that the results feel firm, the formulation may have changed. Such is the hunt for new materials. Thanks, Jamie