I want to make a shaker top for a mason jar–a super simple project, just a plastic circle with a bunch of other circles cut out of it. I’ll prototype in cardstock but once I have a design I like, I would like to make final versions out of food-grade plastic.
I would think, unless your putting large pieces of rock salt and then shaking the crap out of it, acrylic would work just fine. Yes, it can be a little brittle, but not that brittle if you’re worried about it you could always anneal it in the oven first.
You can also anneal acrylic after it has been processed. It does relieve some of the stresses that accumulate and makes the smaller piece a bit less prone to cracking. I did if for a slump bowl with lots of cutouts and it has held up fairly well as a bread basket.
Yes, the 1/8" acrylic might be a bit too thick for being held by the standard ring. Mmm. That makes me think of something. I’ve been wanting to 3D print a cover for a standard mason jar just because. I use them all the time and with the lids separate the seem to always fall out and roll away when I open a lid that is storing beans or rice or whatever. Could do a custom ring that would have extra head space for the acrylic shaker screen.
One of my fave materials is PETG, which is the plastic used in soda bottles, so I know it’s foodsafe. It’s laser-able (and vacuum formable, if you wish). It’s reasonably durable at very thin sheets (I use .02" pretty frequently) but it also comes in a wide variety of thicknesses.
PETG might be a winner. It’s already on my wish list for some other projects.
Guess my next step is figuring out how thick the disc can be before it won’t work with the regular ring.
(I don’t necessarily need virgin USDA approved materials for my own use, especially for something used infrequently, and not at high temperatures… but if these turn out well and I want to give them away or sell a pack, then it would be important.)