I made some coasters using different colors of TPU filament, including some with fluorescent yellow. I had a bottle of olive oil sitting on one of the coasters on the counter next to my stove. I was cleaning and discovered that the oil bottle had some dribbles going down the side and ultimately into the coaster (that’s why I used a coaster). When I moved the coaster to wipe the counter top, I found that the oil had leached some of the fluorescent dye out of the TPU filament onto the counter top.
It’s probably not a good idea to have fluorescent filaments in contact with food, especially if the food is oily.
Agree. Also, the nature of FDM printing creates little crevices for bacteria to thrive regardless of material. If you want to 3D print things for use around food then go resin printing. It won’t solve the “what chemical is near my food” problem, but it would eliminate the tiny crevices (aka layer lines).
OP’s issue seems to be entirely orthogonal to food, it doesn’t make sense for this thread to continue in that direction, it’s been rehashed elsewhere in other threads, go there instead if you want to continue and have a discussion about it with people interested in arguing the subject.
OP discovered solvents can leach the dye out of his filament, that’s it, full stop. He didn’t say that his filament was in contact with food that was going to be consumed, it was food that was spilled on the counter.
If he is actually saying “don’t make food handling things out of special filament XYZ” (which I trust he isn’t, because that would be absurd, you don’t make food handling things out of ANY filament unless they are certified safe) then this thread should be merged with the others and he can be eviscerated there.
This is perhaps a great segue into the [stated] reasoning behind PLA pure [not an ad, but lol]
The PLA is fairly well understood in how it behaves. The additives/colorants are the ones that need vetting, since every mfr is kinda free to just put in whatever soluble, poisonous, radioactive, or heavy metal stuff they need to shove in to create that color/opacity. Youre kidding yourself if you think there’s any regulations or periodic testing.
I wonder if it was just the oil that caused the leach or a combination with the hot environment near the stove? At least at my house that area does get more than warm. If you get curious you could make a science project of it and try different cooking oils, even plain water and test in areas away from the stove. And maybe test a coaster with nothing on it near the stove to see if it leaches without interacting with another substance.
People make gaskets and plugs (from TPU), some associated with gasoline and shoes which come in contact with who knows what from the outside or things like lotions from the inside so it seems like it is normally pretty stable stuff (I know there are different hardnesses) so it makes me think any issue probably comes back to the dye itself.
My point was about mixing oil and TPU filament. If the dye leaches out, what else might be leaching out?
With regards to printing and food contact, I don’t know if it’s worse than any other plastic in contact with food (except for the layer lines providing places for bacteria to grow unchecked). A lot of the food I buy at the store comes in plastic packaging, and a lot of cooking utensils are plastic. I’ve never seen any safety reports on those plastics except for the occasional article about xenoestrogens, carcinogens, and microplastics from plastic food containers, wrap, and utensils. Unfortunately, no governments seem to require safety testing and labeling of plastics used for those purposes.
ANY plastic in contact with food is possibly unhealthy. Are printed plastics any more unhealthy than those other types?
Oil is just another solvent, ideally all the non-PLA/TPU/PETG molecules are not soluble in anything common. But we live in reality Some ebay-grade chinese silkpla I bought a while ago had a color that would run if wiped with isopropyl. Most mfrs do not share their secret sauce so Im just gonna assume it was lead [or worse].
The good news is that [ugh i sound like a bambu shill] the bambu pla pure is really well priced. In the past, filament with an independantly provable tested recipe was always in the $40-50+ range. Maybe there will be more expanded to petg/tpu/asa in the future.
Some ebay-grade chinese silkpla I bought a while ago had a color that would run if wiped with isopropyl. Most mfrs do not share their secret sauce so Im just gonna assume it was lead [or worse].