Comment on More microplastics in glass bottles than plastic: study
Teal@lemmy.zip 4 days ago
They say the glass bottles have plastic caps and that’s the source for this type of container. I can’t understand why those same caps on plastic bottles have less contamination.
Are the caps lined differently on the inside when dealing with plastic or glass?
My guess is the shape of the cap, and maybe even a bit to do with the material (ime pop-off caps are a weaker plastic to allow them to deform around the bottle lip). Screw top plastic bottles have deeper caps than pop-off glass bottle caps.
Thus when stored the inside surface of the pop-off cap has more chance to rub against other surfaces and create plastic dust, and being a weaker plastic it may gouge more easily as well.
Maybe the plastic of the bottle flexes more, whereas glass doesn’t move, so the cap scrapes against it more.
stink@lemmygrad.ml 2 days ago
Reading through it, I assumed that the glass bottles have metal caps, with plastic paint?
It makes sense to me, sorta.
Inside of the cap has a plastic coating to deter corrosion from the acidic drink. And I’m assuming that on the assembly line the caps are face-down, so the metal from the top of one cap is scraping the plastic on the bottom of the other cap. Then it leeches into the drink over time?