Comment on I need to vent about plastic milk jugs
Professorozone@lemmy.world 1 week agoSo I’m simpler terms I think what you’re saying is the bottle shrinks (surface area decreases). When it does, the volume decreases too and it’s a 5:1 ratio. Correct?
I did click on the link someone posted here and the article made sense to me. Number one was structural. Which is what I would think. Number two mentioned this winter summer think but not during manufacturing ( which makes sense to me), but during shipping which still doesn’t make sense to me. What milk or even orange juice is NOT refrigerated?
SoleInvictus@lemmy.blahaj.zone 1 week ago
Bingo, you got it. It only shrinks so much in volume because there’s a ton of surface area. If it was something with less surface area in relation to volume, like a sphere, it’d be much less dramatic.
Yeah, the shipping thing doesn’t really make sense for exactly the reasons you stated. The issue is more about the temperature when the bottle is made. This is done by inflating a warm plastic tube in a mold. Cooler plastic has a bit more rebound, where it shrinks a little when the air pressure is removed. This still happens in the summer, but since the environment is a touch warmer, it shrinks just a bit less. Since a 0.5-1.0% overall change has a significant effect on the volume, you get the compensating dimple.