Comment on I need to vent about plastic milk jugs
Spaceballstheusername@lemmy.world 3 weeks ago
I always thought it was to help prevent it exploding if dropped. I’ve dropped a gallon a couple times and the dimple pops out and the lid stays on. Kinda like an air bag.
The_v@lemmy.world 3 weeks ago
It adds flex to the container for variations of atmospheric pressure. It’s what they mean by the fill levels.
Milk containers are filled by weight. The exact volume of the liquid can vary slightly based upon the atmospheric pressure.
If the container has no flex the top will pop off or the sides will crush in with pressure changes say when a truck drives over a mountain pass to deliver the milk.