Comment on I need to vent about plastic milk jugs
RattlerSix@lemmy.world 3 days agoI knew the OP couldn’t be right because how do you add a dimple after the jug is full?
But I’m not sure ambient air temperature during molding is the whole story either, although I expect that is a concern that is taken into consideration and the article below leaves it out.
The article says “*The high-density polyethylene plastic jugs are made of shrinks slightly over time. It also shrinks more in hot temperatures than cold temperatures…
Producers must make jugs slightly larger to offset inevitable shrinkage if they are exposed to summer heat in transport and/or go to long-term storage before being filled, but they want to keep the jugs smaller in cold months and if jugs go directly to be filled.*”
It’s saying the dimple is to adjust the size of the jug depending on what shrinkage it’s likely to see before being filled. So you can presumably have small dimples in summer if they go directly to be filled, and large dimples in winter if they’re going to be transported and stored first.