You’ve seen it a thousand times—that mysterious circular dent on the side of plastic milk jugs. But have you ever wondered why it’s there?
Turns out, it’s not just a random design quirk. That little indentation actually serves three genius purposes—and once you know them, you’ll never look at milk cartons the same way again!
1. Structural Stability: Preventing the “Milk Jug Bulge”
Ever notice how milk jugs don’t balloon out when sealed? That dent is the reason!
. Prevents Expansion – When milk is packaged, hot liquid is poured in, then cools and contracts. Without the dent, the jug would warp inward and become unstable.
. Reinforces the Jug – The circular shape distributes pressure evenly, keeping the container rigid and preventing leaks or cracks.
2. Safety Feature: A Built-In “Overfill” Indicator
That dent isn’t just for structure—it’s also a clever manufacturing trick!
How It Works:
Read more on next page
You’ve seen it a thousand times—that mysterious circular dent on the side of plastic milk jugs. But have you ever wondered why it’s there?
Turns out, it’s not just a random design quirk. That little indentation actually serves three genius purposes—and once you know them, you’ll never look at milk cartons the same way again!
1. Structural Stability: Preventing the “Milk Jug Bulge”
Ever notice how milk jugs don’t balloon out when sealed? That dent is the reason!
. Prevents Expansion – When milk is packaged, hot liquid is poured in, then cools and contracts. Without the dent, the jug would warp inward and become unstable.
. Reinforces the Jug – The circular shape distributes pressure evenly, keeping the container rigid and preventing leaks or cracks.
2. Safety Feature: A Built-In “Overfill” Indicator
That dent isn’t just for structure—it’s also a clever manufacturing trick!
How It Works:
Read more on next page
