Finally find out why there is a hole in the middle of the plastic stool...
We often have a lot of imagination in our lives
I don't know if you noticed a detail
Whatever the shape
Plastic stools will be opened in the middle of a small hole
Do you know why
1.Convenient for storage and transportation
If you don't make a hole
An enclosed space will be formed between the upper and lower stools
The air pressure makes it difficult to pull the stool apart
It's also hard to stack stools tightly
2.The advantages of round holes
Holes with sharp corners are liable to crack under stress
And the circular hole is easy to make mold
In addition, the pore size will affect the strength of the structure
Holes too small and not conducive to finger hook
Once you know how it works
Let's take a look at some weird answers from different people
Literary youth
It is easy to open the hole like this
Molds are also cheap and save material
Ordinary youth
The stools are stacked up
Take the string through the hole and take it away easily