Imagine a strong zipper that doesn't break easily. It's hard to pull apart, right? But did you know how strong zippers are? They were invented by Gideon Sundback in the 1910s. He created a machine to make zippers using Y-shaped metal wire. The machine cuts the wire into small pieces, then presses down on them to make an indent and a bump. Finally, it clamps the two arms of each Y-shaped piece onto fabric. These zippers are very strong because it's hard for the teeth to become unpaired. But there is one way for a zipper to break: if you put a pen between the teeth, you can create an opening. So, don't rely too much on zipper locks on suitcases.
The machine that makes zippers is very clever. It takes Y-shaped metal wire as an input and cuts it into small pieces. Then, it presses down on these pieces to make an indent on one side and a bump on the other. This makes the zipper very strong. But, if you put a pen between the teeth, you can create an opening in the zipper. This is because the machine spaces the teeth so precisely that there's no room for the teeth to become unpaired.
So, the next time you use a zipper, remember how strong it is. But don't rely too much on zipper locks on suitcases. They might not be as reliable as you think.
