How do zippers work?


For as long I can remember, I’ve been fascinated by the mechanics of zippers. They are probably quite simple but it’s interesting nonetheless and I want to know how they work.

In: Physics

Organized tangles is how I’ve heard it described. The tracks are malleable and have 2 positions that are forced to change shape by the little car that runs along them, basically making the tracks ‘tangled’ and untangled in an orderly way

Poached from an article…

A zipper track is made up of dozens of teeth, each of which combines a hook and a hollow. The idea is to latch every hook on each of the two tracks into a hollow on the opposite track. The latching mechanism, called the slide, is just a collection of wedges. You can see how this system works in the diagram below.

As the slide moves up the zipper, the two teeth strips must enter at a specific angle. As the strips move through the slide, the slide’s inclined edges push the teeth toward each other. The strips are offset from each other, so each hollow settles onto a hook in sequence. For this to work properly, each tooth must be exactly the same size and shape, and they all must be perfectly positioned on the track. This would be all but impossible without modern manufacturing technology.