When the zipper is opened, the triangular object moves together with the zipper between the two chains. The pulling force of the hand produces two component forces on the triangular object. When the included angle is small, the force acting on the sharp corner is very large. Two components of force exert force on the zipper and the component force is greater than the resultant vertical downward force, that is, the component force is greater than the pulling force of the hand, so the zipper that is difficult to be separated directly is easily separated by the triangle.

1. There are different sizes and shapes of teeth, but the teeth on the left and right sides of the same zipper must be the same size. The shape of the zipper head is varied and can be used as both a handle and a decorative zipper head.

The working principle of the zipper is very simple, that is, the two zipper tapes can be pulled or opened at will through the action of the slider, or locked and opened at will.

2. The working principle of the chain teeth is that each tooth is a small hook, which can be matched with the eyelet under a small tooth on the other cloth belt that is next to and opposite. The zipper is so strong that it can only be opened when the slider slides to open the teeth.