Related information:

1, Inventing Zipper: 1893, an American engineer named Judson developed a "sliding locking device" and obtained a patent, which is the initial prototype of zipper. 19 13 years, Sambak, Sweden improved this rough locking device and made it a reliable commodity. The method he adopted was to connect the metal lock teeth to a flexible shaft.

2. Classification of zippers: According to materials, it can be divided into: metal zippers; Resin zipper; Nylon zipper, etc. According to the common number of teeth, it can be divided into: No.3, No.5, No.8 and 10. According to the types of zippers, it can be divided into: invisible zippers; Zip; Zipper closed; Double zipper, etc.

3. Working principle of zipper: Generally, it is explained by the principle of resultant force and component force. When unzipping, a triangular object moves between two chains with the zipper, and the pulling force of the hand produces two components on the triangular object. When the included angle is small, the force acting on the sharp corner is large.

Two components act on the zipper, and the component force is greater than the vertical downward resultant force, that is, the component force is greater than the hand pull, so zippers that are difficult to separate directly are easily separated by triangles. Zipper consists of components, sliders, upper and lower blocks (front code and back code) or locking pieces. The zipper teeth are the key parts, which directly determine the lateral tensile strength of the zipper.