Zipper is a repeatable pull, pull open can mesh with each other by two flexible connector, he can be called a zip. More than one hundred years since the world’s most important one of the greatest inventions, single head closed end type, double head type, double head closed split type as the common forms of zipper. Has size chain tooth, tooth shape is different, pull head, can handle, and as a decorative. Pull head can also be insurance, when the zipper does not automatically slides open: after two zipper by pulling the role of the head, make its can be close or open is the working principle of the zipper that is to say, all kinds of matching two chain tooth belt, through the role of pull head, can close or open, when pull head to move forward, two chain tooth wear chain teeth feet by the shape of a closed cavity in the head Angle limit, got shoved, thus has the rules of engagement, each other it’s formed a zipper closure. When pull head to zipper vertices, after check on the fold is greater than the width of the width of the inner cavity is the most narrow head, and to pull up to a limit, make the head not take off from the chain, when pull the head back, because of the pull head inner cavity body column on both sides of the cylinder composed of splitting Angle (dihedral Angle) the role of the chain tooth’s front teeth with tooth valley separated one by one, make the two chain tooth belt separation. Pull the bottom of the head to the chain, because the check is greater than the width of pull on the size of the cavity mouth of the head and limit the role, make the pull head not take off from the chain.
People had the zipper voted to change the ten great inventions in the 20th century. In 1893, American engineers Judson using the concave and convex teeth malocclusion principle, design a kind of can fast sliding GuanQi system, which is early zippers. It has changed to one thousand people on the concept of traditional connection. In 1912, the Swede’s buck for invention is improved, a female condom was designed on the underside of the zipper teeth teeth, make a slide fastener more solid and beautiful. Like many new things started to like always not easily accepted by people, zipper is through the uniform blending and was well known. 1931 years later, the zipper began to widely used around the world, and its USES are also used in many other industries. Now the total length of zipper production worldwide each year more than 400000 kilometers.