It was said that the zippers could not bear the ignorance of the human kind for a centurary any more. They themselves wanna to heroes of public focus. A revenge war of the zippers started ... ---------------------------------------------- What is a zipper? Device for binding the edges of an opening, as on a garment or a bag. A zipper consists of two strips of material with metal or plastic teeth along the edges, and a sliding piece that interlocks the teeth when moved in one direction and separates them again when moved in the opposite direction. The idea of a slide fastener was first exhibited by Whitcomb L. Judson (died 1909) at the World's Columbian Exposition of 1893. The modern form of the zipper began to appear on clothing in the late 1920s. * Plastic-molded zippers are identical to metallic zippers, except that the teeth are plastic instead of metal. Metal zippers can be painted to match the surrounding fabric, plastic zippers can be made in any color of plastic. Plastic zippers mostly use polyacetal resin though other resins are used too like polyethylene. * Open-ended zippers use a "box and pin" mechanism to lock the two sides of the zipper into place, often in jackets. Open-ended zippers can be of any of the above specified types. * Closed-ended zippers are closed at both ends; they are often used in baggage. * Invisible zippers' teeth are behind the tape. The tape's color matches the garment's, as does the slider, so that, except the slider, the zipper is "invisible". This kind of a zipper is common in skirts and dresses. Invisible zippers are usually coil zippers or to be precise polyester zipper. * Metallic zippers are the classic zipper type, found mostly in jeans today. The teeth are not a coil, but are individual pieces of metal moulded into shape and set on the zipper tape at regular intervals. Coil zippers now form the bulk of sales of zippers world-wide. The slider runs on two coils on each side; the "teeth" are the coils. Two basic types of coils are used: one with coils in spiral form, usually with a cord running inside the coils; the other with coils in ladder form, also called the Ruhrmann type. This second type is now used only in a few parts of the world, mainly in South Asia.