Zipper


A zipper, zip, zip fastener, formerly known as a clasp locker, is a commonly used device for binding together two edges of fabric or other flexible material. Used in clothing, luggage and other bags, camping gear, and many other items, zippers come in a wide range of sizes, shapes, and colors. In 1892, Whitcomb L. Judson, an American inventor from Chicago, patented the original design from which the modern device evolved.
The zipper gets its name from a brand of rubber boots it was used on in 1923. The galoshes could be fastened with a single zip of the hand, and soon the hookless fasteners came to be called "Zippers".

Description

A zipper consists of a slider mounted on two rows of metal or plastic teeth that are designed to interlock, and thereby join the material to which the rows are attached. The slider, usually operated by hand, contains a Y-shaped channel that, by moving along the rows of teeth, meshes or separates them, depending on the direction of the slider's movement. The teeth may be individually discrete or shaped from a continuous coil, and are also referred to as elements. The word zipper is onomatopoetic, as the device makes a high-pitched zip when used.
In many jackets and similar garments, the opening is closed completely when the slider is at the top end.
Some jackets have double-separating zippers with two sliders on the tape. When the sliders are on opposite ends of the tape, the jacket is closed. If the lower slider is raised then the bottom part of the jacket may be opened to allow more comfortable sitting or bicycling. When both sliders are lowered then the zipper may be totally separated.
Bags, suitcases and other pieces of luggage also often feature two sliders on the tape: the part of the zipper between them is unfastened. When the two sliders are located next to each other, which can be at any point along the tape, the zipper is fully closed.
Zippers may:
  • increase or decrease the size of an opening to allow or restrict the passage of objects, as in the fly of trousers or in a pocket;
  • join or separate two ends or sides of a single garment, as in the front of a jacket, or on the front, back or side of a dress or skirt to facilitate dressing;
  • attach or detach a separable part of the garment to or from another, as in the conversion between trousers and shorts or the connection or disconnection of a hood and a coat;
  • attach or detach a small pouch or bag to or from a larger one. One example of this is military rucksacks, which have smaller pouches or bags attached to the sides using one or two zippers;
  • be used to decorate an item.
These variations are achieved by sewing one end of the zipper together, sewing both ends together, or allowing both ends of the zipper to fall completely apart.
A zipper costs relatively little, but if it fails, the garment may be unusable until the zipper is repaired or replaced—which can be quite difficult and expensive. Problems often lie with the zipper slider; when it becomes worn it does not properly align and join the alternating teeth. With separating zippers, the insertion pin may tear loose from the tape; the tape may even disintegrate from use. If a zipper fails, it can either jam or partially break off.

History

In 1851, Elias Howe received a patent for an "Improvement in Fastenings for Garments". He did not try seriously to market it, thus missing the recognition that he might otherwise have received. Howe's device was more like an elaborate drawstring than a true slide fastener. During this year Howe aimed to create automatic garment fasteners after his sewing machine became widely popular. Elias Howe Jr. played an important role in zipper development but he did not create the original concept of this invention.
Forty-two years later, in 1893, Whitcomb L. Judson, who invented a pneumatic street railway, patented a "Shoe-Fastening". Judson already held twelve patents for mechanical devices such as motor system improvements and railway brake innovations before the late 19th century. Judson decided to develop a new shoelace alternative which replaced the standard boot laces for men and women. Judson secured a second patent through his "clasp-locker" design on August 29th of 1893. The initial prototype functioned despite having mechanical problems that resulted in jamming occurrences. Judson along with his partner Lewis Walker had implemented the device directly into their own boots. The device served as a hook-and-eye shoe fastener. With the support of businessman Colonel Lewis Walker, Judson launched the Universal Fastener Company to manufacture the new device. Judson's "clasp locker" had its public debut at the 1893 Chicago World's Fair and met with little commercial success. He exhibited his clasp-locker at the World's Fair in Chicago of 1893 but the invention received minimal public attention. Judson is sometimes given credit as the inventor of the zipper, but his device was not used in clothing.
The Universal Fastener Company moved to Hoboken, New Jersey, in 1901, reorganized as the Fastener Manufacturing and Machine Company. Gideon Sundbäck, a Swedish-American electrical engineer, was hired to work for the company in 1906. The company moved to Meadville, Pennsylvania, where it operated for most of the 20th century under the name Talon, Inc. Sundbäck worked on improving the fastener, and, in 1909, he registered a patent in Germany. The US rights to this invention were in the name of the Meadville company, but Sundbäck retained non-U.S. rights and used these in subsequent years to set up Lightning Fastener Co. in St. Catharines, Ontario, Canada. Sundbäck's work with this firm has led to the common misperception that he was Canadian and that the zipper originated in that country. Sundbäck redesigned the Judson fastener to create a more durable design, and the zipper first went on sale in 1913.
In 1916, newspapers in Australia reported displays of the "new hookless fastener", a device from America that "the world has been waiting for" by a live model in the store window of Raynor's of Melbourne.
Sundbäck increased the number of fastening elements from four per inch to ten or eleven, introduced two facing rows of teeth that pulled into a single piece by the slider and increased the opening for the teeth guided by the slider. The patent for the "Separable Fastener" was issued in 1917. Gideon Sundbäck also created the manufacturing machine for the new device. The "S-L" or "strapless" machine took a special Y-shaped wire and cut scoops from it, then punched the scoop dimple and nib, and clamped each scoop on a cloth tape to produce a continuous zipper chain. Within the first year of operation, Sundbäck's machinery was producing a few hundred feet of fastener per day. In March of the same year, Mathieu Burri, a Swiss inventor, improved the design by adding a lock-in system attached to the last teeth, but his version never got into production due to conflicting patents.
In 1923, during a trip to Europe, Sundbäck sold his European rights to Martin Othmar Winterhalter, who improved the design by using ribs and grooves instead of Sundbäck's joints and jaws and started producing with his company Riri on a large scale first in Germany, then in Switzerland.
The popular North American term zipper came from the B. F. Goodrich Company in 1923. The company used Gideon Sundbäck's fastener on a new type of rubber boots and referred to it as the zipper, and the name stuck. The two chief uses of the zipper in its early years were for closing boots and tobacco pouches. Zippers began being used for clothing in 1925 by Schott NYC on leather jackets.
In the 1930s, a sales campaign began for children's clothing featuring zippers. The campaign praised zippers for promoting self-reliance in young children by making it possible for them to dress themselves. The zipper beat the button in 1937 in the "Battle of the Fly", after French fashion designers raved over zippers in men's trousers. A Talon advertisement in the first Esquire magazine declared the zipper the "Newest Tailoring Idea for Men", and that among the zippered fly's many virtues was that it would exclude "The Possibility of Unintentional and Embarrassing Disarray."
A later innovation in the zipper's design was the introduction of models that could open on both ends, as on jackets. The zipper has become by far the most widespread fastener, and is used on clothing, luggage, leather goods, and various other objects.

Types

  • Coil zippers now form the bulk of sales of zippers worldwide. The slider runs on two coils on each side; the teeth are formed by the windings of 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. Coil zippers are made of polyester coil and are thus also termed polyester zippers. Nylon was formerly used to make them, and though only polyester is used now, the type is still also termed a nylon zipper.
  • Invisible zippers have the teeth hidden behind a tape, so that the zipper is invisible. It is also called the concealed zipper. The tape's color matches the garment's, as does the slider's and the puller's. This kind of a zipper is common in skirts and dresses. Invisible zippers are usually coil zippers. They are also seeing increased use by the military and emergency services because the appearance of a button down shirt can be maintained while providing a quick and easy fastening system. A regular invisible zipper uses a lighter lace-like fabric on the zipper tape, instead of the common heavier woven fabric on other zippers.
  • Reverse coil zippers are a variation of the coil zipper. In a reverse coil zipper, the coil is on the reverse side of the zipper and the slider works on the flat side of the zipper. Unlike an invisible zipper where the coil is also on the back, the reverse coil shows stitching on the front side and the slider accommodates a variety of pulls. Water resistant zippers are generally configured as reverse coil so that the PVC coating can cover the stitching. A rubber- or PVC-coated reverse zipper is called a waterproof zipper.
  • Metal zippers are the classic zipper type, found mostly in jeans and pencil cases today. The teeth are not a coil, but are instead individual pieces of metal molded into shape and set on the zipper tape at regular intervals. Metal zippers are made with brass, aluminium and nickel. YKK pioneered development of the 56S aluminum alloy during 1958 even though specialist Japanese manufacturers failed to achieve it. The new metal material development brought forth substantial technological progress for zipper manufacturing. The product development of concealed zippers led YKK both in international market penetration of this product line as well as opening opportunities for aluminum architectural products sales. All these zippers are basically made from flat wire. A special type of metal zipper is made from pre-formed wire, usually brass, but sometimes other metals, too. Only a few companies in the world have this technology. This type of pre-formed metal zipper is mainly used in high grade jeans-wear, work-wear, etc., where high strength is required and zippers need to withstand tough washing.
  • 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 thermoplastic polymers are used as well, such as polyethylene. Used most popularly for pencil cases, small plastic pouches and other stationery.
  • 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 described types.
  • Two way open-ended zippers have a puller on each end of the zipper tape instead of having an insertion pin and pin box at the bottom. Someone wearing a garment with this kind of zipper can slide up the bottom puller to accommodate more leg movement without stressing the pin and box of a one-way open-ended zipper. It is most commonly used on long coats.
  • Two way closed-ended zippers are closed at both ends; they are often used in luggage and can have either one or two pullers on the zipper.
  • Magnetic zippers allow for one-handed closure and are used in sportswear.