Zipper
A zipper (zip fastener or zip in British English) is a device for temporarily joining two edges of fabric together. It is widely used in clothing, bags and suitcases, purses, tents, sleeping bags and other textiles.
Alternatives that are also frequently used are buttons, Velcro, laces, buckles, and safety pins.
Description
The bulk of a zip consists of two strips of fabric tape, one permanently fixed to each of the two flaps to be joined, and each carrying tens or hundreds of specially shaped metal or plastic teeth. Another part, the slider, which is operated by hand, rides up and down the two sets of teeth. Inside the slider is a Y-shaped channel that pushes the opposing sets of teeth together or apart, depending on the slider's direction of travel. The friction of the slider against the teeth causes a characteristic buzzing noise which is probably the origin of the name zip.
Some zips have slides on both sides, allowing one to vary not only the size, but also the position of the opening.
Applications of zips in clothing:
- to connect and disconnect the left and right front side (usually fitted vertically so that pushing the slider from top to bottom opens it, and pushing it from bottom to top closes it)
- to widen an opening to allow the garment to be put on / taken off:
- to open and close pockets
- for attaching/detaching a hood and legs of trousers
- for decoration
Zippers cost only a fraction of the total cost of the garment. However, if the zipper fails, the whole garment is wasted. Therefore, it is very important to choose a very good quality zipper, even if it costs a few cents more.
History
An early device similar to the zip, 'an Automatic, Continuous Clothing Closure', was patented in the USA by Elias Howe in 1851, but did not reach the market. Whitcomb L. Judson patented a similar 'Clasp Locker', for fastening shoes, in 1891 or 1893, and marketed the invention through his 'Universal Fastener' company. These two designs used hooks and eyes. The design used today, based on interlocking teeth, was invented by an employee of Judson's, Swedish scientist Gideon Sundback, in 1913 as the 'Hookless Fastener' and patented in 1917 as the 'Separable Fastener'. The B. F. Goodrich Company coined the name 'Zipper' in 1923, and used the device on tobacco pouches and boots. The zip became popular for children's clothing and men's trousers in the 1920s and 1930s. At this stage, the zip was permanently joined at one end, so could not be used to fasten jackets. Whitcomb died in 1956.
Today,
leading global companies like the YKK (YKK_Group) and The Tex Zipper
Corp (Tex_zippers) make a variety
of different zippers such as Invisible Zippers, Metallic Zippers and Plastic Zippers.
Types of Zippers
- Coil: These zippers form the bulk of the sales of zippers world-wide - the classic zipper. If you look closely at these zippers, you will notice that the slider runs on two coils on each side. The "teeth" on this zipper are coils.
- Invisible Zippers: The teeth of this zipper are behind the tape. The tape is dyed to match the color of the garment, and so is the slider, so the zipper is "invisible", except for the slider. This kind of a zipper is most common in women's skirts. Invisible zippers are usually coil zippers
- Metallic Zippers: These zippers are the zippers we see in jeans today. The teeth are not a coil - they are individual pieces of metal moulded into shape and set on the zipper tape at precise uniform intervals.
- Plastic Moulded: These zippers are just like metallic zippers - but the teeth are plastic instead of metal. This is because the plastic can be dyed to the color of the garment - and looks natural. This is usually seen in jackets and backpacks.
- Open Ended Zippers: These zippers use a "box and pin" mechanism to lock the two side of the zipper into place. Open Ended Zippers can be of any of the above specified types
- Closed Ended Zippers: Conventional zippers which are closed at both ends
Bibliography
- an history of the evolution of zipper design can be found in: Henry Petroski, The Evolution of Useful things (1992); ISBN 0679740392
External links
Patents
- U.S. Patent 8540 -- Fastening for garments & c
- U.S. Patent 504037 -- Shoe fastening
- U.S. Patent 504038 -- Clasp locker or unlocker for shoes
- U.S. Patent 1060378 -- Separable fastener
- U.S. Patent 1219881 -- Separable fastener