Liukujakapparit

Liukujakapparit, also known as slide fasteners or zippers, are a common fastening device for clothing and bags. They consist of two rows of interlocking metal or plastic teeth that are joined or separated by a slider. The slider, when moved along the teeth, interlocks or disengages them. The basic design of a zipper has remained relatively unchanged since its invention, though variations in materials and styles exist.

The earliest form of a zipper was patented by Elias Howe in 1851, but it did not resemble the modern zipper. Whitcomb L. Judson is credited with developing a practical version in 1893, which was initially used for boots. The zipper as we know it today was further developed by Gideon Sundback, who improved Judson's design and patented a more robust and reliable version in 1917. The term "zipper" itself was coined by B.F. Goodrich in 1923 for their use on rubber boots.

Zippers are composed of several key components: the tape, which is the fabric strip onto which the teeth are attached; the teeth, which interlock to form the closure; and the slider, which moves along the teeth to open or close the fastener. The slider often has a pull tab for ease of use. Different types of zippers include coil zippers, plastic molded zippers, and metal zippers, each offering distinct advantages in terms of durability, flexibility, and appearance. They are widely used in apparel, luggage, tents, and many other products requiring a reliable and adjustable closure.