Editing Perforation (section)

{{Short description|(Making) a small hole in a thin material}}
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{{More citations needed|date=May 2010}}
[[File:Perforations US1940 issues-2c.jpg|right|thumb|300px|A partial image of a sheet of [[US Postage]] [[Postage stamp|stamps]], 1940 issue, featuring perforations]]

A '''perforation''' is a small hole in a thin material or web. There is usually more than one perforation in an organized fashion, where all of the holes collectively are called a ''perforation''. The process of creating perforations is called '''perforating''', which involves removing bits of the workpiece with a [[tool]]. Old-fashioned lick-and-stick postage stamps are perforated. When a tool makes small cuts in the material (without removing anything) it is called 'rouletting', because that tool often resembles a roulette wheel, with blades around the edge. Raffle tickets are a good example of rouletting.

Perforations are usually used to allow easy separation of two sections of the material, such as allowing [[paper]] to be torn easily along the line. [[Packaging]] with perforations in [[paperboard]] or plastic film is easy for consumers to open.   Other purposes include filtrating fluids, sound deadening, allowing light or fluids to pass through, and to create an aesthetic design.<ref name="todd">{{Citation | first1 = Robert H. | last1 = Todd | first2 = Dell K. | last2 = Allen | first3 = Leo | last3 = Alting | year = 1994 | title = Manufacturing Processes Reference Guide | publisher = Industrial Press Inc. | pages = 103–104 | url = https://books.google.com/books?id=6x1smAf_PAcC | isbn = 0-8311-3049-0 | postscript =.}}</ref>

Various applications include [[plastic film]]s to allow the packages to breathe, medical films, [[micro perforated plate]] and [[sound]] and [[vapor]] barriers.