Êtes-vous un étudiant de l'EPFL à la recherche d'un projet de semestre?
Travaillez avec nous sur des projets en science des données et en visualisation, et déployez votre projet sous forme d'application sur GraphSearch.
Concept
Papermaking
Résumé
Papermaking is the manufacture of paper and cardboard, which are used widely for printing, writing, and packaging, among many other purposes. Today almost all paper is made using industrial machinery, while handmade paper survives as a specialized craft and a medium for artistic expression.
In papermaking, a dilute suspension consisting mostly of separate cellulose fibres in water is drained through a sieve-like screen, so that a mat of randomly interwoven fibres is laid down. Water is further removed from this sheet by pressing, sometimes aided by suction or vacuum, or heating. Once dry, a generally flat, uniform and strong sheet of paper is achieved.
Before the invention and current widespread adoption of automated machinery, all paper was made by hand, formed or laid one sheet at a time by specialized laborers. Even today those who make paper by hand use tools and technologies quite similar to those existing hundreds of years ago, as originally developed in China and other regions of Asia, or those further modified in Europe. Handmade paper is still appreciated for its distinctive uniqueness and the skilled craft involved in making each sheet, in contrast with the higher degree of uniformity and perfection at lower prices achieved among industrial products.
History of paper
Hemp paper had been used in China for wrapping and padding since the eighth century BCE. Paper with legible Chinese writings on it has been dated to 8 BCE.
The traditional inventor attribution is of Cai Lun, an official attached to the Imperial court during the Han dynasty (202 BCE – 220 CE), said to have invented paper about 105 CE using mulberry and other bast fibres along with fishnets, old rags, and hemp waste. Paper used as a writing medium had become widespread by the 3rd century and, by the 6th century, toilet paper was starting to be used in China as well. During the Tang dynasty (618–907 CE) paper was folded and sewn into square bags to preserve the flavour of tea, while the later Song dynasty (960–1279 CE) was the first government to issue paper-printed money.
Source officielle
À propos de ce résultat
Cette page est générée automatiquement et peut contenir des informations qui ne sont pas correctes, complètes, à jour ou pertinentes par rapport à votre recherche. Il en va de même pour toutes les autres pages de ce site. Veillez à vérifier les informations auprès des sources officielles de l'EPFL.