What is Paper?
PAPER
Paper is a network of plant fibres laid down as a flat sheet. It is made from a suspension of plant tissues in water known as pulp. Most pulp is made from wood, but recycled paper and other plant sources, including hemp, cotton, esparto grass, sugar cane bagasse and bamboo, can also be used.
History of paper-making
Our word paper is derived from the Egyptian
‘papyrus’, which was applied to sheets of writing
material made by pressing together strips of the
stems of the sedge, Cyperus papyrus.
Paper as we know it, made up of a mesh of randomly arranged plant fibres, was invented by the Chinese in the second century AD.
In AD 105 a Chinese court official, Ts’ai Lun, produced a paper web from a slurry of paper mulberry (Broussonetia papyrifera) fibres in water. A small amount of the slurry was lifted up in a rectangular sieve consisting of a sheet of silk surrounded by a frame. The sieve was shaken gently to spread the fibres evenly and, as the water drained off, they settled to form a sheet which was then dried in the sun. This process produced a long-lasting, high quality paper, as can be seen from the samples preserved in the British Museum. Chinese paper-makers found that they could vary the characteristics of the paper produced by using different plants as the sources of fibres.
Over 600 years later, a Chinese paper-making factory in Samarkand was captured by an Arab army. The Arab conquerors used the expertise of the Chinese paper-makers to set up factories throughout the Moslem world and paper-making techniques first arrived in Europe when the Moors conquered Spain. The raw materials for paper-making were hemp and linen rags, including some from the wrappings of mummies. The first paper-mill in Britain was built in Hertfordshire in 1488 and was referred to in a book printed by Caxton in 1490.
By 1800 paper-making factories were using 24 million tonnes of rags per year and supplies of the raw material fell short of requirements. The search for a cheap, readily available and easily renewable substitute began. A French biologist observed that wasps’ nests were made of a form of paper which the wasps produced by macerating wood and he suggested that wood might be a suitable material for papermakers to use. The first recorded use of wood for paper-making in Europe was in 1769 but it was not until 1840 that paper made entirely from wood pulp appeared. The first newspaper to be made from an all-wood pulp, the New York Times, appeared in 1870. Early wood pulps were made by grinding logs between two slowly spinning stones. Pulp made by dissolving the woody substances in cell walls using strong chemicals did not appear until 1851.
The paper-making process was made faster and cheaper by the invention of the Fourdrinier papermaking machine, which used a continuous wire-mesh belt instead of individual paper moulds for forming a sheet of paper. This machine was first used in England in 1803 and finally ended the slow
process of paper-making by hand.
