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papermaking n : the craft of making paper

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Noun

  1. The craft of making paper

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Extensive Definition

Papermaking is the process of making paper, a material which is ubiquitous today for writing and packaging.
Papermaking, regardless of the scale on which it is done, involves making a dilute suspension of fibers in water and allowing this suspension to drain through a screen such that a mat of randomly interwoven fibers is laid down. Water is removed from this mat of fibers by pressing and drying to make paper. Most paper is made from wood pulp, but other fiber sources such as cotton and textiles may be used.
The word "paper" derives from the Egyptian use of papyrus. Amate paper, resembling papyrus, was also invented independently by the Mayas around the 5th century AD. True paper, made from pulped fibres, is traditionally ascribed to the Chinese court official Cai Lun, at around 100AD. However, excavated examples of paper from China have been dated to the 2nd century BC.
Modern papermaking began in the early 1800s in Europe with the development of the Fourdrinier machine, which produces a continuous roll of paper rather than individual sheets. These machines have become very large, up to 500 feet (~150 m) in length, producing a sheet 400 inches (~10 m) wide, and operating at speeds of over 60 mph (100 km/h).

History

Papyrus

The word paper derives from its mistaken identity by Greek-speaking scholars to the ancient Egyptian writing material called papyrus, which was woven from papyrus plants. The Egyptians invented papyrus around 3000 BC. It is made by crisscrossing thin sections of the papyrus reed, which grows in the delta of the Nile river and is held together by natural glues within the reeds. Papyrus was smoothed on one side by rubbing it against a flat stone surface. A shortage of papyrus occurred because of the development of the great library of Alexandria, which pushed Attalus of Pergamum (who was building his own rival library) to search for substitute for papyrus.

Parchment

Around 200 B.C. parchment, the split skin of sheep or goat, was developed. Parchment, or vellum, which is the best quality, has the great benefit over papyrus of extreme longevity, but was always expensive. The ancient world continued to use papyrus, thus accounting for much of the loss of classical literature, as outside the very dry conditions of Egypt it has a short life, but parchment became increasingly important, and by Late Antiquity had very largely superseded papyrus.

True paper

Papermaking has traditionally been traced to China about 105 AD, when Cai Lun, an official attached to the Imperial court during the Han Dynasty (202 BC-220 AD), created a sheet of paper using mulberry and other bast fibres along with fishnets, old rags, and hemp waste. However a recent archaeological discovery has been reported from near Dunhuang of paper with writing on it dating to 8 BC., while paper used for wrapping and padding was used in China since the 2nd century BC. Paper used as a writing medium became widespread by the 3rd century, and by the 6th century sheets of paper in China were beginning to be used for toilet paper as well. During the Tang Dynasty (618-907 AD) paper was folded and sewn into square bags to preserve the flavor of tea,
The secret of paper and silk manufacture had by then diffused to Damascus, and from there to the rest of the Muslim world, reaching India via Persia. It reached Western Europe via Islamic Spain, with earliest Christian book, or document, on paper being the 11th century Mozarab Missal of Silos, no doubt on Muslim-made paper. Production of paper moved to Italy in the 13th century. They used hemp and linen rags as a source of fiber. Rags from old clothing, etc. were commonly bought by rag collectors and sold to paper makers. Bones were collected to make glue size to seal the paper with
The use of paper became increasingly common during the fourteenth century, and is documented as being manufactured in both Italy and Germany by 1400. It then spread rapidly for letters, records, old master prints and popular prints and manuscript books. Prints were initially in woodcut , and from the 1430s in engraving also.
But it was not until printing with movable type was invented, that rag paper became more popular. Parchment was not ideal for printing, being expensive and susceptible to humidity. Paper on the other hand was ideal. But as the demand for books rose, the supply of rags became more and more inadequate and other sources of fiber were actively sought. A great deal of experimentation took place.
By the invention of movable type printing in Germany about 1450, paper was readily accessible, although still expensive. Vellum remained in use as well, and it was on this that the most expensive copies of the Gutenberg Bible were first printed.
In America, archaeological evidence indicates that paper was invented by the Mayas no later than the 5th century AD. Called Amate, it was in widespread use among Mesoamerican cultures until the Spanish conquest. In small quantities, traditional Maya papermaking techniques are still practiced today. Paper back then was very thick, but overtime has thinned itself out by the way we make paper today.
The Bataks, living in Sumatra, sometimes use as writing material long strips of bamboo, welded by "beating" them together, then folded together, accordion-like, between wooden covers, and bound together with a string of woven rushes. Often long strips of the thin bark of trees -- such books being known as pustakas -- are used. Specimens of writing on bark from India are preserved in the British Museum. The people of the Malabar coast also frequently wrote upon bark with a stylus. Predictions that electronic storage of data would lead to a decline in the demand for paper have not been realized. It has been estimated that by 2020 paper mills will produce almost 500,000,000 tons of paper and paperboard per year

Method

Papermaking, regardless of the scale on which it is done, involves making a dilute suspension of fibers in water and allowing this suspension to drain through a screen such that a mat of randomly interwoven fibers is laid down. Water is removed from this mat of fibers by pressing and drying to make paper.

Manual preparation

Fibers are suspended in water to form a slurry in a large vat. The mold is a wire screen in a wooden frame (somewhat similar to an old window screen), which is used to scoop some of the slurry out of the vat. The slurry in the screen mold is sloshed around the mold until it forms a uniform thin coating. The fibers are allowed to settle and the water to drain. When the fibers have stabilized in place but are still damp, they are turned out onto a felt sheet which was generally made of an animal product such as wool or rabbit fur, and the screen mold immediately reused. Layers of paper and felt build up in a pile (called a 'post') then a weight is placed on top to press out excess water and keep the paper fibers flat and tight. The sheets are then removed from the post and hung or laid out to dry. A step-by-step procedure for making paper with readily available materials can be found online.
When the paper pages are dry, they are frequently run between rollers (calendered) to produce a harder writing surface. Papers may be sized with gelatin or similar to bind the fibres into the sheet. Papers are made of different surfaces depending on their intended purpose. Paper intended for printing or writing with ink is fairly hard, while paper to be used for water color, for instance, are heavily sized, can be fairly soft.
The wooden frame is called a "deckle." The wooden frame or deckle leaves the edges of the paper slightly irregular and wavy, called "deckle edges", one of the indications that the paper was made by hand. Deckle-edged paper is occasionally mechanically imitated today to create the impression of old-fashioned luxury. The impressions in paper caused by the wires in the screen that run sideways are called "laid lines" and the impressions made, unusually from top to bottom, by the wires holding the other wires together are called "chain lines." Watermarks are created by weaving a name into the wires in the mould. This is essentially true of Oriental moulds made of other substances, such as bamboo. Hand-made paper generally folds and tears more evenly along the laid lines.

Laboratory-made paper

Hand-made paper is also prepared in laboratories studying papermaking and in paper mill quality labs. The "handsheets" made according to TAPPI Standard T 205 are circular sheets 15.9 cm (6.25 in) in diameter and are used to measure paper brightness, strength, degree of sizing and so on.
A modern paper mill is divided into several sections, roughly corresponding to the process involven in making hand-made paper. Pulp is refined and mixed in water with other additives to make a pulp slurry, the headbox distributes the slurry onto a moving, continuous screen, water drains from the slurry (by gravity or under vacuum), the wet paper sheet goes through presses and driers and is finally rolled into large rolls, often weighing several tonnes.
The wood-based paper was more acidic and more prone to discolor and disintegrate over time, through processes known as slow fires. Documents written on more expensive rag paper were more stable. Both rag and woodpulp paper will develop tan spots called "foxing" caused by impurities or fungi reacting with humidity. The majority of modern book publishers now use acid-free paper. Modern newspapers are commonly printed on cheaper high-acid paper which turns tan and disintegrates rather rapidly, especially in the presence of strong light and humidity. Woodfree paper most often made from cellulose fibre extracted from wood in a chemical pulping process that removes the lignin. This results in a more stable paper, similar to rag paper.
Archival paper is lignin-free and acid-free (between pH 6.0 and 8 is considered acid-free, between pH 7.1 and 8.0 is called alkaline buffered, this delays the gradual deterioration of the sheet).

Paper sizes

seealso bookbinding
In the beginning of Western papermaking, the paper size was fairly standard. A page of paper is referred to as a "leaf." When a leaf was printed on without being folded, the size was referred to as "folio." It was roughly equal to the size of a newspaper sheet.
When it was folded once, it produced four sides or pages, and the size of the pages or a book made of such pages was referred to as "quarto" (4to).
If the original sheet was folded in half again, the result was eight sides, referred to as "octavo" (8vo), which is the size that most books, such as the average novel, used to this day.
An "octavo" folding produces four leaves, the first two and the second two will be joined at the top by the second fold. The top edge is usually "trimmed" to make it possible to look freely at each side of the leaf. However, many books are found that have not been trimmed on the top, and these pages are referred to as "unopened." Many people reading "unopened" books will use their finger, a pencil, or some other inadequate instrument to rip open the top of the pages, leaving an irregular tear. A letter opener or a knife carefully used is a more appropriate tool.
An octavo book produces a printing puzzle. Pieces of paper are printed when they are folio size. To provide for the proper alignment of numbered pages, pages 8 and 1 are printed right-side-up on the bottom of the sheet, and pages 4 and 5 are printed up-side-down on the top of the same sheet. On the opposite side, pages 2 and 7 are printed right-side-up on the bottom of the sheet, and pages 6 and 3 are printed up-side-down on the top of the sheet. When the paper is folded twice and the folds trimmed, the pages fall into proper order.
Smaller books are produced by folding the leaves again to produce 16 pages, known as a "sixteen-mo" (16mo). Other folding arrangements produce yet smaller books such as the thirty-two-mo (32mo).
When a standard-sized octavo book is produced by a large leaf folded two times, two leaves joined at the top will be contained in the resulting fold (which ends up in the gulley between the pages). This group of 8 numberable pages is called a "signature" or a "gathering." Traditionally, printed signatures were stacked on top of each other in a "sewing frame" and each signature was sewn through the inner fold to the signature on top of it. The sewing ran around leather bands or fabric tapes along the backs of the signatures to stabilize the growing pile of signatures.
The leather bands originally used in the West to stabilize the backs of sewn books appear as a number of ridges under the leather on the spine of leather books.
The ends of the leather strips or fabric bands were sewn or glued onto the cover boards and reinforced the hinging of the book in its covers.

Vatmen Paper

Vatmen Paper was a type of paper made in The Netherlands that was 17 inches wide and 44 inches long. 44 inches was (reputedly) chosen because that is how far the papermaker could stretch his arm. The reason for 17 inches is unknown. A single vatman can generally handle a mould and deckle which produce up to a 25" wide sheet.

Notes

References

  • Needham, Joseph (1986). Science and Civilization in China: Volume 5, Part 1. Taipei: Caves Books, Ltd.
  • Cropper, Mark (2004). The Leaves We Write On. London: Ellergreen Press
  • Westerlund, Leslie C "Science and Practice of Handmade Paper" ISBN 1876141-131: 2004
  • Westerlund Leslie C. "How to Make a Papermaking Hydropulper" ISBN 1876141-441: 2007
  • Westerlund Leslie C. "How to Make a Papermaking Press" ISBN 1876141-44X: 2007
  • Westerlund Leslie C. "Dictionary of Papermaking" ISBN 1876141-247: 2005
papermaking in Russian: Целлюлозно-бумажное производство
papermaking in Chinese: 造纸术
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