quinta-feira, 16 de junho de 2016

Brief history of papermaking

Illustration of procedures for the production of rag paper

The origin of the invention of paper refers to China in the second century AD. However, only in the seventh century, the moors brought the case to Spain and then introduced the western world. With the development of the press in mid-fifteenth century, new manufacturing techniques were developed in order to account for the increasing demand.

The raw material of paper is cellulose obtained from plant fibers. For many centuries, the most used in the manufacture of paper pulp was extracted from rags, linen or cotton which are rich in this substance.

"The roles are strong and durable made from long fibers of flax, cotton or hemp, often derived from rags." (RICKMAN, BALL, 2005, p.103)

The rags were then boiled in a mixture of lime and water in order to remove grease, starch and also soften the cellulose. This mixture of lime and water was an alkaline solution which, by itself, has provided an alkaline reserve to the paper. It was then carried out a mechanical shock to reduce the rags to a pulp. This mixture was sieved by extracting the cellulose fibers that were arrested in the plot of the sieve. Subsequently, this mixture was pressed and dried.

In the eighteenth century, aiming to increase production and reduce costs, new techniques were developed. Pavão lists some of these innovations, for example, the sizing with rosin-alumina which initiated the preparation of papers since the fatty substance previously used was gelatin. It feels like sizing the action of adding adhesive to paper in order impermeable it and make it more suitable for writing. Peacock notes that

"The rosin-alumina, added to the water solution at the time of manufacture, helps to make the fiber dispersion in water, precipitating the adhesive resin on the fibers of the paper and holds the mineral fillers added to the paper and makes the role more tightly. However, their presence is a further contribution to the acidification of paper." (PAVÃO, 1997, p.141)

Another important change in the manufacture of paper was the use of wood pulp cellulose to obtain. This paste is made from the grinding and cooking of wood chips and all substances (lignin, for example) are used in paper production. The change of use of paper obtained by the rag paper made from wood pulp in 1850, marks the beginning of the crisis of acid paper. RICKMAN and Ball argue that "the papers derived from wood pulp are more reactive [...] the greater the amount of untreated wood, the higher its reactivity. (RICKMAN, BALL, 2005, p.104)
However, currently there are methods to remove the harmful substances present in wood pulp leading to production of quality varied roles (roles without any treatment, chemically treated papers among others).


COSTA, Bianca Mandarino da. Conservação e preservação de fotografias albuminadas. Monografia apresentada à Escola de Museologia da UNIRIO. 81p. 2009
PAVÃO, Luís. Conservação de coleções de fotografia. Lisboa: Dinalivro, 1997.
RICKMAN, Catherine; BALL; Stephen. Conservação de obras de arte em papel: gravuras, desenhos e aquarelas. In: Conservação de coleções / Museums, Libreries and Archives Council; [tradução Maurício O. Santos e Patrícia Souza]. Museologia, Roteiros Práticos 9 – São Paulo: Editora da Universidade de São Paulo. Fundação Vitae. 2005. 
Image. Illustration of procedures for the production of rag paper. Available at: <% 20of% http://1.bp.blogspot.com/_bJ3yHEM7rpQ/Rn3tIES9WUI/AAAAAAAAA58/q5EmfFnwGX4/s1600-h/historia 20papel www.celuloseonline.com.br.gif-> Access: 12 February 2011.

Nenhum comentário:

Postar um comentário