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History of Papermaking
HISTORY OF PAPERMAKING
Papermaking goes as far back as 105 A.D. when Ts'ai Lun, an official
at the Imperial Court of China, made a sheet of paper using mulberry and
other fibres along with fish nets, rags and hemp waste. The first paper
was made in 793 A.D. in Baghdad during Harun-ar-Raschid's rule, with the
golden age of Islamic culture that brought papermaking to Europe.
By the 14th century paper mills existed all over Europe, particularly
in Spain, Italy, France and Germany. During the 1450's paper printing(by
machines) was introduced and the demand for paper increased all over the
world. Papermaking remained unchanged till the 18th century, with linen
and cotton rags used for raw materials. This soon presented a shortage,
since no more rags and linen were available and it is was apparent that a
process for utilizing a more abundant material was required.
IMPROVEMENTS IN MATERIALS AND PROCESSES
In 1800 a book was published which stated practical methods for
manufacturing paper from wood and vegetable pulps. Soon many publishing
processes were developed and the paper industry no longer had to depend on
rags and linen and this made mass production possible. There were two main
kinds of pulping processes used in the 18th century and they were,
mechanical or groundwood pulping and chemical pulping. Mechanical pulping
contains certain wood components and therefore, it is not suitable for
paper in which high whiteness and permanence are required. Mechanical pulp
was first made in Germany in the 1840's, but was not used much until 1870.
Chemical wood pulp is used when high whiteness, strength and permanence are
required. VAT SIZING: A sheet of paper composed of cellulosic fibres is
water absorbent. Thus, aqueous liquids will penetrate it and spread in it.
Impregnation of the paper with various substances that require this wetting
and penetration is called vat sizing. During the 18th century paper sheets
were impregnated with animal glue which was an expensive and tedious
process. In 1807 Moritz Friedrich Illig of Germany discovered paper that
could be sized in vats with rosin and alum, but his methods were not
commonly used till 1840.
INTRODUCTION OF MACHINERY
Before the paper machine was invented, paper was made by hand one at a
time. In 1798, a Frenchman named Nicolas-Louis Robert invented a moving
screen belt that would receive a continuous flow of stock and give an
unbroken sheet of paper to a pair of squeeze rolls. The invention was not
really used much, but two Englishmen, the Fourdrinier brothers, improved on
Robert's idea and built a better version in 1807. From these crude
beginnings modern papermaking machines were developed. Although modern
creations and engineering have formed and ancient craft into a technical
industry, the basic procedures remain the same. These procedures are as
follows:
(A) A suspension of cellulosic fibres is prepared by beating it in water so
that the fibres are completely separated and saturated with the water.
(B) The paper stock is filtered on a woven screen to form a matted sheet of
fibre.
(C) The wet sheet is then pressed and compacted to squeeze out the water.
(D) The remaining water is removed by evaporation.
(E) The dry paper sheet is then compressed and impregnated if needed.
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