Page:Paper and Its Uses.djvu/30

From Wikisource
Jump to navigation Jump to search
This page has been validated.

CHAPTER IV

PAPERMAKING BY MACHINE

The Fourdrinier machine bears the same relation to the hand mould that the rotary press does to the hand press. Instead of making paper sheet by sheet, it makes it in a continuous web, on an endless band of woven wire. The machine in a much simpler form was invented by a Frenchman, Nicholas Robert, the first machine being made in 1799, and so rapidly did the machine find favour that in fifty years over 150 papermaking machines were at work.

Papermaking by hand involves the processes of transferring a certain and regular quantity of pulp from the vat to the mould, shaking the mould to felt the fibres and to remove the water, couching the paper and drying the waterleaf. Machine-made paper follows the same processes exactly, everything being done by the one machine, including sizing. Viewing the papermaking machine, it appears to be a collection of machines carrying out the separate functions in proper sequence. The different parts of the machine can be controlled and driven at different speeds for special reasons. Thus a definite and regular quantity of pulp is taken, shaken, the water removed, the soft paper couched, pressed, dried, and a finish given to the surface of the paper, all in the compass of the one machine.

The pulp as left at the end of Chapter II. was merely beaten fibre, and if an unsized paper

18