PAPER.
FIG. 1. SECTION OF RAG ENGINE, WITH DOUBLE ROLLER.
This important article of civilisation is made from rags of various descriptions and qualities, according to the kind of paper to be made, the finest white paper being made of old clean linen rags, while brown paper is made of all sorts of old rope-yarns, sacking, &c., and some kinds of paper have a considerable amount of straw bleached and worked up in them. The rags are first sorted and cut up into small pieces; they are then beaten on a wire screen to separate all dust, and afterwards put into the washing-machine, through which a stream of water runs, and in which they are kneaded and torn by a broad wheel having iron wedges or knives fastened to its edge ([fig. 1]) or surface, which work as it is turned against knives of a similar description fastened to the bottom of the cistern. When the rags are thoroughly washed, and at the same time torn to a coarse pulp, it constitutes what the workmen call “half-stuff.” This is mixed with chloride of lime, and the machine again set in motion; this is for the purpose of bleaching the pulp; after this has been effected, more water is turned on, as in the first washing, and all the chloride of lime washed thoroughly away. The pulp is now either put into another machine of the same description which cuts sharper and finer, or else the same machine used at first is so screwed up as to cause the knives to come more closely together; in either case the rate of turning is greatly increased, so that the wheel turns at about 150 revolutions per minute, and completely grinds up the pulp till it is perfectly smooth: at this part of the process some “indigo” or “smalt” is added if the paper is to be of a blueish tint, as in “foolscap” paper. The “stuff” is now run off into a cistern ready for use. Paper is now nearly all made by machinery, in pieces of a certain width, but of an indefinite length, and is cut up into sheets afterwards by a “cutting machine.”
FIG. 2. PAPER-MAKING MACHINE.
These machines ([fig. 2]) consist essentially of a vat, A, for the pulp, which flows out on to a bed of wire gauze, B B B, covered with felt, and bounded on each side by straps or deckles, and forming a circle or endless band by being stretched over a succession of rollers, C D E F G, which, by turning round continually, move its upper surface onwards and between other cylinders, which press out the superfluous moisture; it is then carried forward till it arrives at several pairs of large hollow cylinders, H H H, heated by means of steam which is passed through them, and which compress and at the same time thoroughly dry the paper, which comes from them as paper perfectly formed, and of any length that may be required. It is then glazed on the surface by the rollers I, and coiled on the cylinder L. Any name, device, or water-mark can be worked in the bed on to which the pulp flows, and which, being repeated at definite distances, appears on each sheet into which the paper is afterwards cut. The apparatus marked K is to conduct to the earth the electricity developed by the friction of the paper against the rollers. Beneath the bed of wire gauze, on which the pulp is laid is a cavity from which the air is pumped, and which causes the air to press upon the surface of the pulp, and force out a great deal of its moisture.
FIG. 3. SIZING MACHINE.
If the paper has to be sized (which is the case in all “hard” papers) it has to pass through a process, the machinery of which is shown in [fig. 3]. A is a reservoir for size, B a trough for the paper to dip into, C the reel of paper to be sized, D rollers to press out all superfluous size, E a pulley to keep the paper on the stretch, F F F a succession of hollow “drums,” to prolong the passage of the paper through the air of the drying-room, which is heated by the furnace G and the tubes I I. H H are openings to admit fresh air, and K openings to allow the exit of the steam from the paper as it dries. L is a series of rollers to glaze it.
FIG. 4. CUTTING MACHINE.
The “cutting-machine” before referred to is represented at [fig. 4]. A is a wheel upon which is fixed a plate with projections and screws for fixing the position of the arm attached to the link B; B link connecting the wheel A with the lever-arm G, and capable of adjustment by means of the plate attached to the wheel A, and the screw D; D a screw regulating the position of the rod B; E the drum by whose motion the web of the paper is carried forward.
FIG. 5. HAND PROCESS.
But the process, as conducted by hand ([fig. 5]), will give a much better notion of how paper is formed from the pulp. A reservoir, A, is filled with pulp, which is supplied by a wheel in the box B, to a strainer C, and passed to a vat D, and a man, E, takes in his hands a mould consisting of a shallow frame of wood of the size the sheet of paper is to be, having a bottom of fine wires laid side by side, and having wires crossing at intervals to keep them firm (the marks of these may be seen in any sheet of laid foolscap paper held up to the light); he dips this mould edgewise into the reservoir, and brings it up horizontally full of pulp; this he gently shakes, to make the pulp lie level and allow all superfluous water to drain through the wires. It is then handed to another man H, who has a sheet of flannel or felt spread out on a table F G, on which the mould is inverted, and the sheet of pulp left on the flannel, which sucks up more of its moisture; over this is placed another piece of flannel, and then another sheet of pulp on it, and so on to the number of five or six dozen F, then the whole is put into a powerful press, and screwed down till all the water is squeezed out, when they are pretty firm, and are lifted out and hung on lines to dry, after which they are immersed in a cistern filled with thin size made by boiling clippings of skin in water (see “[Glue and Size]”), and having some alum dissolved in it—they are once more pressed and dried. What is called “hot-pressed” paper is pressed between smooth sheets of pasteboard, having a hot iron plate placed between every three or four dozen sheets of paper; this gives a smooth surface to the paper. The names, dates, and other marks seen on hand-made paper are formed by wires worked into the bottom of the mould, which, projecting, make the pulp thinner in those places. The water-mark of Bank-notes is made in the same way. More than half-a-million sterling is paid annually for duty upon paper—so vast is the consumption!