Part 125

How Is the Water Mark Put Into Paper?

The pulp, which is now ready to be made into paper, is poured out upon an endless cloth made of fine brass wire. This cloth travels constantly in one direction, by means of rollers, and is given at the same time a sort of vibratory motion, to cause the paper fibers to become more closely felted together. On the wire cloth web are usually woven words, or designs, in wire, that rise above the rest of the surface. These are transferred to the paper, and are called water marks. The machine then winds the finished paper into rolls, so that it may be handled conveniently.

~HOW PAPER IS NOW MADE FROM WOOD~

During the past few years the uses for paper have increased so greatly that there have not been enough rags available to meet the demand for material, and a successful effort was made to find other material from which paper could be made. Many fibers were tried before it was found that wood pulp could be used. Straw and esparto grass, a plant that grows wild in North America, were found to yield cellulose having the desired qualities and were used to some extent. But the problem was solved when it was learned that pulp made from trunks and limbs of trees would serve even then. At first the powder formed by grinding up logs was used, but the paper produced was not strong, and could be used for very few purposes.

PAPER TREES.

This picture shows the trees as they grow in the woods. These trees are good for making paper. Your morning paper, may some morning be printed on what is left of one of these trees.]

It was discovered finally that if wood shavings were boiled in strong solutions of caustic soda, in receptacles that would withstand very high pressure, the wood fibers were separated, and a very good quality of cellulose for paper manufacture produced, provided it was bleached before being made into paper, and most of our paper to-day is, therefore, made of wood.

Later on this process gave way to the sulphite process. In the sulphite process, a solution of sulphite of lime is used. Acid sulphite of lime results when the fumes from burning sulphur are passed through chimneys filled with lime. By this process the separation of the fibers and the bleaching are done at the same time and an even whiter paper making material is obtained.

The sulphite process is now used almost exclusively in making paper from wood.

In this picture we see how the trees are first cut into smaller chunks before being reduced to chips for making pulp.]

The discovery of the process of making paper from wood has led to the use of paper for many purposes for which it could otherwise never have been used. The wood pulp is also used in the form of papier-mâché, a tough, plastic substance, which is made by mixing glue with it, or by pressing together a number of layers of paper having glue between. Papier-mâché can easily be molded into almost any form, and after drying forms a very tough substance and one that will stand rough usage. It has been employed for making dishes, water baskets and utensils of many other kinds, for making the matrices for and from electrotype plates, for car wheels, and many other purposes.

MIXING ROOM.

The wood fiber must be mixed with other ingredients when paper is made from it. This shows a corner of the large electro-chemical department for the production of bleach and soda used in the preparation of rag and wood fibres.]

A good deal of water is needed in making paper. From twelve to fifteen million gallons daily are drawn from the river and filtered through this plant in Maine; clean paper of bright color being dependent upon the use of pure water.]

BEATER ROOM.

The ingredients for making paper are first mixed thoroughly in machines called “beaters” before going to the paper making machines. The operation of beating is one of the most important in paper making.]

As the paper progresses through the machines, it passes over a long series of heated cylinders, drying and hardening the stock until it reaches the finished end. This illustration shows a web 135 inches wide being cut into two rolls. The air pressure in the machine room is slightly greater than the atmospheric pressure outside, preventing dust from entering.]

PAPER MAKING MACHINES.

In the foreground is the so-called wet end showing the vats in which the liquid pulp, about 98 per cent water, is pumped. It is screened and then flows on to an endless wire web beyond, where the free water is taken out by drainage and by suction boxes.]

PAPER STOCK.

A large amount of stock of paper mills. This paper is seasoned by holding it in stock and will be later given such surface as is called for.]

Where the paper passes through a bath of coating mixture to a long drying gallery at the end of which it is rewound preparatory to being given the highly finished surface on the calendaring machine.]

The finished rolls of stock pass through rotary cutters which produce the sheets of various required sizes. The paper in the Book of Wonders was cut in sheets 41x55 inches, thus making it possible to print 32 pages on each side of each sheet.]

Illustrations showing manufacture of paper by courtesy of S. D. Warren & Co.

This picture shows the wonderful Linotype machine by which the type of this book was “set,” as the printers say. The men who operate the machine are compositors. Originally the type matter of books was set by hand and the compositor composed in type what the author of the book had written. By pressing down on the keys which you see in the picture, the compositor sets the words in lines of metal. This machine is almost human. By touching the proper keys, the operator assembles a line of matrices the details of which are explained in another picture, and after this is done the machine automatically casts a slug from them, turns and delivers a slug into a galley ready for use and finally distributes the matrices back into their respective channels in the magazine, where they are ready to be called down again, by the touch of the key button. The latest model linotype has four magazines and can be equipped with matrices which when assembled will cast lines in from six to twelve different sizes and styles of type.

The assembling mechanism is the only part of the linotype where the human mind is applied to the working of the machine. It is necessary for the eye to read what is to be printed, and the mind, through the medium of the fingers, to translate this into assembled lines of matrices; after that the machine acts automatically.]

The keyboard is made up of 90 keys, which act directly on the matrices in their channels in the magazine. The slightest touch on the keybuttons releases the matrix, which drops to the assembler belt and is carried swiftly to the assembler. When a word is assembled, the spaceband key is touched and a spaceband drops into the assembler. When the necessary matrices and spacebands to fill the line have been assembled, the operator raises the assembler by pressing a lever on the side of the keyboard. When the assembler reaches its highest point it automatically starts the machine and the matrices are transferred to the casting position.

This illustration shows the manner in which matrices are constantly circulated in the Linotype. From the magazine they are carried to the assembler, then passed to the mold, where the line is cast, and from the mold after casting they are raised to the top of the machine and redistributed to their proper channels in the magazine.