William Edward Garrett Fisher

“ A very high surface can be quickly given to paper by friction with the assistance of heat; the process is known as “burnishing,” and is used mostly for envelope papers and wrappings where one surface only of the web is required to be glazed. It is produced by the friction of a chilled-iron roll on one of cotton or paper, the ratio of the revolutions being as 4 to 5; steam is admitted to the burnishing iron roll. ”

“ The undue introduction of excessive quantities of mechanical or ground wood-pulp in the period 1870–1880 into the cheaper qualities of printing-papers, particularly in Germany, first drew attention to this matter, since it was noticed that books printed on paper in which much of this material had been used soon began to discolour and turn brown where exposed to the air or light, and after a time the paper became brittle. This important question began to be scientifically investigated in Germany about the year 1885 by the Imperial Testing Institution in Berlin. ”

“ An alteration of a few feet per minute can be effected by changing the driving-speed of the steam-engine governor; for a greater change the machine must be stopped and other driving-wheels substituted. Arrangements are made in the driving-gear by which the various parts of the machine can be slightly altered in speed relatively to one another, to allow for the varying contraction or expansion of the paper web for different kinds and thicknesses of paper. The average speed of a paper-machine on fine writing-papers of medium weight is from 60 to 90 ft. ”

“ India paper is mostly made upon a Fourdrinier machine in continuous lengths, in contradistinction to a hand-made paper, which cannot be made of a greater size than the frame employed in its production. The material used in its manufacture is chiefly rag, with entire freedom from mechanical wood pulp. The opacity of modern India paper, so remarkable in view of the thinness of the sheet, is mainly due to the admixture of a large proportion of mineral matter which is retained by the fibres. ”

“ The refiner is essentially a finishing process as an adjunct to the beating process proper. The advantages to be derived from its use are a considerable saving in the time occupied in beating and the production of a more uniform and evenly divided pulp, particularly where a mixture of different fibres is used. By the use of the refiner the time occupied in the beater can be reduced by nearly one-half, the half-beaten pulp passing through the refiner from the beater on its way to the paper-machine. ”

“ The advantage gained by the use of India paper is the diminution of the weight and bulk of a volume—usually to about one-third of those involved by the use of good ordinary printing paper—without any alteration in the size and legibility of its type and without any loss of opacity, which is an absolute necessity in all papers used for high-class book printing to prevent the type showing through. ”

“ The web of paper is now wound up in long reels at the end of the machine.
Paper-machines are now usually driven by two separate steam engines. The first, running at a constant speed, drives the strainers, pumps, shake motion, &c., while the second, working the paper-machine, varies in speed according to the rate at which it requires to be driven. ”

“ The duty of the roll is to cut and tease out the rags, and also to act as a lifter to cause the stuff to circulate round the trough. The breaker is half filled with water and packed with the boiled rags; an ample supply of clean water is run into the engine for washing the rags, the dirty water being withdrawn by the “drum-washer,” a hollow cylinder fitted with buckets and covered with fine wire-cloth. During the washing process the roll is gradually lowered on the plate to tease out the rags into their original fibres ”

“ There is no manual labour in working the process, perfect cleanliness, and a great saving in power over the old process. Each tower will hold about two tons of dry pulp. When the pulp is fully bleached in the last tower of the series, fresh water is run into it, and a second concentrator, similar to the one on the first tower, is put in motion and washes out all traces of the bleach in about 25 to 30 minutes. These concentrators effect also another purpose, taking to some extent the place of the presse-pâte machine for removing roots, weeds and other impurities. ”

“ Although there are now in use a great many forms of beating engine, they are all, more or less, modifications of the original Hollander, which in its essential details differs little from the breaking engine already described. There are usually more bars in the roll and plate than in the breaker; the bars of the plate are set at a slight angle to the fly-bars of the roll to act as shears in a similar manner to a pair of scissors. Bars and plates of bronze are frequently used for the higher grades of paper to avoid rust and dirt and to produce a softer and less violent action on the fibres. ”

“ Its forms and combinations are extremely varied, but it always consists of the same chemical elements, carbon, hydrogen and oxygen, and in the same proportions. It is the object of the paper-maker to eliminate the glutinous, resinous, siliceous and other intercellular matters and to produce the fibre as pure and as strong as possible. Linen and cotton rags, having already undergone a process of manufacture, consist of almost pure fibres with the addition of fatty and colouring matters which can be got rid of by simple boiling under a low pressure of steam with a weak alkaline solution ”

“ For the best work, hand-cutting, done by women, is still preferred, but it is expensive and good machines have now been designed for this purpose. After further thrashing and dusting, the rags are ready for boiling, the object of which is not only to get rid of the dirt still remaining in them and to remove some of the colouring matter, but also to decompose a particular glutinous substance which would impair the flexibility of the fibres and render them too harsh and stiff for readily making into paper. ”

“ As soon as the wash water is running clear it is shut off, and the necessary quantity of a solution of bleaching powder or chlorine (averaging about 6 to 8% on the raw material) is run into the potcher, and the contents are heated by steam to a temperature of about 90° F. After about four to six hours the bleaching is complete, the drum-washer is let down, fresh water run into the potcher, and the grass washed to free it from all traces of chlorine, an operation generally assisted by the use of a little antichlor or hyposulphite of soda. ”

“ The advantages of this form of beater are that a quicker and more thorough circulation of the pulp takes place than when the roll has to do the double duty of making the pulp travel and beating it up at the same time, and thus tends to reduce the time of the operation. Also more bars can be fixed in the roll, increasing its effect on the pulp, and less power is required than when the roll revolves in the middle of the stuff as in the ordinary form of beater. ”

“ The waste heat is utilized in raising steam in a steam boiler set behind the furnace, and often in keeping the thick liquor hot after leaving the evaporator and before entering the rotary furnace.
Paper-making proper from prepared pulp, whether of rags, esparto, wood or other raw material, may be said to begin with the operation technically known as “beating” which is carried out in one of the various forms of beating engine or “Hollander.” The object of the beater is to reduce the fibres to suitable lengths and also to beat or bruise themBeating. ”

“ Of not less importance are the qualities which belong to paper as a chemical substance or mixture, which are: (1) its actual composition; (2) the liability to change under whatever conditions of storage and use it may be subjected to. For all papers to be used for any permanent purpose these physical and chemical qualities must ultimately rank as regulating the consumption and production of papers. ”

“ Other colours are required in the manufacture of papers of different tints, and with one or two exceptions they must be mixed with the pulp in the beater.
There are two distinct processes of producing the finished paper from the pulp, known respectively as “hand-made” and “machine-made.” The expense of manufacture of hand-made paper and the consequent high price render it too costly for ordinary use; the entire process on the machine occupies a few minutes, while in the ordinaryPaper Machine. ”

“ The drying cylinders of the paper-machine form a convenient and economical condenser for the two steam-engines, and it is customary to exhaust the driving engine into the drying cylinders and utilize the latent heat in the steam for drying the paper, supplementing the supply when necessary with live steam. The speed of the machine has frequently to be altered while in motion. ”

“ It embraces a multitude of most ingenious and delicate operations, and produces in a few minutes, and in one continuous process from the prepared pulp, sheets of paper ready for use. Machine-made paper has now gradually supplanted that made by hand for all except special purposes, such as bank-note, ledger, drawing and other high-class papers—in one word, in cases where great durability is the chief requisite. ”

“ A brief description of the hand-made process will suffice and it will at the same time facilitate the right comprehension of the machine process. Only the finest qualities of rags are used for hand-made paper; and the preparation of the half-stuff is the same as that already described under treatment of rags. The pulp after being prepared in the beating engine is run into large chests from which the vat is supplied ”

“ Shake frame of the machine from the breast-roll to the first suction-box is hung on a pair of strong hinges, and is capable of a slight horizontal motion imparted by a horizontal connecting-rod, one end of which is eccentrically keyed on to the face of a rapidly-revolving disk driven by a pair of speed-cones, so that the speed of the shake can be altered. ”

“ Taking an evaporation of 10 ℔ of water per pound of coal, a single-effect apparatus will evaporate 10 ℔ of water, a double-effect 20 ℔, a triple-effect 30 ℔, and so on. [3] The liquor to be concentrated is pumped from the storage tanks to the top or first effect of the Yaryan apparatus through a series of multiple-effect heaters, corresponding to the number of effects in the machine, by means of which the liquor is heated to as near the boiling point as possible of the liquor in the tubes of the first effect. ”

“ On fine writing-papers an average machine will make from 20 to 40 tons per week, while for common printing and newspapers the weekly output will amount to 50 to 70 tons.
All hand-made papers, and many of the best classes of machine-made papers, instead of being sized in the beater with a preparation of resin are what is called “tub-sized,” that is, coated with a solution of gelatin. Such papers, when machine-made, are reeled off the machine straight from the drying cylinders in the rough state. The web is then led slowly through a tub orTub-sizing. ”

“ France owed the establishment of her first paper-mills to Spain, whence we are told the art of paper-making was introduced, as early as the year 1189, into the district of Herault. At a later period, in 1406, among the accounts of the church of Troyes, paper-mills appear as molins à toile. The development of the trade in France must have been very rapid. And with the progress of manufacture in France that of the Netherlands also grew.
In the second half of the 14th century the use of paper for all literary purposes had become well established in all western Europe ”

“ But this theory has been disturbed by recent investigations, which have shown that the material of the Arab paper was itself substantially linen. It seems that the Arabs, and the skilled Persian workmen whom they employed, at once resorted to flax, which grows abundantly in Khorasan, as their principal material, afterwards also making use of rags, supplemented, as the demand grew, with any vegetable fibre that would serve; and that cotton, if used at all, was used very sparingly. ”

“ From the beating engines, the pulp is emptied into storage tanks or stuff-chests, fitted with revolving arms or agitators; from these the pulp is pumped into a long upright supply box at a higher level, called the stuff box, which communicates with the sand trap or table by means of a regulating valve. ”

“ They are usually about 16 ft. high in the parallel by 81/2 ft. in diameter; the bottom of the tower is conical and connected to a powerful circulator or pump, which discharges the pulp into the top of the tower and causes thereby a continuous circulation and a thorough mixing of the pulp and bleach. A special form of concentrator is fixed on the top of the first tower, which reduces the water in the pulp as it leaves the potcher to the minimum quantity necessary for perfect circulation in the tower ”

“ It is charged through the opening at the top A, and the boiled material taken out from a door B at the side; the grass rests on a false bottom of perforated plates C, through which the liquor drains, and by means of two “vomiting” pipes, D, D, at the sides of the boiler, connecting the space at the bottom with a similar space at the top, a continuous circulation of steam and liquor is maintained through the grass. ”