CHAPTER VMODERN PAPER-MAKING♦The modern mill♦Though the steady march of progress and invention has given to the modern paper-maker marvelous machines by which the output is increased a thousand-fold over that of the old, slow methods, he still has many of the same difficulties to overcome that confronted his predecessor. While the use of wood pulp has greatly changed the conditions as regards the cheaper grades of this staple, the ragman is to-day almost as important to the manufacturer of the higher grades as he was one hundred years ago, when the saving of rags was inculcated as a domestic virtue and a patriotic duty. Methods have changed, but the material remains the same. In a complete modern mill, making writing and other high-grade papers, the process begins with unsightly rags as the material from which to form the white sheets that are to receive upon their spotless polished surface the thoughts of philosophers and statesmen, the tender messages of affection, the counsels and admonitionsof ministers, the decisions of grave and learned judges, and all the“Wisdom of things, mysterious, divine,” that“Illustriously doth on paper shine,”as was duly set forth in rhyme by the “Boston News Letter” in 1769. “The bell cart will go through Boston about the end of next month,” it announced, and appealed to the inhabitants of that modern seat of learning and philosophy to save their rags for the occasion, and thus encourage the industry.♦The methods of to-day♦The rags do not come to the mammoth factories of to-day in “bell carts,” but by the carload, in huge bales, gathered from all sections of this great Republic, as well as from lands beyond the eastern and the western oceans. The square, compact, steam-compressed bundles are carried by elevators well up toward the top of the building, where they await the knife of the “opener.” When they have been opened, the “feeder” throws the contents by armfuls into the “thrasher.” The novice or layman, ignorant of the state in which rags come to the mill, will find their condition a most unpleasant surprise, especially disagreeable to his olfactory nerves. Yet theunsavory revelation comes with more force a little farther on, in the “assorting-room.”♦The thrasher♦The “thrasher” is a great cylindrical receptacle, revolving rapidly, which is supplied with long wooden beaters or arms, passing through a wooden cylinder, and driven by power.♦The sorting room♦When the rags have been tossed in, there ensues a great pounding and thrashing, and the dust is carried off in suction air-tubes, while the whipped rags are discharged and carried to the “sorting” and “shredding” room. Here the rags are assorted as to size, condition, and the presence of buttons, hooks and eyes, or other material that must be removed. Then those that need further attention are passed on to the “shredders,” these as well as the “sorters” being women. The “shredders” stand along a narrow counter; in front of each one there is fastened a long scythe-blade, with its back toward the operator and its point extending upward, the shank being firmly fixed to the table or operating board. Here buttons, hard seams, and all similar intruders are disposed of, and the larger pieces of rags are cut into numerous small ones on the scythe-blades. The rags thus prepared are tossed by the women into receptacles in the tables. The work in this roomis the most disagreeable and unwholesome of any in the entire process of manufacture, and this despite the fact that these rags, too, have been thrashed, and freed from an amount of dust and dirt beyond ordinary belief.♦The higher grades♦While watching the operations carried on here, it is impossible to repress the wish that rags might be bought otherwise than by the pound, for, unfortunately, filth, dust, and dirt weigh, and to wash rags only reduces the weight. While this is a true reflection of the condition in the average mill, it is pleasant to know, however, there are others of the higher class that are decided exceptions, as far as dust and dirt are concerned. Such are the mills making high-grade ledger and bond papers, as well as the mill manufacturing the paper that is used for the printing of our “greenbacks,” to which further reference will be made later. In these exceptional mills everything is neat and perfectly clean, all the stock used being new and fresh from the cotton or linen mills, or from factories producing cloth goods, like shirt and corset factories, and others of the same sort. The sorting and shredding room is always large and light, with windows on all sides, and is well ventilated, offering adecided contrast in many respects to the less cleanly mills first referred to, where the women must wear bonnets or hoods for the protection of the hair. In either case the process is certainly an improvement over the old plan of leaving the rags to decay in a cellar to expedite the removal of the glutinous matter.♦The cutter♦From the “sorting” and “shredding” room the rags are conveyed to the “cutter,” where they are cut and chopped by revolving knives, leaving them in small pieces and much freer from dust and grit. Various ingenious devices are employed for removing metal and other hard and injurious matter, magnetic brushes serving this purpose in some mills.♦The devil♦When the “cutter” has finished its work, the still very dirty rags go for a further cleansing to the “devil,” or “whipper,” a hollow cone with spikes projecting within, against which work the spikes of a drum, dashing the rags about at great speed. Human lives are often freed of their baser elements and restored to purity and beauty through the chastening influences of tribulation or adversity; in like manner the “whipper” carries the rags forward a step in the process of purification that is necessary before they can be brought to theirhighest usefulness. But the cleansing process, which is only a preparation for what is to follow, does not end with the “whipper,” the latter having served merely to loosen, not to dislodge, a great deal of dust and dirt.♦The duster♦The final operation in the preliminary cleaning is performed by the “duster” proper, which is a conical revolving sieve. As the mass of rags is tossed and shaken about the loosened dust is carried away by the suction of the air, which draws the dust particles into tubes furnished with suction fans. In most modern mills the rags are carried forward from the “duster” on an endless belt, and a careful watch is kept upon them as they emerge to detect the presence of unchopped pieces, buttons, or other foreign substances. The journey of the rags over this endless belt or conveyor terminates in a receiving-room, in the floor of which there are several openings, and immediately below these the mouths of the “digesters,” which are in a room beneath.♦The digester♦The “digesters,” as they are suggestively and appropriately termed, are huge revolving boilers, usually upright, which often have as great a diameter as eight feet, with a height of twenty-two feet, and whose digestive capacity is upward of five tons of rags each.♦Cooking of rags♦The rags that are to be “cooked” are fed into the “digesters” through the openings in the floor, and the great movable manhole plates are then put in place and closed, hermetically sealing the openings or mouths through which the boilers have been fed, these having first been charged with a mixed solution of lime and soda, and with live hot steam in lieu of gastric juice as a digesting fluid and force. In some mills the boilers are placed in a horizontal position, while in others they are in the form of a large ball or globe, in either case being operated in the manner described; those of upright form, however, are most commonly in use. The rags are boiled under steam pressure of about forty pounds to the square inch, and the cooking is continued from twelve to fourteen hours.THE MODERN FOURDRINIER MACHINE—Page 73♦The washers or Hollanders♦It is here that the process of cleaning begins in earnest; and as the mass of rags is tumbled about in its scalding bath of steam-heated lime-water, or “milk of lime,” the coloring and glutinous matters, as well as all other impurities, are loosened from the fibers, which are in the end so cleansed and purified as to come forth unstained and of virgin purity. Having been sufficiently boiled and digested, the mushy material, still lookingdark and forbidding, is emptied onto the floor below or into receptacles placed directly beneath the boilers, where the color and dirt are allowed to drain off. The mass is then conveyed to the “washers,” great tub-like receptacles, which are shown among theillustrations, and which are known as “Hollanders,” from the fact that these rag engines were invented in Holland, about the year 1750A. D.They are oval-shaped tubs, about twenty feet long, nine feet wide, and three feet high, varying somewhat according to the conditions. Each tub is divided for two-thirds of its length by an upright partition, or “mid-feather,” as it is called, which makes a narrow course around the vat. On one side of the partition the tub is raised in a half-circle, close to which revolves an iron roll about three or four feet in diameter, and covered with knives; in the bottom of the tub, and directly under the revolving roll, is another set of knives called a “bed-plate,” which is stationary, and against which the roll can be lowered. But not to anticipate. When the emptyings from the boiler have been thrown into the “washer” a continuous stream of water is turned in at one end, the knife-roll having been adjusted so as to open up the rags as they are setin motion. These then begin a lively chase around the edge of the vat, through the racecourse formed by the “mid-feather,” and under the rag-opening knives, where the water is given a chance to wash out all impurities; then on up the incline over the “back fall,” so-called from the elevation in the tub. A cylinder of wire cloth, partly immersed in the moving mass, holds back the now rapidly whitening fibers, while the dirty water escapes into buckets inside the wire cloth drum, and is discharged into and through an escape-spout. The heavy particles of dirt settle into what is termed a “sand-trap” at the bottom of the tub.♦Bleaching material♦As the water clears, the roll is lowered closer and closer to the bottom of the bed-plate, in order to open up the fibers more thoroughly for the free circulation of the water among them. When the several agencies of the “washer” have accomplished their purpose, and the water runs clear and unsullied, a bleaching material is put into the mass, which in the course of from two to six hours becomes as white as milk. The dirty offscourings of all ragdom, first seen in the original bales, and gathered from the four quarters of the globe, have endured many buffetings,many bruisings and tribulations, and having been washed come forth pure, sweet, and clean. From the washers the rags are precipitated through a trap into drainers, which are chambers made of stone and brick, with a false bottom, through which the water is allowed to drain. This rag pulp, now called half stock, is kept in this receptacle until the water and liquor are thoroughly drained off, when it becomes a white and compact mass of fibers.♦The drainers♦The rags should stand in the drainers for at least one week, though better results are obtained if they are left for a period two or three times as long, as the fibers become more subdued. The process of paper-making, as it has already been described, applies more particularly to papers made from rags. To-day a very large proportion of the cheaper papers are made from wood, either entirely or in part, and these wood-made papers are subjected to a different treatment, to which further reference will be made in this chapter.♦The beaters♦From the drainer the mass is carted to the beating engine, or “beater,” which is very similar in construction to the washer just described. The knives on the roll in the beater are grouped threetogether instead of two, and are placed nearer the bottom or bed-plate in order to separate more thoroughly the fibers. In the beater are performed many and varying manipulations, designed not only to secure a more perfect product, but also to produce different varieties of paper. It is the theory of the beating process that the fibers are not cut, but are drawn out to their utmost extent. In watching the operations of the “beater,” one notices on the surface of the slowly revolving mass of fibers, floating bluing, such as the thrifty housewife uses to whiten fine fabrics. This familiar agency of the laundry is introduced into the solution of fibers with the same end in view that is sought in the washtub—to give the clear white color that is so desirable. Many of the inventions and discoveries by which the world has profited largely have been due primarily to some fortunate accident, and according to a pretty story upon which paper-makers have set the seal of their belief for more than one hundred and fifty years, the use of bluing was brought about in the same way.♦The bluing story♦About the year 1746, so runs the story, a Mrs. Buttonshaw, the wife of an English paper-maker, accidentally dropped into a tub of pulp the bag of bluing, or its contents,which she was about to use in a washing of fine linen. Frightened at what she had done, and considering it the part of wisdom to keep silence, she discreetly held her peace and awaited results. But when her husband had expressed great wonder and admiration over the paper made from that particular pulp, and had sold it in London at an advance of several shillings over the price of his other paper, which had not met with any such accident, she realized that the time for silence had passed. Her account of the happy accident led her grateful husband to purchase a costly scarlet cloak for her on his next visit to London town. This accident brought about another result which was to prove of inestimable value to the future paper-maker—the use of bluing in paper when especial whiteness is desired.♦Engine-sizing♦Important as the bluing or coloring is, however, it is only one of the numerous operations or manipulations that take place in the beater. Many of these, such as engine-sizing and body-coloring, require skill and constant watchfulness. Here, too, if anywhere, adulteration takes place. It is sometimes necessary to secure a fine-appearing paper at small cost, and it is profitable to add toits weight. In such cases, a process of “loading” takes place here, and clay or cheap, heavy fibers are added. Clay is of value not only to increase the weight, but also to render the paper more opaque, so as to prevent type or illustrations from showing through, while at the same time it makes possible a smoother surface by filling the pores in the paper. But while it adds to the weight, clay must, of necessity, weaken the paper. In engine-sizing, which is done in the beater, the size is thoroughly incorporated with the fibers as these revolve or flow around the engine. This sizing renders the paper more nearly impervious to moisture. The difference between a paper that is sized, and that has a repellent surface which prevents the ink from settling into it when it is written upon, and an ordinary blotting-paper with its absorbent surface, is due entirely to the fact that the former is most carefully treated with sizing, both in the beating engine and in the size tub or vat referred to later, whereas in the latter paper it is omitted.♦Body-coloring♦If the paper is to be tinted or body-colored, colors made from aniline are generally used. Only in the highest grade of writing-paper, and in some few papers that demand colors fast to the light, is any other order of coloringmatter employed. As may be easily imagined, considerable skill is required to secure exactly the desired tint, and to get the coloring matter so evenly mixed that each small fiber shall receive its proper tint, thus insuring that the paper when finished shall be of uniform color and not present a mottled appearance.♦Machine for making continuous web♦When the operations of the beating engine have been completed, a most interesting process begins, which marks a vast advance over the earlier method of forming the sheets of paper with mold and deckel, straining off the water, and shaking the frame with a quick motion to mat the fibers together. The patient striving toward something better, which has marked all the centuries since man first learned to carve his rude records, finds its consummation in the process of making paper in a continuous web. This result is accomplished by a machine first invented by Louis Robert, a workman in a mill at Enonnes, France, who obtained a French patent, with a bounty of eight thousand francs for its development. This he later sold to M. Didot, the proprietor of the mill, and the latter crossed the Channel into England, where, with the aid of a skilled mechanic, the machine was in a measure perfected, and then soldto Henry and Sealy Fourdrinier. They, with the further aid of Bryan Donkin, their employe and expert engineer, made many additional improvements, and sunk in the enterprise some sixty thousand pounds sterling, for which their only reward was blighted hopes and embittered lives. In 1847 the London “Times” made a fruitless appeal on behalf of the surviving brother, who was eighty years of age, and in great poverty. It is seldom that the world voluntarily makes return to those who have bestowed upon it great material or moral benefits, though it is ever ready to expend its treasure for engines of destruction, and to magnify and reward those who have been most successful in destroying human life.♦First machine mill♦The first “machine” mill was started at Frogmore, Hertz, England, in 1803, which was the year of the great Louisiana Purchase by the United States, and it is not difficult to say which event has been productive of the greater and more beneficial results to this nation. Through this invention and its improvements the modern newspaper and magazine, with their tens and hundreds of thousands of copies daily, have been made possible, and men of all classes have been brought in touch with the best thought of theday. Whatever makes for greater intelligence and enlightenment throughout a nation makes for the greater stability of the national life, and gives new emphasis to Bulwer’s words:“Take away the sword;States can be saved without it—bring the pen.”♦The power of the pen♦If to-day the power of the pen over the sword is greater than it has ever been before, its increased and increasing influence must be credited in large measure to the inventive genius and the public-spirited enterprise that has made possible the great output of our modern paper-mills. So thoroughly did these forces do their work in the beginning, that in the century that has elapsed since the Fourdrinier brothers sacrificed themselves and their means in the perfecting of their machine, there have been really no changes in the fundamental principle. Those that have been made have been in the nature of further development and improvement, such as increasing the speed and widening the web, thereby multiplying the product many fold.THE FIRST PRESS ROLLS—Page 75♦The Jordan engine♦But to resume the interesting journey of the rags, which had reached a state of purification and perfection as pulp, and which we left in thebeaters. In some grades of paper the perfected and prepared pulp is taken from the beaters and passed through what is known as a “refining” or “Jordan” engine; this for the purpose of more thoroughly separating the fibers and reducing them to extreme fineness. The refining engines, are, however, used only in the manufacture of certain grades of paper.♦The stuff chest♦The pulp is next taken from the beater or refining engine, as the case may be, to what is called a “stuff-chest,” an inclosed vat partly filled with water, in which a contrivance for shaking and shifting, properly called an “agitator,” keeps the fibers in suspension.♦The screen♦From the stuff-chest the mixture is pumped into what is known as the “mixing” or “regulating” box. Here the stream first passes over the “sand-tables” in a continuous flow. These are composed of little troughs with cross-pieces, and are covered at the bottom with long-haired felt, to catch any sand or dirt that may still adhere after the numerous operations to which the pulp has been subjected. The flow is then forced through the “screen,” which is a horizontal piece of metal pierced with slots. For very fine paper, these slots are so small as to be only one one-hundredthof an inch in width. They are usually about a quarter of an inch apart. Through these tiny apertures the fibers must find their way, leaving behind in their difficult passage all lumps, dirt, or knotted fibers which would mar the perfection of the product toward which they are tending. A vibrating motion is given to the screen as the flow passes over it, or revolving strainers may be used.♦The flow onto machine♦When the screen has finished its work, the water carrying the pulp in solution flows in an even stream, whose volume varies according to the width of the web of paper to be produced, through a discharge-cock onto the Fourdrinier or cylinder machine, as the case may be, each of which will be duly described. This stream has a filmy appearance, and is of diverse color, depending upon the shade of paper to be produced. From its consistency, which is about that of milk, it is difficult to imagine that it floats separate particles of fiber in such quantities as, when gathered on the wire cloth and passed to a felt blanket and then pressed between rollers, to form in a second of time a broad web of embryo paper sufficiently strong and firm to take definite form. Man’s mastery of the process by which thisstartling and wonderful change is effected has come as one of the rewards of his long and patient study.The Fourdrinier machine, which preserves at least the name of the enterprising developers of the invention, takes up the work that was formerly done by the molder. The wire cloth upon which the fibers are discharged as described is an endless belt, the full width of the paper machine. Upon this the fibers spread out evenly, being aided by a fan-shaped rubber or oil cloth, which delivers the smooth stream under a gate regulated to insure perfect evenness and to fix uniformly the fibers of the web now commencing its final formation.♦Deckel-straps♦Deckel-straps of india-rubber are fastened on both sides of the wire screen, and move with it, thus holding the watery pulp in place. The deckel-straps are adjustable, and fix or regulate the width of the paper. These and the gate, or “slicer,” are attached to what is termed the deckel-frame, which corresponds to the deckel used by paper-makers in the days when the manufacture was carried on by hand.♦Endless wire cloth♦As the stream flows onto the endless belt of wire cloth, the water which has borne the fibers filters into the trough beneath. Being charged with very fine fibers,size, coloring matter, and other similar ingredients, it is carried back into the pulp-chest, to save these materials, as well as to contribute again to the extra supply of water needed.♦The save-all♦For this reason the trough into which it falls from the revolving “wire” is called the “save-all.” A shaking motion is imparted to the “wire” from the frame upon which rest the rolls that keep it in its never-ending round. This aids in draining away the water, and mats or interlaces the fibers together. At the end of the “save-all,” where the fibers are to leave the “wire” for the next stage of their journey, suction-boxes are placed, provided with an air-pump to take up the surplus water that has not yet found its way through the meshes.♦The dandy roll♦Between these suction-boxes above the wire is a wire-covered roll, which impresses the newly formed sheet; this impression cylinder is called a “dandy roll,” and it is from this that the web receives the markings or impressions that characterize different papers. All watermarks, patterns, and designs which it is desired to have appear in the paper are put upon this roll, and here impressed upon the soft sheet, which is clarified and left transparent at the points of contact. Thus the impression is permanently fixed in the fiber, so that it can beseen at any time by holding the sheet to the light. The power of suggestiveness is a quality which is highly esteemed wherever it is found, and which frequently furnishes a standard of judgment. Judged by such a criterion, the impression cylinder, or “dandy roll,” has an added value, for in all probability its operation suggested the idea of printing from cylinders, as in our present web or perfecting presses.♦The press-rolls♦The matted pulp, now having sufficient body, passes on between two rolls covered with felt, which deliver the web of damp paper upon an endless belt of moist felt, while the “wire” passes under and back to continue a fresh supply. The paper is as yet too fragile to travel alone, and the web felt carries it between two metal rolls called the first press-rolls. These squeeze out more water, give a greater degree of compactness to the fibers, smooth the upper surface, and finally deliver the web of paper to a second felt apron, which carries it under and to the back of the second press-rolls. In this way the under surface comes to the top, and is in its turn subjected to the smoothing process. A delicate scraper or blade, the length of the press-rolls, is so placed on each roll that should theendless web from any cause be broken, the blade may operate with sufficient force to prevent the wet paper from clinging to the rolls and winding about them. From this point the paper travels alone, having become firm and strong enough to sustain its own weight; passing above the second press-rolls, it resumes its onward journey around the drying cylinders, passing over and under and over and under.♦The dryers♦The drying cylinders are hollow and heated by steam, their temperature being regulated according to requirements. These driers, made from iron or steel, are usually from three to four feet in diameter, and vary in length according to the width of the machine. There are from twelve to fifty of these cylinders, their number depending upon the character and weight of the paper to be produced, very heavy sheets requiring many more drying cylinders than sheets of lighter weight.♦Tensile strength♦Strange, almost phenomenal, conditions come about in the transformation from filmy pulp to finished paper. A sheet which, though formed, is at the first press-roll too fragile to carry its own weight, becomes possessed of a final strength and power that is almost incredible. The myriad of minute fibers composing the sheet, upon drying uniformly, possesses great aggregate strength. Asheet of paper yields readily to tearing, but the same sheet, when a perfectly even tension is applied, will demonstrate that it is possessed of wonderful resisting power. In evidence may be cited an instance that seems almost beyond belief. Through some curious mishap a web of heavy paper, in fact, bristol board, which had been thoroughly formed, was suddenly superheated and then cooled while still on the driers. This was caused by a difference in temperature of the driers and resulted in the sudden contraction of the web of bristol; the strain on the machine was so great that not only were the driving-cogs broken on two of the driers around which the paper was at the moment passing, but the driers themselves were actually lifted out of place, showing a resisting power in the paper of at least several tons.♦The calenders♦The paper now passes to the upright stack of rolls shown in theillustrations, which are known as “calenders.” The word is derived from calendra; a corruption of cylindrus, a roller or cylinder, they are simply rollers revolving in contact, and heated from the interior by steam. These calenders are used for giving to the paper a smooth and even surface, and are also employed in the smoothing and finishing of cloth.♦Speed of machines♦Thespeed with which the paper passes through these cylinders is remarkable, from one hundred to five hundred feet running through and over the machine in a minute; and in some of the most recent mills the web is as wide as one hundred and fifty-six inches (thirteen feet); this is very nearly double the average machine width of a few years ago, while the speed has increased in proportionate ratio; only a very few years ago the maximum speed was from two hundred and fifty to three hundred feet per minute; at this writing (1900) there are machines in operation which run as high as five hundred feet per minute. But great as has been the increase in the production of paper, the demand has kept pace steadily. The wonderful product of the rag-bag holds an invincible position in the world’s economy.THE SIZE-TUB—Page 81♦Five miles in a roll♦For machine-finished book and print papers, as well as for other cheaper grades, the process ends with the calenders, after which the paper is slit into required widths by disk-knives, which are revolving, and so cut continuously. Paper intended for web newspaper presses is taken off in continuous rolls of the widths required, varying from seventeen to seventy-six inches, according to the size of the paper to be printed. Thesereels contain from fifteen to twenty-five thousand lineal feet of paper, or from three to five miles. The amount of paper used in disseminating the news of the day is enormous; sometimes one or two mills are required to manufacture the supply for a single metropolitan daily, while one New York newspaper claims to have used four hundred and fifty tons of paper in one Christmas edition, which is about four times the amount of its regular daily consumption.After having been slit into the proper widths by the revolving knives, ordinary flat and book papers are cut into sheets by a straight knife revolving at proper intervals on a horizontal drum. The paper, in sheets, is carried by a traveling apron onto a receiving table at the end of the machine, where the sheets as they fall are carefully examined by experts, usually women, who remove any that may be imperfect.♦The immensity of modern machines♦The entire length of a paper machine, from the screens to the calenders, is about one hundred and twenty-five feet, while the height varies, the average being about ten feet. The machines, while necessarily of the finest adjustment, are ponderous and heavy, weighing in some cases as much as four hundred tons, this being the weight of themachine itself, exclusive of its foundations. The machine-room is of necessity well lighted and thoroughly ventilated, and should be kept clean throughout, as cleanliness is an essential factor in the making of good paper.♦Deckel edging♦While the same general process applies to all classes of paper made, the particular character of any paper that is to be produced determines exactly the details of the process through which it shall pass, and regulates the deviations to be made from the general operations in order to secure special results. For example, some papers are wanted with a rough or “antique” finish, as it is called; in such cases calendering is omitted. Another special process is that by which the paper is made with a ragged or “deckel edge”; this result is obtained in some mills by playing a stream of water upon the edge of the pulp, crushing and thinning it, and thus giving it a jagged appearance. At the present time this “deckel-edge” paper is being quite extensively used in high-class bookwork.In the case of writing-papers, as has already been stated in the description of the beating engines, a vegetable sizing made from resinous matter is introduced into the paper pulp while itis still in solution, and mixes with it thoroughly, thus filling more or less completely the pores of the pulp fibers. This is found sufficient for all ordinary book-papers, for papers that are to be printed upon in the usual way, and for the cheapest grades of writing-paper, where the requirements are not very exacting, and where a curtailment of expense is necessary. For the higher grades of writing-paper, however, a distinctly separate and additional process is required.♦Tub sizing♦These papers while on the machine in web form are passed through a vat which is called the size-tub, and which is filled with a liquid sizing made of gelatine from clippings of the horns, hides, and hoofs of cattle, this gelatine or glue being mixed with dissolved alum and made fluid in the vat. Papers which are treated in this way are known as “animal,” or “tub-sized.”♦Loft drying♦We have duly described machine-dried papers, but these higher grades of writing-papers are dried by what is known as loft, or pole-dried process. Such paper is permitted to dry very slowly in a loft specially constructed for the purpose, where it is hung on poles several days, during which time the loft is kept at a temperature of about 100° Fahrenheit.Another detail of considerable importance is that of the “finish” or surface of the paper. When paper with a particularly high or glossy surface is desired it is subjected to a separate process after leaving the paper machine, known as supercalendering.♦Supercalendering♦“Supercalendering” is effected by passing the web through the stack of rolls shown in theillustration, which are similar to the machine calenders already described. These rolls are composed of metal cylinders, alternating with rolls made of solidified paper or cotton, turned exactly true, the top and bottom rolls being of metal and heavier than the others; a stack of supercalenders is necessarily composed of an odd number of rolls, as seven, nine, or eleven. The paper passes and repasses through these calenders until the requisite degree of smoothness and polish has been acquired.♦Electricity in paper♦The friction in this machine produces so much electricity that ground wires are often used to carry it off, in order that the paper may not become so highly charged as to attract dust or cause the sheets to cling together. When the fine polish has been imparted, the rolls of paper go to the cutting machines, which are automatic in action, cutting regular sheets of the requiredlength as the paper is fed to them in a continuous web. In the manufacture of some high grades of paper, such as linens and bonds, where an especially fine, smooth surface is required, the sheets after being cut are arranged in piles of from twelve to fifteen sheets, plates of zinc are inserted alternately between them, and they are subjected to powerful hydraulic pressure.♦Plating♦This process is termed “plating,” and is, of course, very much more expensive than the process of supercalendering described above.♦Sorting♦From the cutters, the sheets are carried to the inspectors, who are seated in a row along an extended board table, before two divisions with partitions ten or twelve inches high, affording spaces for the sheets before and after sorting. The work of inspection is performed by women, who detect almost instantly any blemish or imperfection in the finished product as it passes through their hands. If the paper is to be ruled for writing purposes, it is then taken to the ruling machines, where it is passed under revolving disks or pens, set at regular intervals. These convey the ruling ink to the paper as it passes on through the machine, and thus form true and continuous lines.♦Ruling and folding♦If the paper is tobe folded after ruling, as in the case of fine note-papers, the sheets pass on from the ruling machine to the folding machines, which are entirely automatic in their action. The paper is stacked at the back of the first folding guide, and is fed in by the action of small rubber rollers, which loosen each sheet from the one beneath, and push it forward until it is caught by the folding apparatus. Man’s mechanical ingenuity has given to the machines of his invention something that seems almost like human intelligence, and in the case of the folding machine, the action is so regular and perfect that there seems to be no need of an attendant, save to furnish a constant supply of sheets. The folding completed, cutting machines are again brought into requisition, to cut and trim the sheets to the size of folded note or letter paper, which is the final operation before they are sent out into the world on their mission of usefulness. The finished paper may or may not have passed through the ruling and folding process, but in either case it goes from the cutters to the wrappers and packers, and then to the shipping-clerks, all of whom perform the duties indicated by their names. The wonderful transformation wrought by the magic wand ofscience and human invention is complete, and what came into the factory as great bales of offensive rags, disgusting to sight and smell, goes forth as delicate, beautiful, perfected paper, redeemed from filth, and glorified into a high and noble use.♦Beauty of perfected paper♦Purity and beauty have come from what was foul and unwholesome; the highly useful has been summoned forth from the seemingly useless; a product that is one of the essential factors in the world’s progress, and that promises to serve an ever-increasing purpose, has been developed from a material that apparently held not the slightest promise. Well might the “Boston News Letter” of 1769 exclaim in quaint old rhyme:“Rags are as beauties which concealed lie,But when in paper, charming to the eye!Pray save your rags, new beauties to discover,For of paper truly every one’s a lover;By the pen and press such knowledge is displayedAs would not exist if paper was not made.”And well may man pride himself on this achievement, this marvelous transformation, which represents the fruitage of centuries of striving and endeavor!BLOWPIPES COOLING CALENDER ROLLS♦Wood pulp♦Up to this point the reference has been almostentirely to paper made from rags, but radical improvements have been made, caused by the introduction of wood pulp, and these are of such importance that the account would not be complete without some mention of them. These changes are mainly in the methods of manipulating the wood to obtain the pulp, for when that is ready, the process, from and including the “washers” and “beaters,” is very similar to that already described. All papers, whether made from rags or wood, depend upon vegetable fiber for their substance and fundamental base, and it is found that the different fibers used in paper-making, when finally subdued, do not differ, in fact, whether obtained from rags or from the tree growing in the forest. In the latter case the raw wood is subjected to chemical treatment which destroys all resinous and foreign matters, leaving merely the cellular tissue, which, it is found, does not differ in substance from the cell tissue obtained after treating rags. In either case, this cellular tissue, through the treatment to which the raw material is subjected, becomes perfectly plastic or moldable, and while the paper made from one differs slightly in certain characteristics from the paper made from the other, they are nevertheless very similar, and it might besafe to predict that further perfecting of processes will eventually make them practically alike.♦Mechanical wood♦The woods used for this purpose are principally poplar and spruce, and there are three classes of the wood pulp: (1) mechanical wood, (2) soda process wood, and (3) sulphite wood pulp. The first method was invented in Germany in 1844. The logs are hewn in the forest, roughly barked, and shipped to the factory, where the first operation is to cut them up by steam saws into blocks about two feet in length. Any bark that may still cling to the log is removed by a rapidly revolving corrugated wheel of steel, while the larger blocks are split by a steam splitter. The next stage of their journey takes these blocks to a great millstone, set perpendicularly instead of horizontally. Here a very strong and ingenious machine receives one block at a time, and with an automatically elastic pressure holds it sidewise against the millstone, which, like the mills of the gods, “grinds exceeding fine,” and with the aid of constantly flowing water rapidly reduces these blocks to a pulpy form. This pulp is carried into tanks, from which it is passed between rollers, which leave it in thick, damp sheets, which are folded up evenly for shipment, or for storage forfuture use. If a paper-mill is operated in connection with the pulp-mill, the wood pulp is not necessarily rolled out in sheets, but is pumped directly from the tanks to the beaters.In the preparation of pulp by the other processes, the blocks are first thrown into a chipping machine with great wheels, whose short, slanting knives quickly cut the blocks into small chips.
CHAPTER VMODERN PAPER-MAKING♦The modern mill♦Though the steady march of progress and invention has given to the modern paper-maker marvelous machines by which the output is increased a thousand-fold over that of the old, slow methods, he still has many of the same difficulties to overcome that confronted his predecessor. While the use of wood pulp has greatly changed the conditions as regards the cheaper grades of this staple, the ragman is to-day almost as important to the manufacturer of the higher grades as he was one hundred years ago, when the saving of rags was inculcated as a domestic virtue and a patriotic duty. Methods have changed, but the material remains the same. In a complete modern mill, making writing and other high-grade papers, the process begins with unsightly rags as the material from which to form the white sheets that are to receive upon their spotless polished surface the thoughts of philosophers and statesmen, the tender messages of affection, the counsels and admonitionsof ministers, the decisions of grave and learned judges, and all the“Wisdom of things, mysterious, divine,” that“Illustriously doth on paper shine,”as was duly set forth in rhyme by the “Boston News Letter” in 1769. “The bell cart will go through Boston about the end of next month,” it announced, and appealed to the inhabitants of that modern seat of learning and philosophy to save their rags for the occasion, and thus encourage the industry.♦The methods of to-day♦The rags do not come to the mammoth factories of to-day in “bell carts,” but by the carload, in huge bales, gathered from all sections of this great Republic, as well as from lands beyond the eastern and the western oceans. The square, compact, steam-compressed bundles are carried by elevators well up toward the top of the building, where they await the knife of the “opener.” When they have been opened, the “feeder” throws the contents by armfuls into the “thrasher.” The novice or layman, ignorant of the state in which rags come to the mill, will find their condition a most unpleasant surprise, especially disagreeable to his olfactory nerves. Yet theunsavory revelation comes with more force a little farther on, in the “assorting-room.”♦The thrasher♦The “thrasher” is a great cylindrical receptacle, revolving rapidly, which is supplied with long wooden beaters or arms, passing through a wooden cylinder, and driven by power.♦The sorting room♦When the rags have been tossed in, there ensues a great pounding and thrashing, and the dust is carried off in suction air-tubes, while the whipped rags are discharged and carried to the “sorting” and “shredding” room. Here the rags are assorted as to size, condition, and the presence of buttons, hooks and eyes, or other material that must be removed. Then those that need further attention are passed on to the “shredders,” these as well as the “sorters” being women. The “shredders” stand along a narrow counter; in front of each one there is fastened a long scythe-blade, with its back toward the operator and its point extending upward, the shank being firmly fixed to the table or operating board. Here buttons, hard seams, and all similar intruders are disposed of, and the larger pieces of rags are cut into numerous small ones on the scythe-blades. The rags thus prepared are tossed by the women into receptacles in the tables. The work in this roomis the most disagreeable and unwholesome of any in the entire process of manufacture, and this despite the fact that these rags, too, have been thrashed, and freed from an amount of dust and dirt beyond ordinary belief.♦The higher grades♦While watching the operations carried on here, it is impossible to repress the wish that rags might be bought otherwise than by the pound, for, unfortunately, filth, dust, and dirt weigh, and to wash rags only reduces the weight. While this is a true reflection of the condition in the average mill, it is pleasant to know, however, there are others of the higher class that are decided exceptions, as far as dust and dirt are concerned. Such are the mills making high-grade ledger and bond papers, as well as the mill manufacturing the paper that is used for the printing of our “greenbacks,” to which further reference will be made later. In these exceptional mills everything is neat and perfectly clean, all the stock used being new and fresh from the cotton or linen mills, or from factories producing cloth goods, like shirt and corset factories, and others of the same sort. The sorting and shredding room is always large and light, with windows on all sides, and is well ventilated, offering adecided contrast in many respects to the less cleanly mills first referred to, where the women must wear bonnets or hoods for the protection of the hair. In either case the process is certainly an improvement over the old plan of leaving the rags to decay in a cellar to expedite the removal of the glutinous matter.♦The cutter♦From the “sorting” and “shredding” room the rags are conveyed to the “cutter,” where they are cut and chopped by revolving knives, leaving them in small pieces and much freer from dust and grit. Various ingenious devices are employed for removing metal and other hard and injurious matter, magnetic brushes serving this purpose in some mills.♦The devil♦When the “cutter” has finished its work, the still very dirty rags go for a further cleansing to the “devil,” or “whipper,” a hollow cone with spikes projecting within, against which work the spikes of a drum, dashing the rags about at great speed. Human lives are often freed of their baser elements and restored to purity and beauty through the chastening influences of tribulation or adversity; in like manner the “whipper” carries the rags forward a step in the process of purification that is necessary before they can be brought to theirhighest usefulness. But the cleansing process, which is only a preparation for what is to follow, does not end with the “whipper,” the latter having served merely to loosen, not to dislodge, a great deal of dust and dirt.♦The duster♦The final operation in the preliminary cleaning is performed by the “duster” proper, which is a conical revolving sieve. As the mass of rags is tossed and shaken about the loosened dust is carried away by the suction of the air, which draws the dust particles into tubes furnished with suction fans. In most modern mills the rags are carried forward from the “duster” on an endless belt, and a careful watch is kept upon them as they emerge to detect the presence of unchopped pieces, buttons, or other foreign substances. The journey of the rags over this endless belt or conveyor terminates in a receiving-room, in the floor of which there are several openings, and immediately below these the mouths of the “digesters,” which are in a room beneath.♦The digester♦The “digesters,” as they are suggestively and appropriately termed, are huge revolving boilers, usually upright, which often have as great a diameter as eight feet, with a height of twenty-two feet, and whose digestive capacity is upward of five tons of rags each.♦Cooking of rags♦The rags that are to be “cooked” are fed into the “digesters” through the openings in the floor, and the great movable manhole plates are then put in place and closed, hermetically sealing the openings or mouths through which the boilers have been fed, these having first been charged with a mixed solution of lime and soda, and with live hot steam in lieu of gastric juice as a digesting fluid and force. In some mills the boilers are placed in a horizontal position, while in others they are in the form of a large ball or globe, in either case being operated in the manner described; those of upright form, however, are most commonly in use. The rags are boiled under steam pressure of about forty pounds to the square inch, and the cooking is continued from twelve to fourteen hours.THE MODERN FOURDRINIER MACHINE—Page 73♦The washers or Hollanders♦It is here that the process of cleaning begins in earnest; and as the mass of rags is tumbled about in its scalding bath of steam-heated lime-water, or “milk of lime,” the coloring and glutinous matters, as well as all other impurities, are loosened from the fibers, which are in the end so cleansed and purified as to come forth unstained and of virgin purity. Having been sufficiently boiled and digested, the mushy material, still lookingdark and forbidding, is emptied onto the floor below or into receptacles placed directly beneath the boilers, where the color and dirt are allowed to drain off. The mass is then conveyed to the “washers,” great tub-like receptacles, which are shown among theillustrations, and which are known as “Hollanders,” from the fact that these rag engines were invented in Holland, about the year 1750A. D.They are oval-shaped tubs, about twenty feet long, nine feet wide, and three feet high, varying somewhat according to the conditions. Each tub is divided for two-thirds of its length by an upright partition, or “mid-feather,” as it is called, which makes a narrow course around the vat. On one side of the partition the tub is raised in a half-circle, close to which revolves an iron roll about three or four feet in diameter, and covered with knives; in the bottom of the tub, and directly under the revolving roll, is another set of knives called a “bed-plate,” which is stationary, and against which the roll can be lowered. But not to anticipate. When the emptyings from the boiler have been thrown into the “washer” a continuous stream of water is turned in at one end, the knife-roll having been adjusted so as to open up the rags as they are setin motion. These then begin a lively chase around the edge of the vat, through the racecourse formed by the “mid-feather,” and under the rag-opening knives, where the water is given a chance to wash out all impurities; then on up the incline over the “back fall,” so-called from the elevation in the tub. A cylinder of wire cloth, partly immersed in the moving mass, holds back the now rapidly whitening fibers, while the dirty water escapes into buckets inside the wire cloth drum, and is discharged into and through an escape-spout. The heavy particles of dirt settle into what is termed a “sand-trap” at the bottom of the tub.♦Bleaching material♦As the water clears, the roll is lowered closer and closer to the bottom of the bed-plate, in order to open up the fibers more thoroughly for the free circulation of the water among them. When the several agencies of the “washer” have accomplished their purpose, and the water runs clear and unsullied, a bleaching material is put into the mass, which in the course of from two to six hours becomes as white as milk. The dirty offscourings of all ragdom, first seen in the original bales, and gathered from the four quarters of the globe, have endured many buffetings,many bruisings and tribulations, and having been washed come forth pure, sweet, and clean. From the washers the rags are precipitated through a trap into drainers, which are chambers made of stone and brick, with a false bottom, through which the water is allowed to drain. This rag pulp, now called half stock, is kept in this receptacle until the water and liquor are thoroughly drained off, when it becomes a white and compact mass of fibers.♦The drainers♦The rags should stand in the drainers for at least one week, though better results are obtained if they are left for a period two or three times as long, as the fibers become more subdued. The process of paper-making, as it has already been described, applies more particularly to papers made from rags. To-day a very large proportion of the cheaper papers are made from wood, either entirely or in part, and these wood-made papers are subjected to a different treatment, to which further reference will be made in this chapter.♦The beaters♦From the drainer the mass is carted to the beating engine, or “beater,” which is very similar in construction to the washer just described. The knives on the roll in the beater are grouped threetogether instead of two, and are placed nearer the bottom or bed-plate in order to separate more thoroughly the fibers. In the beater are performed many and varying manipulations, designed not only to secure a more perfect product, but also to produce different varieties of paper. It is the theory of the beating process that the fibers are not cut, but are drawn out to their utmost extent. In watching the operations of the “beater,” one notices on the surface of the slowly revolving mass of fibers, floating bluing, such as the thrifty housewife uses to whiten fine fabrics. This familiar agency of the laundry is introduced into the solution of fibers with the same end in view that is sought in the washtub—to give the clear white color that is so desirable. Many of the inventions and discoveries by which the world has profited largely have been due primarily to some fortunate accident, and according to a pretty story upon which paper-makers have set the seal of their belief for more than one hundred and fifty years, the use of bluing was brought about in the same way.♦The bluing story♦About the year 1746, so runs the story, a Mrs. Buttonshaw, the wife of an English paper-maker, accidentally dropped into a tub of pulp the bag of bluing, or its contents,which she was about to use in a washing of fine linen. Frightened at what she had done, and considering it the part of wisdom to keep silence, she discreetly held her peace and awaited results. But when her husband had expressed great wonder and admiration over the paper made from that particular pulp, and had sold it in London at an advance of several shillings over the price of his other paper, which had not met with any such accident, she realized that the time for silence had passed. Her account of the happy accident led her grateful husband to purchase a costly scarlet cloak for her on his next visit to London town. This accident brought about another result which was to prove of inestimable value to the future paper-maker—the use of bluing in paper when especial whiteness is desired.♦Engine-sizing♦Important as the bluing or coloring is, however, it is only one of the numerous operations or manipulations that take place in the beater. Many of these, such as engine-sizing and body-coloring, require skill and constant watchfulness. Here, too, if anywhere, adulteration takes place. It is sometimes necessary to secure a fine-appearing paper at small cost, and it is profitable to add toits weight. In such cases, a process of “loading” takes place here, and clay or cheap, heavy fibers are added. Clay is of value not only to increase the weight, but also to render the paper more opaque, so as to prevent type or illustrations from showing through, while at the same time it makes possible a smoother surface by filling the pores in the paper. But while it adds to the weight, clay must, of necessity, weaken the paper. In engine-sizing, which is done in the beater, the size is thoroughly incorporated with the fibers as these revolve or flow around the engine. This sizing renders the paper more nearly impervious to moisture. The difference between a paper that is sized, and that has a repellent surface which prevents the ink from settling into it when it is written upon, and an ordinary blotting-paper with its absorbent surface, is due entirely to the fact that the former is most carefully treated with sizing, both in the beating engine and in the size tub or vat referred to later, whereas in the latter paper it is omitted.♦Body-coloring♦If the paper is to be tinted or body-colored, colors made from aniline are generally used. Only in the highest grade of writing-paper, and in some few papers that demand colors fast to the light, is any other order of coloringmatter employed. As may be easily imagined, considerable skill is required to secure exactly the desired tint, and to get the coloring matter so evenly mixed that each small fiber shall receive its proper tint, thus insuring that the paper when finished shall be of uniform color and not present a mottled appearance.♦Machine for making continuous web♦When the operations of the beating engine have been completed, a most interesting process begins, which marks a vast advance over the earlier method of forming the sheets of paper with mold and deckel, straining off the water, and shaking the frame with a quick motion to mat the fibers together. The patient striving toward something better, which has marked all the centuries since man first learned to carve his rude records, finds its consummation in the process of making paper in a continuous web. This result is accomplished by a machine first invented by Louis Robert, a workman in a mill at Enonnes, France, who obtained a French patent, with a bounty of eight thousand francs for its development. This he later sold to M. Didot, the proprietor of the mill, and the latter crossed the Channel into England, where, with the aid of a skilled mechanic, the machine was in a measure perfected, and then soldto Henry and Sealy Fourdrinier. They, with the further aid of Bryan Donkin, their employe and expert engineer, made many additional improvements, and sunk in the enterprise some sixty thousand pounds sterling, for which their only reward was blighted hopes and embittered lives. In 1847 the London “Times” made a fruitless appeal on behalf of the surviving brother, who was eighty years of age, and in great poverty. It is seldom that the world voluntarily makes return to those who have bestowed upon it great material or moral benefits, though it is ever ready to expend its treasure for engines of destruction, and to magnify and reward those who have been most successful in destroying human life.♦First machine mill♦The first “machine” mill was started at Frogmore, Hertz, England, in 1803, which was the year of the great Louisiana Purchase by the United States, and it is not difficult to say which event has been productive of the greater and more beneficial results to this nation. Through this invention and its improvements the modern newspaper and magazine, with their tens and hundreds of thousands of copies daily, have been made possible, and men of all classes have been brought in touch with the best thought of theday. Whatever makes for greater intelligence and enlightenment throughout a nation makes for the greater stability of the national life, and gives new emphasis to Bulwer’s words:“Take away the sword;States can be saved without it—bring the pen.”♦The power of the pen♦If to-day the power of the pen over the sword is greater than it has ever been before, its increased and increasing influence must be credited in large measure to the inventive genius and the public-spirited enterprise that has made possible the great output of our modern paper-mills. So thoroughly did these forces do their work in the beginning, that in the century that has elapsed since the Fourdrinier brothers sacrificed themselves and their means in the perfecting of their machine, there have been really no changes in the fundamental principle. Those that have been made have been in the nature of further development and improvement, such as increasing the speed and widening the web, thereby multiplying the product many fold.THE FIRST PRESS ROLLS—Page 75♦The Jordan engine♦But to resume the interesting journey of the rags, which had reached a state of purification and perfection as pulp, and which we left in thebeaters. In some grades of paper the perfected and prepared pulp is taken from the beaters and passed through what is known as a “refining” or “Jordan” engine; this for the purpose of more thoroughly separating the fibers and reducing them to extreme fineness. The refining engines, are, however, used only in the manufacture of certain grades of paper.♦The stuff chest♦The pulp is next taken from the beater or refining engine, as the case may be, to what is called a “stuff-chest,” an inclosed vat partly filled with water, in which a contrivance for shaking and shifting, properly called an “agitator,” keeps the fibers in suspension.♦The screen♦From the stuff-chest the mixture is pumped into what is known as the “mixing” or “regulating” box. Here the stream first passes over the “sand-tables” in a continuous flow. These are composed of little troughs with cross-pieces, and are covered at the bottom with long-haired felt, to catch any sand or dirt that may still adhere after the numerous operations to which the pulp has been subjected. The flow is then forced through the “screen,” which is a horizontal piece of metal pierced with slots. For very fine paper, these slots are so small as to be only one one-hundredthof an inch in width. They are usually about a quarter of an inch apart. Through these tiny apertures the fibers must find their way, leaving behind in their difficult passage all lumps, dirt, or knotted fibers which would mar the perfection of the product toward which they are tending. A vibrating motion is given to the screen as the flow passes over it, or revolving strainers may be used.♦The flow onto machine♦When the screen has finished its work, the water carrying the pulp in solution flows in an even stream, whose volume varies according to the width of the web of paper to be produced, through a discharge-cock onto the Fourdrinier or cylinder machine, as the case may be, each of which will be duly described. This stream has a filmy appearance, and is of diverse color, depending upon the shade of paper to be produced. From its consistency, which is about that of milk, it is difficult to imagine that it floats separate particles of fiber in such quantities as, when gathered on the wire cloth and passed to a felt blanket and then pressed between rollers, to form in a second of time a broad web of embryo paper sufficiently strong and firm to take definite form. Man’s mastery of the process by which thisstartling and wonderful change is effected has come as one of the rewards of his long and patient study.The Fourdrinier machine, which preserves at least the name of the enterprising developers of the invention, takes up the work that was formerly done by the molder. The wire cloth upon which the fibers are discharged as described is an endless belt, the full width of the paper machine. Upon this the fibers spread out evenly, being aided by a fan-shaped rubber or oil cloth, which delivers the smooth stream under a gate regulated to insure perfect evenness and to fix uniformly the fibers of the web now commencing its final formation.♦Deckel-straps♦Deckel-straps of india-rubber are fastened on both sides of the wire screen, and move with it, thus holding the watery pulp in place. The deckel-straps are adjustable, and fix or regulate the width of the paper. These and the gate, or “slicer,” are attached to what is termed the deckel-frame, which corresponds to the deckel used by paper-makers in the days when the manufacture was carried on by hand.♦Endless wire cloth♦As the stream flows onto the endless belt of wire cloth, the water which has borne the fibers filters into the trough beneath. Being charged with very fine fibers,size, coloring matter, and other similar ingredients, it is carried back into the pulp-chest, to save these materials, as well as to contribute again to the extra supply of water needed.♦The save-all♦For this reason the trough into which it falls from the revolving “wire” is called the “save-all.” A shaking motion is imparted to the “wire” from the frame upon which rest the rolls that keep it in its never-ending round. This aids in draining away the water, and mats or interlaces the fibers together. At the end of the “save-all,” where the fibers are to leave the “wire” for the next stage of their journey, suction-boxes are placed, provided with an air-pump to take up the surplus water that has not yet found its way through the meshes.♦The dandy roll♦Between these suction-boxes above the wire is a wire-covered roll, which impresses the newly formed sheet; this impression cylinder is called a “dandy roll,” and it is from this that the web receives the markings or impressions that characterize different papers. All watermarks, patterns, and designs which it is desired to have appear in the paper are put upon this roll, and here impressed upon the soft sheet, which is clarified and left transparent at the points of contact. Thus the impression is permanently fixed in the fiber, so that it can beseen at any time by holding the sheet to the light. The power of suggestiveness is a quality which is highly esteemed wherever it is found, and which frequently furnishes a standard of judgment. Judged by such a criterion, the impression cylinder, or “dandy roll,” has an added value, for in all probability its operation suggested the idea of printing from cylinders, as in our present web or perfecting presses.♦The press-rolls♦The matted pulp, now having sufficient body, passes on between two rolls covered with felt, which deliver the web of damp paper upon an endless belt of moist felt, while the “wire” passes under and back to continue a fresh supply. The paper is as yet too fragile to travel alone, and the web felt carries it between two metal rolls called the first press-rolls. These squeeze out more water, give a greater degree of compactness to the fibers, smooth the upper surface, and finally deliver the web of paper to a second felt apron, which carries it under and to the back of the second press-rolls. In this way the under surface comes to the top, and is in its turn subjected to the smoothing process. A delicate scraper or blade, the length of the press-rolls, is so placed on each roll that should theendless web from any cause be broken, the blade may operate with sufficient force to prevent the wet paper from clinging to the rolls and winding about them. From this point the paper travels alone, having become firm and strong enough to sustain its own weight; passing above the second press-rolls, it resumes its onward journey around the drying cylinders, passing over and under and over and under.♦The dryers♦The drying cylinders are hollow and heated by steam, their temperature being regulated according to requirements. These driers, made from iron or steel, are usually from three to four feet in diameter, and vary in length according to the width of the machine. There are from twelve to fifty of these cylinders, their number depending upon the character and weight of the paper to be produced, very heavy sheets requiring many more drying cylinders than sheets of lighter weight.♦Tensile strength♦Strange, almost phenomenal, conditions come about in the transformation from filmy pulp to finished paper. A sheet which, though formed, is at the first press-roll too fragile to carry its own weight, becomes possessed of a final strength and power that is almost incredible. The myriad of minute fibers composing the sheet, upon drying uniformly, possesses great aggregate strength. Asheet of paper yields readily to tearing, but the same sheet, when a perfectly even tension is applied, will demonstrate that it is possessed of wonderful resisting power. In evidence may be cited an instance that seems almost beyond belief. Through some curious mishap a web of heavy paper, in fact, bristol board, which had been thoroughly formed, was suddenly superheated and then cooled while still on the driers. This was caused by a difference in temperature of the driers and resulted in the sudden contraction of the web of bristol; the strain on the machine was so great that not only were the driving-cogs broken on two of the driers around which the paper was at the moment passing, but the driers themselves were actually lifted out of place, showing a resisting power in the paper of at least several tons.♦The calenders♦The paper now passes to the upright stack of rolls shown in theillustrations, which are known as “calenders.” The word is derived from calendra; a corruption of cylindrus, a roller or cylinder, they are simply rollers revolving in contact, and heated from the interior by steam. These calenders are used for giving to the paper a smooth and even surface, and are also employed in the smoothing and finishing of cloth.♦Speed of machines♦Thespeed with which the paper passes through these cylinders is remarkable, from one hundred to five hundred feet running through and over the machine in a minute; and in some of the most recent mills the web is as wide as one hundred and fifty-six inches (thirteen feet); this is very nearly double the average machine width of a few years ago, while the speed has increased in proportionate ratio; only a very few years ago the maximum speed was from two hundred and fifty to three hundred feet per minute; at this writing (1900) there are machines in operation which run as high as five hundred feet per minute. But great as has been the increase in the production of paper, the demand has kept pace steadily. The wonderful product of the rag-bag holds an invincible position in the world’s economy.THE SIZE-TUB—Page 81♦Five miles in a roll♦For machine-finished book and print papers, as well as for other cheaper grades, the process ends with the calenders, after which the paper is slit into required widths by disk-knives, which are revolving, and so cut continuously. Paper intended for web newspaper presses is taken off in continuous rolls of the widths required, varying from seventeen to seventy-six inches, according to the size of the paper to be printed. Thesereels contain from fifteen to twenty-five thousand lineal feet of paper, or from three to five miles. The amount of paper used in disseminating the news of the day is enormous; sometimes one or two mills are required to manufacture the supply for a single metropolitan daily, while one New York newspaper claims to have used four hundred and fifty tons of paper in one Christmas edition, which is about four times the amount of its regular daily consumption.After having been slit into the proper widths by the revolving knives, ordinary flat and book papers are cut into sheets by a straight knife revolving at proper intervals on a horizontal drum. The paper, in sheets, is carried by a traveling apron onto a receiving table at the end of the machine, where the sheets as they fall are carefully examined by experts, usually women, who remove any that may be imperfect.♦The immensity of modern machines♦The entire length of a paper machine, from the screens to the calenders, is about one hundred and twenty-five feet, while the height varies, the average being about ten feet. The machines, while necessarily of the finest adjustment, are ponderous and heavy, weighing in some cases as much as four hundred tons, this being the weight of themachine itself, exclusive of its foundations. The machine-room is of necessity well lighted and thoroughly ventilated, and should be kept clean throughout, as cleanliness is an essential factor in the making of good paper.♦Deckel edging♦While the same general process applies to all classes of paper made, the particular character of any paper that is to be produced determines exactly the details of the process through which it shall pass, and regulates the deviations to be made from the general operations in order to secure special results. For example, some papers are wanted with a rough or “antique” finish, as it is called; in such cases calendering is omitted. Another special process is that by which the paper is made with a ragged or “deckel edge”; this result is obtained in some mills by playing a stream of water upon the edge of the pulp, crushing and thinning it, and thus giving it a jagged appearance. At the present time this “deckel-edge” paper is being quite extensively used in high-class bookwork.In the case of writing-papers, as has already been stated in the description of the beating engines, a vegetable sizing made from resinous matter is introduced into the paper pulp while itis still in solution, and mixes with it thoroughly, thus filling more or less completely the pores of the pulp fibers. This is found sufficient for all ordinary book-papers, for papers that are to be printed upon in the usual way, and for the cheapest grades of writing-paper, where the requirements are not very exacting, and where a curtailment of expense is necessary. For the higher grades of writing-paper, however, a distinctly separate and additional process is required.♦Tub sizing♦These papers while on the machine in web form are passed through a vat which is called the size-tub, and which is filled with a liquid sizing made of gelatine from clippings of the horns, hides, and hoofs of cattle, this gelatine or glue being mixed with dissolved alum and made fluid in the vat. Papers which are treated in this way are known as “animal,” or “tub-sized.”♦Loft drying♦We have duly described machine-dried papers, but these higher grades of writing-papers are dried by what is known as loft, or pole-dried process. Such paper is permitted to dry very slowly in a loft specially constructed for the purpose, where it is hung on poles several days, during which time the loft is kept at a temperature of about 100° Fahrenheit.Another detail of considerable importance is that of the “finish” or surface of the paper. When paper with a particularly high or glossy surface is desired it is subjected to a separate process after leaving the paper machine, known as supercalendering.♦Supercalendering♦“Supercalendering” is effected by passing the web through the stack of rolls shown in theillustration, which are similar to the machine calenders already described. These rolls are composed of metal cylinders, alternating with rolls made of solidified paper or cotton, turned exactly true, the top and bottom rolls being of metal and heavier than the others; a stack of supercalenders is necessarily composed of an odd number of rolls, as seven, nine, or eleven. The paper passes and repasses through these calenders until the requisite degree of smoothness and polish has been acquired.♦Electricity in paper♦The friction in this machine produces so much electricity that ground wires are often used to carry it off, in order that the paper may not become so highly charged as to attract dust or cause the sheets to cling together. When the fine polish has been imparted, the rolls of paper go to the cutting machines, which are automatic in action, cutting regular sheets of the requiredlength as the paper is fed to them in a continuous web. In the manufacture of some high grades of paper, such as linens and bonds, where an especially fine, smooth surface is required, the sheets after being cut are arranged in piles of from twelve to fifteen sheets, plates of zinc are inserted alternately between them, and they are subjected to powerful hydraulic pressure.♦Plating♦This process is termed “plating,” and is, of course, very much more expensive than the process of supercalendering described above.♦Sorting♦From the cutters, the sheets are carried to the inspectors, who are seated in a row along an extended board table, before two divisions with partitions ten or twelve inches high, affording spaces for the sheets before and after sorting. The work of inspection is performed by women, who detect almost instantly any blemish or imperfection in the finished product as it passes through their hands. If the paper is to be ruled for writing purposes, it is then taken to the ruling machines, where it is passed under revolving disks or pens, set at regular intervals. These convey the ruling ink to the paper as it passes on through the machine, and thus form true and continuous lines.♦Ruling and folding♦If the paper is tobe folded after ruling, as in the case of fine note-papers, the sheets pass on from the ruling machine to the folding machines, which are entirely automatic in their action. The paper is stacked at the back of the first folding guide, and is fed in by the action of small rubber rollers, which loosen each sheet from the one beneath, and push it forward until it is caught by the folding apparatus. Man’s mechanical ingenuity has given to the machines of his invention something that seems almost like human intelligence, and in the case of the folding machine, the action is so regular and perfect that there seems to be no need of an attendant, save to furnish a constant supply of sheets. The folding completed, cutting machines are again brought into requisition, to cut and trim the sheets to the size of folded note or letter paper, which is the final operation before they are sent out into the world on their mission of usefulness. The finished paper may or may not have passed through the ruling and folding process, but in either case it goes from the cutters to the wrappers and packers, and then to the shipping-clerks, all of whom perform the duties indicated by their names. The wonderful transformation wrought by the magic wand ofscience and human invention is complete, and what came into the factory as great bales of offensive rags, disgusting to sight and smell, goes forth as delicate, beautiful, perfected paper, redeemed from filth, and glorified into a high and noble use.♦Beauty of perfected paper♦Purity and beauty have come from what was foul and unwholesome; the highly useful has been summoned forth from the seemingly useless; a product that is one of the essential factors in the world’s progress, and that promises to serve an ever-increasing purpose, has been developed from a material that apparently held not the slightest promise. Well might the “Boston News Letter” of 1769 exclaim in quaint old rhyme:“Rags are as beauties which concealed lie,But when in paper, charming to the eye!Pray save your rags, new beauties to discover,For of paper truly every one’s a lover;By the pen and press such knowledge is displayedAs would not exist if paper was not made.”And well may man pride himself on this achievement, this marvelous transformation, which represents the fruitage of centuries of striving and endeavor!BLOWPIPES COOLING CALENDER ROLLS♦Wood pulp♦Up to this point the reference has been almostentirely to paper made from rags, but radical improvements have been made, caused by the introduction of wood pulp, and these are of such importance that the account would not be complete without some mention of them. These changes are mainly in the methods of manipulating the wood to obtain the pulp, for when that is ready, the process, from and including the “washers” and “beaters,” is very similar to that already described. All papers, whether made from rags or wood, depend upon vegetable fiber for their substance and fundamental base, and it is found that the different fibers used in paper-making, when finally subdued, do not differ, in fact, whether obtained from rags or from the tree growing in the forest. In the latter case the raw wood is subjected to chemical treatment which destroys all resinous and foreign matters, leaving merely the cellular tissue, which, it is found, does not differ in substance from the cell tissue obtained after treating rags. In either case, this cellular tissue, through the treatment to which the raw material is subjected, becomes perfectly plastic or moldable, and while the paper made from one differs slightly in certain characteristics from the paper made from the other, they are nevertheless very similar, and it might besafe to predict that further perfecting of processes will eventually make them practically alike.♦Mechanical wood♦The woods used for this purpose are principally poplar and spruce, and there are three classes of the wood pulp: (1) mechanical wood, (2) soda process wood, and (3) sulphite wood pulp. The first method was invented in Germany in 1844. The logs are hewn in the forest, roughly barked, and shipped to the factory, where the first operation is to cut them up by steam saws into blocks about two feet in length. Any bark that may still cling to the log is removed by a rapidly revolving corrugated wheel of steel, while the larger blocks are split by a steam splitter. The next stage of their journey takes these blocks to a great millstone, set perpendicularly instead of horizontally. Here a very strong and ingenious machine receives one block at a time, and with an automatically elastic pressure holds it sidewise against the millstone, which, like the mills of the gods, “grinds exceeding fine,” and with the aid of constantly flowing water rapidly reduces these blocks to a pulpy form. This pulp is carried into tanks, from which it is passed between rollers, which leave it in thick, damp sheets, which are folded up evenly for shipment, or for storage forfuture use. If a paper-mill is operated in connection with the pulp-mill, the wood pulp is not necessarily rolled out in sheets, but is pumped directly from the tanks to the beaters.In the preparation of pulp by the other processes, the blocks are first thrown into a chipping machine with great wheels, whose short, slanting knives quickly cut the blocks into small chips.
CHAPTER VMODERN PAPER-MAKING
♦The modern mill♦
Though the steady march of progress and invention has given to the modern paper-maker marvelous machines by which the output is increased a thousand-fold over that of the old, slow methods, he still has many of the same difficulties to overcome that confronted his predecessor. While the use of wood pulp has greatly changed the conditions as regards the cheaper grades of this staple, the ragman is to-day almost as important to the manufacturer of the higher grades as he was one hundred years ago, when the saving of rags was inculcated as a domestic virtue and a patriotic duty. Methods have changed, but the material remains the same. In a complete modern mill, making writing and other high-grade papers, the process begins with unsightly rags as the material from which to form the white sheets that are to receive upon their spotless polished surface the thoughts of philosophers and statesmen, the tender messages of affection, the counsels and admonitionsof ministers, the decisions of grave and learned judges, and all the
“Wisdom of things, mysterious, divine,” that“Illustriously doth on paper shine,”
“Wisdom of things, mysterious, divine,” that“Illustriously doth on paper shine,”
“Wisdom of things, mysterious, divine,” that“Illustriously doth on paper shine,”
as was duly set forth in rhyme by the “Boston News Letter” in 1769. “The bell cart will go through Boston about the end of next month,” it announced, and appealed to the inhabitants of that modern seat of learning and philosophy to save their rags for the occasion, and thus encourage the industry.
♦The methods of to-day♦
The rags do not come to the mammoth factories of to-day in “bell carts,” but by the carload, in huge bales, gathered from all sections of this great Republic, as well as from lands beyond the eastern and the western oceans. The square, compact, steam-compressed bundles are carried by elevators well up toward the top of the building, where they await the knife of the “opener.” When they have been opened, the “feeder” throws the contents by armfuls into the “thrasher.” The novice or layman, ignorant of the state in which rags come to the mill, will find their condition a most unpleasant surprise, especially disagreeable to his olfactory nerves. Yet theunsavory revelation comes with more force a little farther on, in the “assorting-room.”♦The thrasher♦The “thrasher” is a great cylindrical receptacle, revolving rapidly, which is supplied with long wooden beaters or arms, passing through a wooden cylinder, and driven by power.♦The sorting room♦When the rags have been tossed in, there ensues a great pounding and thrashing, and the dust is carried off in suction air-tubes, while the whipped rags are discharged and carried to the “sorting” and “shredding” room. Here the rags are assorted as to size, condition, and the presence of buttons, hooks and eyes, or other material that must be removed. Then those that need further attention are passed on to the “shredders,” these as well as the “sorters” being women. The “shredders” stand along a narrow counter; in front of each one there is fastened a long scythe-blade, with its back toward the operator and its point extending upward, the shank being firmly fixed to the table or operating board. Here buttons, hard seams, and all similar intruders are disposed of, and the larger pieces of rags are cut into numerous small ones on the scythe-blades. The rags thus prepared are tossed by the women into receptacles in the tables. The work in this roomis the most disagreeable and unwholesome of any in the entire process of manufacture, and this despite the fact that these rags, too, have been thrashed, and freed from an amount of dust and dirt beyond ordinary belief.
♦The higher grades♦
While watching the operations carried on here, it is impossible to repress the wish that rags might be bought otherwise than by the pound, for, unfortunately, filth, dust, and dirt weigh, and to wash rags only reduces the weight. While this is a true reflection of the condition in the average mill, it is pleasant to know, however, there are others of the higher class that are decided exceptions, as far as dust and dirt are concerned. Such are the mills making high-grade ledger and bond papers, as well as the mill manufacturing the paper that is used for the printing of our “greenbacks,” to which further reference will be made later. In these exceptional mills everything is neat and perfectly clean, all the stock used being new and fresh from the cotton or linen mills, or from factories producing cloth goods, like shirt and corset factories, and others of the same sort. The sorting and shredding room is always large and light, with windows on all sides, and is well ventilated, offering adecided contrast in many respects to the less cleanly mills first referred to, where the women must wear bonnets or hoods for the protection of the hair. In either case the process is certainly an improvement over the old plan of leaving the rags to decay in a cellar to expedite the removal of the glutinous matter.
♦The cutter♦
From the “sorting” and “shredding” room the rags are conveyed to the “cutter,” where they are cut and chopped by revolving knives, leaving them in small pieces and much freer from dust and grit. Various ingenious devices are employed for removing metal and other hard and injurious matter, magnetic brushes serving this purpose in some mills.♦The devil♦When the “cutter” has finished its work, the still very dirty rags go for a further cleansing to the “devil,” or “whipper,” a hollow cone with spikes projecting within, against which work the spikes of a drum, dashing the rags about at great speed. Human lives are often freed of their baser elements and restored to purity and beauty through the chastening influences of tribulation or adversity; in like manner the “whipper” carries the rags forward a step in the process of purification that is necessary before they can be brought to theirhighest usefulness. But the cleansing process, which is only a preparation for what is to follow, does not end with the “whipper,” the latter having served merely to loosen, not to dislodge, a great deal of dust and dirt.♦The duster♦The final operation in the preliminary cleaning is performed by the “duster” proper, which is a conical revolving sieve. As the mass of rags is tossed and shaken about the loosened dust is carried away by the suction of the air, which draws the dust particles into tubes furnished with suction fans. In most modern mills the rags are carried forward from the “duster” on an endless belt, and a careful watch is kept upon them as they emerge to detect the presence of unchopped pieces, buttons, or other foreign substances. The journey of the rags over this endless belt or conveyor terminates in a receiving-room, in the floor of which there are several openings, and immediately below these the mouths of the “digesters,” which are in a room beneath.♦The digester♦The “digesters,” as they are suggestively and appropriately termed, are huge revolving boilers, usually upright, which often have as great a diameter as eight feet, with a height of twenty-two feet, and whose digestive capacity is upward of five tons of rags each.
♦Cooking of rags♦The rags that are to be “cooked” are fed into the “digesters” through the openings in the floor, and the great movable manhole plates are then put in place and closed, hermetically sealing the openings or mouths through which the boilers have been fed, these having first been charged with a mixed solution of lime and soda, and with live hot steam in lieu of gastric juice as a digesting fluid and force. In some mills the boilers are placed in a horizontal position, while in others they are in the form of a large ball or globe, in either case being operated in the manner described; those of upright form, however, are most commonly in use. The rags are boiled under steam pressure of about forty pounds to the square inch, and the cooking is continued from twelve to fourteen hours.
THE MODERN FOURDRINIER MACHINE—Page 73
THE MODERN FOURDRINIER MACHINE—Page 73
♦The washers or Hollanders♦
It is here that the process of cleaning begins in earnest; and as the mass of rags is tumbled about in its scalding bath of steam-heated lime-water, or “milk of lime,” the coloring and glutinous matters, as well as all other impurities, are loosened from the fibers, which are in the end so cleansed and purified as to come forth unstained and of virgin purity. Having been sufficiently boiled and digested, the mushy material, still lookingdark and forbidding, is emptied onto the floor below or into receptacles placed directly beneath the boilers, where the color and dirt are allowed to drain off. The mass is then conveyed to the “washers,” great tub-like receptacles, which are shown among theillustrations, and which are known as “Hollanders,” from the fact that these rag engines were invented in Holland, about the year 1750A. D.They are oval-shaped tubs, about twenty feet long, nine feet wide, and three feet high, varying somewhat according to the conditions. Each tub is divided for two-thirds of its length by an upright partition, or “mid-feather,” as it is called, which makes a narrow course around the vat. On one side of the partition the tub is raised in a half-circle, close to which revolves an iron roll about three or four feet in diameter, and covered with knives; in the bottom of the tub, and directly under the revolving roll, is another set of knives called a “bed-plate,” which is stationary, and against which the roll can be lowered. But not to anticipate. When the emptyings from the boiler have been thrown into the “washer” a continuous stream of water is turned in at one end, the knife-roll having been adjusted so as to open up the rags as they are setin motion. These then begin a lively chase around the edge of the vat, through the racecourse formed by the “mid-feather,” and under the rag-opening knives, where the water is given a chance to wash out all impurities; then on up the incline over the “back fall,” so-called from the elevation in the tub. A cylinder of wire cloth, partly immersed in the moving mass, holds back the now rapidly whitening fibers, while the dirty water escapes into buckets inside the wire cloth drum, and is discharged into and through an escape-spout. The heavy particles of dirt settle into what is termed a “sand-trap” at the bottom of the tub.
♦Bleaching material♦
As the water clears, the roll is lowered closer and closer to the bottom of the bed-plate, in order to open up the fibers more thoroughly for the free circulation of the water among them. When the several agencies of the “washer” have accomplished their purpose, and the water runs clear and unsullied, a bleaching material is put into the mass, which in the course of from two to six hours becomes as white as milk. The dirty offscourings of all ragdom, first seen in the original bales, and gathered from the four quarters of the globe, have endured many buffetings,many bruisings and tribulations, and having been washed come forth pure, sweet, and clean. From the washers the rags are precipitated through a trap into drainers, which are chambers made of stone and brick, with a false bottom, through which the water is allowed to drain. This rag pulp, now called half stock, is kept in this receptacle until the water and liquor are thoroughly drained off, when it becomes a white and compact mass of fibers.
♦The drainers♦
The rags should stand in the drainers for at least one week, though better results are obtained if they are left for a period two or three times as long, as the fibers become more subdued. The process of paper-making, as it has already been described, applies more particularly to papers made from rags. To-day a very large proportion of the cheaper papers are made from wood, either entirely or in part, and these wood-made papers are subjected to a different treatment, to which further reference will be made in this chapter.
♦The beaters♦
From the drainer the mass is carted to the beating engine, or “beater,” which is very similar in construction to the washer just described. The knives on the roll in the beater are grouped threetogether instead of two, and are placed nearer the bottom or bed-plate in order to separate more thoroughly the fibers. In the beater are performed many and varying manipulations, designed not only to secure a more perfect product, but also to produce different varieties of paper. It is the theory of the beating process that the fibers are not cut, but are drawn out to their utmost extent. In watching the operations of the “beater,” one notices on the surface of the slowly revolving mass of fibers, floating bluing, such as the thrifty housewife uses to whiten fine fabrics. This familiar agency of the laundry is introduced into the solution of fibers with the same end in view that is sought in the washtub—to give the clear white color that is so desirable. Many of the inventions and discoveries by which the world has profited largely have been due primarily to some fortunate accident, and according to a pretty story upon which paper-makers have set the seal of their belief for more than one hundred and fifty years, the use of bluing was brought about in the same way.♦The bluing story♦About the year 1746, so runs the story, a Mrs. Buttonshaw, the wife of an English paper-maker, accidentally dropped into a tub of pulp the bag of bluing, or its contents,which she was about to use in a washing of fine linen. Frightened at what she had done, and considering it the part of wisdom to keep silence, she discreetly held her peace and awaited results. But when her husband had expressed great wonder and admiration over the paper made from that particular pulp, and had sold it in London at an advance of several shillings over the price of his other paper, which had not met with any such accident, she realized that the time for silence had passed. Her account of the happy accident led her grateful husband to purchase a costly scarlet cloak for her on his next visit to London town. This accident brought about another result which was to prove of inestimable value to the future paper-maker—the use of bluing in paper when especial whiteness is desired.
♦Engine-sizing♦
Important as the bluing or coloring is, however, it is only one of the numerous operations or manipulations that take place in the beater. Many of these, such as engine-sizing and body-coloring, require skill and constant watchfulness. Here, too, if anywhere, adulteration takes place. It is sometimes necessary to secure a fine-appearing paper at small cost, and it is profitable to add toits weight. In such cases, a process of “loading” takes place here, and clay or cheap, heavy fibers are added. Clay is of value not only to increase the weight, but also to render the paper more opaque, so as to prevent type or illustrations from showing through, while at the same time it makes possible a smoother surface by filling the pores in the paper. But while it adds to the weight, clay must, of necessity, weaken the paper. In engine-sizing, which is done in the beater, the size is thoroughly incorporated with the fibers as these revolve or flow around the engine. This sizing renders the paper more nearly impervious to moisture. The difference between a paper that is sized, and that has a repellent surface which prevents the ink from settling into it when it is written upon, and an ordinary blotting-paper with its absorbent surface, is due entirely to the fact that the former is most carefully treated with sizing, both in the beating engine and in the size tub or vat referred to later, whereas in the latter paper it is omitted.♦Body-coloring♦If the paper is to be tinted or body-colored, colors made from aniline are generally used. Only in the highest grade of writing-paper, and in some few papers that demand colors fast to the light, is any other order of coloringmatter employed. As may be easily imagined, considerable skill is required to secure exactly the desired tint, and to get the coloring matter so evenly mixed that each small fiber shall receive its proper tint, thus insuring that the paper when finished shall be of uniform color and not present a mottled appearance.
♦Machine for making continuous web♦
When the operations of the beating engine have been completed, a most interesting process begins, which marks a vast advance over the earlier method of forming the sheets of paper with mold and deckel, straining off the water, and shaking the frame with a quick motion to mat the fibers together. The patient striving toward something better, which has marked all the centuries since man first learned to carve his rude records, finds its consummation in the process of making paper in a continuous web. This result is accomplished by a machine first invented by Louis Robert, a workman in a mill at Enonnes, France, who obtained a French patent, with a bounty of eight thousand francs for its development. This he later sold to M. Didot, the proprietor of the mill, and the latter crossed the Channel into England, where, with the aid of a skilled mechanic, the machine was in a measure perfected, and then soldto Henry and Sealy Fourdrinier. They, with the further aid of Bryan Donkin, their employe and expert engineer, made many additional improvements, and sunk in the enterprise some sixty thousand pounds sterling, for which their only reward was blighted hopes and embittered lives. In 1847 the London “Times” made a fruitless appeal on behalf of the surviving brother, who was eighty years of age, and in great poverty. It is seldom that the world voluntarily makes return to those who have bestowed upon it great material or moral benefits, though it is ever ready to expend its treasure for engines of destruction, and to magnify and reward those who have been most successful in destroying human life.
♦First machine mill♦
The first “machine” mill was started at Frogmore, Hertz, England, in 1803, which was the year of the great Louisiana Purchase by the United States, and it is not difficult to say which event has been productive of the greater and more beneficial results to this nation. Through this invention and its improvements the modern newspaper and magazine, with their tens and hundreds of thousands of copies daily, have been made possible, and men of all classes have been brought in touch with the best thought of theday. Whatever makes for greater intelligence and enlightenment throughout a nation makes for the greater stability of the national life, and gives new emphasis to Bulwer’s words:
“Take away the sword;States can be saved without it—bring the pen.”
“Take away the sword;States can be saved without it—bring the pen.”
“Take away the sword;States can be saved without it—bring the pen.”
♦The power of the pen♦
If to-day the power of the pen over the sword is greater than it has ever been before, its increased and increasing influence must be credited in large measure to the inventive genius and the public-spirited enterprise that has made possible the great output of our modern paper-mills. So thoroughly did these forces do their work in the beginning, that in the century that has elapsed since the Fourdrinier brothers sacrificed themselves and their means in the perfecting of their machine, there have been really no changes in the fundamental principle. Those that have been made have been in the nature of further development and improvement, such as increasing the speed and widening the web, thereby multiplying the product many fold.
THE FIRST PRESS ROLLS—Page 75
THE FIRST PRESS ROLLS—Page 75
♦The Jordan engine♦
But to resume the interesting journey of the rags, which had reached a state of purification and perfection as pulp, and which we left in thebeaters. In some grades of paper the perfected and prepared pulp is taken from the beaters and passed through what is known as a “refining” or “Jordan” engine; this for the purpose of more thoroughly separating the fibers and reducing them to extreme fineness. The refining engines, are, however, used only in the manufacture of certain grades of paper.♦The stuff chest♦The pulp is next taken from the beater or refining engine, as the case may be, to what is called a “stuff-chest,” an inclosed vat partly filled with water, in which a contrivance for shaking and shifting, properly called an “agitator,” keeps the fibers in suspension.
♦The screen♦
From the stuff-chest the mixture is pumped into what is known as the “mixing” or “regulating” box. Here the stream first passes over the “sand-tables” in a continuous flow. These are composed of little troughs with cross-pieces, and are covered at the bottom with long-haired felt, to catch any sand or dirt that may still adhere after the numerous operations to which the pulp has been subjected. The flow is then forced through the “screen,” which is a horizontal piece of metal pierced with slots. For very fine paper, these slots are so small as to be only one one-hundredthof an inch in width. They are usually about a quarter of an inch apart. Through these tiny apertures the fibers must find their way, leaving behind in their difficult passage all lumps, dirt, or knotted fibers which would mar the perfection of the product toward which they are tending. A vibrating motion is given to the screen as the flow passes over it, or revolving strainers may be used.
♦The flow onto machine♦
When the screen has finished its work, the water carrying the pulp in solution flows in an even stream, whose volume varies according to the width of the web of paper to be produced, through a discharge-cock onto the Fourdrinier or cylinder machine, as the case may be, each of which will be duly described. This stream has a filmy appearance, and is of diverse color, depending upon the shade of paper to be produced. From its consistency, which is about that of milk, it is difficult to imagine that it floats separate particles of fiber in such quantities as, when gathered on the wire cloth and passed to a felt blanket and then pressed between rollers, to form in a second of time a broad web of embryo paper sufficiently strong and firm to take definite form. Man’s mastery of the process by which thisstartling and wonderful change is effected has come as one of the rewards of his long and patient study.
The Fourdrinier machine, which preserves at least the name of the enterprising developers of the invention, takes up the work that was formerly done by the molder. The wire cloth upon which the fibers are discharged as described is an endless belt, the full width of the paper machine. Upon this the fibers spread out evenly, being aided by a fan-shaped rubber or oil cloth, which delivers the smooth stream under a gate regulated to insure perfect evenness and to fix uniformly the fibers of the web now commencing its final formation.♦Deckel-straps♦Deckel-straps of india-rubber are fastened on both sides of the wire screen, and move with it, thus holding the watery pulp in place. The deckel-straps are adjustable, and fix or regulate the width of the paper. These and the gate, or “slicer,” are attached to what is termed the deckel-frame, which corresponds to the deckel used by paper-makers in the days when the manufacture was carried on by hand.♦Endless wire cloth♦As the stream flows onto the endless belt of wire cloth, the water which has borne the fibers filters into the trough beneath. Being charged with very fine fibers,size, coloring matter, and other similar ingredients, it is carried back into the pulp-chest, to save these materials, as well as to contribute again to the extra supply of water needed.♦The save-all♦For this reason the trough into which it falls from the revolving “wire” is called the “save-all.” A shaking motion is imparted to the “wire” from the frame upon which rest the rolls that keep it in its never-ending round. This aids in draining away the water, and mats or interlaces the fibers together. At the end of the “save-all,” where the fibers are to leave the “wire” for the next stage of their journey, suction-boxes are placed, provided with an air-pump to take up the surplus water that has not yet found its way through the meshes.♦The dandy roll♦Between these suction-boxes above the wire is a wire-covered roll, which impresses the newly formed sheet; this impression cylinder is called a “dandy roll,” and it is from this that the web receives the markings or impressions that characterize different papers. All watermarks, patterns, and designs which it is desired to have appear in the paper are put upon this roll, and here impressed upon the soft sheet, which is clarified and left transparent at the points of contact. Thus the impression is permanently fixed in the fiber, so that it can beseen at any time by holding the sheet to the light. The power of suggestiveness is a quality which is highly esteemed wherever it is found, and which frequently furnishes a standard of judgment. Judged by such a criterion, the impression cylinder, or “dandy roll,” has an added value, for in all probability its operation suggested the idea of printing from cylinders, as in our present web or perfecting presses.
♦The press-rolls♦
The matted pulp, now having sufficient body, passes on between two rolls covered with felt, which deliver the web of damp paper upon an endless belt of moist felt, while the “wire” passes under and back to continue a fresh supply. The paper is as yet too fragile to travel alone, and the web felt carries it between two metal rolls called the first press-rolls. These squeeze out more water, give a greater degree of compactness to the fibers, smooth the upper surface, and finally deliver the web of paper to a second felt apron, which carries it under and to the back of the second press-rolls. In this way the under surface comes to the top, and is in its turn subjected to the smoothing process. A delicate scraper or blade, the length of the press-rolls, is so placed on each roll that should theendless web from any cause be broken, the blade may operate with sufficient force to prevent the wet paper from clinging to the rolls and winding about them. From this point the paper travels alone, having become firm and strong enough to sustain its own weight; passing above the second press-rolls, it resumes its onward journey around the drying cylinders, passing over and under and over and under.♦The dryers♦The drying cylinders are hollow and heated by steam, their temperature being regulated according to requirements. These driers, made from iron or steel, are usually from three to four feet in diameter, and vary in length according to the width of the machine. There are from twelve to fifty of these cylinders, their number depending upon the character and weight of the paper to be produced, very heavy sheets requiring many more drying cylinders than sheets of lighter weight.
♦Tensile strength♦
Strange, almost phenomenal, conditions come about in the transformation from filmy pulp to finished paper. A sheet which, though formed, is at the first press-roll too fragile to carry its own weight, becomes possessed of a final strength and power that is almost incredible. The myriad of minute fibers composing the sheet, upon drying uniformly, possesses great aggregate strength. Asheet of paper yields readily to tearing, but the same sheet, when a perfectly even tension is applied, will demonstrate that it is possessed of wonderful resisting power. In evidence may be cited an instance that seems almost beyond belief. Through some curious mishap a web of heavy paper, in fact, bristol board, which had been thoroughly formed, was suddenly superheated and then cooled while still on the driers. This was caused by a difference in temperature of the driers and resulted in the sudden contraction of the web of bristol; the strain on the machine was so great that not only were the driving-cogs broken on two of the driers around which the paper was at the moment passing, but the driers themselves were actually lifted out of place, showing a resisting power in the paper of at least several tons.♦The calenders♦The paper now passes to the upright stack of rolls shown in theillustrations, which are known as “calenders.” The word is derived from calendra; a corruption of cylindrus, a roller or cylinder, they are simply rollers revolving in contact, and heated from the interior by steam. These calenders are used for giving to the paper a smooth and even surface, and are also employed in the smoothing and finishing of cloth.♦Speed of machines♦Thespeed with which the paper passes through these cylinders is remarkable, from one hundred to five hundred feet running through and over the machine in a minute; and in some of the most recent mills the web is as wide as one hundred and fifty-six inches (thirteen feet); this is very nearly double the average machine width of a few years ago, while the speed has increased in proportionate ratio; only a very few years ago the maximum speed was from two hundred and fifty to three hundred feet per minute; at this writing (1900) there are machines in operation which run as high as five hundred feet per minute. But great as has been the increase in the production of paper, the demand has kept pace steadily. The wonderful product of the rag-bag holds an invincible position in the world’s economy.
THE SIZE-TUB—Page 81
THE SIZE-TUB—Page 81
♦Five miles in a roll♦
For machine-finished book and print papers, as well as for other cheaper grades, the process ends with the calenders, after which the paper is slit into required widths by disk-knives, which are revolving, and so cut continuously. Paper intended for web newspaper presses is taken off in continuous rolls of the widths required, varying from seventeen to seventy-six inches, according to the size of the paper to be printed. Thesereels contain from fifteen to twenty-five thousand lineal feet of paper, or from three to five miles. The amount of paper used in disseminating the news of the day is enormous; sometimes one or two mills are required to manufacture the supply for a single metropolitan daily, while one New York newspaper claims to have used four hundred and fifty tons of paper in one Christmas edition, which is about four times the amount of its regular daily consumption.
After having been slit into the proper widths by the revolving knives, ordinary flat and book papers are cut into sheets by a straight knife revolving at proper intervals on a horizontal drum. The paper, in sheets, is carried by a traveling apron onto a receiving table at the end of the machine, where the sheets as they fall are carefully examined by experts, usually women, who remove any that may be imperfect.
♦The immensity of modern machines♦
The entire length of a paper machine, from the screens to the calenders, is about one hundred and twenty-five feet, while the height varies, the average being about ten feet. The machines, while necessarily of the finest adjustment, are ponderous and heavy, weighing in some cases as much as four hundred tons, this being the weight of themachine itself, exclusive of its foundations. The machine-room is of necessity well lighted and thoroughly ventilated, and should be kept clean throughout, as cleanliness is an essential factor in the making of good paper.
♦Deckel edging♦
While the same general process applies to all classes of paper made, the particular character of any paper that is to be produced determines exactly the details of the process through which it shall pass, and regulates the deviations to be made from the general operations in order to secure special results. For example, some papers are wanted with a rough or “antique” finish, as it is called; in such cases calendering is omitted. Another special process is that by which the paper is made with a ragged or “deckel edge”; this result is obtained in some mills by playing a stream of water upon the edge of the pulp, crushing and thinning it, and thus giving it a jagged appearance. At the present time this “deckel-edge” paper is being quite extensively used in high-class bookwork.
In the case of writing-papers, as has already been stated in the description of the beating engines, a vegetable sizing made from resinous matter is introduced into the paper pulp while itis still in solution, and mixes with it thoroughly, thus filling more or less completely the pores of the pulp fibers. This is found sufficient for all ordinary book-papers, for papers that are to be printed upon in the usual way, and for the cheapest grades of writing-paper, where the requirements are not very exacting, and where a curtailment of expense is necessary. For the higher grades of writing-paper, however, a distinctly separate and additional process is required.♦Tub sizing♦These papers while on the machine in web form are passed through a vat which is called the size-tub, and which is filled with a liquid sizing made of gelatine from clippings of the horns, hides, and hoofs of cattle, this gelatine or glue being mixed with dissolved alum and made fluid in the vat. Papers which are treated in this way are known as “animal,” or “tub-sized.”
♦Loft drying♦
We have duly described machine-dried papers, but these higher grades of writing-papers are dried by what is known as loft, or pole-dried process. Such paper is permitted to dry very slowly in a loft specially constructed for the purpose, where it is hung on poles several days, during which time the loft is kept at a temperature of about 100° Fahrenheit.
Another detail of considerable importance is that of the “finish” or surface of the paper. When paper with a particularly high or glossy surface is desired it is subjected to a separate process after leaving the paper machine, known as supercalendering.
♦Supercalendering♦
“Supercalendering” is effected by passing the web through the stack of rolls shown in theillustration, which are similar to the machine calenders already described. These rolls are composed of metal cylinders, alternating with rolls made of solidified paper or cotton, turned exactly true, the top and bottom rolls being of metal and heavier than the others; a stack of supercalenders is necessarily composed of an odd number of rolls, as seven, nine, or eleven. The paper passes and repasses through these calenders until the requisite degree of smoothness and polish has been acquired.♦Electricity in paper♦The friction in this machine produces so much electricity that ground wires are often used to carry it off, in order that the paper may not become so highly charged as to attract dust or cause the sheets to cling together. When the fine polish has been imparted, the rolls of paper go to the cutting machines, which are automatic in action, cutting regular sheets of the requiredlength as the paper is fed to them in a continuous web. In the manufacture of some high grades of paper, such as linens and bonds, where an especially fine, smooth surface is required, the sheets after being cut are arranged in piles of from twelve to fifteen sheets, plates of zinc are inserted alternately between them, and they are subjected to powerful hydraulic pressure.♦Plating♦This process is termed “plating,” and is, of course, very much more expensive than the process of supercalendering described above.
♦Sorting♦
From the cutters, the sheets are carried to the inspectors, who are seated in a row along an extended board table, before two divisions with partitions ten or twelve inches high, affording spaces for the sheets before and after sorting. The work of inspection is performed by women, who detect almost instantly any blemish or imperfection in the finished product as it passes through their hands. If the paper is to be ruled for writing purposes, it is then taken to the ruling machines, where it is passed under revolving disks or pens, set at regular intervals. These convey the ruling ink to the paper as it passes on through the machine, and thus form true and continuous lines.♦Ruling and folding♦If the paper is tobe folded after ruling, as in the case of fine note-papers, the sheets pass on from the ruling machine to the folding machines, which are entirely automatic in their action. The paper is stacked at the back of the first folding guide, and is fed in by the action of small rubber rollers, which loosen each sheet from the one beneath, and push it forward until it is caught by the folding apparatus. Man’s mechanical ingenuity has given to the machines of his invention something that seems almost like human intelligence, and in the case of the folding machine, the action is so regular and perfect that there seems to be no need of an attendant, save to furnish a constant supply of sheets. The folding completed, cutting machines are again brought into requisition, to cut and trim the sheets to the size of folded note or letter paper, which is the final operation before they are sent out into the world on their mission of usefulness. The finished paper may or may not have passed through the ruling and folding process, but in either case it goes from the cutters to the wrappers and packers, and then to the shipping-clerks, all of whom perform the duties indicated by their names. The wonderful transformation wrought by the magic wand ofscience and human invention is complete, and what came into the factory as great bales of offensive rags, disgusting to sight and smell, goes forth as delicate, beautiful, perfected paper, redeemed from filth, and glorified into a high and noble use.♦Beauty of perfected paper♦Purity and beauty have come from what was foul and unwholesome; the highly useful has been summoned forth from the seemingly useless; a product that is one of the essential factors in the world’s progress, and that promises to serve an ever-increasing purpose, has been developed from a material that apparently held not the slightest promise. Well might the “Boston News Letter” of 1769 exclaim in quaint old rhyme:
“Rags are as beauties which concealed lie,But when in paper, charming to the eye!Pray save your rags, new beauties to discover,For of paper truly every one’s a lover;By the pen and press such knowledge is displayedAs would not exist if paper was not made.”
“Rags are as beauties which concealed lie,But when in paper, charming to the eye!Pray save your rags, new beauties to discover,For of paper truly every one’s a lover;By the pen and press such knowledge is displayedAs would not exist if paper was not made.”
“Rags are as beauties which concealed lie,But when in paper, charming to the eye!Pray save your rags, new beauties to discover,For of paper truly every one’s a lover;By the pen and press such knowledge is displayedAs would not exist if paper was not made.”
And well may man pride himself on this achievement, this marvelous transformation, which represents the fruitage of centuries of striving and endeavor!
BLOWPIPES COOLING CALENDER ROLLS
BLOWPIPES COOLING CALENDER ROLLS
♦Wood pulp♦
Up to this point the reference has been almostentirely to paper made from rags, but radical improvements have been made, caused by the introduction of wood pulp, and these are of such importance that the account would not be complete without some mention of them. These changes are mainly in the methods of manipulating the wood to obtain the pulp, for when that is ready, the process, from and including the “washers” and “beaters,” is very similar to that already described. All papers, whether made from rags or wood, depend upon vegetable fiber for their substance and fundamental base, and it is found that the different fibers used in paper-making, when finally subdued, do not differ, in fact, whether obtained from rags or from the tree growing in the forest. In the latter case the raw wood is subjected to chemical treatment which destroys all resinous and foreign matters, leaving merely the cellular tissue, which, it is found, does not differ in substance from the cell tissue obtained after treating rags. In either case, this cellular tissue, through the treatment to which the raw material is subjected, becomes perfectly plastic or moldable, and while the paper made from one differs slightly in certain characteristics from the paper made from the other, they are nevertheless very similar, and it might besafe to predict that further perfecting of processes will eventually make them practically alike.
♦Mechanical wood♦
The woods used for this purpose are principally poplar and spruce, and there are three classes of the wood pulp: (1) mechanical wood, (2) soda process wood, and (3) sulphite wood pulp. The first method was invented in Germany in 1844. The logs are hewn in the forest, roughly barked, and shipped to the factory, where the first operation is to cut them up by steam saws into blocks about two feet in length. Any bark that may still cling to the log is removed by a rapidly revolving corrugated wheel of steel, while the larger blocks are split by a steam splitter. The next stage of their journey takes these blocks to a great millstone, set perpendicularly instead of horizontally. Here a very strong and ingenious machine receives one block at a time, and with an automatically elastic pressure holds it sidewise against the millstone, which, like the mills of the gods, “grinds exceeding fine,” and with the aid of constantly flowing water rapidly reduces these blocks to a pulpy form. This pulp is carried into tanks, from which it is passed between rollers, which leave it in thick, damp sheets, which are folded up evenly for shipment, or for storage forfuture use. If a paper-mill is operated in connection with the pulp-mill, the wood pulp is not necessarily rolled out in sheets, but is pumped directly from the tanks to the beaters.
In the preparation of pulp by the other processes, the blocks are first thrown into a chipping machine with great wheels, whose short, slanting knives quickly cut the blocks into small chips.