The Pulp and Paper IndustryBJARNE JOHSSEN Hammermill Paper Company, Erie, Pa.
P.4PER
h f . 4 K I S G BY
HAXD IN
THE
center of paper making, the industry spread in the following years to New Jersey (1729), Massachusetts (1729), Maine ( 1 7 3 4 , Virginia (1744), Connecticut (1769), and New York, where the first mill x-a$ built a t Hempstead, Long Island, in 1768. The industry continued to expand in these and neighboring states throughout the century, but the mills were small and the equipment primitive, the principal improvement in equipment during the period being the introduction of the hollander or beating engine in place of the original hand- or water-driven stamping rods previously used for the disintegration of the rags. All paper was made by hand, each individual sheet being formed on a hand mold, pressed, and dried. As an illustration of the output of the individual mills, the total annual production in 1810 of all kinds of papers in 180 paper mills n a s 3000 tons, which represents the weekly production of one single newsprint mill today. The productive capacity of the individual establishments mas greatly increased by the development in France and England of the paper machine which made possible the production of paper in a continuous web. This machine was introduced in this country in 1827 and was quite generally adopted so that by 1850 all of the 450 paper mills were equipped with this improvement, with the exception of two mills which continued the production of handmade papers only. At this time the annual production had reached 80,000 tons and the consumption of paper per capita had increased from 1 pound in 1810 to 7 pounds.
EARLYh f I L L s
@A
UERICA’S firct printing presb TI a- .et u p in Cambridge, in the hlassachusetts Bay Colony, almost three hundred years ago (1638). But not until more than fifty years later wa. paper made in this country. The demand for paper in thoqe day5 was not great and the requirementq \\-ere easily satisfied by importation from Europe. It is reported that from the time of the first printing press until the end of the century-a period of sixty-two years-leis than a thouaand books and pamphlets were printed. iYewspapers did not exist until after 1700. The first paper mill in this country was built as a result of the desire of a prominent printer of Philadelphia, William Bradford, to become entirely independent of importation of paper for his own printing establishment. Bradford, together with a paper maker, TVilliam Rittenhouse, and a fern wealthy friends, built the first paper mill a t Germantown in 1690. This mill was destroyed in 1701, but a new one was built the following year not far from the location of the original mill. During the early part of the e i g h t e e n t h century a number of paper mills were built a t Philadelphia by generations of several wellknown paper-making families-Rittenhouse, De Wees, a n d W i l c o x . From this early ONE OF
Paper from W-ood Fiber K i t h the greatly increased demand for paper and the improvements in productive capacity of the mills due to developments in mechanical equipment, the problem of the nineteenth century was to find new sources of fibrous raiy material in place of rag., the shortage of which became critical a t times.
THE
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RITTEYHOUSE MILLS OF
THE
EIGHTEENTH CESTURY
Many attempt. had been made in paper-making countries to produce suitable fibers from other material. than rags, but with the exception of straw, which was used in some coarse paperb, the problem was not solved until it was discovered that vood could be reduced into a suitable form for paper making by mechanical and chemical processes. When these processes were introduced in this country during the latter part of the century, they found rapid application. I t is interesting that the most important of the chemical processesthe sulfite-was originally invented by the American chemist, B. Tilghinan, of Philadelphia. Both the processes and rnodifications have been applied to other fiberb than wood, but wood mill remain the most important raw material for paper making, because oi the suitability of the various species of wood fiber for the manufacture of different types of paper and because of the compactn e s of the material, which makes transportation, storage, and handling economical. The industry, which for centuries had been limited to paper making only, now also included the manufacture of pulp, which developed into a separate industry furnishing raw material not only to the paper maker but to other manufacturers as well, and the industry extended to parts of the country where wood was plentiful and power easily available. Wisconsin and Michigan became important pulp- and paperproducing states, and, when the sulfate process was introduced to this country in 1’310, its first developments took place in the northern states. Later on, in the twenties, this kraft paper industry was attracted to the southern states because of their enormous pine forests and waste wood supplies. More recent years have seen a rapid development of pulp and paper making in the western states where excellent wood at low cost has been available from the large forest&and in the form of waste from the sawmills. At the present time a further extension in the southern states is widely discussed as a result of researches carried out by Charles Herty and associates a t Savannah, Ga. It is predicted that by selecting the young trees from the fast-growing pines, white pulp and paper can be produced according to the standard processes, and that newsprint, book, and bond papers will be manufactured in the South where previously the production v a s distinctly limited to the coarse-paper field.
THE BEGINSINGOF
MODERNFOURDRIXIER PAPER MACHINE
THE
the various factors affecting the pulping results, including the quality of the woods, have resulted in greatly improved qualities, higher yields from the woods, economy in the use of raw materials, and, as a consequence, reduction of waste. I n some laboratories research has brought about the development of new types of wood pulp which are produced on a large scale and used for special purposes. I n the sulfite pulping process the corrosive action of the cooking liquid delayed the employment of improved methods until recent years when acid-resistant steel became available. This permitted the application of forced circulation of liquor during the cooking, which had already been practiced in the alkaline process. Much closer control with a more uniform product resulted. The method of bleaching has also been vastly improved as a result of continued research. For many years hypochlorite solutions were used exclusively in the bleaching of pulps, and the effect of the bleaching depended a great deal upon equipment and the proportioning of the bleaching agent to the pulp, which, in turn, was based largely on the judgment of the operator. Improvement in equipment, proportioning of bleaching material b y means of chemical analysis of the pulp, bleaching in several stages, control of pulp concentration, and temperature, as well as greater econoniy in the w e of materials, are factors responsible for the higher quality of presentday products. I n the last few years several mills have adopted a method of bleaching by which the fibers receive a preliminary treatment with chlorine bexfore being exposed to the action of hypochlorite; perhaps one of the most interesting developments of recent year.. is the succecsful bleaching of so-called Kraft pulps which previously could not be bleached without serious destruction of quality. Tn the pulping and bleaching processeq, washing either by displacement or by dilution and concentration plays an important part. The application of equipment used originally in the mining industry is only one example of the improvement.. which have
Improvements in Pulp-Making Technic The physical expansion of the industry has in recent years been accompanied by a rapidly increasing improvement in quality and economy in operation as a result of the application of technical knowledge. This phase of the development is of comparatively recent date when we consider that about twenty-five years ago relatively few technical men -rere employed in the industry. The pulp-making pro(-esses vere conducted according t o knowledge gained from practical experience but with very limited scientific knodedge. The chemistry of cellulose was not far advanced and was taught only in a few educational institutions. Little was known about the chemistry of lignin and the chemical composition of wood, of which these two substances are the principal conqtituents. The original research work was carried out at -ome universities and government laboratories and in the laboratories of a few pulp mills. The contributions in this field b y the Forest Products Laboratory in Madison, TTis., have been and continue to be of immeasurable value to the industry. The studies of the composition of a large number of American woods and the pulping of practically all species of woods by various processes brought to light information upon which individual mill> could continue their researches, and have created an interest which has been of benefit to the entire industry. Studies of 515
VOL. 27, NO. 5
INDUSTRIAL AND ENGINEERING CHEMISTRY
516
P L L P .4UD P 4 P E R P L 4 X T OF H4\r\IERMILI, P A P E R COMPAN1 IY PROIICCTIO\ OF 175 Tons OF F I ~ E P ~ P EFROX R~
come to pulp and paper mills from contacts x-itli other industries. Paper maiiufacturers remain the principal users of ~vootl pulp, but with the refinements in processes and with increased knowledge of cellulose chemistry, wood pulps have found their way into ot,her fields. Already enormoii3 quantities of wood pulp are consumed in the manufacture of rayon and Cellophane, plastic products, cellulo-e wadding, insulating and packing material, threads and carpets, but undoubtedly the uses will be extended in the future more generally to industries m-here cotton is non- the principal raw material, in the manufacture of cellulose eaters, filins, lacquers, etc. Combinations of pulp with other materials-for instance, rubberto form a high-grade product' used largely for inner soles in shoes or with viscose to produce a splendid quality of towels, represent only a beginning of what may in the future become the basis of inany pulp-wing developments. The sulfite pulp industry is a t present confronted with oiie big problem-the recovery of the waste liqiior from the cooking process. Waste of wood in the barking process has been pract,ically eliminated by impro7Ted mechanical equipment: higher yields are obtained in cooking, and fiber l o s e s are al-
PRESENT
DISTRIBUTIOU OF h
L P AYD P A P E R P L 4 X T S I S
ERIE,P 4 . , WITH U o o ~PCLP
A
DAILY
most eliminated but it remains for the research chemist to develop inethodr by which commercial, marketable products can be made from the substances which are dissolved from the Tvood during the cooking and representing about half the weight of t'he wood. I n practically every mill this constitutes a constant waste. Paper mills have obviously benefited greatly from the imIiroT-ements in quality of wood pulps and the development of new pulps either by refining processes or the employment of new species of wood. The blending of various types of fibers in order to create papers of certain distinct qualities is practiced mnre and more.
Technical Control in Paper 3Iaking Technical control of operations, which was perhaps originally exercised to a greater extent in pulp mills, has been extended t o paper mills generally with accompanying results of qualit>yimprovement and economy. I t is often said that the paper mill is equipped with the .sine type of machinery as was used one hundred years ago. It i. true that the principle of the beater engine construction, for esample, is the same now as when originally built, but many improvements have been made and much work is in progress in efforts to design a machine which will accomplish the ,same purpose with lower consumption of power. The principle of the paper machine is the same today as i t was when the Fourdrinier brothers in England spent their entire fortune on the development of the first machine more than one hundred years ago. B u t nobody mill deny t h a t the electrically driven paper machines which today produce a sheet of paper a t a speed of 1200 feet per minute, represent a wonderful example of the accomplishments of modern engineering. The high speeds generally refer to newsprint paper and could not have been reached by mechanical perfection of the machine only. Wonderful improvements have been made in the quality of the mechanical pulp or groundwood pulp, which represents more than three-fourths THE t-.6 .
MAY, 1935
INDLSTHIlL . i S D E l GINEERISG CHE31ISTH I-
of the fiber Composition of a newsprint paper. The present methods of grinding and the close operating control are ba.ed upon very thorough btudies over a long period of years Generally speaking, the quality of all papers ha. miproved enormously in a comparatively short time because of technical control and scientific research. There have been great developments in the printing industry, and paper manufacf urer- hare been able to meet the constantly increasing demand for greater perfection of papers required for the new printing proce+eand modern presses. Different types of printing and engraving demand different kinds of paper surfaces in ordcr to make possible the wonderful effects of modern printing. I n this direction much has been achieved by application of colloid chemistry to the coating processes and by the use of various forms of sizing solutions in tlie treatment of paper >urfaces Originally, fillers such as clay and talc were added to the paper for the purpose of improving the surface for printing and writing and for reducing the cost. Clay \$-as inoqtly imported from England but at the present time domestic c l a y are ubed; the total annual consumption of clay and talc by paper mills has reached more than 450,000 tons. Other bocalled fillers which have recently been introduced in paper making from the paint industry, are zinc and titanium pignicnts. Because of the high refractive index of these materials, the addition to the paper of comparatively small quantitie. produces a very desirable opacity and high whiteness. Since the development of the American dyestuff industry. there has been close cooperation between the maiiufacturerof dyestuffs and the paper makers. The result i j reflected not only in the niany attractively colored paper-, but al-o 111 their greater fastness to light and reduced two-sidednePresent-day papers are more durable and Liermanent. First of all, the fibers are of a better quality liecauqe of the rigid control in pulping and bleaching, but secondly tlie eifects of the presence in the paper of certain material- which influence permanence, are generally better understc od. This is particularly important in the sizing operation x here rosin and alum are added to the fibers. The presence of e x c e 4 v e amounts of theqe two materials i i detrimental to the 1a.tliig Q
517
quality of a sheet of paper, and high acidity is particularly harmful. The realization of these facts and the consequent reduction in the amounts used in t'he making of paper through constant control are perhaps greater advances in the art than the substantial improvements in the preparation of sizing solutions. Obviously, the increased efficiency of the sizing process, which makes possible the use of less sizing material, i q a direct result' of research by many laboratories. Xethods and equipnient for testing of papers have been developed and a great nuinher of these have been thoroughly studied by the Sational Bureau of Standards, which has over a period of years contributed generously to the knowledge of paper-making processes and construction of special testing equipment. By means of such equipment it is possible to express paper characteristics in definite terms, and specifications based on physical a i d clieniical tests are gradually being developed.
Paper and Pulp Consumption ;1little
more than one-half of the entire world's production of paper is consumed ill the United St,ates. I n 1929 the people of this country used more t,han 13,000,000 tons of paper and paper products, or 220 pounds per capita. Only about 4 per cent of the total is classified as so-called fine papers; 11 per cent is book paper: 12 per cent, wrapping; 33 per cent, fiber board; and 29 per cent, newsprint paper which is largely imported froin Canada. Most of the requirements of all papers are, however, manufactured xithin the borders of the Gnited States, a i d tmheindustry has become one of the largest of the country, giving direct employment to more than 100,000 people and consuining hundreds of thousands of tons of materials. -1ccording to a 1933 publication by tlie American Paper and Pulp Association (from which the foregoing figures are also taken) the industry uses annually about 100,000 tons of alum; 250,000 tons of sulfur; more than 350,000 tons of lime; 7,500,000 cords of wood; besides a n enormous tonnage of rosin, chlorine, salt cake, soda ash, salt, caustic: soda, casein, starch, etc.
~IODERN PAPERMACHISE,200 INCHESWIDE AND 300 FEETLONG,KITH CAP.4CITY OF 7.5 T O N S OF FIXEPAPERSPER D . ~ Y
A
it.: ;ieco~nplisliiiieirt;;so far, this organization will umloubtedly lie one of the iniportaiit factors in future developments in tlie industry tlirougli training of teciiniral nlcn and contrihiit,ions in research Fu1ore I ~ e v e l o p n l m l l i
It is rather i l i f f i c i i l t til pre(liet a t this tinie aloiig wliat lincr tlic major ilevnlrljrii~.iitswill colltinoe. Prol~alAythe vnrious t,ypes of yiooil j m l p Kill Istwtititte the principal raw material in marly new iidnsi,rics wliii:lr will he foiinded oil cellulose reactions; i:ornlriiintioiii i $ pitlp and papers with other matcrids will be u$ed to nn iiicreiisitig degree in the I>uildingand packag~ J I Rtrades, For insointitrg i,iirpo , and for containers of ail kiritls t o replace metals, glass, wood, and other niaterials. Tlrc piilp and paper irrduhtries of tiiii country vi11 continiie lo expand as research and expcririientatim make available IIBW raw inateria.ls, atid this t~xpansionis likely to take place in those seotions of the country wliere tliese materials are fiiund in greatest abuiidance. It i s the opinion of nisny today t h a t in the future a. large an~ountof the pulp aiid paper tsonnagc which i s now imported from other countries will be ixoduced from the pines of t.lie South and the large for&.: of tiernlock and fir of the Pacific Vhast. REeaivrD Maroi, 22. 1955.
T@FE AjLC H E M 1ST BY
Thomas
FP'I.X
(1617-1677)
The original of this, Nu. 53 in the Wemlai~rimerseries u i Alchemical and Historical Reproductions, is in the Kijksmuseum, Amsterdam. It is much brighter than the Gve previous paintings by the same artist, which we have presented, possibly because of the woman assistant in the background. rhe floor presents the usual messy appearance, altlmugh the boy assistant, who is presenting the bowl for inspection, is lidy enough. "Chy,mists are a sfrange class of mortals impel!ed 137 m i zrimost insane impulse to seek their pleasure amid smoke ancl vapor, soot and flame, poison and poverty."--J. 1. Hecher.
A detailed l i t of the Grst thirty-pi? reproduciiuris in t l h mica, together wit.h full aitied?.m fur nbtsmmiw photographic copies of tbe oiiaindm. nppearJin our lssue i?r Sanuarv, 1834. page 112. A PUPplernentary list of Nw. 37 to 48 IS m o m January 1935 ieme pa80 102. No. 49 is in the January. 1935, isme, DRSB a'6, No.' 50 is \n the Februaryisauc, psse 204, No. 51 i a in the l l s r c h issue. page 314, snd No. 52 i* in the Aprii iesue. page 400.
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