US1277737A - Process and means for producing all-wood paper. - Google Patents

Description

A. H. LEFEBVRE. PROCESS AND MEANSIOR PRODUCING ALL woon PAPER.

. APPLICATION nuzu rs.|.a.1e1i.

Paten ted Sept. 3, 1918.

HLBERT H .LE EBVRE expensive snares earner curios;

ALBERT HENRY LEFEIBVBE, 01E WATERTOWN, NEW YGB'KL PROCESS AND MEANS FOR PRODUCING ALL-W091) PAPER.

Specification of Letters Patent. Patentgd Sgpfig, 3, eggs,

Application filed February 1 6, 1917. Serial 1%. 149,-M5.

To all whom it may concern:

Be it known that I, ALBERT HENRY LE- rnnvnn'a citizen of the United States, residing at- Watertown, in the county of Jefferson and State of New York, have invented a certain new and useful Process and Means for Producing All-l/Vood Paper, of which the following is a specification;

In the manufacture of paper from wood disintegrated into its constituent fibers by. processes that are mainly or wholly mechanical, it has been the practice, in order to secure a paper of proper texture and strength, to introduce into the mechanically reduced fiber stock, through means of mixers that are more or less expensive to erect and operate, strengthening fibers obtained from varius isources foreign to the wood, such as ragslgtor instance, which have themselves been already reduced by amuch more process involving the use of chemicals. v a

I have discovered by extended research that there are in wood, as it comes from the forest, all the materials necessary as making a strong and satisfactory paper without; the addition of foreign materials; that the failure to produce such a paper from wood pulp heretofore, has resulted mainly from the discarding of the stronger and more desirable fibers; that this discard has been due to lack of the proper method of utilizing the discarded materials; and that the discarded or rejected portion of the wood has amounted to such a large percentage of the raw material as to work enormous waste.

1'. have further discovered by reseamllh that in the methods heretofore employed i'dr producing paper mainly from mechanically reduced wood, .the waste, pollution of streams and use of bleaching chemicals can all be avoided by proper methods, and much of the expensive apparatus heretofore employed can be done away with bya proper procedure. These considerations become additionally important when it is reniem-' bered': that the use of chemicals is particiu larly destructive of the screensqand other apparatus. y

The present invention teaches a novel method of producing paper from wood with use of substantially all of the fibrous portions of the wood'a'nd through means of apparatus of a greatly simplified natlhre and with great economy in materials arid-work required; and it produces a new all-wood paper having superior strength and supe rior qualities, particular y in the matters of opaqueness and non-absorption of printing ink.

to the article paper, and the process and means for producing same,-because paperis the ultimate article'to be produced, but it is to be understood that the distinguishing characteristics which lend novelty to the article are present in the finished pulp stock 'as it issues from the screen, and the novel characteristics which distinguish the method of producing the stock, and the means for producing the same, relate to what takes place, at one stage or another, hetweenthe b In the following disclosure, I shall fiefer step of reducing the, wood and forwarding the screened pulp to the forming apron of woven wire at the receiving end of the paper machine. Therefore, except when the con-q text otherwise indicates, a reference to pulp is to be understood as including paper made from the pulp, and vice Versa, whether it goes to the paper machine, or merely passes to the dehydrator, to form pulp for subsequent use in paper manufacture.

The underlying theory of the present inventiou is that everything which nature puts into the sustaining structure of the wood is valuable as building material for incorpo ration into the structure of the paper to be paper. This theory lends itself with peculiar advantage to a procedure depending ma ni y or wholly upon mechanical steps for the reduction of the wood, because in such procedure as generally practised in'the art, the reduced fibrous portions vary greatly in length and strength, so that if properly dist-ributed, the particles of greater length or strength become strengthening elements' throughout the larger mass of shorter fibers,

and make it unnecessary to add strengthen suggested.

mg 'fiber sifrom a foreign stock; moreover, in the disintegration of the-wood,- the longer or stronger parts resist reduction-to the r ultimate dimensions more than the shorter I 5 fibers, with the result that they break off in larger piecesand do not pass through the screens as promptly as the other, but pass 1 over as failings. In-the methods heretofore practised, it has been customar Y to discard thesetailings and bass them directly to the streanrjor waste out-let.

I. have found in practice that if these tailings be su'bjected to a further reduction treatment, they yield up th'e-very elements of strength'which the paer needsthat if the be Jassed to a means I P a which I shall herein call a refiner, subject-' ing them to a refinement or further reduction, and then delivered with the fresh stock coming in from the original grinder or reroducer, and again.v passed over the screens,

sulfieient of this material" of increased strength isiningled with the bulk of the stool; to properly strengthenit; that there is much of the fine and valuable fiber wh ch a passesover \Vi tlrthe failings from thesoreen,

due to its adhering to the unreduced mate;

' rial whim -would pass off, with the latter,

if discarded; and that if the tailings' be' continuously passed to the refiner, returned to the screens with the freshxstock, and re screened, and this treatment be conducted in such mannerthat the secondary reduction or refinement is repeated for'e aeh particle untillit is in ctmdition to pass through the screen, distribution of the strengthening fibers is continuous and uniform; the totalv gbulk of stool-(produced is increased not only by the refinement, but by saving the finer fibers adhering to the tailings or remaining 130 suspended in the water which is used over and over again, and soluble binding mate rials may-all be retained in theultimate paper structure, unless special steps be taken to withdraw, a portion thereof as already Whileit is my belief that thelargenparticles whichbreak ofi in the original reduction, oontainjstronger 'fibers, the success of 'my invention is not wholly dependent upon this:condit1on, -as it w ll be'seen that the distribution Iof, strengthening material throughouttlie stock may be due in greater or less measure to the fact that the secondary reduction or refinement, wl'ulc eondit-ioning thei'mitcrial to pass through the screen dbes not get it to its ultimate fiber.

In either instance, the strengthening material is present and it owes its distribution l0 the tart that it is prodmzed by the secondary treatnu-nt and delivered constahtly into the fresh stock from the grinder, and it adds to the output of the plant and reduces thecost: of production by, saving to the stock what formerly was discarded, while it further at cheapcns the cost of production of a sails- Lawyer factory paper stock by substituting these Wasite materials for foreign fibers heretofore use Erom the foregoing, it will, be seen that- One feature of the present invention con sists in an all-wood or substantially allwood paper, composed mainly of the finer fibrous constituents of the Wood structure, but having-the stronger or coarser constitticuts of the Wood uniformly distributed throughout the paper structure and constituting a strengthening filler therefor.v

Another feature consists in the production of paper from wood by disintegrating the and en iciently refinedlproductsof the refiner into the incoming stock,- utilizing the same water as the vehicle for the materials in passing them from ,stage to stage in the process, and dlvlding up-the screen into successive sections over which the material to be screened passes in succession, preferably with a settling riifie for the coarser material at the end of each section, and with the screenings from all the sections passing into a common passageway to the dehydrator, paper "machine or other place of use ofthe pulp: 'Another'feature of the invention subordinate to the generalidea of continued circulation and repeated screening of coarser material in the presence of fresh material and with repeated refinement of the coarse material, relates to the treatn'ient of the fresh material and added product of the refiner in its passage .tothe -screens, according to which feature, the stock is floated through an elongated scrubber or scrubbing tanks having a series of, compartments through which it successively passes by cascading over the dividing walls between the compartments and from'which it escapes into a tank which 1s of sufficiently larger area to permit it to spread out and suddenly lose its speed of,

travel, so that the heavier. portions settle or assume a lower stratum, and from this settling chamber, passing it by means of a gentle pui'nping action upward through a hyurostatic gravity separator whence 1t escapes c at the top and passes directly to the screens! n The scrubbing tanks afford opportunity for detaclnnent of bark, sand and. otherifoi'eign matter; the settling tank affords an opportun ty for much of this barkand foreign materlal to precipitate, gland I the hydrostatic gravity sepanetorthmflgh which there-is a,

sure production of a paper of satisfactory color without the addition of chemicals. If desired, a suitable proportion of alum may be thrown into the scrubbing tanks or settling tank to assistthe dirt to precipitate, but this will not be necessary in all cases, although when added, it can be used with greatest economy, since the same Water is being circulated indefinitely through the system.

A third feature consists in the apparatus? employed for carrying out the process above outlined and producing the new paper de-l scribed. This consists essentially in a primary reducer, preferably in the form of a grinder; a secondary reducer or refiner, which may be of any one of a number of different machines, but which is preferably an ordinary Jordan engine, which delivers into the same channel as the primary re-- ducer, so that the refined material is systematically mingled with the product of the grinder; an elongated scrubbing tank" through which the material is floated from end lac/end, but which is divided by transverse partitions into a number of pockets through which the material successively flows from one to another by cascading over the partition walls; a settling chamber which is preferably a number of times larger in area than the sectional area ofthe scrubhing tank,- and into which the material may be spread out and ,lose its momentum, so as to favor settling of foreign matters; a hydrostatic gravity separator in the form of a stand-pipe, preferably .of much less hori- 'zontal area" than thc'settlin tank, but rising vertically a distance su cient to afford ample opportunity for complete separation of the stock that is already conditioned or to be passed over the screens to the refiner; and finally. the screens to which the material is delivered directly from the stand-pipe and which preferably comprise a longitudi 1 series of screening sections arranged .in

the form of r iiilewpla-tes having scttliilg pockets between'them with outlets for passed material, delivering preferably to a common escape passage and with a tailingpassage leading-to the refiner.

carries, will gradually'rcducc toward the 'tailing end, and there may be someditfer- 30 once n the character of the fiber passing ,through the different sections. By .deliver- ()bviously, by passing the water, with its burden of mate rial in suspension, successively over a series' of plates, the proportion of water as the vehicle, to the fibrous material which it Water that goes out with the finished fiber,

either in the form of matted pulp stock or as the sheet upon the forming apron of the paper machine, and to this extent, the supply of water will be continuously replenished. This may be conveniently done by delivering fresh water at the surface of the grinder,

or fresh water with a part of the wateralreadyv in circulation. A constant flow of water at this point is'necessary, in order to keep down the heat resulting from the friction of grinding, which'should not-be allowed to go above 170 F.to avoid curling the fiber. Otherwise heat is conserved as far as practicable, as it makes for economy in that it favors the solution of the binding materials and economizes in heat required for drying the paper-web when it reaches the felts in the paper machine.

A11 illustrative apparatus embodying one part of the present invention and capable of operating for carrying out the method which constitutesaairbther partof the invention in the production of'paper, which divided by partitions 3 into a number-of successive scrubbing chambers through which the liquid passes successively'by cascading over said partitions. 4 represents a settling tank having a much larger capacity than the sectional area of the scrubbing tank, in which the fluid can lose its momentum so as to favor precipitation of foreign matter remaining insuspension. 5 is a stand-pipe rising upwardly a considerable distance above'the settling tank 4 (about 12 feet in height-will be found effective), and

inft o this stand-pipe the fluid is forced by means of the rotary pump 5, driven by shaft 5", or otherwise as may be convenienuso as to maintain in the stand-pipe a hydrostatic gravity separator. the pump 5 is just suiiicient to keep up gentle progressof the fluid upward through I the stand pipe 5 and cause it to overflow at The capacity of y the brim 5, whence it'passes to the screens slots of such width as will pass Qierof the .6. The screens are made up of a number of desired nneness The seveml collectors 6 are made'to discharge into the common whence the finished pul espassagewey 6?,

capes and is conducted for the use to w ich it is to he's-put. The'tailings from the screen stream of Water temporarily applied from an extraneous source, or forced from. some point in the circulatory system. These tailings pass through tail-pipe to the secl ondsry reducer or refiner. 7, Where they are further reduced and delivered through a discharge pipe 7" into the recover 2 for the incoming new stock that is being reduced by the grinder l, and here the re ned tailings' mix with the new stock, pass through the scrubbing tank 3, settling chamber l, hydrostatic gravity spparator 5, and again reach the screens 6, where more of their fibrous constituency passes through the screens. he -.;sti1l unreduced or insulticiently refined parts, whether they have once been throdgh the refiner, or come for the first time from the grinder, puss into-the tailing 4 structure.

before.

pipe 6 and to the refiner 7, and thence to the receiving point for new stock just us This process is kept up continuously on. the. theory that there is no part of the Wood that will not ultimately, by repeated treatment and after sutlicient soaking, be reduced s-ufiiciently to enter into the paper stock. The refiner 7 delivers the fiber inn condition somewhat different from that of the fiber which comes from the grinder. That is to say, it is either made up of longer fibers or of fiber groups that 'are of greater dimensions and strength, yet sufiiciently re duced to enter satisfactorily into the paper A very satisfactory form of apparatus to be used for the refiner 7 is a Wellknown Jordan engine,- eniploying two closely acting concentric'cmies. Cooling water for thegrin-der may be conveniently supplied by the pipe 8, which may lead fron'i any convenient source, as for instance from the pipe 9 leading from the machine 9 (either dehy- I l v dral'er or paper i'orn'ier) which utilizes the to them and arranged in va system substsn tially as set forth.

I claim 2- A 1. In the rocess of manufacturing paper, the st ms W llCh consists in reducing Wood to progzuce finely divided fibrous material and partially reduced portions; pessingthe material. collectively through a scrubbing tank; then separating foreign inatters hy the action of gravity; then screening; then refining the screenn'ejected parts to produce relatively coarse fib'lOllSyHliltQllfil; delivering the refined ports with the incoming stock of the original reduction, and again circulnting the material collectively through the scrubbing tank nnd sepnmting means and over the screens, and so on in continuous operation.

2. In a pu ler-rnuking bination of a primary reducing menus for reducing wood into fine fibrous material and partly reduced material; means for refining the partly reduced material, delivering its output to the material issuing from the )ll niary reducing means; rubbing tau treatment of all the material, gravity SQPQUHIOI' receiving the inuterinl after treatment in the ,scruhliing tank. screens for treating the material after pussing through the separator, and a tailing-pipe leading from the screen to the refiner.

3. In a paper making a pnrutus for making paper from structm'ully .difl'criug parts of Wood comprising a. primary reducer, u refiner, end an endless h'ydrzuilic circulatory system including the (.lischurgcs from the reducer and refiner, a scrubber, and 11 screen, the railings discharge the screen being connected to the rcfiner.

4;. In :1 paper making apparatus for llldl ing paper from structurally differing ports of WO0(l comprising a primary reducer, n refiner, and an endless l1 -drn-ulic circulstmy system including the discharges from the reducer and refiner, a scrubber, a settling; chamber, and a screen, the tailings discharge of the screen being connected to the refiner.

In a mper making apparatus for male ing paper from structurally differing parts of Wood comprising a primary reducer, n

system including the discharges from tho reducer and refiner. n scrubbing tank, a set tling chamber, and n llydrostutic grown, separator, and screen, the toilin 's I charge-of the screen being connected to me refiner. The foregoing specification signed at lVstel-town, New, York, this 9th day of Febrnsry, 1917:;-

ALBERT HENRY Lnrnsynn.

apparatus, the coin- P

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