US2624245A - Modified paper and method for its manufacture - Google Patents

Description

Jan. 6, 1953 s. 1.. CLUETT MODIFIED PAPER AND METHOD FOR ITS MANUFACTURE 5 Sheets-Sheet 1 Filed Dec. 16; 1947 5'. L. CLUETT MODIFIED PAPER AND METHOD FOR ITS MANUFACTURE Jan. 6, 1953 '6 Sheets-Sheet Filed Dec. 16, 1947 Jan. 6, 1953 v s. L. CLUETT 2,624,245

MODIFIED PAPER AND METHOD FOR ITS MANUFACTURE Filed Dec. 16, 1947 3 Sheets-Sheet I5 Patented Jan. 6, 1953 MODIFIED PAPER AND METHOD FOR ITS MANUFACTURE Sanford L. Cluett, Troy, N.

Peabody & 00., 1110., Troy, N.

of New York Y., assignor to Cluett, Y., a corporation Application December 16, 1947, Serial No. 791,997

13 Claims.

This invention relates to a modified form of paper and particularly aims to increase the extensibility and flexibility of a paper web and the extent to which it can be shaped or worked, particularly when dry; The invention aims to accomplish these results without producing a creping of the paper, and aims to leave the paper in at least approximately as smooth a condition as before or as without the treatment.

The invention contemplates a paper web, such as a strip having plain parallel surfaces with constituent fibres of the material distorted and locally flexed and crowded together by compression of the web in directions parallel with such surfaces, the fibres being cementitiously held together by the finely beaten fibrils and the natural adhesives that are the product of the beaten pulp as well as by the molecular attractive forces that are made possible by the extremely intimate contacts of the fibrillated material, the amount of compression of the web and distortion, flexing and crowding of the fibres being suificient to impart a marked and controllable and useful extensibility to the web also generally an increased density. Extensibility in paper products has heretofore been secured principally by creping, which has certain limitations and disadvantages. The invention aims to provide a different kind of extensibility which does not depend upon straightening-out of bodily folded or creased zones as in the extension of a crepe paper, but involves rather an extension of distorted or locally flexed or crowded fibers within the body of material between the boundary faces of the web.

Preferably I employ a paper web which is already in a moist and plastic condition such as the newly-laid web in a paper making machine, for example the water-laid web taken from a typical Fourdrinier machine, from which excess water has been removed, but which has not yet been dried and set. A paper wet in this condition is in an excellent condition for further treatment by this invention. Where this newly-laid web is not available, I may employ a previouslymade web of paper, but it must be first conditioned to a plastic state, such as by prolonged contact'with water, preferably hot, until the web has become plastic and deformable.

The conditioning may comprise simply causing a suitable amount of moisture to penetrate the paper thoroughly to render it plastic, for example, soaking the paper in water and allowing it to remain in a wet condition long enough to' render it amenable to the subsequent treatment, Such time of soaking may be as' shortas one minute or as long as one hour or more, dependent upon the paper.

In some cases, dependent upon the constitution of the paper, the plasticizing action of wateror other liquid plasticizing agent is supplemented by the heat to which the paper is subjected-in the succeedin parts of theprocess, it'being evident that heat tends ingredients of certain types of paper.

The paper, suitably plastic, or being near to being plastic sequent step of the process will render it plastic, and having sufilcient moisture removed to cause a certain amount of voids between the fibres, is subjected to the compressing step of the process. In this step the paper is subjected to compression in a direction parallel to the surfaces of the paper productive of a substantial decrease'in dimension of the paper, and while the paper is under considerable pressure perpendicular to its surface to restrain it from creping. As the sheet is dried, adherence between the intertwined longer fibres is achieved chiefly by matting together in close adhesion of the longer fibres and the mass of fibrils including both those fibrils attached to the longer fibres and those which have previously been brokenfree from the longer fibres. The resistance of such a paper to breaking under tensile stress arises from the length and strength of the fibres and from the firmness by which the fibres are bound into a common mass by the matted and mutually adhering fibrils.

In the manufacture of paper according to this invention the paper after the removal of sufficient water to produce a coherent structure, but before drying, is submitted to a process which introduces a distortion of the longer fibres by contractin the area in which they lie and thus the length of the sheet, but without decreasing the actual length of the fibres themselves, while at the same time holding the surfaces of the paper web flat and parallel and preventing thickening the web. During this operation a heavy pressure is maintained on the surfaces of the paper web so as to prevent creping ofthe web and also for the purposes of forcing the distorted fibres into voids within the paper web so as to bring the fibres into such close contact with each other and with the entangled fibrils as to cause strong bonding and adhesions within the web.

Ilpon subsequent drying, the modified orientatlon of the fibres and fibrils is retained in the dry state and the sheet takes on firmness and.

to soften some of thesufficiently that the heat of the sub-' 3 strength from the mutual adherence of the finely entangled fibrils and other small structures.

When this paper is subjected to tensile stress there is an inertia to reformation arisin from the mutual adhesion of the almost continuous distribution of fine fibrils. However as the tensile stress is increased the nearly continuous structure of fine fibrils progressively yields and the internal stress is gradually assumed by the larger fibres until they are straightened out from the r previously distorted configuration and the paper sheet assumes an added length closely approximating the length to which thepaper web had been compressed. Upon still. further increasing the tensile stress the mutual adherence of the fine fibrils which maintains. the structure of the larger fibres breaks down locally and the sample ruptures. Paper treated according to this process may be made to haye almost any desired elongation even up to as: high as 100% of its length. The amount of extensibility imparted to the paper can becontrolled by adjustments and the operation of the mechanism for carrying out the process.

When a paper web that has been compressed in this manner is later stretched or extended to impart thereto its full permanent extensibility in excess of the resiliency and elasticity of the Web, there appears, to be no observable decrease in the thickness of the stretched or elongated web over that before stretching or elongation. In fact, the compressed Web slightlyincreases in thickness when elongated.

A variety of types of apparatus may be employed to practice the. process. of this invention. Preferredforms of apparatus employ an element having an elastic contractable surface which has relatively high friction a ainst-Which the paper is pressed'by asurface which has relatively low friction, while such contractablesurface is contracting, such pressure being sufiicient not only to restrain the, paper from creping but also to force. the paper into such frictional contact with thecontracting surface that thepaper partakes of some ofthe dimensional contraction of such surface and ccnsequently is compressed inthe direction in which such surface iscontracting.

Thus the contracting surface maybe that'cf a traveling beltor blanket runnin in an endless path, the contractin surface. being caused to contract at a place in such path where the direction of such contracting surface of the beltor blanket changes from; a convex to a concave course. The low friction surface may be a heated, smooth, highly polished metal surface. The amount of stretchability imparted to the web is substantiallyequal to the degree to Which the web is shortenedlby the longitudinal compression. One mechanism ofthis type that can be utilized is shown and described in-United states Patent No. 2,021,975. In general, the resistance of the paper to contraction maybe such that a number of treatments by suchamechanism may be necessary in order to attain the desired degree of future extensibility. The water must be gradually extracted from the paper Web as it is additionally compressed in order to permit increased longitudinal compression of the web and thus additional extensibility. It is impossible to materially increase thedensity orto decrease the volume of the web if .the Web is fully saturated.

Itispreferable to bring the Wet Web to the compressing machine with suflicient voids in the web to. allow compressionto be accomplished. The water may be extracted by any of the known ace secs means such as by suction boxes, rolls or heat, or it may be extracted by the compressing machine itself, in which case the first run through the machine will act largely as a dryer and will not materially compress the web. Thus the paper may be passed a number of times through a single such mechanism; or any desirable number of such mechanisms may be arranged to receive and treat the paper successively, preferably so that both surfaces of the Web are alternately in contact with the heated surface. Although mechanism of this type causes a certain amount of drying; by applying heat to the web, it is preferred to provide supplemental drying apparatus to facilitatedryi'ng. This may comprise the regular drying cylinder or means employed in present paper" making, or it may comprise a special apparatus.

In the drawings;

Fig. 1- is adiagrammaticside elevation ci-simple apparatus usefulin performing the: compressive contracting step or. steps employed inthe invention;

Fig. 2 is a, diagrammatic side elevation of apparatuswhich may also be employed in conjunction with theapparatus of Fig. 1-;

Figs. Sand 4' together constitute adiagrammatic view ofequipment suitable for continuously subjecting paper totratment in successive apparatus, the paper first passing from leftto right in Fig. 3 and then from left to right in Fig 4;

Fig. 5 is a sectionalelevation on an enlarged scale of a portion of a; web of modified'paper produced by the' invention; and- Fig. .6,is:an enlarged view' partly in elevation and wrapped with y the the invention. 7

The invention will first be'explained by referring to the production of'typical products by use of the apparatus'of Figs. 1 and 2.

The'apparatus'of Fig. l-comprises rolls it, H, 12. and a heated driven roll [3 (corresponding respectively to the rolls-indicated at! 13, I i I, I l 2, and N3 of said patent) and a thick belt H5 with a contractablesurface layer, preferably of rubber of du-rometer hardness sui'licient to prevent crepingof the paper web. This belt'may'be formed of natural rubberor rubber substitutes, and prefer modified paper produced by ably it has a strong'relatively inextensible layer faced with a readily-extensibleand contractable surfacelayerof any suitable material of smooth contractible surface of sufficient hardness and extensibility,- rolls; i5 and 13 being adjustably movable toward or from each other so as to properly nip the belt l5 between them where the belt passes fromroll It to roll l3; and. roll (2 being.

spaced awayfrom roll l3-sufiiciently to givethe belt a short straight run from roll [3' to roll l2. As the belt passes fromroll it to'roll. [3, the

outer surface-of the rubber belt whichis convexly' curved on roll H3 becomes.concavelycurvedon roll it and accordingly shortens Apaper'web fed in between-the belt and: roll i3:where this shortening of thebeltp-surfaceis taking place is forced into such'frictional contact with the contracting surface of the belt that the. beltsurface tends to compress the web longitudinally, parallel With the surfaces of the :web. The roll 13 must be accurately machined ground and finished to a true cylinder of smooth gperiphery; It is heated not only to cause a partial drying of the web but also to lower the coefficient of friction between the drum and the time heating the contained water and thus cause partly in longitudinal section showing a cable moist :web .While. at the samea Softening andincr'eased flexibility of the fibres.

The resulting lossof water in the web makes room between the fibres for further compression of the web as'may be desired. The coeilicient of friction between the wet web and the heated drum [3 is most effectively reduced at d-rum temperatures about212" F. The coefficient of friction of the surface of the roll l3 is relatively low as compared to the coefficient of friction of the web-, contacting surface of the belt [5, so that under the'contracting belt surface the paperswebtendsto partake of such contraction of the belt surface and slide with relation .to the roll surface. During the longitudinal compression of the paper, the tension in the rubber belt is maintainedsufilciently high so that with the selected hardness of the belt surface the pressure between the rubber belt 15 and the roll [3 prevents the paper from creping and keeps the surfaces of-the paper plain and parallel so that as the, web is .compressively shortened, individual fibers of the paper which lie generally lengthwise of theweb or in the direction of shortening are compressively distorted lengthwise within .the bodyofthe web. Rubber is preferred as thematerial for the contracting surface, such as that of the belt, [5, because of its ability to withstand strong tension and heavy pressure transverse to its surface, thus enabling a relatively large and effectivecontraction of this surface to take place without allowing the paper to crepe in response to such contraction. Rubber is also preferred for its continuously smooth surface and for its ability to grip the paper frictionally to the extent of compressing thepaper longitudinally in the presence of the heavy pressure exerted between the belt and roll l3, for, prevention of creping. In the apparatus as shown it is preferable that therubber is reinforced by comparatively inextensible material such as heavy canvas or layers of strong cords so that the necessary high tension in the belt may be maintained and also so that the surface of the belt will expand and contract uniformly while passing over the roller Hi and the heated driving roll IS.

The apparatus of Fig. 2 was employed in con- ;junction with the apparatus of Fig. 1 principally to facilitate drying the paper web. As shown in Fig. 2 a moisture-permeable felt belt 2| passes over an intake roll 2| and thence onto and around a heated drum 20, holding the paper web against the drumduring drying.

, To be strongest, paper made by this process should be from the freshly laid web as received from the Fourdrinier or other paper forming machine, and must not be allowed to fully set or dry while being compressed in length; nor must the paper surface be fully dried or set until the desired compression is attained. Fibres when fresh from the pulp have, when pressed together and dried, a strong affinity for each other caused not only by the entwining of the fibres but also by the entanglement of fibrils and by the adhesion of finely beaten parts of the fibrils which cement the papermass in a strong bond.

In making stretchable paper in this application it is therefore desirable to crowd and distort the fibres to as full extent as it may be desired beforejinitial bonding or irreversible adh'esions take place. 7

When regularly manufactured paper is later rewet, and compressed according to this improved method, the rearrangement of the fibres with local and individual crowding and flexing thereof with the space between th faces of the .web

as laid breaksv some of the earlier formed adhesions and these broken adhesions are not readily reestablished with the same original strength.

Thus although the paper exhibitsextensibility, the ultimate strength is generally less than is achieved when freshly laid webs are used.

Webs were made. of kraft paper which had been 'beaten to a freeness of 21 (Schopper Riegler), these webs being made as hand-sheets of approximately pounds ream weight (24- x 36 x 500 basis) and pressed to reduce their moisture content to approximately 70%. The webs were kept in moisture-proof packing so as to retaintheir moisture and avoid hardening of the paper until the compressive contracting operation.

Various runs of such webs were made, using various combinations of numbers of passes through the apparatus ofFigs. 1 and 2, and in the two examples tabulated below the web was initially passedtwice through the apparatus of Fig. 2, which had been found helpful in order somewhat to reduce the moisture content and to warm the web, then was passed a number of times through the apparatus of Fig. l, and then again passed once more through th apparatus of Fig. 2 for final drying.

Average Fig. 5 is a drawing, enlarged about times, showing the relation of the fibers of Example (b) This view readily illustrates the locally crinkled conditions of the fibers, the plainness and smoothness of the top and bottom surfaces of thewweb, and the fact that th slight surface indentations (greatly magnified in the drawing) do not traverse the thickness of the web and are not reflected 'in' corresponding projections from the opposite surface. g

It will be observed thatthe products were relatively strong but had a marked and useful amount of extensibility. This extensibility when expressedin percent represented an extension of the web to and slightly beyond its original lengthwise dimension. That is, taking example (b), a contraction of 33% results in a contracted length of 67% of the original length, and an extensibility of 52.3% of such contracted length of 67% represents areturn to 102% of the original dimension.

As will readily be apparent, the amount of extensibility imparted to, the paper may be varied by varying the'amount which the paper" is compressively contracted from, its initial condition. It is contemplated that in most cases the demand will be for products capable of 10% or more extensibility. .The extensibility of paper of the present invention can be distinguished from extensibility produced by creping, in that extension of the present paper involves extension of distorted fibers within the body defined by'plain parallel faces of the sheet of web material, whereas extension of creped paper takes place primari- Y ly by straightening-out of bodily folded or creased zones of the web with resultant decrease'ofthickness of theweb.

The preferred product of thepresentinvention may readily be distinguished bysight-0r 'touch zeal-gate from. many extensible paper products: ink that effect also 'facilitatingruse of. the heavier" grades both its faces are sinoothplairrparallel; faces; of paper for mechanical purposes. U .7 It maybe noted heref that the'prd'duetsiofexam-- Although the preferred; procedure isto leaveple's (adand (-b)" discussed above: as well: as other the surfaces of the paper'u'ncreped;athe paper may product's of thi's: invention r'eceivewriting well. 5'- additionally be'subje'cted to cre'ping;-.in whichicase The smoothness of v the product of the present it will have not only theaextensibilityr due" to the invention is especially useful where -itis desired ability o f' its material to elongate. as; explained that liquid coating be app-liedz. Thus, liquid above, but also whatever extensibility may result water=proofihgor Water-repellentcoatingscan be from the creping. In any such case the total economically applied to the smooth modified ro extensibility of the web will very substantiallypa er of the present invention; whereas; such xceed that extensibility whichis' attributableto coatings would be'diificultland costly of a'pplica straightening-out of the foldsorrcreases which tion: to creased 1 or wrinkled: produ'ctsi- V have been imparted b5; the creping;

The compressive actioir which the product has An excessive quantity or moisture. theweb receivedmateriallyincreases: itsde'n'sity over'that' l5" priorto' processing is l'ikely to sQ impedethe'cOm of the web from which it is made. Likewise the pressive contractiiig' operatieniasrtogivertheiini product-'has-a density at least approximately" as pression that the paperiwill:beiincapable of being great as, and generally materially higher than; compressively 'contracted. For instance; it: has results from ordinary"production of: a water-laid lz'ie'en' observed itha't' one-r or even-several passes of web from the same or similar paper-mairing amoist paper through theapparatus'has failed fibers-and ordinary finishihgiof such'web-a'spaper to shorten the paperior has" resulted in actual of about the' sam'e thickness. For instance-,-vari'- elongation ofthe paper. When; instead of stopousseries of extensible papers have" been prepared pin'gtthe' treat'ment because 'of s'uc'h apparentfail according to the invention by'compressively conure; the treatment isnevertlieless continued and tractingzfreshly'laid but incompletely dried Kraft the'paper is subjected to further passes,- it'lias paper. In one such series of relatively heavy been found. that eventually a" pass of'the paper weight the amounts of contraction applied to through theapparatus wouldiresult insubstantial the paper ranged from 14.9% to 38.9% and the shortening'and further passes wouldresuliiin fiirresulting ream weight of the products ranged bether substantial shortening. This is explainabfle' tween-108 pounds and 229- pounds. In this series by the theory that moisture in' sufiicient quantity the density of each-product lay within the range will fill up the body'of the web'andmakeit iu 17.3% to 24.3% and the resulting ream weights through thea'pparatu's removesmois'turefrom thepounds. ln this series the density ofeach prodductive of shortening, the moisture will-be reuotlayv within :the rangeof I 0025 to: 0.028 pound duced to a value which allows the webto shorten. per cubic inch. Thus papers that are apparently incapable of- In general, thecom-pressive actionto-which the- 40' shortening can neverthelessbeshortened by surf-'- paperof the present 'invention' has beensubficiently-continuingxthe treatment.- However, the jected" during. its treatmentv will not havepronecessarynumber of passesof the web through duced morethana,fractionalincreaseinapparent the-apparatus can be reduced by avoidin too thickness of thepaper, either as measuredfor a high a: moisture content atthe first runl- For piled in bulk, nor any substantial increase in ap-' about a per cent moisture content well disparent volume, either as calculated for a single tributed throughout the material of the web at sheet or for a number of sheets piled in bulk. all portions 01 its thickness, operates well and Forinstance,- aseries of extensiblepapers has b s s S g 'b 's ia fi s i been prepared accordingto the-invention 'bymois 5 or'n rly fir p f he pap r hroueh the tening.and-compressivelycontracting kraft paper apparatusof3dpoundsreamweight which before treatment On the o-therh n' sufiicient'm ismr' h' u had a thickness'of 0;0036'inch and an extensibility be present to render the"paperamenable'f-to disseriesranged from 2 g 7 and t e thibk s 'z lel with the surfaces of the paper inthe presenceranged from 0.0041 inch to 0.0052 inch. of confinement g t repi'n'g or the plain creping but also to heavy weight; f r: tus. Reduction in'plasticity-ofthe paper reduces instance, in starting with-relatively heavifkraft' the of t ng p p 90poundsTeamweighuthe;ream Weight Uniformity. 7 of; distribution of themoisture of; the; resulting modified paper is greater'tha'n' thmugh the lsdeslrable;

weightsof paper, is that thesame compressive t screen of m m ac u be treatment that imparts extensibility also infound advantageous jnicarr jn fofifth sti creases the flexibility of the web-along.lines:per -evenly.throughout -thethicliness'"of"the vi b more p ndia l o e i c n r extensibility; this' rapi ly than is-practicable by'use or' sii rracentact of the web with a hot cylinder and thus leave a stronger and more even bond between the fibres when they are crinkled and pushed together in the machine.

In processing large quantities of the material to a predetermined degree of contraction and extensibility, it may be advantageous to pass the web continuously through a plurality of devices such as those of Figs. 1 and 2 arranged to act successively. Thus in Fig. 3 the web P, which has previously been conditioned to an appropriate moisture content, is shown as assing successively through, fol-example, four devices such as shown in Fig. l, alternate ones of these devices being inverted so that each surface of the web makes contact alternately with a driven roll l3 and with a rubber belt l5, thus equalizing the finish of the two surfaces of the paper. 7

For final drying, the web may pass from the last device of Fig. 3 over the drying cylinders usual in pap-er making machinery or it may pass into and through the lar e felt belt dr er of Fig. 4, similar in "principle to the apparatus of Fig. 2, bein there held in contact with a large rotating steam heated drum 20 by means of a moisturepermeable felt belt 2|. An auxiliary steam heated drum 22 may be employed to dry the felt belt. Following this treatment, the product may be wound up in a roll.

The speeds of the several devices of Figs. 3 and 4 are adjusted relative to each other by any suitable means so that they are progressively slower, to accommodate the progressively shortened web and bring it to its desired final lengthwise condition by the time it is dried and of the drum 20 of Fig. 4.

The speed of the felt belt dryer of Fig. 4 may also be adjusted relative to the speeds of the preceding mechanisms so as to adjust the total or net amount of longitudinal and thus, if the web has been contracted to a somewhat greater extent than desired during passage through the several devices of Fig. 3, the felt belt dryer of Fig. 4 maybe set to run at a speed which will stretch the web sufficiently in length to deliver the web in the final desired state of contraction.

One of many uses for the modified paper of the present invention is as covering material shaped to fit a tapering support. In this use the enhanced extensibility of the paper enables it to be stretched locally where needed while at the same time allowing th paper to have a snug, smooth fit with its underlying support.

In Fig. 6 of the drawings there is illustrated on an enlarged scale an electric cable 25 wrapped with modified paper produced by this invention. In wrapping a strip of paper spirally around a cable, the strip will overlie one or more thicknesses of itself [or of other wrapping material, excepting at its forward or leading edge where it will lie in contact with'the bare cable. It must therefore occupy a larger diameter where it overlies one or more thicknesses of itself or other wrapping material than where it overlies simply the bare cable. With ordinary substantially nonextensible paper there is the tendency for the spirally wrapped fit smoothly and snugly at the bare cable where the spiral has its smallest diameter, and to fail I snugly the various other diameters of underlying layers of the wrapping. With the modified paper of the present invention, however, the portions of "the paperstrip that overlap other portions thereof are na e 7 a ia lely ithout eset by the heat contraction of the web to fit smoothly and 10 of the'portion that is to over- The result as shown in Fig. 6 is that each portion of the wrapping strip, at each diameter, has a smooth snug fit with its underlying support. Also, the product may be used to cover snugly any surface having local irregular projections; or the product may be used where it is desired that there may be extension of the paper without rupture, such as in shotgun shells.

The present invention is particularly useful in the manufacture of twisting tissue and paper for use in twine; the product being. stronger than paper twine as regularly produced owing to ability of the edges of the employed material to stretch along the edges without rupture, while at the same time retaining resistance against elongation.

The Web of cellulose fibers after compression in accordance with my process, has resiliency and elasticity, and as it is stretched beyond its primitive elastic limit it retains retraction resiliency and elasticity until rupture, but during the stretching to rupture, the primitive elastic limit of the web also progressively changes,so that if the stretching forces are removed at any point short of rupture, the web retains its stretched condition except for the retraction due to a residual resiliency and elasticity.

I claim:

1. The process of producing an uncreped paper web of water-laid, adherent, cellulose fibres, with smooth, substantially parallel faces and substantial permanent extensibilityin excess of the primitive elastic limit of the web, and which suifers no substantial decrease in thickness when elongated by stretching, which comprises moving said web in a direction lengthwise thereof, and while in the hysical condition it possesses as it leaves the wet end of a paper making machine, slowly removing a part only of the moisture fromsaid paper web, and uniformly pushing and crowding the fibres of the partially dried web together in the space between the faces of the web as laid, continuous through the web, and by forces acting in a direction parallel to the faces of the web, opposite to the direction of .movement, and throughout the pushing andcrowding confining the web against creping by pressures on the web normal to said web faces.

2. The process of producing an uncreped paper of water-laid. adherent, cellulose fibres, with smooth, substantiallyparallel faces and substantial permanent extensibility in excess of the resiliency and elasticity of the web, and which suffers no substantial decrease in thickness when elongated by stretching, which comprises heating the web, while in the physical condition it possesses as it leaves the wet end of a paper making machine, until. a part only of the moisture of the web has been removed, then confining said partially dried web between two moving bodies having spaced surfaces, one of which is heated and has relatively low frictional resistance to movement of said web thereover, andthe otherof which is smooth, oontractible and has a relatively high frictional resistance to movement of said web thereover, preventing .creping .of the web while between said surfaces of said bodies with applied forces normal to and opposing separation of said bodies, and while the web is so confined contracting the area of said surface of said body with said relatively high frictional resistance to carry said web with it over said heated body and thereby compress the web in 'the direction of contraction and crowd the web fibres into a more compactmass;

sponding stretching lie the bare cable.

3. Process ofproducing an uncreped paper web of water-laid, adherent, cellulose fibres, with smooth, substantially parallel faces and substan-' tial permanent extensibility in excess'of theresiliency and elasticity of the web, and which suffers no substantial decrease in thickness when elongated by stretching, which comprises confining said web, while in a plastic condition, between two moving bodies having spaced surfaces, one of which is heated and offers relatively low frictional resistance to the movement thereover of said paper web, and the other of which is smooth, contractible and .ofi'ers relatively high frictional resistance to the movement thereover of said paper web, preventing creping of the confined web while between said surfaces of said bodies with applied forces normal to and opposing separation of said bodies, and while the web is so confined contracting the webccntacting area of said other body having the surface offering said relatively high frictionalresistance, to contract said web with it over said heated body and thereby compress the web in the direction of contraction of said area and crowd and push the web fibres into a more compact mass.

4. The process of producing an uncreped paper web of water-laid, adherent cellulose fibres, with smooth, substantially parallel faces and substantial permanent extensibility in excess of the resiliency and elasticity of the web, and which suffers no substantial decrease in thickness when elongated by stretching, which comprises slowly removing a part only of the moisture from a paper web in the physical condition it possesses as it leaves the wet end of a paper-making machine before drying, then subjecting this partially but not fully dried web to a plurality of similar successive treatments, in each of which the web is confined between two moving bodies having surfaces, one of which is heated, smooth, and offers relatively low frictional resistance to movement of a wet paper web thereover, and the other of which is smooth, contractible and offers relatively high frictional resistance to the movement thereover of said paper web, preventing creping of the confined web while between said surfaces of said bodies by applied, opposing forces normal to and opposing .separation of said bodies, and while the web is so confined contracting the web-contacting area of said body having the surface offering said relatively high frictional resistance, to contract said confined web with it over said heated body and thereby compress the web in the direction of contraction of said area, and crowd and push the web fibres into a more compact mass, and removing moisture from the web between treatments to free the voids in the web of moisture and enable the compressed fibres to fill them.

5. A relatively dense, uncreped paper w b formed from adherent, natural cellulose fibers, in their natural physical shape said Web being characterized by an uncreped body of approximately uniform density throughout itsflensthand width, .devoid'of folds and pleats, and having smooth, substantially parallel faces and -sub stantial extensibility beyond its primitive elastic limit, continuous throughout it in a direction parallel to its faces, those the web which lie lengthwise generally in said direction of extensibility being locally, laterally and individually rearranged and icompressively distorted lengthwise within the space between said web faces, said web when elcngatedheyo d of said fibers within its elastic limit by tension in said direction suffering no substantial decrease in its thickness.

6. A relatively dense, uncreped paper web formed from adherent, cellulose fibers in their natural physical shape, said web being characterized by an uncreped' body, devoid of fold and pleats, and having smooth, substantially parallel faces and substantial extensibility continuous throughout it in a direction parallel to its faces and to an extent well beyond its primitive elastic limit, those of said fibers in said web which lie lengthwisegenerally in said direction of extensibility being locally; laterally and .individually re arranged and compressively distorted lengthwise within the space between said web faces.

7. A relatively dense, uncreped paper web formed of water-laid, adherent cellulose fibers in their natural physical shapasaid Web being Characterized by substantially parallel faces, and by substantial extensibility well in excess of its rimitive elastic limit in a direction paral el to it faces, said extensibility being continuous throu hout it. in said direction of extensi- 'lity and those of said fibers within said Web which extend erally lengthwise in said direction of extensibility being locally, laterally, and individually rearranged and undulatory lengthwise within the space between said web face 8. The process of producing an uncreped paper web of water-laid, adherent, cellulose fibers, with smooth, substantially parallel faces, devoid of folds and pleats, having substantial extensibility in excess ofprimitive elastic limit, and suffermg .no substant al decrease in t ckness when elongated by stretching beyond its said elastic limit, which comprises conditioning the web to contain less moisture than its maximum capacity to hold moisture, but sufiicient to give the fibers thereof substantial plasticity, then pushing and crowding together, and locally flexing, rearranging and distorting lengthwise, the fibers of the conditioned web, continuous throughout the web, by forces applied in a direction parallel to the faces of the web and opposed to the direction of desired extensibility of the web, and, during such pushing and crowding together and local flexing, rearrangement and lengthwise distortion of the fibers, confining said web against creping, and drying this treated web.

'9. A process of producing an uncreped paper web of water-laid, adherent, cellulose fibers, with smooth substantially parallel faces and substantial permanent extensibility in excess of the primitive elastic limitof the web, which comprises establishing a uniformly distributed moisture content in said web which is. considerably less than the max mum the Web can carry u u ificientto give substantial plasticity to the fibers of the web, moving said web with it established moisture content in a lengthwis direction, and while the web isso moving pushing andcrowding the fibers of the web together in the space between the fa es of the web a aid and by fo applied in the direction ,pnltallel to the faces of the weband op osed to theuirection of it lene hwise movement continuously and uniformly over the web, and throughout .thepushing and crowdins confining the e esa nst'c i e y p sures on the web normal to said web faces.

10. The process of produci an uncre paper web of water laidadherent, cellulose fibers, with smooth, substantially parallel faces and substantial extensibility .beyQI1d the primitive elastic l mit of the web. andwh cb :sufierls zoo-substantial de eas th ckness when elon ated :by st etch- 13 ing, which comprises moving said web in a direction lengthwise thereof, and while in the physical condition it possesses as it leaves the Wet end of a paper making machine, applying high frequency heating to the web until a part only of the moisture of the web has been removed, while the web is still in a plastic condition, uniformly pushing and crowding the fibers of the moving web together in the space between the faces of the web as laid, continuously throughout the web, and by forces applied in a direction parallel to the faces of the web and opposite to the direction of movement, and throughout the pushing and crowding confinin the web against creping by pressures on the web normal to said web faces.

11. The process of producing an uncreped paper web of water-laid, adherent, cellulose fibers, with smooth, substantially parallel faces and substantial extensibility beyond its primitive elastic limit, and which sufiers no substantial decrease in thickness when elongated by stretching, which comprises moving said web in a direction lengthwise thereof, and while in the physical condition it possesses as it leaves the wet end of a paper-making machine, slowly removing a part only of the moisture from said paper web, confining said moving partially dried web against creping and simultaneously contracting the face areas of said confined web and pushing and crowding together the fibers of the confined web in the direction parallel to the faces of said web and opposed to said movement, and continuously over said web to increase the density of the web, then removing further but not all of the remaining moisture from the moving compressed web, then reconfining the moving compressed web against creping and while the web is so reconfined her C ct the face areas of the confined web and similarly and further pushing and crowding further together the fibers of the reconfined web, to further increase the density of the web, and then drying this treated web.

12. The process of producing an uncreped paper web of water-laid, adherent, cellulose fibers, with smooth substantially parallel faces and substantial extensibility beyond its primitive elastic limit, and which suffers no substantial decrease in thickness when elongated by stretching, which comprises conditioning said web to contain less moisture than its maximum capacity to hold moisture, but sufficient to give the fibers thereof substantial plasticity, moving said conditioned web in the direction of its length, confining said moving web, while its fibers are still in a plastic condition, against creping and, while so confined uniformly, over the entire area of the web, pushing and crowding the fibers of the web together by forces acting in a web, and parallel to its faces and causing local relative flexing and rearrangement of, adjacent fibers, entirely within the space between the face areas of the web, to create a denser mass in the web.

13. A relatively dense uncreped paper web formed of water-laid, adherent cellulose fibers in their natural physical shape, said web having smooth, substantially parallel faces and substantial extensibility in a direction parallel to its faces, continuous throughout it in said direction of extensibility and well in excess of its primitive elastic limit, whose fibers have been crowded and pushed together uniformly over the web, in a direction parallel to the faces of the web, in the space between the faces of the web as laid, to provide such extensibility, the crowded and pushed fibers having between them, in that relation, 2. bond due to initial drying giving maximum and continuing resistance to permanent elongation in said direction, short of rupture of the web.

SANFORD L. CLUETT.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,643,147 Angier Sept. 20, 1927 1,679,996 Tracy Aug. 7, 1928 2,021,975 Wrigley et al. Nov. 26, 1935 2,167,440 Mason July 25, 1939 2,217,691 Mason Oct. 15, 1940 2,245,014 Sherman June 10, 1941 2,409,066 Powell et a1. Oct. 8, 1946 2,429,706 Wood Oct. 28, 1947 2,447,784 Wood Aug. 24, 1948 2,535,734 Grettve Dec. 26, 1950 FOREIGN PATENTS Number Country Date 467,307 Canada Aug. 15, 1950 418,432 Great Britain Oct. 24, 1934 direction lengthwise of the

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