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Sept. 10, 1946. J_ GOLDMAN 2,407,548 FIBROUS STRUCTURAL MATERIAL AND METHOD AND APPARATUS FOR MAKING SAME Filed Aug. 1, 1940 3 Sheets-Sheet l 52 ~ g5 CARDING lNVENTOR W ATTORNEYS Sept. 10, 1946. J_ GOLDMAN 2,407,548 FIBROUS STRUCTURAL MATERIAL AND METHOD AND APPARATUS FOR MAKING SAME Filed Aug. 1, 1940 5 Sheets-Sheet 2 51 INVENTOR 14 ATTORNEY§ Sept. 10, 1946.v J. GOLDMAN 2,407,548 FIBROUS STRUCTURAL MATERIAL AND METHOD AND APPARATUS FOR MAKING SAME Filed Aug. 1, 1940 as 3 Sheets-Sheet 5 86’ nllllllllllllllllll @716: w B INVENTOR ATTO R N EYS 2,407,548 Patented Sept. I 10, 1946 UNITED ‘STATES "PATENT OFFICE" ' . METHOD AND APPARATUS FOR MAKING SAME Joseph Goldman, New Brunswick, N. 3., assignor _ to Fibre Products Laboratories, Inc., a corpo ration of New Jersey Application August 1, 1940, Serial No. 349,311 ' 27 claims.‘ (ohm-71) . 1 ~ not is the disposition and‘ straightness 'of the ?bers in the elemental web whereby high strength This invention relates to ?brous structural material and method of and apparatus for mak ing same. It relates especially to structural ma terial fabricated by bonding together unspun ?bers into integral coherent sheet material. i to weight of ?ber and web thickness is secured. ‘ The web material also has high resistance to stretch in the direction of longitudinal disposi tion of the ?bers in the'elemental web material and composite ?brous sheet material can be made having special directional strength char acteristics suitable for different purposes. It is a purpose of this invention to provide structural material made from unspun ?bers that has very high strength for its weight and thick ness. Thus, according to preferred embodiments It is a feature of this invention that the ?bers of this invention a structural web or sheet can 10 in the unspun ?brous web material are disposed be made from cotton ?bers, for example, that has so as to take full advantage of the strength of greater tensile strength for a given gauge. than the ?bers. According to this invention a mul non-ferrous metals, such as aluminum and magtiplicity of the unspun ?bers are straightened out nesium metals, and has much greater strength, e.‘ g. twice as much strength for a given weight 15 so as to be disposed substantially at their maxi mum length. when tensioned lengthwise and are as such non-ferrous metals. likewise bonded together for the most part in Features of this invention relate to the method, to the apparatus and‘ to the product. From the point of view of the method it is oné‘of the fea tures of this invention that unspun ?bers which 20 have been brought into such disposition in web ' is very uniform in its ?ber density and thickness even in sheets of relatively large lateral dimen material that they are predominantly in one direction are bonded together while the ?bers of strumental in achieving the uniformity of the striated web material, for while the ?bers may be originally in theform of slivers or the like, ?bers the web material are under tension, thereby set ting the ?bers notv only as disposed predom one direction or nearly so in a sheet or web that sions. The method and the apparatus are in 25 are caused to be distributed very uniformly as inantly in one direction but also in a condition by repeated lapping and drafting operations until of tensioned straightness. Other features of this invention» relate to the steps utilized in connec the ?bers occur in a dense striated web of sub stantially uniform ?ber density and thickness throughout. The ?bers are cobonded in this tion with the bonding step including the steps whereby the ?bers are straightened and oriented 30 dense and uniform ?brous web or sheet so that the bonding effect is very uniform throughout the lateral extent and thickness of the web ma terial. ; Furthermore, any wrinkling tendency in together the ?brous striated web material will cident to drafting is compensated for by a spread have been conditioned in a manner especially suited for the bonding step. Other features of 35 ing step to insure uniformity of the striated web I material when the bonding ‘material is applied this invention relate to the manufacture of un to the web. In this manner a structural mate spun ?brous web material during the condition rial that not only has high strength, but also has ing steps and bonding step and in directing the very uniform strength characteristics through web material from the conditioning step to the bonding step. ' 40 out, is afforded that renders the material suit able for numerous structural applications where Certain apparatus features of this invention in a strong and light structural material is de relate to the means employed for drawing and sired that can be made uniformly throughout to bonding under tension in web form unspun ?bers predominantly in one direction by tensioning and drawing so that when the ?bers are bonded and for handling the web material between the ‘ 7 close speci?cations. In order to afford a better understanding of 45 drawing and bonding steps. ‘The product of this invention is a unique web the practice of this invention, it will be described for purposes of exempli?cation in connection with the fabrication of unspun cotton ?bers into material. The product. of this invention in its thin coherent web material of high strength and elemental form is a thin coherent striated web 50 density, reference being made to the accompany ing drawings, wherein of cobonded unspun ?bers which is useful per ‘Fig. 1 is a diagrammatic representation of- a se and is also useful as 9, ply sheet in the forma plant layout of machinery for making the unspun tion of composite sheet material e. g. comprise web material according to this invention, ing a plurality of thicknesses or layers of the Fig. 2 is a diagrammatic side elevational repre . elemental web material. a feature of the prod 55 or sheet material that is of great value for a number of commercialpurposes as a structural 2,407, 648 a 4 3 sentation of apparatus for carrying out a draft ing and bonding operation, ‘ .. running yard of the cotton ?ber. \ Fig. 3 is a plan view of the drafting and spread ' ing apparatus, ' Fig. 4 is a side elevationalview partly in sec tion of the apparatus of Fig.3 and of means for applying the bonding material, by the reference character 26. In this machine about 20 of the slivers 24 for example may be taken from cans 25 and passed while, arranged side by side between a series of drafting rolls 21. _ Fig. 5 is a perspective view of one of the spreader bars used in connection with the appa ratus shown in Fig. 4, - The- ?ber is next subjected to. a drawing operation in some suitable device which may for example be a sliv er lapping machine which is indicated generally _ A series of three pairs of rolls may be used with 10 the nips of‘ adjacent pairs of rolls spaced from _ Fig. 6 is a top view of an elemental web of vun-_ spun ?brous material made according to this in vention, Fig. 7 is a top view of a portion of the web ma- ‘ each other by a distance that is'slightly greater than the length of the ?bers. Each pair of. rolls is operated at a speed that is, different from the immediately preceding pair ofrolls so that the terial of Fig. 6 on a very greatly enlarged scale, 15 ?bers in the slivers 24 are drawnsuf?ciently to Fig. 8 is a transverse cross-sectional view of a straighten'them somewhat and arrange them so portion of the web on a very greatly enlarged that at least partially the ?bers become disposed scale on the line 8-8 of Fig. 6, Fig. 9 is a longitudinal sectional view of the longitudinally of the ?brous material passing through the drafting rolls. For example the last web material on a very greatly enlarged scale on the line 9—9 of Fig. 6,» Fig. 10 is a plan view on a reduced scale of a drafting roll may rotate so that the peripheral 20 speed is twice the peripheral'speed of the ?rst pair of drafting rolls in the series and so that the ?brous mass will be drawn approximately 2 to 1. vention, If 20 slivers each containingabout ,50 grains per 'Fig. 11 is a side elevational view of a modi?ed 25 running yard are run into the sliver lapping ma form of apparatus for spreading under tension a chine the ?brous web material that is discharged drawn web, ‘ ' from the drafting rolls will contain about 500 Fig. 12 is a cross section of the spreading ap grains per running yard. The web 28 which is paratus on the line l2-I2 of Fig. 11,‘ discharged from the drafting rolls is approxi Fig. 13 is a cross section of the spreading ap 30 mately 10 inches in width and ‘may be passed be paratus on the line |3—I3 of Fig. 11, . tween calender rolls 98 and rolled up into aroll Fig. 14 is a cross section of the spreading ap 29. The roll 29 can be removed from the lapping paratus on the line Ill-I4 of Fig. 11, machine and taken to the ribbon lapping ma Fig. 15 is a modi?ed form of drafting means chine which is indicated generally by the refer that may be used in the practice of this inven 35 ence character 30 and which subjects the ?bers tion, and ’ to a further drafting operation. Fig. 16 is a further modi?ed form of drafting In the ribbon lapping machine the web mate means that may be used according to this inven rial 28 from each of four of the rolls 20 that are tion shown in association with part of a spread carried by the ribbon lapping machine is passed ing means. 40 between drafting rolls 3|. These drafting rolls Forthe purpose of affording a speci?c exam may be similar to the drafting rolls 2'! except that ple of the practice ‘of this invention in the man in this case the speed of the rolls is adjusted so ufacture of a highly desirable product, cotton ? that the drafting will be about 4 to 1. Thus if ber may for example be used which ?ber con each of the webs 28 contains about 500 grains of tains about 70% of ?ber that is about an inch or 45 cotton per running yard that enters the draft more in length although other grades of cotton ing rolls 3| the web discharged from each of the may be used. Before the bonding step the un sets of drafting rolls will weigh about 125 grains composite sheet material that’ embodies this in spun ?bers are acted upon so as to distribute , them uniformly in a sheet or web so as to be ar per running yard. In the ribbon lapper four pairs of rolls in each set of drafting rolls may for ex ranged predominantly‘ in one direction and 50 ample be used. The webs discharged from the straightened. This treatment can be accom drafting rolls 3| are passed through bookfolds 32 plished using different types of apparatus, the which cause the four Webs to become superposed type of apparatus varying depending‘ largely up on the type of ?ber being handled. For cotton ?bers that for the most part are about one inch in length the treatment is preferably accom plished by repeated drafting and lapping opera tions whereby the ?bers are drawn predominant ly in one direction and are straightened and at the same time are averaged so as to result in a web material having a high degree of uniformity. A convenient arrangement of apparatus for and the superposed webs are passed between cal- . ender rolls 99 to form a composite web 33 which, according to the present example, would con tain about 500 grains of cotton per running yard and would be 10 inches in width. The web 33 is then made up into the roll 34. By the foregoing operations the ?brous sliver . 60 material from the carding machine has been drawn to an extent of about 8 to 1 and the web 33 discharged from the ribbon lapping machine producing a web comprising unspun cotton ?bers corresponds to an average of 80 slivers. The web of the character mentioned is shown in Figs. 1 material taken from the ribbon lapping machine is therefore very uniform in ?ber structure and has also been treated so that the fibers have been arranged for the most part in one direction and then straightened considerably so that the ?bers instead of being in the form of bends and crimps 70 are fairly well straightened. Inasmuch, how to 5. The ?ber stock e. g. ?ber that has been cleaned and made into a picker lap may ?rst be passed through a conventional carding machine which is indicated generally by the reference character 20 in Fig. 1 and which may comprise such conventional parts as a “licker-in” 2|, a cylinder 22 and a doffer 23. The sheet material from the carding machine is condensed into a sliver 24 that is received by any suitable means such as a can 25. The sliver thus produced may ever, as there is no binder applied to the web the ?bers tend in a considerable degree to assume ’ their natural curved and crimped state. f The foregoing operations are largely ofa pre for example contain approximately 50 grains per 75 paratory nature adapted to condition. the unspun I 2,407,548 5 ?brous material for the subsequent operations. 48 that passes over sprocket wheels 49, 50, 5|, 52 In order to complete the manufacture of the structural material the web material 33 from roll 34 is fed into another drafting frame which is indicated generally by the reference character 35. This draftingframe may be of the general and 53 which are‘ carried for rotation with rolls than the speed at which the ?brous web material - is discharged from the set ‘of drafting rolls 36. type referred to above and may comprise ?ve pairs The peripheral speeds of rolls 42, 43, 44, 45 and 42, 43, 44, 45 and 45 respectively. The peripheral speed of roll 42 is caused to be slightly greater 46 are successively somewhat increased so that of drafting rolls 36, the nips of which are spaced the web material 33 is continuously subjected to apart by a distance slightly greater than the max imum ?ber lengthof'the fibers being handled. 10 tension.‘ This may be done either by making the sprocket wheels 49, 50, 5|, 52 and 53 successively The drafting rolls 36 are operated at successively somewhat smaller or by utilizing rolls which suc increased speeds as the web material passes be cessively have increased diameters. Placed be tween them so as to further draw out the ?bers tween the rolls 42, 43, 44, 45 and 46 are spreader in such a way as to straighten them and arrange them in one direction. The drafting may be 15 bars 54, 55, 56 and 51 which are secured to ro-. tatably mounted bars 58, 59, 60 and 6! so that carried on so that in the drafting frame 35 the by rotating the bars the bowed portion 62 of web material 33 is drafted about 4 to 1. If the the bars can have its position in the path of the web going into the drafting frame weighs about web material between rolls 42, 43, 44, 45 and 46 500 grains per running yard the web that is dis charged from the drafting frame 35 will contain 20 adjusted as desired so as to avoid all contact with the web material or so as to exercise maximum about 125 grains of ?ber per running yard of the spreading action on the web material. By any . web material which is about 10 inches wide as suitable means not shown the spreader bars 54, it is discharged from the drafting frame. 55, 56 and 51 may be locked in the desired posi The drafting rolls 36 (and the drafting rolls 21 and 3|) may be provided with suitable means 25 tion. In Fig. 5 one of the spreader bars, i. e. bar for adjusting them both laterally and vertically 56, is shown. This bar has approximately a semi circular bowed portion "62. The bars 54 and 55 so as to secure desired action. Moreover, the rolls are curved somewhat more sharply adjacent the may be ?uted or covered with special materials sides than toward the center, this being the case such as leather, impregnated fabric, cork or the like to augment the drawing action. 30 particularly with bar 54. It has been found de As the striated web material is discharged from sirable to commence the spreading action at the the drafting frame 35 it is not permitted to relax sides and gradually extend the spreading action but while maintaining at least some degree of to the center of the web 33 in passing successive tension thereon is passed between the applicator ly over the spreader bars. For convenience in rolls 31. These rolls may apply material adapted making adjustments the spreader bars can be to bond the ?bers of the sheet together which made of material which has sufficient ?exibility material may be a temporary bonding material to permit them to be curved to the shape: that or a permanent bonding material. The bonding affords the desired results. material may be carried in troughs 38 which The spreading action takes place by moving supply the bonding material by feed rolls 39 40 the web material under tension over the ‘bowed (driven by any suitable means not shown) that portion 62 of the spreader bars thereby tending uniformly deposit the bonding material on the to spread the web laterally. The primary ten rolls 31. The rolls 31 may for example be cov sion is exerted by the roll 46 which has associ ered with some material such as a fabricwhich ated therewith a press roll 63 that imposes its carries the desired amount of the binder material weight upon the sheet 33 passing between it and and applies it‘to the web material 33 as it passes the roll 46 so that the drag on the sheet 33 will between rolls 31. If desired and depending some be more positive. The spreading apparatus dis what on the type of binder material applied, doc poses the web material so that it is presented tor blades llil may be associated with the rolls more evenly to the applicator rolls 31 and tends 31 to control the amount of binder material car to remove any longitudinally extending ripples ried to the bite between the rolls. . that may be in the web material as discharged Between the drafting frame 35 and the appli cator rolls 31 are means for spreading somewhat the sheet material that is discharged from the drafting frame 35. ,The sheet material as dis charged from the drafting frame 35 may for ex- ' ample be 10 inches in width. I have found that it is desirable to spread the sheet 33 that is dis charged from the drafting frame 35 before'a bonding material is applied to the fabric. For example the sheet 33 may be spread laterally from a width of about 10 inches as it is discharged from the drafting frame to a width of about 14 to 18 inches as it passes between the applicator from the drafting rolls 36. Preferably the spread ing is merely sufficient to remove the ripples and cause the Web to lie ?at without substantially pulling the ?bers laterally away from each other. The drafting and spreading‘operation can be car~ ried out at any suitable speed. In ordinary prac tice the web material is preferably passed from the drafting rolls to the applicator rolls at a speed of about '70 to 120 feet per minute. The web material may be moved out of the other drafting operations at approximately a similar speed. It is also possible to secure substantial spreading action without employing the spreader rolls 31. To accomplish this spreading action any suitable device may be used. One device for laterally spreading the web ma terial ‘that is discharged from the drafting rolls 3B which I have found to be effective and the action of which is readily controllable is shown in Figs. 3, 4 and 5. By any suitable supporting bars inasmuch as the web material tends to spread laterally when passed over a plurality of rollers. The spreader bars serve to accelerate means such as support members 40 and 4| rolls material will be described. The web material is caused to pass from the roll 46 between the ap 42, 43, 44, 45 and 46 are carried in suitable bear this spreading action, however. Continuing the foregoing example of this in vention the bonding together of the unspun ?bers in the web material by means of a casein binder plicator rolls 31 the peripheral speed of which sprocket wheel 41 by means of a sprocket chain 75 is somewhat greater than the peripheral speed ings. The rolls are driven from a power driven 2,407,548 8 of roll 46 so that the. tension on the web ma terial 33 will be maintained. The rolls 31 can I be conveniently driven as by causing the chain 43 driven by sprocket wheel 41 to pass over sprocket wheel I04 that rotates with one of the rolls 31. Whileycasein solution might be applied by rolls 31 I have found that it is preferable in obtaining 15. In this way the web material is prevented from wrinkling during its travel through the apparatus and any tendency of the ?bers to relax, before the bonding material has set, to a non; straightened condition is minimized with the re sult that the ?bers in the web, after the bonding material has set, will still be ‘substantially as a uniform application of casein» as a binder to straight as'when they were introduced into the ?rst apply a temporary binder, which may be ' bonding step. The conveyors 63 and 13 may be merely water. Accordingly water 64 is placed'in 10 of any desired length so that the time interval troughs 38 and is carried over the surface of rolls during which the web material rests thereon may 39 and 31 to the web 33, preferably enough water be controlled as desired. Alternatively the con being carried to form small beads 65 at the bitev veyors may be drawn by any suitable means not of the rolls 31. If desired‘doctor blades l0! may shown so as to travel more slowly than the speed be associated with the rolls 31 or other equiv at which the web material is deposited thereon so alent means may be used to control the amount as to plait the web material thereon and there of binder, temporary or otherwise, applied to the ' by increase the period of time during which the web material. The water temporarily bonds the web is carried thereby. ~ ‘ , ?bers together by surface tension effect and this The permanent binder that is applied may be bonding effect. coupled with the relaxing effect 20 a 20% solution of soluble casein, for example. of the water on the ?bers tends to set the ?bers Due to the preliminary moistening of the web by »in the condition of tensioned straightness that applicator rolls 31, the casein solution applied they are in upon reaching the applicator rolls. by applicator rolls 66 impregnates the web mate In this operation therefore the ?bers of the rial very uniformly and evenly so that the web ?brous web are. bonded while the ?bers of the 25 will retain about 25%, for example, of thecasein web are in the condition that they occupy when (dry weight) on the dry weight of the ?ber. the web is under tension. As above mentioned It remains to dry the bonded web material and the ?bers have been oriented so that for the if desired subject it to some further treatment. most part they are in one direction, particularly To this end the web material may fall from the the longer ?bers and are loosely associated so 30 applicator rolls 66 to a carrier 13 and thence to that they can be drawn out and straightened without rupturing the ?bers or the web. These ?bers are drawn out to maximum tensioned a, treating chamber or 'zone 14. From the treat ing chamber the fabric can pass to a drying straightness and while still-thus drawn out are plurality of heated drying rolls 16 until the mois 35 ture in the web has been reduced to about 10%. The treating chamber 14 may be omitted if de bonded together. . The application of the temporary binder is vfol lowed by the application of a permanent binder while the bonding eifectof the temporary binder persists. The permanent binder may be applied by another pair of applicator rolls 66 which have a peripheral speed substantially that of rolls 31 and to which the binder material in troughs 68 may be supplied by feed rolls 61. The supply of bonding material can, if desired, be controlled by doctor blades I02 or by ‘other equivalent means. For convenience in handling the web material after leaving the applicator rolls 31 the material may drop to traveling conveyor 69, over rolls 10, 1| and 12 and thence to the applicator rolls‘66. While the tension on the web 33 may be momen tarily relaxed during this handling of the web material the temporary binder (e. g. water) maintains the ?bers in the web in substantially the same condition that they were in when~ they passed between the applicator rolls 31. Prefer ably, the rolls 10, 1| and 12 are power driven so as to lift~ the web material against its own weight chamber or zone 15 in which it‘ may pass over a sired. The treating chamber is shown, however, in order to illustrate that the bonded web may be treated in any way that may be desired. For example, the casein bonded ?brous web above de— scribed may be subjected to some gaseous or liq uid environment which may be introduced into the chamber from jets 11. For example formalde hyde gas or tannic acid solution may be applied to the bonded web to insolubilize the casein. After the bonded web material has been dried it can be made up into a roll 18 and is available for any purpose. In addition to drying the web on drying rolls it may ‘be dried in festoons or on a carrier that is passed through a drying cham- ' her or in any other suitable way. Web material that has been made as above described is shown in Figs. 6, 7, 8 and 9. In Fig. 6 a fragment of the material is shown and illus trates the predominant straightness and unidi directional characteristics of the ?bers. If the ?brous material is examined under magni?ca and again subject it to tension, and these rolls tion it appears somewhat as shown in Fig. 7, preferably are driven at successively increased namely the ?bers have one predominant direc speeds and at a rate such that the peripheral 60 tion. This is especially true with regard to the speed is slightly greater than the peripheral speed longer ?bers 19 inasmuch as some of the shorter of rolls 31 so as to augment the tensioning effect ?bers 80 [which usually occur in cotton ?bers as commonly sold may be disposed with someir in the direction of the ?bers. Moreover, the rolls 66 are driven at a rate such that the peripheral regularity as indicated. This is due to the fact speed is slightly greater than the peripheral speed 65 that it is the longer ?bers that are acted upon of roll 12 so that the‘ web is carried into these most vigorously in the drafting operations and rolls under slight tension. The peripheral speed which are drawn to tensioned straightness when of rolls 66 may conveniently be about .5% greater the web is maintained under tension in the di than the peripheral speed of rolls 31 for example. rection of the ?bers. The small amount of mis Similarly the rolls contacting the web material 70 cellaneously disposed short ?bers doesnot, how subsequent to rolls 66 are preferably driven at ever, impair the great strength of the web ma successively slightly increased peripheral speeds terial in the predominant ?ber direction and acts (e. g. a small fraction of one percent increase) as a ?ller that ‘to a slight degree augments the until the binder is set in a setting step, e. g. in strength of the web material in a lateral direc chamber 14, or .during drying, e. g. in chamber 75 tion. Figs. 8 and 9 indicate the disposition of 2,401,549 the shorter ?bers being largely eliminated by the fibers in a dense coherent mass with the long ?bers ‘l9 essentially unidirectional. the combing step so that the drafting operation it The indi may result in a material consisting essentially ‘ cation of the ?bers in Figs. 6, 7, 8 and 9 is largely of long cotton ?bers, e. g. % inch or more, sub stantially all of which are straightened and are diagrammatic, no attempt being made to show relative proportions or ?ber count. Moreover, arranged in one direction prior to the bonding the showing of the web material in Figs. 1, 3- and step. A material thus produced will be found to have maximum strength per unit weight of ?bers in the direction of the ?bers and will be very 5 is diagrammatic to showthe striated charac ter of the web material, the ~?bers actually being in intimate but loose association in a substantiaily ' continuous-web more than 1 ?ber diameter in 10 dense and will require a minimum of bonding thickness. No attempt is made to indicate in Figs. 8 to 10 the presence of the binder inas material. - ~ ' A web material made as above described is suitable for many commercial purposes‘. -In such ‘ ‘ much as the binder in the fabric will be present a material at least. about 70% of the ?bers have in different ways depending primarily upon the amount of the binder. If the binder constitutes 15 substantially tensioned straightness, namelm'the I straightness that the ?bers assume when about 25% or less of the material by dry weight, stretched taut, and are arranged approximately the binder is distributed for the most part on r in one direction, e. g. within about 15° of the the surface of the ?bers and acts to bond the sur mean direction of those ?bers that are for the face of the individual ?bers to the surface of adjoining ?bers. Inasmuch as the ?bers are 20 most part in one direction. In this type of fabric web about 80% of the ?bers over 3A. of an inch, straightened and- are essentially unidirec in length are among ‘those ?bers which are ar tional the binder in the amount used is most ranged approximately in one direction and are effective in‘bonding the ?bers together. The ?bers instead of being bonded together at only a few points of contact as is the case with 25 miscellaneously disposed ?bers, are brought into vintimate contact and each , straightened ?ber becomes bonded over most of the surface there substantially of tensioned straightness. As aforesaid the extent to which the cotton ?bers are drawn depends largely upon the type of fabric that is to be produced. Thus for webs that when made ‘up are to be quite‘light and are to ex bit great uniformity of texture and very high strength in the direction of the ?bers the elemental web material may be subjected binder are employed the fabric becomes more to the conditioning operation until about 90% _ completely dominated by the binder component of the ?bers are disposed substantially in one while still retaining the inherent advantages of direction and exhibit tensioned straightness as I the ?ber base for the material. Due to the conditioning steps wherein a large 35 they are led to the bonding step. On the other hand the drawing may be dis number of slivers are lapped and drawn the web continued when only a major proportion of the material is very uniform in thickness and ?ber ?bers are disposed in one direction and exhibit density and binder distribution affording uniform of with adjoining substantially parallel ?bers . that are likewise straight. If larger amounts of high strength throughout. tensioned straightness. This can be accom In the example above given the cotton ?ber 40 plished for example by taking the material dis charged from the sliver lapping step which has contained over about 70% of ?ber that is one been above described and in which the ?bers inch or more in length. Of course, other grades are drawn about 2 to 1 to afford a web weighing of cotton ?ber may be used. In order to achieve about 500 grains per‘ running yard, and then the advantages of the invention in marked degree, however, over about 50% of the cotton ?ber stock 45 passing the material through the drawing frame 35 on which the ?brous sheet is drawn 4 to 1 should be 1% of an inch in length, and preferably and thence tov the‘applicator rolls 3‘! so that over 60% to 70% of the cotton ?ber should be the ?brous material will be drawn a total of over % inch in length. Fiber material which 8 to 1. Such a fabric web is not as uniform as contains about 50% or more of fibers at least about % inch in length is regarded as “long” 50 a fabric web which has been subjected to addi tional lapping and drawing steps before the ?ber. The percentages of ?ber given above and elsewhere herein and in the claims are percent ages by weight. The characteristics above mentioned of the structural web are those which result from man ufacturing steps above described wherein ordi nary cotton ?brous stock is used and wherein ?brous material is bonded together. In any such web material it is preferable that the major proportion of the ?bers that are arranged ap 55 proximately in‘ one direction and are straight ened, include at least about 70 % of the ?bers that are over about % of an inch or more in length. 1 in preparing it for the bonding step. In such 'A ?brous web which has only approximately 50% of the ?bers disposed in one direction and case, as above mentioned, some of the shorter straightened by tension nevertheless exhibits ?bers remain somewhat indiscriminately dis posed. It is possible, however, by subjecting the ?brous web material to repeated drafting and ‘lapping operations prior to the bonding step to cause substantially all of the ?bers to‘ become 65 great strength. Such a web is especially useful in making relatively heavy sheet materials con taining a plurality of the elemental‘webs, e. g. about 8 to 20, thereby minimizing any lack of uniformity in the elemental webs. Even with such heavy composite fabrics, however, it is pref the stock is subjected to a drawing of about 32 to straightened and arranged in one direction. For certain uses of the ?nished material this may be desirable but for most purposes it is not neces sary to obtain such a high degree of ?ber erable to draft the ?brous material prior to bond ing until about 70% of the ?bers is straightened by tension and are approximately in one direc straightnessand arrangement in one direction. 70 tion. A fabric which contains about 800'grains The occurrence of miscellaneously distributed ?bers may likewise be eliminated by subjecting the cotton to a combing operation using any of cotton ?ber per square yard and which con tains about 200 grains per square yard of casein binder, for example, has a tensile strength of about 50 pounds per inch in each direction when suitable type of combing machine designed for handling cotton ?bers of .which many are known, 75 the individual webs are disposed with the pre 2,407,648 - ' l1 12 . ponderant ?ber direction of half the webs at a right angle to the preponderant ?ber direction per square inch and preferably at least about 20,000 pounds per square inch. In the practice of this invention I have found that it is distinctly preferable, especially in con nection wth cotton ?bers to bond the ?brous material which has been arranged in one direc of the other half of the webs and when in each web about 50% of the ?bers are bonded while straightened in one direction by tension. This compares with a .tensile strength of ‘about 25 pounds per inch in each direction for av fabric containing the same weights of ?ber and of casein tion and has been straightened by tension, while . the ?bers are disposed‘in thin elemental striated binder which is made by weaving cotton threads webs ranging from about 75 to about 250 grains so that about equal weights of ?ber are in the per square yard in weight. warp and the weft. If in the material embodying this invention 70% of the ?bers in each web are disposed substantially in one direction and are straightened, then even greater strength, e. g. 75 pounds per inch in each direction, can be at 15 action ‘on the‘ ?bers in tensioning and bonding tained. A ' In such case the the same is superior and the ?bers become more uniformly‘bonded together. In connection with cotton ?bers it is desirable not to 'carry on the bonding step when the material being treated weighs more than about 400 grains per square yard inasmuch as while heavier webs maybe brought to the bonding step somewhat inferior . Somewhat more generally web material com posed of unspun ?bers vcobonded in the manner referred to can readily be made according to this results are obtained. ' ‘ invention so as to, have a_tensile strength of at 20 Somewhat more generally the striated web least about 10 pounds per inch width for each 100 material should be of su?icient thickness so that ' grains per square yard of ?ber and preferably , the ?bers at least in major proportion will be ob ‘ a tensile'strength of at least about 20 pounds per tained in juxtaposition when oriented to ten inch width for each 100 grains per square‘yard sioned straightness and approximately in one of ?ber. These tensile strengths can be obtained direction, and should preferably be in thickness using other binders than casein in an amount su?l about 2 to about 8 times the diameter of the ?ber cient to prevent longitudinal relative slippage of the ?bers when the sheet material is subjected to tension in the preponderant direction of the ?bers. that is used. mental webs until a sheet of desired thickness and webs are preferably bonded together before be ing assembled 'in a composite sheet and may be made up into a composite sheet by bonding to‘ per se, are substantially non-stretchable. Accord ing to the present invention .the ?bers are sub , ’ jected to tension which straightens them out and gether webs in‘which the ?bers have previously been cobonded together. In Fig. 10 there is illustrated afcomposite sheet which includes elemental webs 8 l' and 82 in which the preponderant ?ber direction extends longi tudinally of the sheet. If desired the composite " they are bonded together while very uniformly Therefore sheet can include a web 83 in which the ?bers ex ' tend transversely so as to give transverse strength to the composite sheet as a whole. In such case . the presence of the transverse sheet 83 tends to keep the ?bers in webs 8i and 82 from spread ing and thereby increases the strength of the binder that is used is.also substantially non‘- , material in the ?ber direction of the webs 8| and 82 so that the strength in this directioniis some what greater than if the web 83 were‘ not in cluded. The number and ?ber direction of the ?brous webs can be widely varied and it is an advantage of this invention that means are af forded whereby strength in the direction or direc stretchable very strong structural web materials can be obtained. The .web material‘ made according to this inven- ' tion is- preferably dense and compact for the weight of ?b'er contained therein. Thus, a web material which contains about 200 grains of ?ber per square yard can be made of such compact 8 weight is produced. The ?bers in the elemental ' y is highly resistant to stretching. Cotton ?bers, and evenly» distributed in this state. ~. this can be done by laminating or plying the ele Another feature of the web material is that in addition to being strong it can be made so that it sincethe ?bers are substantially straightened the material does not stretch when subjected to ten sion in the direction of the ?bers but remains substantially unyielding. Moreover, since a pre ponderant proportion of the ?bers are disposed in one direction, the load is borne by all of these ?bers as well as by the binder, thus affording great strength in resisting rupture. When the ~ When it is desired to make heavier material ‘ tions of greatest strains can be attained with ness and ?ber density that .the web will be only in an minimum of ?ber material. __ . about one-thousandth of an inch or less in thick The nature‘ and amount of the bonding agent ‘ness. By “?ber density" the weight of- the ?ber that issued can be varied widely depending- upon per square yard per unit thickness is intended. the type of material to be produced. For most purposes binder to the extent of about 20%_to The structural material of this invention either ' in the elemental web form or in the form of a 60 50% by weight (dry) of the weightpf the ?bers is incorporated with the ?bers especially when composite sheet containing a plurality of ele the binder is relatively inelastic or non-plastic at “ mental webs can be made so that the ratio of ordinary temperatures. Lesser amounts, e. g. thickness in thousandths of an inch to weight of about 10%, is sufficient for many purposes. On ‘?ber, in grains per'square yard is. about 1 to 200. While such materials are preferable, even those 65 the other hand, 50% to 100% may be used if highly impregnated ?brous material is. desired. materials according to this invention wherein the The use of amounts of'binder as high‘as about ratio of thickness in thousandths of an inch to 100%, may be desirable, e. g. in the production grains per square yard is only about 1 to 100 are ‘very dense as compared ‘with materials hereto fore produced by any other means. ‘ _ ‘. In the practice of this invention one can readily produce structural sheet or web' material which has a tensile strength in the ‘preponderant direc of waterproof material in which the binder is a natural or synthetic rubber material or a bitumi nous material. ' ~ The particular bonding material that is se lected is largely optional. 'Among bonding ma terials applied in an aqueous medium there are, tion of the ?bers of at least about 10,000 pounds 75 in addition to casein'above mentioned, numer r 2,407,548 13 , m 14-:-~ . ~. . or ether type- afford structural sheet materials ous others such as glue, latex, asphalt emulsions and the like. When the bonding agent is applied of intermediate sti?ness. Structural sheet ma terial vcomprising .relatively- (soft ~ binders such‘ as in an aqueous medium it is preferable to ?rst apply water to the elemental web material as a low softening point bituminous'materials, rub ~ber and the like can be made which arev very pliable. ' temporary binder so that the permanent binder may be more uniformly deposited on and among the ?bers. In such case two application steps, one 7 While reference has been made to'the em- ' ployment of a'bonding material which remains involving the application of the temporary binder on the surfaces of the ?bers it is also possible to and the other the application of the permanent binder constitute preferredv practice. If desired 10 treat the ‘?bers with‘ a material that attacks them ‘sumciently so that'the surface becomes sticky in the application of water as a temporary bond and bonded and then removing the material but ‘ ing step a wetting agent may be employed such leaving the ?bers bonded together. Thus, in as pine oil soap, and the like, in order ‘to promote more uniform impregnation of the fabric with the the case of cotton ?bers (the ?brous web may be permanent binder. Moreover, reactive materials 15 treated with sulphuric acid, zinc chloride or the like, e. g. by the applicator rolls 31, Theadded material that attacks the, ?ber may thereafter such as coagulants may be incorporated in the ‘ ?rst application, e. g. a coagulant such as alunr,‘ tannic acid, formaldehyde, etc., may be included be neutralized or washed away by suitable means, ' to insolubilize or harden the permanent binder the extent of“ the action being dependent upon subsequently added. ' 20 the time interval during which the material in .When the binder is added in an aqueous me dium subsequent treatment of the web is largely con?ned to drying, although before, during, or after drying ‘the web may be subjected to further active condition remains in contact with the fibers prior to neutralizing it or washing it away. Any - such material, since it results in bonding the treatment, _e. g. in a treating chamber such as 25 chamber 14. ' Other bonding materials such as bitumens, cel lulose esters, cellulose ethers, synthetic resinous materials and the like, may be applied when dis ?bers together, is regarded herein as a bonding material. ' ' . Where a plurality of the elemental webs are combined to form a composite sheet this can be done in several ways. For example, the web material after having been bonded while the web solved in an appropriate solvent therefor. When 30 is under tension can be laminated while the bond a volatile non-aqueous solvent such as naphtha, ing material is adhesive so that the webs will acetone, etc., is used subsequent evaporation of adhere together. Alternatively, the bonding ma the solvent in a suitable solvent recovery system, terial as a result of evaporation of solvent, cool is preferable. When a volatile non-aqueous sol ing and the like may be permitted to‘ harden and vent is employed the temporary bonding step may thereafter the web materials may be ‘bonded to be omitted. In this'case the binder solution can gether. If the bonding material can be reacti be applied by applicator rolls 31, for example. However, it is frequently desirable especially vated, e. g. by heating a reversible thermoplastic ‘ material or by peptizing a solventactivatable when the binder material is relatively'tacky as adhesive, the adhesive may be reactivated by the applied, to ?rst incorporate a small amount of a 40 heating or the solvent peptization so that the temporary binder, e. g. about 1 to 2% of starch, webs may be bonded together. Of, course, in any silicate of soda, methyl cellulose or the like and event additional adhesive or other bonding ma thereafter apply the permanent binder as 21. sep terial the same as or different from the bonding arate step. material on the ?ber in the elemental webs may Binder materials which are thermoplastic may 45 be employed. If the ?brous material is sufficient likewise be employed by applying them in a heat ly porous after having been bonded under ten lique?ed condition or by applying them in a ?nely sion, a bonding material‘ may be applied after divided condition and then heating the ?brous the webs have been laminated so that it may ‘ web material to render the incorporated thermo penetrate sufficiently through the composite sheet plastic material sticky and bond the ?bers to to bond the laminations togethen, Another de gether. Thus, bitumens such as asphalts, pitches, sirable way to bond the elemental webs together tars, etc.,- cellulose esters and cellulose ethers is to dispose ?nely divided thermoplastic ma such as cellulose acetate, cellulose nitrate, ethyl terial such as asphalt, cellulose esters or ethers, cellulose, benzyl cellulose, etc., a wide variety of resins or the like between superposed webs and synthetic and natural resins such as urea-fur then subject the composite sheet to heat as by fural resins, vinyl resins, etc.,,may be employed. The binder material may be a reversible thermo— passing it between or over rolls heated su?icient to render the thermoplastic material tacky and plastic such as asphalt which after application bond the webs together. ~' may be softened by reheating or may be ther Whether the sheet material is in theform mosetting such as phenol-formaldehyde resins of 60 of an elemental web or a composite sheet it is the “Bakelite” type. After the ?bers have been preferable as‘aforesaid to employ only about 20% cobonded-by the thermoplastic binder in a tacky to 50% of the weight of the ?ber of binder that or sticky condition it is usually sufficient merely remains incorporated with the sheet material. to permit the web material to cool until the The ?bers that are arranged approximately in binder is substantially non-sticky. one direction and are of substantially tensioned The ?exibility or pliability of the structural straightness“ will have any tensile load in the web or sheet material will depend largely upon direction of the ?bers distributedamong them, the character and amount of binder that is used. and excess of binder tends to detract from the Thus a web or sheet containing about 50% of the weight of the ?ber of a relatively rigid binder 70 strength of the material per unit weight rather than otherwise since the‘ fiber is usually stronger such as a rigid synthetic resin binder of the phenol-formaldehyde type will be quite stiff espe cially when a plurality of the individual ply sheets than the binder material. " The amount of bind are made up into a composite sheet of consid together to prevent relative slippage of the ?bers I er that is appropriate for cementing the ?bers erable thickness. Binders of the cellulose ester 75 is all that is required and since the ?bers are in 2,407,548 15 . a dense compact arrangement‘ the amount of binder required is relatively small. It is to be understood that the foregoing op eration whereby the improvements of the inven tion may be attained merely constitute an illus trative example of the practice of this invention and that the drawing or drafting can be per formed in other ways and that the spreading vof the ?brous web, if the spreading step is per formed,” can be carried out by other means. Thus, in Fig. 11 there is shown an alternative de vice that may be employed for spreading the i1 brous web between the drafting and the applica tion of the bonding material. In this modifica tion the web material in passing from the draft 15 ing rolls 36 to the rolls 31 passes over a saddle backed part I03 which is downwardly curved and 16 - bearrangedtoothicklyinordertoobtain agood drawing action. _ ‘ ‘ ' For drafting ?bers that are longer than cot~ ton’ ?bers modi?ed equipment is desirable such as that shown in Figs. ‘15 and 16 which may be a gill box or draw box or the like. There are a number of relatively long ?ber materials e. g. bast ?bers such as jute, sizal, hemp, ramie, flax, and coir, or natural silk. In mtking web mate rial from such ?bers the fibers are preferably caused to Occur in lengths averaging about 6 to Sinchesandthe?bersinthisforrhairecarded and run into heavy sliver form. The slivers, e. g. two, may be run for example into the gill box‘ shown in Fig. 15 comprising the sliver guide II, the retaining rolls '2 and 33, the slip roll 84, the drawing roll 85 and pres roll I5. The rolls I3 and 35 are spaced apart by a distance that is is: bowed outwardly, e. g. as indicated in the cross-sectional views shown in Figs. 12, 13 and greater than the length of the ?bers and between _ 14. The peripheral speed of the rolls 3'! is slight 20, them are the movable fallers 81 on the pins of ly greater‘. than the-peripheral speed of the last which the ?bers are carried from the roll I3 to of the drafting rolls 36 so that the web material the roll 85. The fallers move at a speed that is 33 is maintained under tension in passing over somewhat greater than the peripheral speed of the part I03 which because of the curvature the roll 83. The drawing roll 35 may have a pe thereof ‘causes the web 33 to spread, e. g. from 25 ripheral speed about 4 times that of roll 33 there about 10 inches as discharged from the drafting by drawing the ?bers by about 4 to 1. Any suit rolls to about 14 to 18 inches when the web able means (not shown) such as screw means reaches the applicator rolls. It is apparent that may be used to move the fallers, lower them at equivalent means may likewise be employed. the end of their travel toward roll 85, return In carrying on the spreading step the extent 30 them and elevate them at the end of the return ‘of the spreading will depend somewhat on the travel. material being handled. For cotton ?bers it is It is usually desirable to subject the ?brous usually desirable to spread the material prior to material to further drafting. In such case the the bonding step by about 25% to ‘75% of its web ‘material discharged from rolls 85 and 85 original‘ width. Especially‘with heavier ?bers which tend to be more uniformly distributed as discharged from the drawing apparatus less spreading, e. g. about 10%» to 25% of its original width is usually su?icient prior to the bonding 35 maybemadeupintoarollll orifdesiredmay be passed to sliver form. Apparatus for carry ing on a second drafting operation is shown in Fig. 16 which includes the retaining rolls so and‘ SI, the slip roll 92, the drawing roll 53 and the 40 press roll 94. The roll of material 33 feeds into The bonding material can also be applied in the rolls 36, 3| and 52 andis carried bythe fallers ‘a other ways, for example, as illustrated in Fig. 11, 35 to rolls 93 and 94. The fallers travel at a . As shown, the bonding material is sprayed onto speed somewhat greater than the peripheral the web 33 before it goes between the rolls 31 speed of roll SI and roll 33 has a peripheral speed from nozzles I06. This method of application of 45 about 8 times the peripheral speed of mll 3| bonding material is especially suitable when a thereby drawing the ?bers about 8 to 1. If de relatively small amount of bonding material is sired one or more webs, e. g. from roll 88' in ad' to be applied.v It is also possible to seize the con dition to roll 33, may be fed into the device of ditioned web material while the ?bers are, drawn Fig. 16 so that the ?brous web will not become to tensioned straightness and thereafter apply 50 excessively attenuated by the drafting. Alter step. > the bonding material, e. g. through a forami natively one or more slivers may be fed into the nous restraining member. Alternatively a. ther device of Fig. 16 as may be desired. , moplastic binder such as asphalt may be blown In the device of Fig. 16 the fallers vl5 are car into the web 33 in powdered form from the noz ried in the form of a continuous belt about rolls zles I00 and the rolls 31 may be heated to soften 55 3i and 31. Theactionisessentiallythesame as the asphalt and bond the ?bers in the web ma the action of the fallers in the device of Fig. 15 terial together. Various other ways of applying and the devices of either Figs. 15 or 16 may be ‘ binder are also possible although for most purused although the device of Fig. 15 is somewhat poses the ways above described have been found preferable. The different mechanisms are shown ‘ to be preferable. The type. of drafting apparatus that is used may be varied. The type of apparatus that is used should be that which is best suited for han dling the particular ?ber to be made into a web. For drawing and lapping cotton ?ber some ap paratus such as that described above for purposes of exempli?cation is usually most desirable. The use of drafting frame equipment containing a primarily to illustrate the fact that the drafting mechanism may take many different forms. It is preferable however when the ?ber is subjected to more than one drafting operation that the pins on the fallers used for any drafting after the ?rst drafting ‘be somewhat more numerous thanthepinsonthe fallersusedinthe?rst drafting Operation. ‘ After the ?brous web material has passed from rolls 33, 33 it is taken over spreading means such plurality of adjacent rolls that have successively asthatshowninFigs.2to5 orinFlg. 11 forex increased peripheral speeds is very effective in 70 ample to means for applying bonding material straightening the ?bers and arranging them in‘ while maintaining the web material imder ten one direction. The extent of the drafting in each sion as it travels from the rolls 33, 34 to the drafting frame and the sequences of lapping may be varied widely although the ?bers should not 75 means for applying the bonding material. By way of example two very heavy slivers of 2,407,548 17 18 about 14 to 18 inches ‘wide is described.“ It is. of ‘course, pos'sible‘tojmake the web‘rinaterialjof ‘other widths; This can be done by varying the lateral capacity of the" equipment‘ usedf‘eij‘g‘. equipment jute ?ber weighing about 1200 grains per run-7 ning yard may-be (into the‘ ‘drafting appaé ratus of Fig. 15 wherein it is drawn about tl‘to ‘1 to‘form‘web material about‘ll'inches wide weigh ing.600 grainsper running'yard. Four‘of'the webs thus made; (weighing in all“ about ‘2400 grains‘per running yard) are then run ‘to the drafting apparatus shown in Fig. 16 whereinv the such as described above. ‘ItNis ‘preferable ‘that ?brous web material is‘drawn about 8 to l to‘ form aiweb material about 11 inches wide‘ weighing 10 about 300 grains per running yard. Thislatter material is ‘then‘spread to about 15 inches in width‘ before the bonding‘ materialis ‘applied. The bonding‘ material may be‘ any‘ of those‘ deg web material during the?draftingoperation‘ be at least ‘Qinches‘in widthand that the drafted striated web‘m‘aterial be at least about 12 inches in‘width ‘when the ‘?bers are integrally ‘cobonded; For‘m‘akingl'wideweb material it is also possible operate ‘them simultaneously, at the‘ samespeed,‘ ‘ to ‘mount a plurality of ‘the units in parallel ‘and the ‘output of each unit‘ being placed‘ alongside the‘ output of‘ an adjacent “one, "Thus. a, P111-‘ rality of the drafting‘lframes‘;35‘can be‘ placed scribed above and used in similar‘proportions. The bonding material may be‘ applied by ‘any’ of side by side and the‘ web material discharged ‘i from each‘ spread‘ laterally‘ until the‘ marginal’ the ‘means heretofore referred to‘ or‘ the ‘equiv edges abut ‘each other. ‘The wide web can then alent thereof.‘ For 'such‘very coarse ?ber‘the be passed between a common pair of applicator web preferablylweighs‘about-2400 to 800‘ grains per ‘square yard when the bonding‘ material is 20 rolls ‘for applying the bonding material.“ If ?bers from a v‘cardir‘ig machine or the like are‘used as a sourcev of ?brous material it is not ‘necessary to The process ‘can also be carried out inconnec pass the carded sheet to sliver form, inasmuch tion with ?bers of intermediate length such‘as as‘the‘ carded material in sheet ‘form ‘may be‘ wool‘, in which the ?bers may ‘run about 2 ‘or 3 applied. a ‘ I ‘ ‘ ‘ ‘ l ‘ inches in length. In such case a draw‘box or gill 25 subjected'to repeated lapping and drafting opera box or the like‘ may ‘be u‘sed‘to straighten the “ tions to condition ?brous material in theman ?bers and arrange them in one direction but, ner above referred, to. , ,d e , In order to ‘obtain material having uniform of course, the spacing between the retainer rolls density and thickness so as to achieve a product‘ and the drawing rolls will beless than ‘when 30 having uniform strength characteristics through longer ?bers such as jute, hemp, etc., are used. out, it is desirable to make ‘at least two ribbon or sheet~like intermediate webs and then lap. them and‘ subject the composite web to drafting Any operation or apparatus forv drawing ‘?bers, by some such action as‘ ‘drafting rolls, ‘gill ‘box, or draw box wherein ?bers are seized and pulled out essentially in one direction thereby straight to attenuatethe composite ‘intermediate web and‘ ening them in one direction, is referred to here 35 draw the ?bers thereof to increased straightness in as a drafting operation ‘or apparatus and is ‘ ‘ in a direction corresponding to that of theid‘r‘aft‘r ' to‘ be distinguished ‘from ‘mere sheet-forming actions such as felting or the action of a carding web ‘or sheet-like bodies are made‘and lapped , machine. so'as to obtain a drafted web that is very uni ing. Preferably at least four such intermediate In addition to ?bers such as those above men tioned, other ?bers may be made up ‘into web structural ‘material e. g. synthetic ?bers such ‘as rayon, cellulose acetate and the like. Web struc tural material consisting wholly or partially ‘of mineral ?bers e. g. asbestos ‘?bers may also be form. ‘ ‘ ‘ 1 , “ " d ‘It is apparent fromthe foregoing that ?brous structural material having great strength for the weight‘ of the ?ber can be produced according to .45 made according to this invention." In cobond ing mineral ‘?bers cobonded into striated web material any suitable binder therefor such as 1‘ this invention in a‘ ‘very economical way. Fabric-i like sheet ‘material‘having the strength of woven fabrics can be made without going through the costly operations‘ of spinning and weaving, Moreover, sheet‘material resembling sheet metal in strength per gauge thickness can be made and , sodium silicate may be employed. Moreover, ?bers which are‘ unspinnable, e. g. kapok, mil-k 50 which is much stronger than non-ferrous metals,‘ such as aluminum, for, their weight. . High weed ?bers, ‘manila, Spanish" m‘oss and the like, strength can be obtained ‘with a minimum of can be made up into structural material accord binder material and a material ‘can be‘ produced ing to this invention. according to this invention that is very dense Regardless of the character of the ?ber that‘ and of great strength for its thickness. ,The is employed it is desirable that the proportion ?brous material is also so uniform in thickness, of the ?ber that is arranged- approximately in one direction and brought to tensioned straight ' ness correspond ‘substantially with the propor ?ber density and binder distribution‘as to have throughout ‘very‘uniform strength characteris tions above mentioned in connection with cotton tics. ‘ A new structural material, therefore, is ?bers for the reasons mentioned in connection afforded having great commercial utility. with the foregoing description ‘of web materials While this invention has been described in con and composite sheet materials made from ‘cotton nection with certain speci?c embodiments there- . In the, practice of this invention the web ma of it is to be understood that this‘ has been done merely ‘for the ‘purpose of illustrating the prac terial can be treated in various ways during the 65 tice ofthis invention and affording a better un- , ‘ dersta-nding thereof. Accordingly, the“ scope of “ this invention is to be governed by the language“ terial can be treated with a dye or stain or pig of the following claims construed in the‘ light‘of vment during the application of either the tem-, performance of the method. Thus, the web ma: porary or permanent‘ binder or as awseparate operation. Moreover, waterproo?ng or water 70 repeilent material may similarly be incorporated. If desired, a‘?ller material such as ?nely divided clays (bentonite, kaolin, etc.)', silica dust or the H like may be incorporated in‘a similar way. In the ‘foregoing description a web material the foregoing’ description. I claim: ‘ ' I I 1. ‘Amethod ofmaking afabricated web of‘ co-bonded unspun ‘?bers which“ comprises sub- ‘ jecting unspun ?bers to draftinguntil the?bers are ‘preponderantly‘straightened and arranged . in one direction longitudinally of an‘ elongated ' 3,407,548 ?brous web, spreading said ?brous web laterally while under longitudinal tension, and bonding said ?bers together while said web is under lon gitudinal tension. . v 2. A process of making a ,web of cobonded un spun ?bers which comprises forming a plurality tween ‘said rollers: to spread’the web material ‘ laterally. 8. Apparatus according tooclaim 5. wherein the , spreading means comprises an elongated cen trally bowed part over which the fabric is adapted to pass and thereby become spread of elongated bodies of unspun ?bers, subjecting laterally. , > said bodies to drafting to draw the ?bers there 9. Apparatus for making a web of cobonded in in the direction of the drafting and orient and straighten said ?bers in the direction of the 10 unspun ?brous’material which comprises draft ing means'for straightening said ?bers and ar drafting to form a plurality of webs with the ranging them in a preponderant ?ber direction ?bers so oriented and straightened therein, lap in an elongated striated web, said drafting means ‘ ping a plurality of said webs to form a compo including a plurality of adjacent pairs ‘of rolls site web containing a plurality of web laminabetween which said ?bers pass and means for. tions, subjecting the composite web to a draft 15 driving said rolls at successively increased speeds ing operation to attenuate the composite web to accelerate the movement of said web as it and draw the ?bers to increased straightness in passes successively between said rolls and draw a direction corresponding to the direction of the said web material longitudinally, means for draftingjwhile said ?bers are in a dry and essen spreading saidlweb discharged from the last pair tially unbonded conditio , and thereafter co 20 of drafting rolls laterally upon being discharged bonding the ?bers together while in striated at tenuated web form to form a coherent integrally bonded web material, the ?bers not being per from said drafting means, applicator means for ' applying a bonding material to the web, and . means for maintaining said 'web material con mitted to relax between the drawing step and tinuously under tension during the travel there the bonding step. 25 of between said drafting means and said applif 3. Apparatus for making a ‘web of cobonded unspun ?bers which comprises drafting means for straightening and arranging the ?bers in a predominant direction longitudinally of an elon cator means. . 10. Apparatus for making a web- of cobonded unspun fibers. which comprises drafting means for producing an attenuated webin which the gated web, means spaced from said drafting 30 ?bers have a preponderant ?ber direction, a means for applying a bonding material to the pair of rolls, means for carryingsaid web .of ?brous web after the web is discharged from material under tension in‘ said ?ber direction the drafting means, and means for maintaining su?icient to straighten the ?bers in said direc said web under tension between said drafting tion between said drafting means and said rolls‘ means and said means for applying the bonding and means for applying bonding'material to material to said web. , ' said web received by said rolls after said web is 4. Apparatus for making a web of cobonded discharged from said drafing means and while unspun ?bers which comprises drafting means said ?bers are in said condition of tensioned straightness. ‘ for straightening and arranging the ?bers in a predominant ?ber direction longitudinally of an 40 11. A method of making structural sheet ma elongated web, said drafting means including a terial which comprises forming a striated web plurality of adjacent ‘pairs of rolls between which of loosely associated contiguous ?bers about 50% said ?bers pass and means for driving said pairs of which are at least about % inch in length, in of rolls at successively increased speeds to ac which about 70% of the ?bers at least % inch in celerate the movement of. said web material and 45 length have a preponderant mean direction and draw the web material longitudinally, applicator are disposed within about 15° of said mean di rolls for applying a bonding material to said rection and in which the ?bers are arranged in ?bers of said web discharged from the last of substantially uniform thickness and ?ber density, said pairs of drafting rolls acting on said web, subjecting said web material to pulling tension and means for rotating said applicator rolls so 50 in said direction at a ?rst zone while said web that the peripheral speed of said applicator rolls is restrained at a second zone so as to prevent is at a somewhat greater speed than the pe movement of said web at said second zone at a ripheral speed of the last pair of said drafting rate that is as great as the rate at which said rolls to maintain said web under tension lon web is pulled at said v?rst zone, said‘?rst zone gitudinally thereof when fed into the nip of said 55 being spaced from said second zone by a distance applicator rolls. greater than the length of the ?bers in said web, ‘ 5. In apparatus for making unspun ?brous " thereby causing said ?bers disposed in said di material, the combination with drafting means rection between said ?rst and second zones to for straightening unspun ?bers and arranging be dragged relatively to contiguous ?bers and them in a preponderant ?ber direction, of ten 60 become tensioned and straightened while in an sioning means for subjecting said ?brous webv essentially unbonded striated web form, and material discharged from said drafting means bonding said ?bers of said web together before to tension‘ and ’ means between said drafting said pulling tension imposed on said web is re means and said tensioning means for laterally laxed to form a coherent integrally bonded sheet spreading web material discharged from the 65 material of substantially uniform ?ber density drafting means. and binder distribution throughout wherein said 6. Apparatus according to claim 5 whereinvthe ?bers brought to said condition of tensioned straightness as aforesaid are maintained in said spreading means comprises a plurality of rollers condition by said binder after said pulling tension over which the web material ,is adapted to pass. 7. Apparatus according to claim 5 wherein the 70 is relaxed. 12. A method of making structural sheet ma . spreading means comprises a plurality of rollers terial comprising unspun cotton fibers, which over which the web material is adapted to pass comprises carding cotton ?bers about 50% of and means between said rollers for bowing out the center of the web material as it passes be 75 which are at least % inch in length, then draft ing the carded cotton ?bers to draw the ?bers 2,407,543 21 at least 8 to 1 in the ‘direction of the drafting ~ 22 . straightness during the travel of the sheetlike and orient‘ said ?bers in“ the direction ‘of the body from the nip of saidrollaand, .while?so drawing said sheetlike body? with said'?bersin nally in an elongatedsheetlikebody, said ?bers being drawn‘ under tension in the ?nal stagebf said drafting into and between‘ the nip of apair said condition or tensioned‘straightnesspbondlng ' drafting ‘and straighten‘ said ?bers; longitudi of rolls which ‘grip “the ‘sheetlikebody there betwe‘en, ‘drawing‘said sheetlike body ‘from the the said ?bers of said sheetlike body together to formna coherent integrally bonded sheet matee rial wherein‘ the ?bers are fixed in; co-bonded relation insaid condition of tensioned ‘straight nip of said pair of rolls under‘tension and with '17., A method of making a‘fabricated sheet of dragging ‘of, individual‘ ?bers ‘disposed longie 10i cobonded unspun ?bers which comprlsessuba tudinally, thereof‘v relative to contiguous ?bers je'ctingunsp'un ?bers‘ loosely ‘associated in dry in frictional contact therewith, thereby‘ main-4 non-co-bonded condition‘to draftingiin a, sheet ‘ taining said ?bers‘ in a‘condition ‘of tensioned .like body wherein ‘the’ ?bers are positively straightness and longitudinally of the sheetlike ness.,\ l, I , l b N . body ‘during the travel of the ?bers from‘the 15 straightened by, gripping‘ the ,?b‘ers'between nip‘of said rolls, and thereafter, and, ‘while so I drafting‘rolls-and by drawing the sheetlike ‘body by‘ said rolls while the ?brous material of ‘said drawing said sheet-like body with said ?bers in said condition‘ of tensioned straightness, bond ing the said ?bers of said sheetlike body together sheetlike body is restrained at a distancegreater than the length of the ?bers‘ from the nip of said by application of a binder thereto ‘to form’ a co rolls, therebyorienting said ?bers, in the direc said ?bers are ?xed in said ‘condition of ten ening the‘ ?bers in said direction ‘longitudinally of the sheetlike body, the drafting accomplish 20 herent integrally bonded sheet material‘ wherein , tion of travel of said sheetlike bodyand straight‘ sioned straightness by the said binder, so applied ing‘ a drawing of at least 8 to 1, then ‘further 13. A method according to claim 12 wherein 25 drawing and attenuating said sheetlike body of ?bers by gripping the sheetlike body between rolls the cotton ?bers after the carding step are, sub ‘which are rotated‘at a peripheral speed that jected to the drafting to draw and partially draws, the ?bers in said non-co-bonded‘condi orient and straighten the ?bers in the direction tion and as oriented by the drafting with drag of the drafting and wherein a plurality of bodies of the so drawn and partially straightened ?bers 30 ging of individual ?bers disposed longitudinally of the sheetlike body relative tocontiguous ?bers are lapped and then subjected to further draft in frictional contact therewith; thereby main ing prior to the ?nal step wherein the ?bers in a the ?bers in a condition of tensioned sheetlike body are ?xed by application of binder > taining straightness during ‘the travel of the sheetlike thereto while travelling in a condition of ten-‘ sloned straightness longitudinally of the sheet 35 body to said last mentioned rolls, and first 8,131 plying a binder to bond said ?bers together im like body, the total ‘drawing accomplished by the mediately adjacent said last-mentioned rolls and drafting steps subsequent to carding being at thereto. ‘ ’ v least 32to l. 14. A method according to claim ‘12 wherein the ?bers when drawn into the bonding step are 40 disposed in a sheetlike, body ‘weighing between rI5-and 400 grains per square yard and are drawn by gripping the sheetlike body between the nip of a second pair of rolls which pull individual ?bers and drag them relative to other ?bers in frictional contact therewith so as to tension said ?bers and dispose said ?bers in tensioned straightness in the sheetlike body when the binder is applied to cobond the ?bers together into a coherent sheet'material. 15. A method according to claim 12 wherein the ?brous sheetlike body is maintained under longitudinal tension after the binder is applied and during setting of the bonding material ap plied to the ?bers. 16. A method of making a fabricated sheet of cobonded unspun ?bers which comprises ar ranging the ?bers in an elongated body, and prior to discharge ‘of said ?bers fromthe ‘nip of'said last-mentioned rolls, thereby?xing said ?bers in cobonded relation in said condition of‘ tensioned straightness in a coherent sheet, 18. A method according’ to claim 1'? wherein the ?brous sheetlike body, afterleaving the rolls last mentioned in claim 17 adjacent to which the binder is applied, is subjected to tension during the setting of the binder. 19. A method of making a sheet of co-bonded unspun cotton ?bers which comprises forming a thin striated sheetlike body of ?bers which are arranged approximately in one direction and a major proportion of which are substantially straight, drawing said sheetlike body in the direc tion of said straightened ?bers while said ?bers are in non-co-bonded dry state with dragging of said ?bers relative to other ?bers in frictional contact therewith to maintain said ?bers in" straightened condition, and, while so drawing said sheetlike body, applying a ?rst binder material thereto to ?x said ?bers in said straightened con subjecting the ?bers while in elongated body form to drafting to draw the ?bers at least 8 to 60 dition in said sheetlike body, and then applying further binder to said sheetlike body while said 1 in the direction of the drafting and orient the ?bers are maintained in said straightened condi ?bers in the direction of the drafting in a sheet tion by said ?rst binder material to additionally like body wherein the ?bers are straightened in bond said ?bers in straightened condition into a said direction longitudinally of the sheetlike coherent and integrally bonded sheet material. body, said sheetlike body being drawn under ten 20. A method according to claim 19 wherein sion in the ?nal stage of drafting into and be said ?rst binder is water and said further binder tween the nip of a pair of rollers which grip the material is a non-volatile adhesive substance and material of the sheetlike body therebetween. is applied in an aqueous medium to said web drawing said sheetlike body of ?bers from the while the ?bers in said web are still moist. nip of said pair of rollers under tension and with 21. Structural sheet material comprising a web dragging of individual ?bers disposed longitudi of unspun ?bers at least about 50% of which are nally of the sheetlike body relative to contiguous 3/; inch or more in length, said web being char ?bers in frictional contact therewith, thereby acterized by the fact that at least about 70% of disposing and maintaining said ?bers in said the ?bers of 3/; inch or more in length are dis sheetlike body in a condition of tensioned 2,407, 548 ’ . ‘23 - , posed approximately in one direction, are, of sub r 24 I . disposed approximately‘ in one direction in'each web and being of substantially tensioned straight stantially tensioned straightness, are substantially ‘ non-stretchablel’and'iare co-bonded together in longitudinally non-slippable relation by a sub stantially non-stretchable binder distributed sub ness, and said ?bers in each of said webs being co-bonded ‘ together by a. substantially non; stretchable binder material distributed substan tially uniformly about and among said ?bers, the ?ber density in said webs. of said structuralma terial being such that the ratio of thickness in stantially uniformly about and among said ?bers. 22. Structural sheet material in the form of a rigid, hard, dense body, said structural material consisting primarily of unspun ?ber and binder, at least 50% of the ?ber component being ?bers 10 thousandths of an inch to weight of ?ber in grains per square yard is 1 to at least 200. of % inch or more in length, and said structural ' 25. Structural sheet material according to claim material being characterized by the fact that at least 70% of the ?bers over % inch in length are maintained in a condition of tensioned 24 wherein the ?bers in said webs are unspun cot- ' ton ?bers distributed in \substantially .uniform thickness in each web so that the ?ber in each, straightness by said binder and are disposed in approximately the'same direction in each indi vidual layer of one ormore layers comprised ‘in said structural material, and said structural ma terial being further characterized by the‘ fact that said binder for said ?bers is a substantially non stretchable binder that is distributed substantially ' uniformly about and among said ?bers, and the ?ber'density in said structural material being such‘that the ratio ‘of thickness in ‘thousandths web weighs about 70to 400 grains per square yard . I and wherein said weight of the ?bers. substantially non-stretchable ' v 26. Apparatus for making'a web of‘ co-bonded' unspun ?bers which comprises draftingmeans for producing an attenuated web in- which the ?bers ' have a. preponderant ?ber direction in the direc tion of the drafting, a pair of rolls arranged for of an inch to weight of ?ber in grains per square 25 passage of said web therebetween after discharge yard is 1 to at least 100. 23‘. [Structural sheet material according to from said drafting means, means including said pair of rolls for drawing said web in said ?ber ‘direction to dispose the ?bers in said web in‘ a and wherein said substantially non-stretchable condition of tensioned straightness in said web binder constitutes about 10% to about 50% by dry weight of said structural material and where 80 after said web is discharged‘ from said drafting means and when said ‘web is fed between said in the ?ber density is such that the ratio of thick claim 22 wherein said ?bers comprise cotton ?bers rolls, and means immediately adjacent said pair of rolls forapplying bonding material to said web 24‘. Structural sheet material in the form of 35 passing between said rolls while said ?bers in said web are in said condition of tensioned ‘straight aprigid, hard, dense body, said structuralmate ness. rial being characterized by comprising a plurality 27. Apparatus according to claim 26 which also of integrally bonded superposed webs of unspun includes means for subjecting said web after leav ?bers, at least 60% of the ?brous material of said ing said pair of rolls‘ ' ness in thousandths 01’ an inch to weight of ?bers in grains per square yard is 1 to at least 200. I with said binder applied web being substantially unstretchable ?bers % 40 thereto to tension during the setting of the binder. inch or more in length and at least about 70% of the ?bers of % inch or more in length being JOSEPH GOLDMAN. '