US3153816A

US3153816A - Methods and apparatus for producing fibrous structures

Info

Publication number: US3153816A
Authority: US
Inventors: Kalwaltes Frank
Original assignee: Johnson and Johnson
Current assignee: Johnson and Johnson
Priority date: 1961-12-29
Filing date: 1961-12-29
Publication date: 1964-10-27
Anticipated expiration: 1981-10-27

Description

Oct. 27, 1964 F. KALWAITES 3,153,316

METHODS AND APPARATUS FOR PRODUCING FIBROUS STRUCTURES 2 Sheets-Sheet 1 Filed Dec. 29, 1961 INVENTOR fie/4mm 124M055 By %radv M ATTORNEY Oct. 27, 1964 F. KALWAITES METHODS AND APPARATUS FOR PRODUCING FIBROUS STRUCTURES 2 Sheets-Sheet 2 Filed Dec. 29, 1961 ATTORNEY United States Patent 3,153,816 METHODS AND APPARATUS FER PRGDUCEING FIBRQUS STllUCTilRd-S Frank Kalwaites, Seinerville, N31, assignor, by mesne assignments, to Johnson 8: .lohnson, New Brunswick, N.J., a corporation of New .iersey Filed Dec. 29, 196i, Ser. No. 163,140 8 Claims. {Cl 1915G} The present invention relates to improved methods and apparatus for producing fibrous structures, and more particularly is concerned with the production of drafted sliver and sliver ribbons having a high degree of weight regularity, as well as excellent fiber orientation and alignment along the main axes thereof and well suited for further processing into yarns.

In the processing of textile fibers whereby they are converted from raw, randomly-intermatted fibrous masses into relatively uniform, fibrous textile materials having a generally predominant fiber orientation in the long direction thereof, the inter-matted fibers are fed, usually in the form of a picker lap, to the lickerin of a textile card. Such a picker lap is a continuous, compressed sheet of interm'atted cotton tufts which has been rolled under pressure into a generally cylindrical package. The fiber uniformity of such a picker lap is not extremely high and there are normally occasional localized thick and thin places throughout its length and across its Width. As a consequence, therefore, the uniformity and evenness of the rate of fiber feed of a picker lap to the lickerin often could be improved.

The picker lap is, nevertheless, fed as uniformly as is possible under the circumstances to the lickerin of the card and the fibers are separated and formed into a fibrous web on the main cylinder and the dofiing cylinder thereof. This fibrous web, in which the individual fibers are relatively aligned generally in the long direction thereof, is removed from the dotting cylinder of the card, usually by a rapidly reciprocating doffer comb.

Immediately after the fibrous web has been removed from the dolfing cylinder by the reciprocating dolfer comb, it is usually pulled and drawn together in a triangularly converging form from the flat, full width which it possessed on the dofiing cylinder to the cylindrical, narrow form in which it passes through a condensing trumpet as it is being formed into a sliver.

During this conversion from a fiat, full width web usually about forty inches wide to a cylindrical sliver only about one inch in diameter, the outer edges of the triangularly converging, fibrous web necessarily have to travel a longer distance than the central part thereof which travels in a shorter, more direct line to the condensing trumpet. As a result, there is an undesirable haphazard folding or bunching of the fibrous web just prior to entering the mouth of the condensing trumpet whereby a loss of fiber orientation in the long direction occurs.

Also, with regard to the weight regularity of the fibrous web, it has been established that there never is complete weight regularity of a fibrous web removed from the doffing cylinder of a card, as regards lengthwise and crosswise directions. This is necessarily so inasmuch as a textile card is not a perfect machine and there are bound to be heavy fibrous portions and light fibrous portions in various places along and across the web. Of course, it must be realized that a card is essentially unable to selectively shift fibers in any direction, either forward or sideward, to correct the heaviness or lightness in Weight of the uneven portions.

As a consequence of the above factors, card webs and fibrous materials prepared therefrom, such as slivers, sliver ribbons, and the like, have not possessed the com- M5331. Patented Oct. 27, 196a ice pletely desired weight regularity and fiber orientation and alignment along the main axes thereof.

One of the principal objects of the present invention is therefore to provide improved methods and apparatus for producing slivers and sliver ribbons having a high degree of Weight regularity, as well as excellent fiber orientation and alignment along the main axes thereof.

It has been discovered that the Weight irregularities of prior art products may be avoided by first taking a plurality of separate card webs, as they are delivered from a plurality of separate cards which are being fed by a plurality of separate picker laps, bringing this plurality of separate card Webs together into a single combined fibrous Web, carrying such a combined fibrous web around a continuously movable, endless conveyor in a plurality of convolutions with each convolution being laterally shifted or displaced a predetermined amount from the preceding convolution whereby the fibers of each convolution are brought into close, contacting adjacency to other fibers of other convolutions, these other fibers originally having spaced crosswise and lengthwise positions in the combined fibrous web with respect to the fibers of the first-mentioned convolutions, and then separating a predetermined narrow width from the plurality of convolu tions of the laterally displaced combined fibrous web. In this way, there is formed a doubled and levelled sliver ribbon comprising fibers in close contacting adjacency but derived from different convolutions and from spaced crosswise and lengthwise positions in said combined fibrous web which, in turn, is derived from a plurality of separate picker laps. This provides sliver ribbon having a high degree of weight regularity along the main axis thereof but with only moderate improvement in the fiber orientation and alignment.

It has been further discovered that the orientation and alignment of the fibers in the doubled and levelled sliver ribbon may be vastly improved and the separation of such a sliver ribbon from the plurality of convolutions of the laterally displaced combined fibrous web be greatly facilitated by drafting the fibrous webs of the combined web subsequent to their formation but prior to the sliver ribbon separation step. The increased drafting leads to increased fiber orientation and alignment with fewer cross fibers being present which require cutting before the individual narrow sliver ribbon can be separated from the full-width web.

The fibrous web or layer which is processed to form the products of this invention may contain natural or synthetic, vegetable, animal or mineral cardable fibers such as: cotton, silk, wool, etc.; synthetic or man-made fibers such as the cellulosic fibers, notably cupr-ammonium, viscose or regenerated cellulose fibers; cellulose ester fibers such as cellulose acetate (Celanese) and cellulose triacetate (Arnel); the polyarnide fibers such as nylon 6 (polycaprolactam), nylon 66 (hexamethylene-diamineadipic acid), nylon 610 (hexamethy-lene-diarnine-sebacic acid); protein fibers such as Vicara; halogenated hydrocarbon fibers such as Tefion (polytetrafluoroethylene); hydrocarbon fibers such as polyethylene, polypropylene, and polyisobutylene; polyester fibers such as Kodel and Dacron; vinyl fibers such as Vinyon and saran; acrylic fibers such as Dynel, Verel, Orlon, Acrilan, Creslan, etc.

The lengths of the fibers in the starting fibrous web may vary from about /2 inch up to about 2 /2 inches or more in length, depending upon the particular properties and characteristics required or desired in the resulting fibrous web.

The denier of the individual synthetic fibers referred to above is preferably in the range of the approximate thickness of the natural fibers mentioned and consequently deniers in the range of from about 1 to about 5 are preferred. Where greater opacity or greater covering power is desired, special fiber deniers of down to about A or even about /2, may be employed. Where desired, deniers of up to about 5.5, 6, 8, 10, 15, or higher, may be used. The minimum and maximum deniers are naturally dictated by the desires or requirements for producing a particular fibrous web, by the machines and methods for producing the same, and so forth.

The weight of the individual fibrous web or layer of starting material as measured on the dofiing cylinder may be varied within relatively wide limits above a predetermined rninimum value but below a predetermined maximum value, depending upon the requirements of the intermediate or the final products. A single, thin web of fibers, such as produced by a card and as presented by the dofiing cylinder to the dofiing means, may have a weight of from about 30 to about 250 or more grains per square yard and may be used in the application of the principles of the present invention. Within the more commercial aspects of the present invention, however, web weights on the dofi'ing cylinder of from about 60 grains per square yard to about 200 grains per square yard are contemplated.

Such a fibrous web as described above may be drafted by any desired drafting or drawing means capable of increasing the fiber orientation to any desired value such as above 70% in the case of cotton, or above 75 or 80%, or even up to 90 or 95%, in the case of rayon or other synthetic fibers, depending upon the staple length. One particular drafting procedure, such as described in my copending patent application, Serial No. 9,969, filed February 19, 1960, now US. Patent No. 3,119,152 is of special application.

Such a drafting procedure substantially simultaneously d'offs and drafts the fibrous web as it is being removed from the dofiing cylinder. Such a procedure involves initially forming a carded fibrous web on the doffing cylinder of a card, and then positioning a relatively smooth-surfaced, movable, dofiing belt closely adjacent to but spaced from the doffing cylinder by a predetermined distance, whereby the carded fibrous web is transferred from th doffing cylinder to the movabe dofiing belt. This movable belt, being fiexible, may be trained over relatively small diameter rods or bars or equivalent elements positioned in close proximity to the surface of the dofiing cylinder so that the movable belt gradually approaches that surface at a desired acute angle, and then sharply and rapidly departs therefrom at another desired larger angle, as required. This sharp angular departure is to be contrasted to the gradual angular departure which prevails in the case of a roller dofiing device, for example, the roller radius of which cannot be made too small for physical strength reasons. The flexible belt, by then cooperating with a second rotatable or movable surface which presses against the belt and forms a nip therewith, is able to seize the leading ends of the fibers at a point relatively close to the periphery .of the dofiing cylinder and to draw the fibers in positive fashion therefrom.

By suitably adjusting the surface linear velocity of the movable flexible belt with reference to the surface peripheral linear velocity of the dofling cylinder, the movable belt may be made to draw the fibersaway from the dofiing cylinder at any desired greater velocity whereby they are drafted or drawn and assume a more highly oriented or aligned configuration with respect to the long axis of the drafted fibrous web.

The degree of drafting employed willdep'end primarily upon the degree of orientation desired in the drafted fibrous web and is, of course, determined by the ratio of the surface linear velocity of the doffing and drafting 'beltto the surface linear velocity of the dofiing cylinder.

The ratio of the surface linear velocity of the doffing and drafting belt to the surface linear velocity of the dofiing cylinder must be greater than 1 to 1 in order that drafting and increased alignment of the fibers is accomplished. In some instances, ratios as low as about 1.1

to 1 have been used successfully depending primarily upon the nature and characteristics of the fibers involved. In most instances, ratios of from about 1.5 to 1 to about 4 to 1 have been found preferable, with optimum results being noted at about 3 to l. Ratios higher than 4 to l are utilizable within the principles of the present invention, with values of up to 10 to 1 or higher being of use in special cases.

Although the present invention will be described with reference to the use of only two card machines, it is to be appreciated that a greater number of cards may be employed. Four or six cards arranged in aligned fashion is one variation; three pairs of tandem cards (effectively six cards) is another variation. Other modifications are, of course, possible.

The invention will be more fully understood from the description which follows, taken in conjunction with th accompanying drawings in which there are illustrated preferred designs of machines and modes of operation embodying the invention. It is to be understood, however, that the invention is not to be considered limited to the constructions disclosed except as determined by the scope of the appended claims. In the drawings:

FIGURE 1 is a schematic side elevation of one form of apparatus suitable for carrying out the improved methods of the present invention, with some parts being fragmentary or omitted for the purpose of clarity of illustration;

FlGURE 2 is a schematic plan view of the conveying means of the apparatus of FIGURE 1 for carrying the combined fibrous web in a series of convolutions, with the carding, doffing and drafting means being fragmentary or omitted for the purpose of clarity of illustration.

FIGURE 3 is an exploded cross-sectional view, taken on the line 33 of FIGURE 2, showing the fibrous web and sliver ribbon obtained by the present invention, with the several layers thereof exploded to show more clearly the internal construction and width of the individual layers;

FIGURE 4 is a schematic side elevation of a modified form of apparatus, suitable for carrying out the improved methods of the present invention, with some parts being fragmentary or omitted for the purpose of clarity of illustration; A

FIGURE 5 is a schematic plan view of the conveying means of the apparatus of FIGURE 4 for carrying the combined Webs in a series of convolutions, with the carding, doffing and drafting means being fragmentary or omitted for the purpose of illustration;

7 FIGURE 6 is an exploded cross-sectional view, taken on the line 66 of FIGURE 5, showing the fibrous web and sliver ribbon obtained by the apparatus of FIGURES 5 and 6, with the several layers thereof exploded to show more clearly the internal construction and width of the individual layers; and

FEGURE 7 is an exploded cross-sectional view, similar to FIGURE 6, but showing an intermediate fibrous web and sliver ribbon product which is obtained during the initial start-up of the apparatus and which is customarily discarded.

In the embodiment of the invention illustrated in the drawings, a conventional textile card A is used and comprises a conventional, rotatable main card cylinder 10 and lickerin 12 to which is fed a conventional picker lap (not shown). Such a card cylinder 10 is used to provide for the normal carding of the fibers fed thereto whereby the fibers are disentangled and the bunches or tufts of fibers are separated more or less into individual fibers. The initial attenuating of the fibers into a generally aligned condition takes place on the rotatable surface of the main cylinder 10 and the individualized fibers are sparsely spread thereover in an amount weighing but a few grains per square yard.

These substantially individualized fibers which do not normally constitute a self-sustaining fibrous web are presented to and deposited on the surface of a doffing 'cylinder 14 which rotates on a shaft mounted in bearings secured to the card frame 13. The doffing cylinder 14. rotates at a much lower peripheral surface linear velocity than the main cylinder 10, in accordance with standard practice. This velocity differential, which may be varied as desired, creates a condensing of the individual fibers into a thin, fibrous carded web normally weighing from about 30 grains to about 250, and preferably from about 60 to about 200 grains per square yard, on the peripheral surface of the rotatable dolfing cylinder 14.

The main cylinder 16 and the dolfing cyl nder 14 are conventional; the main cylinder being about 50 inches in outside diameter and about 40 inches wide; and the doffing cylinder being about 26 or 27 inches in outside diameter and also about 40 inches wide. The main cylinder and the dofiEing cylinder are both covered with conventional card clothing, comprising a large number of wire teeth or pins which constitute protuberances acting together as a carrier surface, adapted to have fibers entwined with the protuberances in slidable engagement therewith.

Immediately adjacent the doing cylhider 14, and approximately at the position where the fibrous web formed thereon is conventionally removed by the usual textile dofiing comb, there is located a dofling and drafting mechanism 20 which not only removes the fibrous Web from the dofiing cylinder 14 but also substantially simultaneously drafts the same whereby its degree of fiber orientation and alignment is improved. As shown more particularly in my copending patent application referred to hereinabove, the doffing and drafting mechanism cornprises a stationary, angular nose bar 22 having an elongated nose portion and a reinforcing base portion. The reinforcing base portion strengthens and steadies the nose portion but may be omitted when the nose portion is sufiiciently strong and steady by itself. The nose bar 22 is adjustable so that the nose portion thereof can be controllably and accurately positioned at any desired angular relationship, or with any desired clearance, with respect to the peripheral surface of the dofiing cylinder 14.

An endless, flexible doffing and drafting belt 24 is passed around the nose portion of the nose bar 22 and is brought into close proximity with the surface of the doffing cylinder 14 so that the fibers thereon are transferred from the dofifing cylinder 14 to the dofiing and drafting belt 24. A pressure-applying rotatable nip roll 26 presses against the drafted card web on the dofiing and drafting belt 24 at a point closely adjacent to the fiber-transfer point and presses the fibers removed from the doffing cylinder 14 against the belt 24.

The doffing and drafting belt 24, after passing under the rotatable nip roll 26, passes upwardly over a driving rotatable guide roll 28. The driving rotatable guide roll 28 may be driven by any suitable driving means, such as an electric motor.

The dofiing and drafting belt 24 is then directed downwardly and passes over an adjustable, rotatable, guiding and tensioning roll 30. The mounting of the rotatable, guiding and tensioning roll 39 is so arranged that it can be adjusted, as desired, in order to supply the desired tension to the belt.

The dofiing and drafting belt 24 then passes around a rotatable guide roll 32 and is then directed upwardly over the nose portion of the nose bar 22. As can be seen the belt is endless and moves in a continuous cycle, as described.

By having the doffing and drafting belt 24 move with a linear velocity which is greater than the peripheral surface linear velocity of the doffing cylinder, the individual fibers are drawn or drafted forwardly and slid off the teeth or needles of the dofiing cylinder 1 whereby they are straightened and aligned with a considerably higher degree of orientation on the doifing and drafting belt 24. All this is described in greater detail in the patent application referred to herein.

The drafted card web with its increased degree of fiber orientation or alignment is then led forwardly under a guide press roll 34 mounted for rotation in extensions of the card sides 13. The drafted card web, in passing under the press roll 34, is guided thereby and is deposited on the movable surface of an endless tape or belt conveyor which is looped around a pair of rotatable rear and front conveyor rolls 72 and '74.

A second conventional textile card B is positioned in aligned fashion with the first conventional textile card A and comprises a conventional rotatable main card cylinder 4i? and lickerin 42 and a conventional doffing cylinder 44. A second doffing and drafting mechanism 56) is also provided and comprises an adjustable angular nose bar 52, an endless, flexible doffing and drafting belt 54, a pressureapplying, rotatable nip roll 56, a driving rotatable guide roll 58, an adjustable, rotatable, guiding and tensioning roll as, and a rotatable guide roll 62.

The fibrous web formed on the second main card cylinder 443 and doffing cylinder 44 is dolfed and substantially simultaneously drafted as it is being removed from the dotfing cylinder 44. It is then guided downwardly, passes under a second rotatable press roll 64 and is brought into pressing, preferably aligned contact with the first web formed on the first textile card. The two fibrous webs thus form a combined fibrous web which is carried forwardly by the upper reach of the collecting conveyor 79.

A rotatable severing device comprising a pair of rotatable cutting knives is so positioned near the extreme forward position of the conveyor 7li as to separate from the combined fibrous web a narrow, flat sliver ribbon having a predetermined width.

The first sliver ribbon separated from the combined fibrous web comprises merely one combined fibrous web, or two fibrous card webs pressed together. As the operation continues and as will be described hereinafter, the number of layers of fibrous Webs in the sliver ribbon increases to a determined maximum which, in the particular apparatus shown in FIGURES 1 through 3, is 8 layers of combined fibrous webs, or 16 fibrous webs pressed together.

That portion of the combined fibrous web which has not been separated from the main body thereof is advanced over a front rotatable web transfer roll 78 and is reversed in direction thereat to be guided rearwardly onto a lower, laterally shiftable belt conveyor 8i). The web transfer roll 78 should be positioned relatively closely to the belt conveyors 7t and 8% so as to reduce the space through which the fibrous web is conveyed unsupported.

As shown more clearly in FIGURE 2, the lower, laterally shiftable belt conveyor 89 is mounted on a pair of rotatable conveyor rolls 82 and 84 which are offset angularly with respect to the pair of rotatable conveyor rolls 72 and 74 which support the upper collecting conveyor '76. Such an angular offset is obtained by canting the rear roll 82 and then moving the forward roll 84 angularly to take up the slack.

As a result of such an angular ofiset configuration, the fibrous web which is deposited on the lower, laterally shiftable conveyor 89 is carried in a direction generally opposite to and at an angle to the direction it originally possessed when it was on the upper collecting conveyor 70. The degree of angularity is clearly shown in FIG- URE 2 and it is to be appreciated that the web will move upwardly as well as to the right, as viewed in that figure.

As a consequence, the web will be carried to the right rearwardly on the laterally shiftable conveyor 30 and will pass around a rear web transfer roll as and be returned to the upper surface of the collecting conveyor 7% at a position which i displaced laterally by an amount proportionate to the degree of angularity of the two conveyors. The fibrous web will then be carried to the left forwardly on the coflecting conveyor 7 ti and two additional card webs will then be deposited thereon by cards A and B. The two webs which are so deposited, however, will be wider than the web passing over the rear web transfer roll 86 7 and will extend over the far end thereof in a manner similar to that shown in FIGURE 7. The sliver ribbon then being separated from the fibrous web by the severing device 76 Will, at that moment, be 4 card webs thick. The operation continues until the configuration shown in FIG- URE 3 is obtained completely as shown and from that moment on, the sliver ribbon which is separated will be 8 combined fibrous webs thick or a total of 16 card webs thick. The sliver ribbon previously separated has varying thicknesses and is normally discarded. The sliver ribbon subsequently separated is forwarded for further processing, such as being made into yarn.

Although the present invention has been described and illustrated with reference to a laterally shiftable conveyor which shifts the webs approximately one-eighth of its width for each convolution around the collecting conveyor, whereby a sliver ribbon comprising eight combined card webs is obtained, it is to be appreciated that other amounts of shifts and other thicknesses of sliver ribbons are obtainable. The less the shift per convolution, the greater the number of layers in the sliver ribbon is the general rule. Shifts of one-tenth of the width of the card web per convolution yield sliver ribbons of ten layers; shifts of one-twentieth of the width of the card web per convolution yield sliver ribbons of twenty layers. The smaller the shift, the greater the number of layers and the greater is the levelling effect on the fiber weight uniformity along the main axis of the sliver ribbon.

A modification of the present inventive concept is illustrated in FIGURES 4 and 5 wherein a different laterally shiftable conveyor means is used to replace the laterally shiftable conveyor belt 80 used in the apparatus illustrated in FIGURES 1 and 2.

In FIGURE 4, there is shown an endless upper collecting belt conveyor 90 which is looped around a rotatable rear conveyor roll 92 and a front conveyor roll 94. This upper collecting conveyor 90 and the rear and front conveyors rolls 92 and 94 are very similar in structure and operation to the upper collecting conveyor 76 and the rear and front conveyor rolls 72 and 74 of the apparatus illustrated in FIGURE 1. Fibrous webs deposited on the upper collecting conveyor 90 by the textile cards are conveyed to the left, as viewed in FIGURE 4.

A rotatable severing device 96 similar to severing device 76 of FIGURE 1 is provided to separate a sliver ribbon from the deposited fibrous web. The remainder of the fibrous web passes over a rotatable front web-transfer roll 98 and is then directed rearwardly over a narrow, endless, laterally shiftable conveyor belt 109 which is looped a plurality of times (9 in FIGURE 4) around a pair of rotatable rear and front conveyor rolls 192 and 104.

It is to be recalled that the lateral displacement of the fibrous web was accomplished in the apparatus illustrated in FIGURE 1 by the angular relationship of the rotatable rear and front conveyor rolls 82 and 84. In the embodiment illustrated in FIGURE 4, the lateral displacement is accomplished by the use of the upper reach of the laterally shiftable conveyor belt 100 which is looped a plurality of times around the rear and front conveyor rolls in a somewhat generally helical fashion whereby any web deposited on the lefthand or forward end thereof will move rearwardly to the right and simultaneously laterally a distance equal to the width of one section of conveyor belt 1%. The principle of such a lateral displacement is described more particularly in my copending, commonly-assigned patent application Serial No. 114,156, filed June 1, 1961. The structure and principles involved are similar to those described in said patent application and should need no further discussion herein other than to state that the fibrous web is conveyed and displaced, as illustrated. It is merely to be observed that the narrow, endless belt Illtl proceeds helically, laterally shifting the fibrous web. When a particular helical convolution of the narrow belt 19%) reaches its end position,

; 8 7 it is returned by means of two rotatable return rolls to its other end position at which it starts its somewhat generally helical path. Such helical movement is, of course, endless and continuous.

The operation of the embodiment in FIGURE 4 is substantially identical to the operation of the apparatus illustrated in FIGURE 1. Fibrous webs are deposited on the upper collecting conveyor 9%, move forwardly to the left, have a narrow sliver ribbon separated therefrom, and then are transferred via the front web-transfer roll 98 to a lower laterally shiftable conveyor 100 moving rearwardly in the opposite direction (to the right) with a predetermined lateral displacement for the full length of the conveyor. Upon reaching the end of its travel in the reverse direction, the fibrous web is transferred back over a rear web-transfer roll 106 to the upper collecting conveyor 9i) whereat it receives additional fibrous webs, has a narrow silver ribbon removed therefrom, is trwsferred back to the lower laterally shiftable conveyor 1%, etc.

The angular relationship of the individual runs of the upper reach of the lower laterally shiftable conveyor 100 may be kept in position on their conveyor rolls either by individual crowning or by the use of end flanges as 110 and 112 on rear conveyor roll 102, with corresponding means on the front conveyor roll.

Substantially any reasonable number of convolutions of the narrow, endless, laterally shiftable conveyor belt 109 may be used. As few as 5 convolutions and as many as 40 are of utility in practicing the present inventive concept. The width of the indivdual run of the laterally shif-table conveyor is correspondingly increased or decreased as desired, say, from as wide as 8 inches each or as narrow as 1 inch each.

In the apparatus illustrated in FIGURES 1-2 and 4-5, the fibrous webs are deposited on an upper collecting conveyor in aligned edge-to-edge fashion and. receive their lateral displacements when they are on the lower conveyor belt. It is to be appreciated that the reverse of this configuration is possible and the lateral displacement may take place on the upper collecting conveyor with the lower conveyor belt merely being used to reverse the web direction to produce the required number of convolutions of the fibrous web. In such a reversal of parts, the fibrous webs deposited by the plurality of textile cards are normally not deposited in aligned edge-to-edge fashion but are aligned in slightly laterally displaced comfigurations. Normally, this is not as desirable as the aligned edge-to-edge configuration but in some uses it possesses advantages.

The invention will be further illustrated in greater detail by the following specific examples. It should be understood, however, that although these examples may describe in particular detail some of the more specific features of the invention, they are given primarily for purposes of illustration and the invention in its broader aspects is not to be construed as limited thereto.

Example I The starting fibrous material comprises two fibrous webs delivered by the dofiing cylinders of two textile cards arranged as shown in FIGURE 1. Each fibrous web is a 40-inch-wide card web of viscose rayon staple fibers having a web weight of about 75 grains per yard and containing fibers having a staple length of about 1 inch and a denier of about 1%. The peripheral surface linear velocity of each doffing cylinder is about 10 yards per minute.

The fibrous webs are transferred from the dofiing cylind ere to flexible, movable dofiing and drafting belts such as illustrated in FIGURE 1. These belts have peripheral surface linear velocities of about 12 yards per minute.

This is equivalent to a 1.2 to 1 drafting ratio (belt to dofilng cylinder). The webs delivered by the doffing and drafting mechanisms pass under rotatable press rolls and are positioned with their edges in substantial alignment on a collecting conveyor, as illustrated in FIGURE 1.

A rotatable cutting device separates a -inch wide sliver ribbon from one edge of the combined card webs and such sliver ribbon is carried forwardly into a sliver can. The remainder of the combined card webs measures only 35 inches in width and is carried forwardly over a ront web-transfer roll and is reversed in direction thereon and placed on a rearwardly moving laterally shiftable conveyor. The axes of the rotatable rolls driving the laterally shiftable conveyor are positioned angularly with respect to the axes of the rotatable rolls driving the colecting conveyor to such an extent that the laterally smftable conveyor is displaced sidewards by 5 inches by the time it reaches its most rearward point. The combined card webs carried thereon are also correspondingly shifted 5 inches. The combined card webs then pass around a rear web-transfer roll and reverse direction to be placed on the forwardly moving collecting conveyor. The cut edge of the combined card webs which was originally 5 inches from the edge of the first laid-down combined card webs, however, now has been moved over 5 inches due to the displacement of the laterally shiftable conveyor and is now located along the line of the original edge of the first laid-down card webs. The operation continues and a second pair of card webs is placed on top of the first laid-down pair of card webs. Such an intermediate product is shown in FIGURE 7.

After the apparatus has been in operation for a period of time and a sufiicient number of fibrous webs have been conveyed around the collecting conveyor, the sliver ribbon which is separated by a rotatable severing device is examined. It is found to comprise 8 combined fibrous Webs or 16 card webs in thickness. The weight is about 125 grains per running yard. It possesses an excellent degree of fiber alignment and orientation along the main axis and is superior in that regard to a similar fibrous web prepared from similar materials on conventional equipment but removed from the doffing cylinders by conventional dofilng combs. The weight regularity and fiber uniformity are excellent. The drafted sliver ribbon is forwarded between a pair of calender rolls to a 3-roll drafting frame wherein it is drafted at a ratio of about 3 to 1. The drafted sliver ribbon then passes through a condensing trumpet and calender rolls and is deposited in a coiler can. The sliver wei hs about 42 grains per yard and possesses excellent weight uniformity and fiber orientation along the main axis and is well suited for spinning into yarn.

Example I] The procedures of Example I are carried out substantially as set forth therein except that the amount of displacement of the laterally shiftable conveyor is decreased to 4 inches whereby the final sliver ribbon is 4 inches wide and comprises layers of combined card webs, or a total of 20 card webs. The degree of fiber alignment and orientation is about the same as in Example I but the levelling effect is better and enhanced weight uniformity is obtained.

Example 111 The procedures of Example I are carried out substantially as set forth therein except that the amount of displacement of the laterally shiftable conveyor is decreased to 2 inches whereby the final sliver ribbon is 2 inches wide and comprises 20 layers of combined card webs, or a total of 40 card webs. The degree of fiber alignment and orientation is about the same as in Example 1 but the levelling effect is considerably better and the fiber weight uniformity is superior.

Example IV The procedures of Example I are carried out substantially as set forth therein except that four aligned cards ill are used (instead of two) and the lengths of the collecting conveyor and laterally shiftable conveyor are increased so they pass under all four cards and process the card webs delivered thereby. The weights of the card Webs are each about grains per yard. The ratio of the peripheral surface linear velocity of the dofimg and drafting belt to that of the dofiing cylinder in each case is about 1.2 to l. The sliver ribbon separated from the combined card webs comprises 32 layers of card web material and weighs about 250 grains per running yard. The weight regularity and fiber uniformity is excellent. The sliver ribbon is well suited for further processing into yarn.

Although several specific examples of the inventive concept have been described, the same should not be construed as limited thereby nor to the specific features mentioned therein but to include various other equivalent features as set forth in the claims appended hereto. It is understood that any suitable changes, modifications and variations may be made Without departing from the spirit and scope of the invention.

What is claimed is:

1. A method of doubling and levelling fibrous materials which comprises: forming a fibrous web on a rotatable surface; removing said fibrous Web from said rotatable surface; forming a second fibrous Web on a second rotatable surface; removing said second fibrous web from said second rotatable surface; bringing said fibrous webs together to form a combined fibrous web; supporting said combined fibrous web and moving said supported Web in the direction of its length through a first longitudinal path; separating the fibrous Web from its support; re-supporting said fibrous Web and moving said supported web through a second path having a direction opposite to the direction of movement in said first path and angularly disposed thereto; separating the angularly disposed web from its support; again re-supporting said web and moving said Web through a third path cooperating With said first path and moving in the same direction as said first path, said Web being laterally displaced from its position in said first path; repeating said movements of said web through said first, second and third paths whereby a plurality of convolutions with each convolution laterally displaced from the preceding convolution is formed, having the fibers of one convolution in close adjacency to other fibers of other convolutions, said other fibers originally having spaced crosswise and lengthwise positions in said combined fibrous web with respect to the first mentioned fibers; and separating a predetermined width from the plurality of convolutions of said laterally displaced combined fibrous web to form a doubled and levelled sliver ribbon comprising fibers in close adjacency but derived from different convolutions and from spaced crosswise and lengthwise positions in said combined fibrous web.

2. A method of doubling and levelling fibrous materials which comprises: forming a fibrous Web on a rotatable surface; removing said fibrous Web from said rotatable surface; drafting said fibrous web; forming a second fibrous Web on a second rotatable surface; removing said second fibrous web from said second rotatable surface; drafting said second fibrous Web; bringing said fibrous webs together to form a combined fibrous web; supporting said combined fibrous web and moving said supported web in the direction of its length through a first longitudinal path; separating the fibrous web from its support; resupporting said fibrous web and moving said supported Web through a second path having a direction opposite to the direction of movement in said first path and angularly disposed thereto; separating the angularly disposed web from its support; again re-supporting said web and moving said web through a third path cooperating with said first path and moving in the same direction as said first path, said web being laterally displaced from its position in said first path; repeating said movements 11 a of said web through said first, second and third paths whereby a plurality of convolutions with each convolution laterally displaced from the preceding convolution is formed, having the fibers of one convolution in close adjacency to other fibers of other convolutions, said other fibers originally having spaced crosswise and lengthwise positions in said combined fibrous web with respect to the first mentioned fibers; and separating a predetermined width from the plurality of convolutions of said laterally displaced combined fibrous web to form a doubled and levelled sliver ribbon comprising fibers in close adjacency but derived from different convolutions and from spaced crosswise and lengthwise positions in said combined fibrous web.

3. A method of doubling and levelling fibrousmaterials which comprises: forming a fibrous web on a rotatable surface; removing said fibrous web from said rotatable surface and simultaneously drafting the same; forming a second fibrous web on a second rotatable surface; removing said second fibrous web from said second rotatable surface and simultaneously drafting the same; bringing said fibrous webs together to form a combined fibrous web; supporting said combined fibrous web and moving said supported web in the direction of its length through a first longitudinal path; separating the fibrous web from its support; re-supporting said fibrous web and moving said supported web through a second path having a direction opposite to the direction of movement in said first path and angularly disposed thereto; separating the angularly disposed web from its support; again r e-supporting said web and moving said web through a third path cooperating with said first path and moving in the same direction as said first path, said web being laterally displaced from its position in said first path; repeating said movements of said web through said first, second and third paths whereby a plurality of convolutions with each convolution laterally displaced from the preceding convolution is formed, having the fibers of one convolution in close adjacency to other fibers of other convolutions, said other fibers originally having spaced crosswise and lengthwise positions in said combined fibrous web with respect to the first mentioned fibers; and separating a predetermined width from the plurality of convolutions of said laterally displaced combined fibrous web to form a doubled and levelled sliver ribbon comprising fibers in close adjacency but derived from dilferent convolutions and from spaced crosswise and lengthwise positions in said combined fibrous Web. 7

4. Apparatus for doubling and levelling fibrous mat 'rials which comprises: a rotatable surface for forming a fibrous web; means for removing said fibrous web from said rotatable surface; a second rotatable surface for forming a second fibrous web; means for removing said second fibrous web from said second rotatable surface; a first endless belt located adjacent said rotatable surface and said second rotatable surface for receiving and combining said fibrous webs; a second endless belt located adjacent the first belt and being angularly disposed thereto for continuously receiving said combined fibrous web from said first endless belt at one end thereof and returning said fibrous web to said first endless belt at the opposite end thereof and for moving said combined fibrous web a predetermined lateral distance to form a plurality of convolutions with each convolution laterally displaced from the preceding convolution whereby the fibers of one convolution are brought into close adjacency to other fibers of other convolutions, said other fibers originally having spaced crosswise and lengthwise positions in said combined fibrous web with respect to the first mentioned fibers; and means for separating a predetermined width from the plurality of convolutions of said laterally displaced combined fibrous web to form a doubled and levelled sliver ribbon comprising fibers in close adjacency but derived from different convolul2 tions and from spaced crosswise and lengthwise positions in said combined fibrous web.

5. Apparatus for doubling and levelling fibrous materials which comprises: a rotatable surface for forming a fibrous web; means for removing said fibrous web from said rotatable surface; a second rotatable surface for forming a second fibrous web; means for removing said second fibrous web from second rotatable surface; a first conveyor means comprising an endless belt mounted on conveyor rolls located adjacent said rotatable surface and said second rotatable surface for receiving and combining said fibrous webs; a second conveyor means comprising an endless belt mounted on conveyor rolls located adjacent said first conveyor means and having the axes of the conveyor rolls angularly disposed with respect to the axes of the conveyor rolls of said first conveyor means for continuously receiving said combined fibrous web from said first conveyor means at one end thereof and returning said fibrous web to said'first conve 'or means at the opposite end thereof and for moving said combined fibrous web a predetermined lateral dis tance to form a plurality of convolutions ith each convolution laterally displaced from the preceding convolution whereby the fibers of one convolution are brought into close adjacency to other fibers of other convolutions, said other fibers originally having spaced crosswise and lengthwise positions in said combined fibrous web with respect to the first mentioned fibers; and means for separating a predetermined width from the plurality of convolutions of said laterally displaced combined fibrous web to form a doubled and levelled sliver ribbon com prising fibers in close adjacency but derived from different convolutions and from spaced crosswise and lengthwise positions in said combined fibrous Web.

6. Apparatus for doubling and levelling fibrous materials which comprises: a rotatable surface for forming a fibrous web; means for removing said fibrous web from said rotatable surface; a second rotatable surface for forming a second fibrous web; means for removing said second fibrous web from said second rotatable surface; a first conveyor means comprising an endless belt mounted on conveyor rolls and having a surface moving in a direction at right angles to the axes of said conveyor rolls and located adjacent said rotatable surface and said second rotatable surface for receiving and combining said fibrous webs; a second conveyor means comprising an endless belt mounted on conveyor rolls parallel to the conveyor rolls of said first conveyor means and having a surface moving in a direction angularly disposed to the axes of the conveyor rolls of said second conveyor means located adjacent said first conveyor means for continuously receiving said combined fibrous web from said first conveyor means at one end thereof and returning said fibrous Web to said first conveyor means at the opposite end thereof and for moving said combined fibrous 'eb a predetermined lateral distance to form a plurality of convolutions with each convolution laterally displaced from the preceding convolution whereby the fibers of one convolution are brought into close adjacency to other fibers of other convolutions, said other fibers originally having spaced crosswise and lengthwise positions in said combined fibrous web with respect to the first mentioned fibers; and means for separating a predetermined width from the plurality of convolutions of said laterally displaced combined fibrous web to form a doubled and levelled sliver ribbon comprising fibers in close adjacency but derived from different convolutions and from spaced crosswise and lengthwise positions in said combined fibrous web.

7. Apparatus for doubling and levelling fibrous materials which comprises: a rotatable surface for forming a fibrous web; means for removing said fibrous web from said rotatable surface; means for drafting said fibrous web; a second rotatable surface for forming a second fibrous web; means for removing said second fibrous web from said second rotatable surface; means for drafting said second fibrous web; a first endless belt located adjacent said rotatable surface and said second rotatable surface for receiving and combining said drafted fibrous webs; a second endless belt located adjacent the first belt and being angularly disposed thereto for continuously receiving said combined fibrous web from said first endless belt at one end thereof and returning said fibrous web to said first endless belt at the opposite end thereof and for moving said combined fibrous web a predetermined lateral distance to form a plurality of convolutions With each convolution laterally displaced from the preceding convolution whereby the fibers of one convolution are brought into close adjacency to other fibers of other convolutions, said other fibers originally having spaced crosswise and lengthwise positions in said combined fibrous web with respect to the first mentioned fibers; and means for separating a predetermined width from the plurality of convolutions of said laterally displaced combined fibrous web to form a doubled and levelled sliver ribbon comprising fibers in close adjacency but derived from different convolutions and from spaced crosswise and lengthwise positions in said combined fibrous web.

8. Apparatus for doubling and levelling fibrous materials which comprises: a rotatable surface for forming a fibrous web; means for removing said fibrous web from said rotatable surface and substantially simultaneously drafting the same; a second rotatable surface for forming a second fibrous web; means for removing said second fibrous web from said second rotatable surface and substantially simultaneously drafting the same; a first endless belt located adjacent said rotatable surface and said second rotatable surface for receiving and combining said fibrous webs; a second endless belt located adjacent the first belt and being angularly disposed thereto for continuously receiving said combined fibrous web from said first endless belt at one end thereof and returning said fibrous web to said first endless belt at the opposite end thereof and for moving said combined fibrous web a predetermined lateral distance to form a plurality of convolutions with each convolution laterally displaced from the preceding convolution whereby the fibers of one convolution are brought into close adjacency to other fibers of other convolutions, said other fibers originally having spaced crosswise and lengthwise positions in said combined fibrous web with respect to the first mentioned fibers; and means for separating a predetermined width from the plurality of convolutions of said laterally displaced combined fibrous web to form a doubled and levelled sliver ribbon comprising fibers in close adjacency but derived from difierent convolutions and from spaced crosswise and lengthwise positions in said combined fibrous web.

References Cited in the file of this patent UNITED STATES PATENTS 1,189,873 Rooney July 4, 1916 1,712,124 Stack May 7, 1929 2,055,411 Hurst Sept. 22, 1936 2,055,412 Hurst et al Sept. 22, 1936 2,168,775 Hurst et al. Aug. 8, 1939 2,385,873 Melton Oct. 2, 1945 3,081,658 Witschi Mar. 19, 1963 FOREIGN PATENTS 1,127,219 France Aug. 6, 1956 1,167,842 France Aug. 18, 1958

Claims

1. A METHOD OF DOUBLING AND LEVELLING FIBROUS MATERIALS WHICH COMPRISES: FORMING A FIBROUS WEB ON A ROTATABLE SURFACE; REMOVING SAID FIBROUS WEB FROM SAID ROTATABLE SURFACE; FORMING A SECOND FIBROUS WEB ON A SECOND ROTATABLE SURFACE; REMOVING SAID SECOND FIBROUS WEB FROM SAID SECOND ROTATABLE SURFACE; BRINGING SAID FIBROUS WEBS TOGETHER TO FORM A COMBINED FIBROUS WEB; SUPPORTING SAID COMBINED FIBROUS WEB AND MOVING SAID SUPPORTED WEB IN THE DIRECTION OF ITS LENGTH THROUGH A FIRST LONGITUDINAL PATH; SEPARTING THE FIBROUS WEB FROM ITS SUPPORT; RE-SUPPORTING SAID FIBROUS WEB AND MOVING SAID SUPPORTED WEB THROUGH A SECOND PATH HAVING A DIRECTION OPPOSITE TO THE DIRECTION OF MOVEMENT IN SAID FIRST PATH AND ANGULARLY DISPOSED THERETO; SEPARATING THE ANGULARLY DISPOSED WEB FROM ITS SUPPORT; AGAIN RE-SUPPORTING SAID WEB AND MOVING SAID WEB THROUGH A THIRD PATH COOPERATING WITH SAID FIRST PATH AND MOVING IN THE SAME DIRECTION AS SAID FIRST PATH, SAID WEB BEING LATERALLY DISPLACED FROM ITS POSITION IN SAID FIRST PATH; REPEATING SAID MOVEMENTS OF SAID WEB THROUGH SAID FIRST, SECOND AND THIRD PATHS WHEREBY A PLURALITY OF CONVOLUTIONS WITH EACH CONVOLUTION LATERALLY DISPLACED FROM THE PRECEDING CONVOLUTION IS FORMED, HAVING THE FIBERS OF ONE CONVOLUTION IN CLOSE ADJACENCY TO OTHER FIBERS OF OTHER CONVOLUTIONS, SAID OTHER FIBERS ORIGINALLY HAVING SPACED CORSSWISE AND LENGTHWISE POSITIONS IN SAID COMBINED FIBROUS WEB WITH RESPECT TO THE FIRST MENTIONED FIBERS; AND SEPARATING A PREDETERMINED WIDTH FROM THE PLURALITY OF CONVOLUTIONS OF SAID LATERALLY DISPLACED COMBINED FIBROUS WEB TO FORM A DOUBLED AND LEVELLED SLIVER RIBBON COMPRISING FIBERS IN CLOSE ADJACENCY BUT DERIVED FROM DIFFERENT CONVOLUTIONS AND FROM SPACED CROSSWISE AND LENGTHWISE POSITIONS IN SAID COMBINED FIBROUS WEB.

4. APPARATUS FOR DOUBLING AND LEVELLING FIBROUS MATERIALS WHICH COMPRISES: A ROTATABLE SURFACE FOR FORMING A FIBROUS WEB; MEANS FOR REMOVING SAID FIBROUS WEB FROM SAID ROTATABLE SURFACE; A SECOND ROTATABLE SURFACE FOR FORMING A SECOND FIBROUS WEB; MEANS FOR REMOVING SAID SECOND FIBROUS WEB FROM SAID SECOND ROTATABLE SURFACE; A FIRST ENDLESS BELT LOCATED ADJACENT SAID ROTATABLE SURFACE AND SAID SECOND ROTATABLE SURFACE FOR RECEIVING AND COMBINING SAID FIBROUS WEBS; A SECOND ENDLESS BELT LOCATED ADJACENT THE FIRST AND BEING ANGULARLY DISPOSED THERETO FOR CONTINUOUSLY RECEIVING SAID COMBINED FIBROUS WEB FROM SAID FIRST ENDLESS BELT AT ONE END THEREOF AND RETURNING SAID FIBROUS WEB TO SAID FIRST ENDLESS BELT AT THE OPPOSITE END THEREOF AND FOR MOVING SAID COMBINED FIBROUS WEB A PREDETERMINED LATERAL DISTANCE TO FORM A PLURALITY OF CONVOLUTIONS WITH EACH CONVOLUTION LATERALLY DISPLACED FROM THE PRECEDING CONVOLUTION WHEREBY THE FIBERS OF ONE CONVOLUTION ARE BROUGHT INTO CLOSE ADJACENCY TO OTHER FIBERS OF OTHER CONVOLUTIONS, SAID OTHER FIBERS ORIGINALLY HAVING SPACED CROSSWISE AND LENGTHWISE POSITIONS IN SAID COMBINED FIBROUS WEB WITH RESPECT TO THE FIRST MENTIONED FIBERS; AND MEANS FOR SEPARATING A PREDETERMINED WIDTH FROM THE PLURALITY OF CONVOLUTIONS OF SAID LATERALLY DISPLACED COMBINED FIBROUS WEB TO FORM A DOUBLED AND LEVELLED SLIVER RIBBON COMPRISING FIBERS IN CLOSE ADJACENCY BUT DERVED FROM DIFFERENT CONVOLUTIONS AND FROM SPACED CROSSWISE AND LENGTHWISE POSITIONS IN SAID COMBINED FIBROUS WEB.