US3119152A - Methods and apparatus for doffing and drafting fibrous webs - Google Patents

Methods and apparatus for doffing and drafting fibrous webs Download PDF

Info

Publication number
US3119152A
US3119152A US9969A US996960A US3119152A US 3119152 A US3119152 A US 3119152A US 9969 A US9969 A US 9969A US 996960 A US996960 A US 996960A US 3119152 A US3119152 A US 3119152A
Authority
US
United States
Prior art keywords
fibers
web
point
fiber
movable
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US9969A
Other languages
English (en)
Inventor
Kalwaites Frank
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Johnson and Johnson
Original Assignee
Johnson and Johnson
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority to NL274230D priority Critical patent/NL274230A/xx
Application filed by Johnson and Johnson filed Critical Johnson and Johnson
Priority to US9965A priority patent/US3098265A/en
Priority to US9969A priority patent/US3119152A/en
Priority to CH192661A priority patent/CH403578A/de
Application granted granted Critical
Publication of US3119152A publication Critical patent/US3119152A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • D—TEXTILES; PAPER
    • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
    • D01G—PRELIMINARY TREATMENT OF FIBRES, e.g. FOR SPINNING
    • D01G15/00—Carding machines or accessories; Card clothing; Burr-crushing or removing arrangements associated with carding or other preliminary-treatment machines
    • D01G15/02—Carding machines
    • D01G15/12—Details
    • D01G15/46—Doffing or like arrangements for removing fibres from carding elements; Web-dividing apparatus; Condensers

Definitions

  • KALWAITES METHODS AND APPARATUS FOR DOFFING AND DRAFTING FIBROUS WEBS Filed Feb. 19, 1960 4 Sheets-Sheet 1 INVENTQR "F' Fawx K14 kI/A/I'ES ATTORNEY Jan. 28, 1964 F. KALWAITES METHODS AND APPARATUS FOR DOFFING AND DRAFTING FIBROUS WEBS Filed Feb. 19, 1960' 4 Sheets-Sheet 2 Tia-z!- BY flmma A441- ATTORNEY Jan. 28, 1964 F. KALWAITES 3,119,152
  • the present invention relates to the dofiing or removing of textile fibers from movable carrier surfaces, such as the rotatable doffing cylinder of a card, for example, and more particularly is concerned With the removing of fibers from such surfaces and the-simultaneous drafting or drawing thereof to increase the fiber orientation in the long or machine direction of the resulting web containing these fibers.
  • the individual fibers are initially separated and formed into a fibrous web on a card.
  • This web in which the individual fibers are relatively aligned generally in the long direction of the web, is doffed or removed from the dofiing cylinder of the card, usually by a rapidly reciprocating dofier comb, and then further processed, as desired or required, such as by being drafted or drawn whereby the orientation of the fibers in the long direction of the web is increased.
  • the fiber orientation or alignment thereof is usually increased to a limited extent say, up to 70 or 75% and, therefore, subsequent drafting or drawing operations are required to increase the orientation or alignment of the individual fibers in the Web above such percentages. These subsequent drafting or drawing operations have had so much orienting or aligning of the fibers to do to produce the desired highly oriented web that difficulties in these operations have ensued.
  • individual fibers in a web are removed from the doffing cylinder of a card, or from some other rotatable or movable carrier surface, in a manner which simultaneously increases the fiber orientation in the resulting web.
  • a more highly oriented web is obtained and subsequent operations to increase the orientation and alignment of the fibers are minimized and thereby greatly facilitated and expedited.
  • the apparatus of the said copending application does not lend itself to the same general effectiveness in dofiing and drafting these fibers as it does for the longer fibers. This is due largely to the absence of the same physical control over the shorter fibers during the drafting operation as the machine exercises upon the longer fibers.
  • the present invention provides novel methods and apparatus particularly adapted for dofiing and simultaneously drafting fibrous webs containing a wide range of fiber lengths; either the shorter fibers of from /2 inch to 1 inch in length, the longer fibers up to about 2 /2 inches or more in length, or mixtures of such fibers.
  • the machine exercises positive physical control over the longer fibers and substantially the same physical control over the shorter fibers. The extent of physical control over the shorter fibers by the machine of the present invention has not been achieved by other machines insofar as is known.
  • Simultaneous doifing and drafting may be obtained in accordance with the present invention by initially providing a carded fibrous Web on a movable carrier surface, such as the dofiing cylinder of a card, and then positioning a relatively smooth-surfaced endless flexible belt adjacent to but spaced from the clotting cylinder by a predetermined distance, whereby the carded fibrous web is transferred from the doifing cylinder to the movable belt.
  • This movable belt being flexible, may be trained over relatively small diameter rods or bars or equivalent elements positioned in close proximity to the movable fiber-carrying surface so that the moving belt approaches that surface at any desired angle, and rapidly departs therefrom at any other angle as desired.
  • 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 first movable or fiber-carrying surface and to draw the fibers in positive fashion therefrom.
  • the movable belt may be made to draw the fibers away from the fiber-carrying surface 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.
  • Such a more highly oriented web is more suitable for further processing, as desired or required.
  • the fibrous web or layer which is processed to form the products of this invention may contain natural or synthetic, vegetable, animal or mineral fibers such as cotton, silk, Wool, vicuna, mohair, alpaca, flax, ramie, jute, etc.; synthetic or man-made fibers such as the cellulosic fibers, notably cuprammonium, viscose or regenerated cellulose fibers; cross-linked cellulosic fibers such as Corval and Topel; cellulose ester fibers such as cellulose acetate (Celanese) and cellulose tri-acetate (Arnel); the saponified cellulose ester fibers such as Fortisan and Fortisan-36; the polyamide fibers such as nylon 420, nylon 6 (polycaprolactam), nylon 66 (hexarnethylene diamine-adipic acid), nylon 610 (hexa methylene diamine-sebacic acid), nylon 11 (ll-amino undecanoic acid-Rilsan); protein fibers
  • 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. If desired, the fibrous layer may have fibers other than those of textile length added thereto.
  • the amount of such other fibers to be added will depend upon the properties desired in the final products to be produced from the fibers, and upon how close to the fiber-carrying surface the fibers can be gripped for doffing. The amount may vary from about 1 or 2% by weight up to about 100% by weight, but will usually be preferably less than about 50% by weight. These other fibers may be of papermaliing length, which extend from about inch in length down to about ,1 of an inch or less in length, which shorter fibers normally are not used in conventional methods of producing fibrous webs.
  • these short paperrnaking fibers are the natural cellulosic fibers such as woodpulp and wood fibers, cotton linters, cotton hull shavings fibers, mineral fibers such as asbestos, glass, rocl-zwool, etc., or any of the hereinbefore-mentioned natural or synthetic fibers in lengths less than about /2 inch and down to about A of an inch or less.
  • 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 are preferred. Where greater opacity or greater covering power is desired, special fiber deniers of down to about /4 or even about /2 may be employed. Where desired, deniers of up to about 5.5, 6, 8, 1O, 15, or higher, may be used.
  • the minimum and maximum denier 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 fibrous web or layer of starting material on the dofiing cylinder may be varied within relatively wide limits above a predetermined minimum 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 doffing cylinder, 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.
  • web weights on the dofiing cylinder of from about 60 grains per square yard to about 175 grains per square yard are contemplated.
  • lighter web weights are desired for the final Web of highly aligned fibers, such as up to 1800 grains, for example, several individual webs of highly aligned fibers produced in accordance with this invention may be com-- bined into a laminated structure to obtain the desired weight.
  • the product of one doffing and drafting machine may be folded, doubled, tripled, etc., on itself to reach the heavier Weight, or the products from a plurality of dofiing and drafting machines may be used and the individual products stacked or laminated for a similar purpose.
  • FIGURE 1 is a simplified, fragmentary, schematic view in elevation showing the general principles of operation of the present invention
  • FIGURE 2 is a simplified, fragmentary, schematic view in elevation showing in greater detail the structure and operation of one embodiment of the dofiing and drafting mechanism of the present invention
  • FIGURE 3 is a simplified, fragmentary, schematic view of a l-inch strip of Web disposed upon the surface of the dofiing cylinder, extending across the width thereof at approximately the four oclock position in FIGURE 1, showing a few illustrative individual fibers as seen by 4. one looking at the surface of the doffing cylinder from the right hand side of FIGURE 1;
  • FIGURE 4 is a showing of the same l-inch strip of web upon the surface of the doffing cylinder at approximately the eight oclock position in FIGURE 1, showing the same illustrative individual fibers as are seen in FIG- URE 3 except that in this figure they are shown as seen by one looking at the surface of the doffing cylinder from the left hand side of FIGURE 1;
  • FIGURE 5 is a simplified, fragmentary, schematic view in elevation, very similar to FIGURE 2, but showing in detail the dotfing and drafting of an illustrative fiber;
  • FIGURE 6 is a simplified, fragmentary, schematic view in elevation showing the structure and operation of another embodiment of the dofiing and drafting mechanism of the present invention.
  • a conventional textile card is used and comprises a conventional rotatable main card cylinder It) which is used to provide for the normal carding of the fibers fed to the card whereby the fibers are disentangled and the bunches or tufts of fibers are separated more or less into individual fibers.
  • the initial attenuatin. of the fibers into a generally aligned condition takes place on the surface of the main cylinder 16 and the individualized fibers are sparsely spread over the rotating surface in an amount weighing but a few grains per square yard.
  • the individual fibers which were hooked upon the pins of the card cylinder are pulled off those pins by the teeth of the dofiing cylinder and are deposited on the surface of the doffing cylinder in U- shaped or hook-shaped fashion.
  • One end of the fiber lies in a leading or forwardly-directed position on the dofiing cylinder, and normally the trailing portion is hooked reversely to form a U-shaped configuration, but occasionally it meanders rearwardly in various shapes and random configurations.
  • the forward direction of movement of the dofiing cylinder corresponds to the downward direction in the drawing.
  • the lengths of the leading leg portion and trailing leg portion vary from some shapes in which the trailing leg portion is very small and constitutes only a minor fraction of the total length of the individual fiber to other shapes in which the trailing leg portion is almost as long as the leading leg portion and thus constitutes almost 50% of the total length of the individual fiber.
  • the trailing portion merely meanders rearwardly, the configurations are almost infinite and defy any specific classification. In substantially all configurations, however, it is noted that one end of the fiber extends forwardly more than the other portions of the fiber, and that portion of the fiber is thus the so-called leading end portion to be discussed in greater detail hereinafter.
  • FIGURE 4 shows the same strip of fibrous web engaged with the pins of the doffing cylinder as is shown in FIG- URE 3. However, the web is now shown at approximately the eight oclock position on the dofling cylinder of FIGURE 1. FIGURE 4 may be considered to be the result obtained by flopping FIGURE 3 over.
  • FIGURE 4 one observes the same illustrative individual fibers as are contained in FIGURE 3, except that they are now in the position occupied by them after they have moved through substantially one-third of a revolution of a doffing cylinder from their positions shown in FIGURE 3.
  • the main cylinder and the dofiing cylinder 12 are conventional; the main cylinder being about 50 inches in outside diameter and about 45 inches Wide; and the doifing cylinder being about 26 or 27 inches in outside diameter and also about 45 inches wide.
  • the main cylinder and the doifing cylinder are both covered with conventional card clothing, comprising a large number of pins which constitute protuberances acting together as a carrier surface, adapted to have fibers entwined with the protuberances in slidable engagement therewith.
  • the top portions of the pins of the doifing cylinder are slanted in the opposite direction from the direction in which the leading free ends ofthe fibers slant which are intertwined with the pins as described above.
  • the latter direction is the direction of linear movement of the surface of the doffing cylinder.
  • a doffing and drafting mechanism 20 Immediately adjacent the doffing cylinder 12, and approximately at the position where the fibrous web formed thereon is conventionally removed by the usual textile doffing comb, there is located a doffing and drafting mechanism 20.
  • the dotfing md drafting mechanism 20 comprises a stationary, angular nose bar 22 having an elongated nose portion 24 and a reinforcing base portion 26.
  • the reinforcing base portion 26 strengthens and steadies the nose portion 24- but 'may be omitted when the nose portion 24 is sufficiently strong and steady by itself.
  • the nose bar 22 is adjustable so that the nose portion 24 thereof can be controllably and accurately positioned at any desired angular re lationship, or with any desired clearance, with respect to the peripheral surface of the dofi'lng cylinder 12.
  • the point of closest proximity of the nose portion 24 to the peripheral surface of the dofiing cylinder 12 is referred to herein as the pickoff point P and is of importance for reasons to be made clear hereinafter.
  • An endless, flexible idofiing and drafting belt 3h is passed around the nose port-ion 24 and is then passed under a movable pressure member--in the embodiment under discussion a rotatable, pressure nip roll 32-which is adjustably positioned with respect to the nose portion 24 and the peripheral surface of the doffing cylinder 12. Due to the elongated configuration of the nose portion 24-, the rotatable nip roll 32 is able to be positioned not only very close to the nose portion 24 but also to the adjacent pick-off point P on the peripheral surface of the doffer cylinder 12.
  • the nip roll 32 is able to make initial contact with the flexible dofiing and drafting belt 30 at a point relatively close to the pick-off point P, as measured along the flexible belt 30.
  • This point of first contact between the rotatable nip roll 32 and the doffing and drafting belt 30 is referred to herein as the nip poin N and is of importance for reasons to be made clear hereinafter.
  • the region through which the endless doffing and drafting belt passes which begins at about the pick-off point P in FIGURE 2 and extends around the nose portion 2 to nip point N may be characterized as the dofiing Zone. it will be noted that a portion of the guide means or nose bar 22 is located within the dofiing zone.
  • guide means or nose bar 22 acts to position dotting and drafting belt 30, as it travels through the doffing zone, in close'proximity to the carrier surface constituted of the pins on doffing cylinder 12.
  • the guide means positions belt 36 in pressing contact with the movable pressure member or nip roll 32.
  • the guide means presses the endless belt into first contact with the movable pressure member or nip roll 32 at nip point N, which is in closeproximity to the moving carrier surface 12, and as a result exposed free ends of individual fibers engaged by the carrier surface are grasped by the bite formed by the nip roll 32 and the endless belt 30.
  • the dofiing and drafting belt 3t is so guided in its approach to the pick-off point that the space lying between the belt and the doffing cylinder gradually narrows down over a considerable arcuatev area to a relatively narrow throat. In this way, any fibers which protrude more or less from the Wire-toothed surface of the doffing cylinder are gradually pressed against such wire teeth into a more compacted, denser web.
  • the nip roll 32 is adjustably pressed against the movable doffing and drafting belt 30 and has a surface linear velocity which is substantially equal to the surface linem velocity of the belt.
  • the pressure of the nip roll 32 against the movable belt is such that a definite arcuate length is formed in which the nip roll contacts the belt and in which fibers positioned therebetween are pressed over a substantial portion of their lengths. This increased length of pressing contact on the fiber is vastly superior to the pressing contact obtained by using two cylindrical tangentially positioned rolls having only a rolling point contact on the fibers whereby slippage is possible and probable.
  • this arcuate contacting region is concavely curved as compared to the convexly curved region where the fibers pass over the nose bar 22. It is believed that such configuration assists in the grasping of the fibers properly.
  • the downstream end of the arcuate contacting region may be identified as point N.
  • the region through which endless belt 30 passes which extends from point N to .N may be characterized as the gripping zone.
  • the arcuate path followed by drafting belt 36 through the gripping zone has a center of curvature C which coincides with the axis of nip roll 32.
  • the path followed by the belt in passing through the gripping zone has a corresponding radius of curvature, which is measured from point C to the surface of roll 32.
  • the dofiing and drafting belt 30 after passing under the rotatable nip roll 32 passes upwardly over a driving rotatable guide roll 40.
  • the driving rotatable guide roll 40 may be driven by any suitable driving means such as an electric motor (not shown).
  • the doffing and drafting belt 30 is then directed downwardly and passes over an adjustable, rotatable, guiding and tensioning roll 42.
  • the mounting of the rotatable, guiding and tensioning roll 42 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 39 passes around a rotatable guide roll 44 and is then directed upwardly over the nose portion 24 of the nose bar 22. As can be seen, the belt is endless and moves in a continuous cycle, as described.
  • the operation of the dofiing and drafting mechanism is as follows.
  • the carded web which is formed on the doffing cylinder is carried on the periphery thereof around to the pick-oft point P.
  • the elongated nose portion 24 positions the dofling and drafting belt 30 with the desired clearance from the periphery of the doffing cylinder 12 and the fibers are doffed or removed from the doffing cylinder and positioned on the dotting and drafting belt 30 by adhesion and perhaps by electrostatic attraction.
  • the leading ends of the fibers of the web on the dotfing cylinder 12 are picked off first and are carried from the pick-off point P to the nip point N and are then pressed against the dofiing and drafting belt 30 by the rotatable nip roll 32.
  • the individual fibers are drawn or drafted forwardly and slid off the teeth or needles of the doifing cylinder 12 whereby they are straightened and aligned with a considerably higher degree of orientation on the dotfing and drafting belt 30.
  • 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 1. Ratios higher than 4 to 1 are utilizable within the principles of the present invention, with values of up to to 1 or higher being of use in special cases.
  • the nose portion 24 of the nose bar 22 so positions the dofling and drafting belt 30 that the clearance between the belt and the dotfing cylinder 12 is maintained within closely controlled limits.
  • this clearance should be as small as physically possible and should be on the order of from about 0.005 inch to about 0.150 inch for cotton or rayon fibers of typical lengths.
  • a narrower range of from about 0.007 inch to about 0.040 inch is preferred.
  • the rotatable nip roll 32 is also adjustably positioned in such a way that the clearance between its peripheral surface and the peripheral surface of the dofiing cylinder 12 is a small as physically possible and is in the range of from about 0.005 inch to about 0.150 inch for the types of fibers just referred to. Within the more commercial aspects of the present invention, such clearance is preferably in the range of from about 0.007 inch to about 0.040 inch for fibers of the type indicated.
  • the maximum distance between the pick-off point and the nip point should be not more than about one-half the staple length of the fibers being carded. More specifically, it has been found that the distance from the fiber pick-01f point to the nip point should be from about 20% to about 50% of the average staple length of the fibers. Within the more commercial aspects of the present invention, however, from about 30% to about 50% of the average staple length has been found preferable. These percentages will be discussed in greater detail hereinafter and the scientific basis for such values will be made clear.
  • the distance from the fiber pick-off point to the nip point may be decreased even further by providing a narrower and more elongated nose portion 24.
  • the requirements for adequate physical strength of the nose portion prevent the making of the nose portion too thin.
  • the wear and tear on the clotting and drafting belt increases as it is flexed more sharply over narrower nose portions whereby its service life is drastically reduced. It has been found that a nose portion with a controlling end portion having a radius of from about inch to about W inch is satisfactory for best over-all performance characteristics when cotton or rayon fibers of typical lengths are involved.
  • Nose portion 24 has a center of curvature C;., as shown in FIGURE 2.
  • the corresponding radius of curvature is measured from point Cp to the end of the curved portion of the guide means or nose bar 22 around which the endless dofiing and drafting belt 30 moves as it passes through the dofiing zone into the gripping Zone.
  • the radius of curvature for the portion of the nose bar 22 located in the dofiing zone is less than the radius of curvature of the path followed by the endless belt 30 from point N to point N through the gripping zone makes the distance from nip point N to pick-off point P smaller than has heretofore been achievable in the prior art.
  • the distance between the nip point N and pick-off point P is reduced by the fact that the center of curvature C is closer to the carrier surface of the dofiing cylinder 12 than is the center of curvature O
  • the materials of which the doffing and drafting belt and nip roll are made are of importance. Substantially any suitable material is satisfactory including metal, leather, rubber, plastic, fabric, film, etc.
  • the surface of the roll be made of a harder material than the belt, to improve the grip on the fibers during drafting. If incorrect materials are used, the nip roll will tend to slide on the dofiing and drafting belt and the advantages of the present invention are lost.
  • the diameter of the nip roll is also a factor to be considered. If the nip roll is too small, there is a tendency for the fibers to lap or wrap around the nip roll rather than to stay with the dofling and drafting belt. If the nip roll, however, is made too large, the distance between the pick-off point P and the nip point N becomes too large and the advantages of the present invention are lost.
  • the diameter of the nip roll is in the range of from about inch to about 3 inches for cotton or rayon Commercially, the range for such fibers has been found to be preferably between 1 /1 inches and 2% inches.
  • the individual fibers of the fibrous web on the dofiing cylinder are dofied at the pick-off point P, are gripped between the dofiing and drafting belt 30: and the rotatable nip roll 32 at the nip point N and, due to the higher linear velocity of the drafting belt 39, are simultaneously drawn forwardly at a greater speed, and are drafted.
  • the fibers on the doifing cylinder are for the most part positioned thereon in a hooked or U-shaped configuration with the open end of the U facing forwardly in the direction of movement of the doffing cylinder.
  • FIGURE 3 and also in FIGURE 4 A simplified, diagrammatic showing of how fibers having a U shape or other configuration such as just described may be distributed in a typical portion of a card web is given in FIGURE 3 and also in FIGURE 4.
  • the following description although specific with respect to using a U-shaped fiber as the illustrative fiber nevertheless is generically applicable to all fibers of the web.
  • the lengths of the legs of the u shaped fibers are of all varying lengths, depending to a large extent upon the manner in which they are transferred from the main card cylinder and deposited on the dofiing cylinder.
  • the two legs of a U-shaped fiber will rarely, if ever, be exactly equal and consequently in practically every case one leg of a U-shaped fiber is ahead of the other leg.
  • this leading leg of the U-shaped fiber (or the leading end of a non-U- shaped fiber) which is first positioned on the flexible movable belt 30 and first gripped by the pressure nip roll 32 and drawn forwardly in positive fashion.
  • FIGURE 5 illustrates four illustrative fibers: the first two fibers and F) as they approach the pick-off point P; the third (F), as it is being pulled forwardly by the doffing and drafting belt 30 and the nip roll 32 and aligned thereby with its trailing portion still being restrained on the pins of the doffing cylinder; and the fourth (f after it has been drafted and aligned and is moving forwardly over roll All.
  • Fibers f and f would occupy substantially the position shown at the extreme right end of FIGURE 4, when observed by one looking at the doffing cylinder from the left hand side of FIGURE '1 or FIGURE 5 Since the movable belt 3% and nip roll 32 have a higher surface linear velocity than the dofling cylinder, as soon as they grasp the leading end of a fiber they immediately begain to draw the leading leg forwardly at an increased velocity and, since the base or trailing portion of the U- shaped fiber is hooked around a wire or a tooth on the dofiing cylinder, the shorter leg of the U-shaped fiber is gradually pulled or slid around that point or tooth whereby it is ultimately drawn out as straight as possible, considering its inherent physical characteristics, and so positioned on the drafting belt. In this way', the individual fibers are straightened or aligned in the machine direction to a very high degree and considerably higher than previously possible.
  • a nip point to pick-0E point distance of less than 50% of the average fiber length is, of course, preferred, and
  • FIGURE 1 there is shown a trumpet 52 which is used to form the fibrous web into a conventional cylindrical sliver which passes between pressing rollers 54 and 56 and is then led forwardly by conveyor or other delivery means for further processing.
  • Other devices than a trumpet 52 could be employed, or the fibrous web could be further processed in web form or in other shapes, as desired, and the trumpet 52 is employed to illustrate merely one of many devices which could be used.
  • FIGURE 6 Another embodiment of the dofiing and drafting mechanism of the invention is shown in FIGURE 6.
  • the movable pressure member of the embodiment described in detail above (rotatable nip roll 32) is re placed by the endless belt 6% Endless belt 6%) passes around guide means 62 and adjustable rotatable guide and tensioning roll 64. Endless belts 3t ⁇ and 6%) move at substantially the same rate of speed.
  • guide rolls 4t 42 and 44 of the embodiment of FIGURE 6' are the same as in the embodiment previously described.
  • guide means or nose bar 22, with its nose portion 24, is the same as in the previous embodiment.
  • the material of which the endless belts 3t and 69 are formed should be or" different hardness, in order to produce the best grip on the fibers in the gripping Zone extending from point N to N.
  • the guide means 62 may be provided with openings 65 to assist in dissipating the frictional heat produced by passage of the endless belt 69 over the guide means.
  • Other suitable lubricating and cooling means may also be employed to diminish and dissipate this heat of friction.
  • the guide means 62 has a radius of curvature greater than the radius of curvature of the portion of the nose bar 22 located in the doffing zone, with the attendant adv-antage of reduction in the distance from the nip point N to the pick-off point P.
  • the radius of curvature of the guide means 62 is measured from its face which is in contact with endless belt 6% to center of curvature C
  • the radius of curvature of the nose portion 24 of guide means 22 is measured from the curved surface at the end of the nose portion to center of curvature C
  • the radius of curvature of the guide means 62 is constant throughout the gripping zone. It may be desired to provide a curvature that is not constant for the path followed by .is substantially Zero.
  • the path will still have a general curvature which can be approximated by drawing an arc through point N at one end of the gripping zone, another point near the middle of the zone, and point N at the other end of the gripping zone.
  • the general radius of curvature thus approximated must be greater than the radius of curvature of the curved portion of the guide means 22 within the doifiug zone.
  • the movable pressure member of the dofling and drafting mechanism of this invention is a rotatable .nip roll or a rotatable endless belt, it is desirable to make the gripping zone at least as long as the longest fiber being doffed and drafted. A gripping zone of this length insures positive control at the forward end of each fiber as it is straightened out while being slid off the fiber carrying surface.
  • the gripping zone formed by the pressing contact of that member against the endless doffing and drafting belt should have as large a radius of curvature as is consistent with the remainder of the mechanism. The more gradual the curve of the path followed by the doffing and drafting belt through the gripping zone, the less the tendency will be toward fouling by the adhering of fibers to the movable pressure member.
  • the starting fibrous material as delivered by the dotting cylinder to the dotting and drafting belt, is a 45 inch-wide card web of viscose rayon staple fibers, weighing about 75 grains per square yard and containing fibers having a substantially uniform length of about 1 inch and a denier of about 1 /2.
  • the peripheral surface linear velocity of the dofiing cylinder is yards per minute.
  • the doffing cylinder is covered with metallic clothing having 11 points per inch with 2.6 wraps per inch of cylinder.
  • the fibrous web is transferred to a flexible movable dotfing and drafting belt which passes over a nose bar and is accurately spaced 0.005 inch from the peripheral surface of the doffing cylinder.
  • the dofi'ing and drafting belt has a peripheral surface linear velocity of 22 yards per minute. This is equivalent to a 1.1 to 1 ratio (belt to dofiing cylinder).
  • the nose portion of the nose bar is about inch thick and the radius of the controlling end is about inch.
  • the belt then passes under a nip roll having a diameter of 2 inches.
  • the distance from the pick-off point the doffing cylinder to the nip point on the nip roll, as measured along the flexible belt, is about /2 inch, or 50% of the average staple length of the fibers.
  • the degree of fiber orientation of the fibrous web on the dofling cylinder is about 70%; the degree of fiber orientation of the drafted web is about 85%.
  • the web is well suited for further processing and ultimate spinning into yarn.
  • Example 11 The starting fibrous material, as delivered by the clotting cylinder to the dofiing and drafting belt, is a 45 inch-wide card web of viscose rayon staple fibers, weighing about grains per square yard and containing fibers having a substantially uniform length of about 1% inches and a denier of about 1 /2.
  • the peripheral surface linear velocity of the doffing cylinder is 20 yards per minute.
  • the doffing cylinder is covered with metallic clothing having 11 points per inch with 26 wraps per inch of cylinder.
  • the fibrous web is transferred to a flexible movable doffing and drafting belt which passes over a nose bar and is accurately spaced 0.007 inch from the peripheral surface of the dofiing cylinder.
  • the dofiing and drafting belt has a peripheral surface linear velocity of 25 yards per minute. This is equivalent to a 1.25 to 1 ratio (belt to dofiing cylinder).
  • the nose portion of the nose bar is about 5 inch thick and the radius of the controlling end is about inch.
  • the belt then passes under a nip roll having a diameter of 2 inches.
  • the distance from the pick-off point on the dofiing cylinder to the nip point on the nip roll, as measured along the flexible belt, is about /2 inch, or 40% of the average staple length of the fibers.
  • the degree of fiber orientation of the fibrous web on the doffing cylinder is about 70%; the degree of fiber orientation of the drafted web is about The web is well suited for further processing and ultimate spinning into yarn.
  • the starting fibrous material as delivered by the dotting cylinder to the doffing and drafting belt, is a 45 inch-wide card web of viscose rayon staple fibers, weighing about grains per square yard and containing fibers having a substantially uniform length of about 1% inches and a denier of about 1 /2.
  • the peripheral surface linear velocity of the dotting cylinder is 20 yards per minute.
  • the dofiing cylinder is covered with metallic clothing having 11 points per inch with 26 wraps per inch of cylinder.
  • the fibrous web is transferred to a flexible movable dotling and drafting belt which passes over a nose bar and is accurately spaced 0.010 inch from the peripheral surface of the dofling cylinder.
  • the dofling and drafting belt has a peripheral surface linear velocity of 30 yards per minute. This is equivalent to a 1.5 to 1 ratio (belt to dotfing cylinder).
  • the nose portion of the nose bar is about /4 inch thick and the radius of the controlling end is about ,5; inch.
  • the belt then passes under a nip roll having a diameter of 2 inches.
  • the distance from the pick-off point on the doifing cylinder to the nip point on the nip roll, as measured along the flexible belt is about /2 inch, or 32% of the average staple length of the fibers.
  • the drafted web has a weight of about 67 grains per square yard and a much higher degree of fiber orientation than that present in a similar fibrous web prepared from similar materials on similar equipment but removed from the dofiing cylinder by a conventional doffing comb.
  • the degree of fiber orientation of the fibrous web on the dofiing cylinder is about 70%; the degree of fiber orientation of the drafted web is about 92%.
  • the web is well suited for further processing and ultimate spinning into yarn.
  • Example IV The starting fibrous material, as delivered by the dofiing cylinder to the dofiing and drafting belt, is a 45 inch-wide card web of cotton staple fibers having an average staple length of about 1 inch and weighing about 100 grains per web is about 90%.
  • the peripheral surface linear velocity of the dofling cylinder is yards per minute.
  • the domng cylinder is covered with metallic clothing having 11 points per inch with 26 wraps per inch of cylinder.
  • the fibrous web is transferred to a flexible movable drafting belt which passes over a nose bar and is accurately spaced 0.015 inch from the peripheral surface of the doffing cylinder.
  • the drafting belt has a peripheral surface linear velocity of 30 yards per minute. This is equivalent to a 1.5 to 1 ratio (belt to doffingcylinder).
  • the nose portion of the nose bar is about A inch thick and the radius of the controlling end is about inch.
  • the belt then passes under a nip roll having a diameter of 2 inches. The distance from the pick-off point on the doffing cylinder to the nip point on the nip roll, as measured along the flexible belt, is about inch or 37% of the average staple length of the fibers.
  • the drafted web has a weight of about 67 grains per square yard and a much higher degree of fiber orientation than that present in a similar fibrous web prepared from similar materials on similar equipment but removed from the doffing cylinder by a conventional dofiing comb.
  • the degree of fiber orientation of the fibrous web on the doffing cylinder is about 70%; the degree of fiber orientation of the drafted The web is well suited for further processing and ultimate spinning into yarn.
  • Example V The starting fibrous material, as delivered by the doifing cylinder to the drafting belt, is a inch-wide card web weighing about 100 grains per square yard and containing by weight of cotton staple fibers having an average length of about 1% inches and 50% by weight of viscose rayon staple fibers having a length of about 19 inches and a denier of about 1 /2.
  • the peripheral surface linear velocity of the doffing cylinder is 20 yards per minute.
  • the doffing cylinder is covered with metallic clothing having 11 points per inch with 26 wraps per inch of cylinder.
  • the fibrous web is transferred to a flexible movable drafting belt which passes over a nose bar and is accurately spaced 0.012 inch from the peripheral surface of the doffing cylinder.
  • the drafting belt has a peripheral surface linear velocity of 30 yards per minute. This is equivalent to a 1.5 to 1 ratio (belt to doffing cylinder).
  • the nose portion of the nose bar is about A inch thick and the radius of the controlling end is about inch.
  • the belt then passes under a nip roll having a diameter of 2 inches. The distance from the pick-off point to the nip point is about inch or about 40% of the average staple length of the fibers.
  • the drafted web has a weight of about 67 grains per square yard and a much higher degree of fiber orientation than that pres ent in a similar fibrous web prepared from similar materials on similar equipment but removed from the deffing cylinder by a conventional dofiing comb.
  • the degree of fiber orientation of the fibrous web on the doffing cylinder is about 70%; the degree of fiber orientation of the drafted web is about 90%.
  • the web is well suited for further processing and ultimate spinning into yam.
  • Apparatus for dofiing a web of fibers from a rotatable surface and substantially simultaneously drafting the same which comprises:
  • guide means for gradually bringing said movable surface into a position of close proximity to said rotatable cylindrical surface whereby the protruding ends of the fibers contact the movable surface at a point well in advance of a hereinafter-mentioned pick-off point, said guide means including stationary means contacting said movable surface substantially only at said pick-off point;
  • (d) means within said closed path to drive said movable surface at a linear speed greater than the linear speed of the rotatable cylindrical surface whereby the ends of the fibers contacting the movable surface are gradually inclined forwardly and drawn forwardly in the direction of movement of the movable surface as they approach the hereinafter-mentioned pick-off point, said fibers bcing gradually pressed by said movable surface against an arcuate area of the rotatable cylindrical surface to form a more compacted web thereon having increased fiber-to-fibcr cohesion, said movable surface being brought into such close proximity to said rotatable cylindrical surface as to provide for fiber transfer from said rotatable cylindrical surface to said movable surface at a pick-off point which is the point of closest proximity of said movable surface to said rotatable cylindrical surface; and
  • said driving means in direct contact with said movable surface driving the same and drawing said leading free ends of the individual fibers away from said pick-off point with a linear speed greater than the surface linear speed of the rotatable cylindrical surface, While maintaining substantially the uniformity of the fiber weight distribution of the fibrous web and while restraining the trailing ends of said fibers by sliding engagement with said rotatable cylindrical surface and by the increased fiber-to-fiber cohesion, whereby the individual fibers are straightened and their degree of orientation in the long direction of the web is increased.
  • Apparatus for doffing a web of fibers from a rotatable dofiing cylinder and substantially simultaneously drafting the same which comprises:
  • guide means for gradually bringing said movable doffing and drafting belt into a position of close proximity to said rotatable doffing cylinder whereby the protruding ends of the fibers contact the movable dofiing and drafting belt at a point well in advance of a hereinafter-mentioned pick-off point, said guide means including stationary means contacting said movable dofling and drafting belt substantially only at said pick-olf point;
  • (d) means within said closed path to drive said movable doffing and drafting belt at a linear speed greater than the linear speed of the rotatable dolfing cylinder whereby the ends of the fibers contacting the movable doffing and drafting belt are gradually inclined forwardly and drawn forwardly in the direction of movement of the movable dofiing and drafting belt as they approach the hereinaftermentioned pick-off point, said fibers being gradually pressed by said movable doffing and drafting belt against an arcuate area of the rotatable doffing cylinder to form a more compacted web thereon having increased fiber-to-fiber cohesion, said movable doffing and drafting belt being brought into such close proximity to said rotatable dofiing cylinder as to provide for fiber transfer from said rotatable dofiing cylinder to said movable doffing and drafting belt at a pick-off point which is the point of closest proximity of said movable dofiing and
  • said driving means in contact with said movable dofiing and drafting belt driving the same and drawing said leading free ends of the individual fibers away from said pick-off point with a linear speed greater than the surface linear speed of the rotatable doffing cylinder, while maintaining substantially the uniformity of the fiber weight distribution of the fibrous web and while restraining the trailing ends of said fibers by sliding engagement with said rotatable doffing cylinder and by the increased fiber-to-fiber cohesion, whereby the individual fibers are straightened and their degree of orientation in the long direction of the web is increased.

Landscapes

  • Engineering & Computer Science (AREA)
  • Textile Engineering (AREA)
  • Preliminary Treatment Of Fibers (AREA)
US9969A 1960-02-19 1960-02-19 Methods and apparatus for doffing and drafting fibrous webs Expired - Lifetime US3119152A (en)

Priority Applications (4)

Application Number Priority Date Filing Date Title
NL274230D NL274230A (enrdf_load_stackoverflow) 1960-02-19
US9965A US3098265A (en) 1960-02-19 1960-02-19 Methods for doffing and drafting textile fibers
US9969A US3119152A (en) 1960-02-19 1960-02-19 Methods and apparatus for doffing and drafting fibrous webs
CH192661A CH403578A (de) 1960-02-19 1961-02-17 Verfahren und Einrichtung zum Abnehmen und Strecken von Faserfloren

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US9969A US3119152A (en) 1960-02-19 1960-02-19 Methods and apparatus for doffing and drafting fibrous webs

Publications (1)

Publication Number Publication Date
US3119152A true US3119152A (en) 1964-01-28

Family

ID=21740769

Family Applications (1)

Application Number Title Priority Date Filing Date
US9969A Expired - Lifetime US3119152A (en) 1960-02-19 1960-02-19 Methods and apparatus for doffing and drafting fibrous webs

Country Status (3)

Country Link
US (1) US3119152A (enrdf_load_stackoverflow)
CH (1) CH403578A (enrdf_load_stackoverflow)
NL (1) NL274230A (enrdf_load_stackoverflow)

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3296663A (en) * 1963-07-03 1967-01-10 Whitin Machine Works Arrangement for guiding the web at the discharge side of the doffer in carding machines
US3708831A (en) * 1970-05-04 1973-01-09 Kimberly Clark Co Method and apparatus cross-drafting fibrous nonwoven webs
US3983273A (en) * 1973-05-09 1976-09-28 Bonded Fibre Fabric Limited Carding machines
EP0155656A3 (en) * 1984-03-22 1986-08-27 Spinnbau Gmbh Apparatus for introducing a nap into a roll system
US5700254A (en) * 1994-03-31 1997-12-23 Kimberly-Clark Worldwide, Inc. Liquid distribution layer for absorbent articles
RU2161213C1 (ru) * 1999-12-06 2000-12-27 Санкт-Петербургский государственный университет технологии и дизайна Устройство для съема прочеса
US20050140057A1 (en) * 2003-12-30 2005-06-30 Kimberly-Clark Worldwide, Inc. Apparatus and method for deforming sheet material
WO2006051294A1 (en) * 2004-11-11 2006-05-18 Super Spinning Mills Limited A drafting assembly and method of drafting a web
WO2013144748A1 (en) * 2012-03-28 2013-10-03 Lakshmi Machine Works Limited Web drafting assembly of carding machine

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1422581A (en) * 1921-05-26 1922-07-11 Laurency Guillaume Clement Process of and apparatus for preparing textile fibers for spinning
US1862542A (en) * 1930-02-13 1932-06-14 Laurency Guillaume Clement Carding engine
FR1127219A (fr) * 1955-07-06 1956-12-11 Système détacheur-paralléliseur de voile de carde

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1422581A (en) * 1921-05-26 1922-07-11 Laurency Guillaume Clement Process of and apparatus for preparing textile fibers for spinning
US1862542A (en) * 1930-02-13 1932-06-14 Laurency Guillaume Clement Carding engine
FR1127219A (fr) * 1955-07-06 1956-12-11 Système détacheur-paralléliseur de voile de carde

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3296663A (en) * 1963-07-03 1967-01-10 Whitin Machine Works Arrangement for guiding the web at the discharge side of the doffer in carding machines
US3708831A (en) * 1970-05-04 1973-01-09 Kimberly Clark Co Method and apparatus cross-drafting fibrous nonwoven webs
US3983273A (en) * 1973-05-09 1976-09-28 Bonded Fibre Fabric Limited Carding machines
EP0155656A3 (en) * 1984-03-22 1986-08-27 Spinnbau Gmbh Apparatus for introducing a nap into a roll system
US5700254A (en) * 1994-03-31 1997-12-23 Kimberly-Clark Worldwide, Inc. Liquid distribution layer for absorbent articles
US5876388A (en) * 1994-03-31 1999-03-02 Kimberly-Clark Worldwide, Inc. Liquid distribution layer for absorbent articles
RU2161213C1 (ru) * 1999-12-06 2000-12-27 Санкт-Петербургский государственный университет технологии и дизайна Устройство для съема прочеса
US20050140057A1 (en) * 2003-12-30 2005-06-30 Kimberly-Clark Worldwide, Inc. Apparatus and method for deforming sheet material
US7198742B2 (en) 2003-12-30 2007-04-03 Kimberly-Clark Worldwide, Inc. Apparatus and method for deforming sheet material
WO2006051294A1 (en) * 2004-11-11 2006-05-18 Super Spinning Mills Limited A drafting assembly and method of drafting a web
US20090094793A1 (en) * 2004-11-11 2009-04-16 Super Spinning Mills Limited Drafting assembly and method of drafting a web
CN101061266B (zh) * 2004-11-11 2010-06-16 超级纺织厂有限公司 牵伸组件及纤维网牵伸方法
WO2013144748A1 (en) * 2012-03-28 2013-10-03 Lakshmi Machine Works Limited Web drafting assembly of carding machine

Also Published As

Publication number Publication date
NL274230A (enrdf_load_stackoverflow)
CH403578A (de) 1965-11-30

Similar Documents

Publication Publication Date Title
US3079746A (en) Fasciated yarn, process and apparatus for producing the same
US4321789A (en) Process for spinning of core/mantle yarns and yarn products
US3380131A (en) Method and apparatus deflecting and drawing tow
EP0174112B1 (en) Method of handling a sliver
US3787930A (en) Process for randomizing card webs
US3119152A (en) Methods and apparatus for doffing and drafting fibrous webs
GB1270935A (en) Improvements relating to the spinning of textile yarns
US2468827A (en) Electrostatic control of fibers
GB748434A (en) Improvements in and relating to apparatus for processing filamentary tows
GB1361172A (en) Composite spun yarn
US3983273A (en) Carding machines
US3636693A (en) Method and apparatus for forming yarn
US3481004A (en) Apparatus for forming a sliver of textile fibres
US3230584A (en) Methods and apparatus for making strands, rovings, yarns and the like
US4070811A (en) Machine for spinning textile fibers
US3345700A (en) Apparatus for producing slivers
US2181535A (en) Production of sliver
US3334483A (en) Method of making direct spinner novelty yarn
US3370326A (en) Method and apparatus for forming a web of highly parallelized textile fibers
US2773297A (en) Process and apparatus for making yarn and fabric
US3283366A (en) Apparatus for removing a fibrous web from a rotatable surface
US3373461A (en) Method for carding fibers
US4067181A (en) Fiber-disintegrating unit for a spinning machine
US4926626A (en) Flamme fancy yarn manufacturing method and apparatus
US3195187A (en) Methods and apparatus for producing fibrous structures