US2705692A - Laterally extensible polyoriented nonwoven fabric and method of producing same - Google Patents

Description

April 5, 1955 DE WITT R. PETTERsoN 2,705,692 LATERALLY EXTENSIBLE POLYORIENTED NONWOVEN FABRIC AND METHOD OF' PRODUCING SAME Filed April 7, 1952 2 sheets-'sneak ws" www QTTORNEY April 5, 1955 DE wn-T R. PETTERsoN LATERALLY ExTENsIBLE POLYORIENTED NoNwovEN FABRIC AND METHOD oF PRoDucING SAME Filed April 7, 1952 2 Sheets-Sheet 2 INVENTOR OEM/VWF.' Dern-PSOM BY ATTORNEY United Sees aan o LATERALLY EXTENSIBLE PLYORIENTED NGN- ;IVYVEN FABRIC AND METHOD 0F PRODUC- De Witt R. Patterson, West Springfield, Mass., assignor to Chicopee Manufacturing Corporation, a corporation of Massachusetts Application April 7, 1%52, Serial No. 280,968 17 Claims. (Cl. 154-101) The invenwith and nonwoven substantially in the continuously from the sheet-forming machine.

` he bonding operation by which such a web is converted into a fabric may be accomplished in one of several different ways. One Way is to impregnate the web over its entire width with various well-known bonding Another spaced, binder extending continuously '(hereinp islands of binder arranged lapping columns parallel to each other and to the direction of fiber orientation, to form a uniform, staggered pattern such that every line within the overlap web.

` Where the individual islands are physically separated from each other by an appreciable distance but are direction. `A fabric of this type wherein the binder areas are annular or ringlilce in configuration is characterized by lateral extensibility to an outstanding degree.

When an island bonded web of high lateral extensibility is stretched cross wise, it expands on the lazy tongs principle with a major reorientation of the originally parallelized fibers, and the formation of a netlike or reticular structure. This reorientation is accompanied by what may be termed a serpentine effect, i. e., with the generation of a series of parallel, sinuous or serpentine bands of fibers each band being the substantial refiection or mirror image of adjacent bands on either side with the bands united into a reticular structure by binder areas located at their points of apposition.

Dimensional stability may be given to the resulting ICC stretched fabric by rebonding it in its laterally extended con.d1tion. Depending in part on the degree to which the basic fabric was stretched before rebonding, the ratio of differs markedly from the corresponding ratio of the bric from which it was made. Indeed, if the basic or starting fabric is stretched to a substantial degree (e. g., 170% of its original width) before rebonding, the normal ratio of long-to-cross tensile strength may actually be reversed. It is thus possible to convert a non-isotropic, oriented fabric into a pseudo-isotropic fabric, whose foregoing type, the binder areas constitute, in effect, the pivotal points of the azy tong parallelograms, while the bands of fibers connecting the pivotal points form the four sides of the collapsible parallelograms. Due to the far greater strength of the fiber bands relative to that of the binderareas which hold the serpentine bands tol`n such fabrics, rupture is thereof the binder areas.

principle strength and tear resistance cornths general type.

' bias lay nonprovide means whereby the in.- strength of the fibers may be utilized to a substantially greater degree in producing a nonwoven fablric that is laterally extensible on the lazy tongs princip e.

Another object is a nonwoven fabric of the character described wherein substantially more bers are utilized in the lazy tong structure.

A still further object is to provide that is inherently stronger and more resistant to tear than a similar nonwoven fabric which tation with the serpentine action.

A more specific object is to provide a fabric of the character described wherein the pivotal points of the lazy tongs are inherently the strongest links of the fabric, being formed, ing separated sinuous fiber bandsV at their points sition, but by binder areas joining intersecting at their points of intersection and therefore by the intersecting fibers of the respective bands.

Another object is a gation in either the long or cross direction,

trollable degrees.

Still another object is to provide means by which to reduce the degree of cross-drafting that is necessary in order to reverse the normal long-to-cross tensile strength ratio in the manufacture of a pseudo-isotropic nonwoven fabric by crossedrafting a prebonded nonwoven fabric and then rebonding the stretched fabric in its extended condition.

A further object is an improved pseudo cross-lay larninated fabric made from the pseudo-isotropic product described above.

Another object is to provide a simple method for producing fabrics of the foregoing type.

Other objects and advantages 'of the present invention will become apparent as the description progresses in such drawings:

Figs. 1, 3 and 5 are, respectively, plan views of fragments of three different fabrics made from a two-ply di-oriented base web bonded in accordance with one embodiment of the invention, the fabrics being in their relaxed unextended state; A p I Figs. 2, 4 and 6 are plan views of the fabrics of Figs.

Y bands in each avancee l, 3 and 5, respectively, the fabrics being in their extended or stretched condition;

Figs. 7 and 9 are, respectively, plan views of frag* ments of two different fabrics made from a three-ply trioriented base web bonded in accordance with the present invention; k

Figs. 8 and l0 are plan views of fragments of the fabric of Figs. 7 and 9, respectively, the fabrics being in their extended or stretched condition.

Referring now particularly to Figs. l and 2 of the drawing, one embodiment of the invention comprises two series of parallel, substantially straight bands of fibers, generally .indicated by the reference characters 10, i2, 14, 16 and 1S. Each band in each series is composed predominantly of substantially parallelized, unspuii textile fibers (e. g., 20) that are oriented with the axis of the band in which they lie. The two series of parallel bands are obliquely disposed with respect to each other at the angles a and from the horizontal, so that the bands of one series obliquely intersect the bands of the other series. The intersecting bands are held together at their points of intersection by discrete areas of binder (22, 24, 26, 28, 30, 32, 34 and 36) infused localiy into the body of the bands at selected points of intersection. Preferably a multiplicity of unspun and unbonded (i. e., free) textile fibers (e. g., 3S and 40) are disposed b..- tween, and substantially oriented with, each pair of the of the two series.

The resulting fabric may be likened to a collapsible lazy tong gate in its partly condition, the intersecting bands of fibers acting as linkages of the gate, the binder areas at selected points of intersection forming the pivotal points of the,lazy tong. In any event, regardless of the aptness or inaptness of the analogy suggested, the resulting fabric is laterally extensible when subjected to extensional stress in a direction parallel to either axis of the parallelograms formed by the intersection of the two series of parallel (fiber bands. in the extended condition, the fabric of Fig. l assumes the condition shown in Fig.. 2.

A modification of the fabric of Figs. l an 2 is shown 'in Figs. 3 and 4. In this case the binder areas, generally indicated by the reference character 42, are arranged in parallel courses (extending horizontally across the page) and also in parallel but non-overlapping columns (extending vertically on the page). The net effect of this rionstaggered arrangement of binder areas is a pair of lazy tong mechanisms, the pivotal points of one of the pairs (e. g. 44) being disposed in the centers of the parallelograms of the other (e. g. 46, 48, 50, 52).

In Figs. 5 and 6, another modification is shown. In this case the binder areas are arranged in staggered courses, as in Figs. l and 2, but are much closer together so that the net ecct is a series of three lazy tong mechanisms, the p'votal points (e. g., 54 and 56) of two of them being disposed in the parallelograms of the third (e. g., S8, 60, 62 and 64).

From a comparison of the three fabrics illustrated in Figs. l-6, it will be apparent that the fabric of Figs. l and 2 will have the greatest amount of free fiber between the fiber bands forming the parallelograms, while the fabric of Figs. 5 and 6 will have the least free fiber. The fabric of Figs. 3 and 4 will, of course, have an intermediate amount of free fiber.

it will also be apparent from inspection of Figs. l to 6 that the basic web from which these three embodiments are made comprises a sheet of loosely associated textile fibers that are predominantly oriented in two principal directions, one of the primary directions of orientation being obliquely disposed with respect to the other. Thus the basic web utilized in these examples may be termed a di-oriented web, i. e., a web having two primary axes of orientation as indicated by the arrows in Figs. l to 6.

One method of forming simply to ply together two such a dii-,oriented web is webs each consisting of substantially oriented textile fibers, with their respective axes 'of orientation obliquely disposed with respect to each other; the bonded di-oriented web may therefore be termed a bias lay" fabric as distinguished from a cross lay fabric. The smaller of the two pairs of angles formed by the intersection of the respective axes of orientation of the two plies may lie between, say, 10 and 80. Preferably, however, the angle (or) between the orientation axes of the respective webs should be in the unextended or collapsed` `-upon the geometry of the binder pattern,

lower range of, say, 10 to 45, corresponding Yto the angular relation of the linkages in a collapsible gate in its relatively unextended or collapsed condition; this gives the fabric greater capacity for lateral extension. The proportion of oriented fibers in the individual plies may vary within wide limits ranging from about 75% (as in a normal card web that has not been drafted and is not under tension) to as high as about 95 to 100% (as in the case of a highly drafted card web maintained in a state of tension in the long direction).

Referring now to Figs. 7 to l0, the base web in these examles is a tri-oriented web, formed, for example, by plying together three different plies, each ply being sublstantially oriented in a given direction, the orientation direction of each ply being obliquely disposed with re spect to the orientation directions of the other two plies. ln such a tri-oriented web, interesting fiber reorientation effects are obtainable upon cross drafting after island bonding. The nature of these effects will depend in part particularly on whether the parallel columns of binder areas (i. e., vertically on the page of the drawing) are overlapping or nonoverlapping with respect to each other.

ln Figs. 7 and 8, the individual binder areas 72 ,74, 76, 78, 80, 82, and 84 are annular in configuration and are arranged in parallel, nonoverlapping courses (i. e., horizontally on the page) and also in parallel, nonoverlapping columns (i. e., vertically on the page). The fiber orientations are indicated by the three crossed arrows. When the fabric of Fig. 7 is stretched in the direction generally across the three axes of orientations, thefabric exhibits the same lazy tong action as in the case of the fabrics of Figsjl to 6 that were made from the di-oriented webs, assuming the condition shown in Fig. 8. in addition, the fabric of Fig. 7, upon cross drafting to form thefabric of Fig. 8 develops punckered fibers 86, i. e., fibers that are bent out of the plane of the .fabric proper. These puckered fibers originate in part with the fibers which originally were oriented in the vertical direction and which connect binder areas in the same column (e. g., 72, 76 and 80).

ln Figs. 8 and 9, he base tri-oriented web, formed, for example, from three plies, each ply being substantially oriented 1n a given direction, each orientation direction being oblique with respect to the orientation directions of the other two webs, as indicated in the three crossed arrows. However, in this example the individual binder areas are arranged in parallel nonoverlapping courses, and in parallel but overlapping columns. When the fabric of Fig. 8 is stretched crosswise, the collapse of the lazy tong structure produces not only free fibers and puckered fibers 92, but also serpentine fibers 94 and 96. The latter or serpentine fibers were generated by the serpentine effect from the fibers that originally were oriented in the vertical webagain consists of a vdirection and lay in the overlapping zone of the overlapping vertical columns, connecting opposite sides of adjacent resin areas (e. g., 72, 74, 76) in overlapping columns. Thus, the lazy tongs formed by coaction of the serpentine bands with the resin areas located at their points of apposition, are reinforced by lazy tongs formed by intersecting, substantially straight bands of parallelized fibers bonded together at their points of intersection.

it will thus be apparent that the nonwoven fabric of the present invention comprises an island bonded web composed of two or more plies of oriented fibers, the` directions of orientation of the respective plies being inclined obliquely with respect to each other. The multi-ply web is bonded into a self-sustaining fabric by discrete areas of binder infused locally into the body of the web at selected, uniformly spaced points of intersection of the fibers. The binder areas coact with the oriented fibers form a plurality of interconnected c ollapsible polygons, whose pivotal points are the discrete binder areas and whose sides consist of bundles of substantially paraliel, straight (nonsinuous) fiber bands con necting the binder areas.

The base web may consist of either two or more plies. Where the base web consists of three or more plies whose individual fiber orientations are obliquely disposed with respect to each other, in addition to the normal lazy tong effects of cross drafting, the serpentine effect may also be obtained. It is thus possible to produce laterally extensible fabrics which expand on the lazy tongs principle but which are inherently stronger and more resistantto 6 tear than the laterally extensible fabrics produced by the 2. A nonwoven fabric comprising an island bonded serpentine effect alone. web composed of at least two plies of oriented textile n carrying the invention into practice the conventional fibers whose directions of ber orientation are obliquely binder media and island bonding operations of the prior disposed with respect to each other, said fabric being art may be used Typical procedures and binder media 5 characteiized by high capacity for extension on the lazy of the general type applicable to the practice of the present tongs principle when subjected to extenzsional stress in a invention include those disclosed in the Joshua Goldman direction generally transverse to the fiber orientations of Patent 2,039,312 or in the Joseph Goldman Patent 2,407, said plies. 543 or in the Esther Goldman Patent 2,545,952. Such 3. A nonwoven fabric comprising a web composed of operations and media, being well known and convenl at least two plies of oriented textile fibers whose directions tional, need not be described herein, since reference may of fiber orientation are obliquely disposed with respect readily be made to the prior art including the patents to each other, said web being bonded into a self-sustainmentioned. ing fabric by a multiplicity of discrete areas of binder l prefer to use island bonding wherein the lateral suradapted to coact with the fibers in said plies to form face covered by the binder areas does not substantially l a plurality of interconnected, geometric figures that are exceed about 35% of the total lateral surface of the web. collapsible when the web is subjected to extensional stress This condition insures attainment of lateral extensibility in a direction generally transverse to the liber orientations and also desirable textile-like properties of softness, drape of said plies. and loft. However some of the advantages of the iiiven- 4. A nonwoven fabric comprising a web composed of tion may be attained to a degree with line bonding. For at least two plies of oriented textile fibers whose directions example, the di-or tri-oriented webs may be bonded by of fiber orientation are obliquely disposed with respect imprinting thereon a diamond grid binder pattern conto each other, said web being bonded into a self-sustain sisting of two series of parallel continuous lines of binder ing fabric by a multiplicity of discrete areas oi bindet saine angles of inclination as the angles of orientation to formwith the oriented fibers in each of said plies of the plies of the base web Island bonding, however, is a plurality of interconnected, collapsible polygons whose preferable, particularly the type of island bonding illuspivotal points are formed by said binder areas and whose trated in the drawings herein. sides are formed by bundles of substantially parallel fibers After the bonding operation, the bonded fabric may be connecting said binder areas. cross drafted to expand the fabric on the lazy tongs prin- 5. A nonwoven fabric comprising a web composed of ciple. Such cross drafting produces a peach fuzz effect at least two plies of oriented textile berswhose directions from non-oriented fibers, especially those lying in a direcof fiber orientation are obliquely disposed with respect to tion substantially parallel to the horizontal axis of the each other, said web being bonded into a self-sustaining lazy tong parallelograms. In addition, as mentioned fabric by a multiplicity of discrete areas of binder infused above, in the case of the tri-oriented webs, cross drafting locally into the body of the web and adapted to form pi oduces the serpentine effect if the discrete binder areas with the oriented fibers in the respective plies at least aie arranged in parallel, overlapping columns that are two series of parallel, substantially straight obliquely parallel to one of the three axes of fiber oiientation of disposed fiber bands, the bands of one parallel series the three ply base web. intersecting the bands of the other parallel series, said fter cross drafting, the laterally extended fabric may binder areas being located at the points of intersection be used as such, if desired, or it may be rebonded, followof said bands. ing in general the process described above in connection 6- A HOD-WOVeri fabric haVihg el relic-Iller Structure with the manufacture of a pseudo-isotropic fabric, Since and comprising two series of parallel, substantially straight the cross strength of the unextended, polyoriented fabric` bands 0f textile fibers, the bands of the two parallel series is greater than an otherwise identical fabric wherein the being diSpOSedin different bu. parallel planes and at an bers are substantially oriented in a single direction, the oblique intersecting angle with respect to each other, said amount of cross drafting before rebonding that is necesblhd being United tcgether by fllSCrete areas 0f binder sary to reverse the normal long to cross tensile strength lbcally infused ihtO the bOCly Of bOth SerieS Of baDdS at ratio is correspondingly reduced. their overlying angles of intersection.

`The cross drafted product of the present invention, 7. The fabric of claim 6 wherein each of said bands either before or after rebonding, may be plied with an COITlPrScS e multiplicity 0f Substarliielly PralleliZcd, Uhunbonded web of either singly or polyoriented fibers, to SPUH teXtile liberS- produce alaminated structure that can be bonded together 8- The fabric 0f claim 6 Wherclh multiplicity 0f to form a product corresponding to the above mentioned substantially parallelized, unspun textile fibers is disposed pseudo Cross lay, If desired, @f Coursey th@ bcndd bwell, and SubSlalliliy Oriented With, 636i] Of Said polyoriented web of the present invention, in either its bands in each 0f Said Series. extended 0r unextended condition, may be laminated 9. A HOB-WOVEN fabric having l letiCtllal Structure with other fabrics or materials, such as a non-woven and. Comprising tWO Series Of Parallel, Sllbsflntlally fabric of the same or different structure or design. Straight bands 0f libere, the barllS 0f cach Ser ieS being The term polyoriented as used herein is understood diSPOSeCl ih different but Parallel Planes, cec-h bend irl to include the di-oriented as well as the tri-oriented webs each Series Comprising a multiplicity 0f Slibtatltially and the fabrics made therefrom. The term textile fibers perellclized UhSPllh tcXtilc fibers, the bands 0f @he Paralincludes fibers of any type that are as long as the conlel Series Overlying and bcilg Obllflllely inclined With venn'onal textile fibers which am Capable of being Spun respect to the bands of the other parallel series and being into yarn and woven into clot Generally speaking, this united together by discrete areas of binder infused locally includes fibers whose average length is about one-half lhtO lliebOCly cf bcth bHhClS it their cycrlyirlg PGihtS 0f inch or longer. intersection, said bands coacting with said binder areas avng now described my invention in detail and illusto form a multiplicity of interconnecting parallelograms trated the preferred manner in which it may be carried that??? collapsible 0h the lazy tongs Principle When the into practice, it will be readily apparent to those skilled fabric 1S subjected t0 eXtehSiOrll StreSS in a direeton in the art that many variations, applications, modifications Parallel t0 clthfl dltgollals 0f Said Parallele/gramsan extensions of the basic principles involved may be The fabric 0f, clalm 9 Whcrclh e mtlllillclty 0f made Without departing from its spirit or Scope- Thus, substantially parallelized unspun textile fibers is disposed for example, although I have illustrated the invention between, and Substantially Oriented With, each 0f Said in conneciton with diand tri-oriented webs (both of bands 1n each of said series. which I term polyoriented), it is apparent that the ll- A mcthod Which comprises Plylhg atleSttWO Webs principles involved are applicable to webs made from Qf Substantially Orlchtcfl teXtilefibcrS, With their respecmore than three plies, each oriented obliquely with respect llVe Orientation dlreclchs obliquely dlSPOSeCl With reto the others. l therefore intend to be limited only in SPect t0 each ether, whereby to form a composite web accordance with the appended patent claims, having two primary directions of fiber orientation that I Claim; are oblique to each other; and then bonding said 1. A nonwoven fabric comprising a bonded web Corncomposite web to convert it into a selfesustaining nonposed of at least two plies of oriented textile fibers, the woven fabric. directions of orientation of the respective plies being inl2. A method which comprises plying at least two clined obliquely with respect to each other. webs of substantially oriented textile fibers, with their 14. The method of claim l2 wherein said fabric is respective axes ,smetto sash. ether,

-then cross drafted, in order to expand said fabric on the lazyrtongs principle and to effect a uniform reorientation of a substantial proportion of the fibers oriented in either of said primary orientation directions.

.'15. The. method lof claim 12 wherein said fabric is order to expand said fabric on the lazy l CII tongs principle and effect uniform reorientation of a substantial proportion of the fibers oriented primary'orientation directions; and the cross drafted fabric is then 'dimensionally stabilized in its expanded State. 4 16. A method which comprises plying at least two webs of substantially oriented textile fiber with their respective primary orientation directions obliquely disposed with respect to each other; converting said plied webs into an island bonded fabric by bonding the same with a discontinuous binder pattern uniformly disposed over not more than 35% of the lateral surface of said plied webs; cross drafting the island bonded fabric in order to expand the same on the lazy tongs principle with substantially uniform reorientation of fibers originally oriented in either of said primary orientation directions; and then rebonding the cross drafted fabric to dirdnensionally stabilize .said fibers in their reoriented conition.

r17. A method which comprises continuously forming at least two separate webs of substantially parallelized or oriented textile fibers, the webs being of substantially equal width and moving along separate paths whose axes are lat erally displaced from, but converging toward, each other at an oblique angle; bringing said convergmg web into face-to-face relationship, with one web overlying the other with their corresponding edges in substantial alignment laminated web comprising at least two plies whose primary orientations are obliquely disposed with .respect posite web lnto an island bonded discontinuous binder pattern covering not subweb with a stantially more than about 35 to each other; converting the comfabric by bonding the of the total lateral surface of the web; cross drafting the island bonded fabric after the binder pattern thereof has set, in order to effect further reorientation of the fibers, and then dimensionally stabilizing the cross .drafted fabric by rebonding the cross drafted fabric.

References Cited in the le of this patent UNITED STATES PATENTS Angier Sept. 9, 1924 Woodward Nov. 10, 1931 Goldman May 5, 1936 Hurst et al Sept. 22, 1936 Goldman Sept. 10, 1946 Gurwick Sept. 10, 1946 Baxter Feb. 2l, 1950 Vogt July 4, 1950 Budden Sept. 26, 1950 Goldman Mar. 20, 1951 Goldman May l, 1951 Modigliani Nov. 6, 1951 FOREIGN PATENTS Great Britain Nov. 12, 1942 Belgium Dec. 30, 1950

Claims (1)

1. A NONWOVEN FABRIC COMPRSING A BONDED WEB COMPOSED OF AT LEAST TWO PLIES OF ORIENTED TEXTILE FIBERS, THE DIRECTIONS OF ORIENTATION OF THE RESPECTIVE PLIES BEING INCLINED OBLIQUELY WITH RESPECT TO EACH OTHER.

Images