US2705686A - Laterally extensible non-woven fabric - Google Patents

Description

April 5, 1955 1. s. Nl-:ss Erm.. 2,705,686

LATERALLY EXTENSIBLE NON-WOVEN FABRIC Filed May 7, 1952 3 Shee'tS-Sheet l April 5, 1955 l. s. NEss ETAL 2,705,686

LATERALLY EXTENSIBLE NON-WOVEN FABRIC I Filed May 7, 1952 3 Sheets-Sheet 2 April 5 1955 s. NEss ErAL 2,705,686

LATERALLY EXTENSIBLE NoN-WOVEN FABRIC Filed May '7, 1952 3 Sheets-Sheet y3 United States Patent O 2,705,686 LATERALLY EXTENSIBLE NON-WOVEN FABRIC Application May 7, 1952, Serial No. 286,482 2 Claims. (Cl. 117-38) The present invention relates to textile fabrics and their manufacture. More particularly, it is concerned with socalled nonwoven fabrics, i. e., fabrics produced from textile bers without the use of conventional weaving or knitting operations. Although not necessarily limited thereto, the invention is of primary importance in connection with oriented nonwoven fabrics composed of unspun textile fibers, the major proportion of which are substantially parallelized or oriented predominantly in one direction.

napkins; surgical dressings; casket liners; or disposable table napkins, hand towels, diapers, the like.

Nonwoven fabrics are conventionally manufactured at the present time by producing a more or less tenuous web of loosely associated and then subjecting the web or sheet to a bonding operation to anchor or bond` the individual fibers together.

These over-al1 applications as textile fabrics.

It has also been known to print nonwoven webs with continuous straight or and hand of the material woven textile fabric. However, the Joshua Goldman type of product in the cross direction is characterized by 2,705,686 Patented Apr. 5, 1955 relatively low elongation properties, low degree of elasticity, and a low energy absorption t o break. For these product disclosed in the Esther Goldman Patent 2,545,952. Such spot bonded products are flexible when the fabric is folded upon itself. However, flexibility has been attained at the sacrifice of other desirable properties.

tile properties of hand, loft and softness.

enerally speaking, the object of the present invention is to provide a nonwoven fabric that obviates the foregoing disadvantages. xpressed armatively, one of the objects of the invention is the provision of a nonwoven fabric characterized by the desirable properties of "spot bonded fabrics but substantially free of the undesirable properties thereof.

more specific object is the provision of a nonwoven fabric characterized by the following combination of properties:

l. High cross-elongation;

2. Good cross-strength;

3. Relatively high energy absorption to break in the cross-direction; and

4. Excellent textile-like properties such as softness or hand, flexibility or drape, and the three-dimensional appearance or loft characteristic of woven fabrics.

A further object is a nonwoven fabric that is additionally characterized by an inherent capacity to develop a more pronounced loft, softness and drape when stretched in the crosswise direction.

Another object is the provision of au oriented nondowny-like surface.

Still another object is a nonwoven fabric characterized by a pronounced 10ft, drape and hand; a uniformly open, netor lace-like rcticular pattern, and a uniform downylike surface.

scale, diagrammatically showing portions of the of Figs. l and l-A when'uniforrnly stretched or extended direction of ber orientation;

Figs. 3 and 3-A are similar views, also on an enlarged scale, diagrammatically showing portions of the fabric of Figs. 1 and l-A, after t e fabric has been uniformly stretched or Fig. 4 is a plan View, approximately full scale, showing the geometry of the binder pattern involving annular binder areas in accordance with a preferred embodiment of the present invention;

Figs. and 6 are similar views, also approximately full scale, showing an alternative binder pattern involving, respectively, hexagonal-shaped rings and ovalshaped rings in accordance with othef embodiments of the present invention.

In accordance with the present invention, a web of oriented textile fibers containing a substantial but minor proportion of non-oriented fibers is bonded into a fabric by means of a novel binder pattern that may conveniently be characterized as lazy tong multiannulate bonding. Such a binder pattern is composed of a multiplicity of discrete, physically separated, cyclic or ringlike binder areas infused locally into interrelated as to coact with each other and with the non-oriented fibers of the web to form lazy tong parallelograms whose diagonals are, respectively, parallel and transverse to the primary fiber orientation of the web. The resulting fabric exhibits a high degree of lateral extensibility, acting on the lazy tongs principle.

The base web from which our laterally extensible fabric is produced consists of a sheet of loosely associated textile fibers that are, in the main, predominantly parallelized or substantially oriented in one direction. Such a web may be formed by using a conventional cotton or wool card or a garnetting machine. In handling the web formed by either of these conventional sheet forming devices, it is preferable to avoid, insofar as possible, those operations (e. g., long drafting) that tend substantially to increase the degree of liber parallelization, and desirable to employ those operations (e. g., across drafting) which tend to reduce somewhat the degree of fiber parallelization. The optimum web in accordance with the present invention desirably contains a substantial but minor portion of non-oriented fibers in addition to the predominantly oriented fibers which constitute the major component of the sheet. When such a web is examined microscopically it is evident that very few, if any, of the fibers are 100% straight and 100% parallel, in the precise Euclidean sense of these terms. Nevertheless, When such a web is viewed macroscopically (e. g., with the naked eye), it will clearly be evident that it is comprised in the main of fibers oriented predominantly in one direction and also that it contains a substantia but minor proportion of non-oriented or random fibers more or less loosely interfelted or interlaced with the oriented fibers.

In bonding such a web according to the present invention, discrete, physically separated binder areas are utilized, each area consisting of an inherently elastic, compressible, closed linear figure or curve. The closed figure may be polyhedral (e. g., octagonal), cyclic (e. g., oval), ringor doughnut-shape in configuration and preferably but not necessarily should have a single point of symmetry. In any event, all such cyclic structures, whether perfectly symmetrical or substantially so, will hereinafter be termed annular. Each discrete, annular area may be likened to an atoll or coral reef island comprising, so to speak, a small lagoon of unbonded lengths of parallelized fibers entirely surrounded by binder, the atoll itself being an island in a sea of otherwise unbonded lengths of fibers.

The atoll analogy suggested above is helpful in describing the geometry of the binder area. However, like all analogies, it has its limitations: it is not useful in explaining the dynamics or kinematics of the system when an annulate bonded oriented web according to our invention is subject to extensional stress. Accordingly, in the ensuing discussion, the atoll analogy will be used at times in describing the system in a state of rest, while entirely different analogies will be suggested in describing the system in motion. It should be clearly understood, however, that the present invention is in no way dependent upon the aptness or inaptness of any analogies that are herein suggested for the purpose of relating the invention to more familiar concepts.

Referring now particularly to Fig. l, the over-all binder pattern of the present invention comprises a multiplicity of discrete, physically separated, inherently elas tic, annular binder areas or atolls 10, 12, 14, 16, 18, 20, 22 and 24 infused locally into the body of an oriented web containing a substantial but minor proportion (e. g., 15% or 40%) of randomlv disposed fibers in addition to the oriented or parallelized fibers constituting the major component (e. g., 60% to 85%) of the web. In order to attain otherwise desirable textile-like properties and cross-extensibility in the bonded fabric, the total lateral surface of the binder areas should cover not substantially more than about 35% of the total lateral surface of the web.

The binder areas, atolls or islands are uniformly spaced from each other preferably in parallel courses or rows (R, S, T, U and V) extending across the web in a direction preferably transverse to the direction of orientation of the fibers. The binder areas in one course (e. g., T) should be positioned in staggered relationship with respect to corresponding areas in the courses immediately above and below it (e. g., S and U) and so dimensioned and positioned relative to each other that the transverse width (D) of any given binder area or island (e. g., 18) is substantially equal to the transverse distance (a) between the adjacent-most binder areas (e. g., 24 and 16; 22 and 20) in the rows of courses (e. g., T and V) immediately above and below the area in question. This is most conveniently accomplished by disposing annular binder areas of equal diameter not only in horizontal courses or rows (R. S, T, U and V) extending across the oriented fibers of the web, but also in a series of contiguous columns (M, N and O) that are substantially parallel to each other and to the direction of fiber orientation as shown in Fig. 1.

By virtue of the foregoing relationship between binder areas, each areais separated from every other area by fiber lengths that are otherwise substantially unbonded. Nevertheless, as shown in Fig. l, because of the nonoriented fibers in the base web, each annular area (e. g., 18) is hinged, jointed, or articulated with respect to the two adjacent-most areas (e. g., 16 and 24, 20 and 22) in each of the adjacent courses, (e. g., T and V), i. e., in the courses immediately above and immediately below the area in question. Articulation between corresponding areas in adjacent courses is effected by lengths of non-oriented fibers interconnecting the binder areas in question, The right hand side of any given binder area (e. g., 18) will thus be jointed or articulated with the left hand sides of the closest areas (e. g., 16 and 20) in the courses (T and V) immediately above and immediately below it. The join or articulation consists of a bundle or group of non-oriented fibers (e. g., 31 and 32). On the left hand side of the given binder area (e. g., 18) the relationship of the fibers to the given area and to the adjacent-most atolls immediately above and below it will, in effect, be the mirror image or refiection of the relationship on the right hand side of the same area. In other words, a bundle or group of non-oriented fibers (e. g., 34 arid 35) will interconnect the left side of the given area (18) with the right side of the two areas (22 and 24) immediately above and below it and closest to that side. The middle portion of the given binder area will be connected by a bundle of parallelized or oriented fibers (e. g., 38) to the closest areas (14 and 21) in the second courses (S and W) above and below it. Thus, the third bundle (38) comprising parallelized fibers hingedly interconnects corresponding areas (14 and 21) in alternate courses, passing through the central portion of each binder area.

In order to understand the dynamics or kinematics of this binder arrangement, a wholly different analogy may be helpful. When an annulate bonded web as described above is stretched in a crosswire direction, its action is suggestive of a parallel-motion mechanism or parallelogram-type device familiar as lazy tongs, collapsible gates or the pantograph device utilized in drafting. Referring to Fig. 1, in the web of the present invention, the nonparallel fibers (e. g., 30, 32, 34 and 36) interconnect the binder areas (e. g., 14, 16, 18 and 24) in three adjacent courses (S, T and U) to form a parallelograrn', the fibersr act as the linkages in a collapsible gate acting on the lazy tong principle, while the annular binder areas (14, 16, 18 and 24) act, in effect, as the pivotal joints holding the links of the parallelogram together. As the web is stretched in the cross direction the bundle of parallel or oriented fibers (38) interconnecting corresponding areas (14 and 18) in alternate courses (S and U) tends to pucker. This puckering of oriented fibers (38) connecting diagonally opposed points (14 and 18) in the parallelogram (14, 16, 18 and 24) tends to restrain further extension of the collapsible gate and to restore the extended collapsible gate to its original unextended position.

Regardless of the aptness of the analogy suggested above,

the individual annular binder areas and the fibers comprising the web are so positioned and interrelated as to interact in a novel manner when the web is stressed in a crosswise direction. By virtue of this mode of interaction, an extraordinary combination of properties is attainable in the bonded web, including among other fibers forming the sides of the collapsing parallelogram may rupture (e. g., 44' in Fig. 2): when the fabric is permitted to relax, the ends formed by rupture of such fibers tend to bend out of the plane of the fabric, producing a napped or downy-like peach fuzz effect (e. g., 36 in Fig. 3). In the third place, those non-oriented fibers which happen to lie along the lengthening diagonal parallelogram (e. g., 40, Fig. 1-A; 40', Fig. 3-A) will also be ruptured. The ends of these broken fibers also tend to move out of the rming a uniform nap or down.

The puckered oriented fibers, (e. g., 38, 38 and 38;

Figs. l and 1-A, 2 and 2-A, and 3 and 3-A, respectively) plus the ruptured non-oriented fibers (e. g., 36 and 42 in Figs. 2 and 2-A; 36" and 42 in Figs. 3 and 3-A) impart a high degree of loft and softness to the resultant fabric, rendering it especially attractive in applications where these properties are important.

Referring again to Figs. 1 and 2, the number of nonoriented fibers ized; and partly upon the relative ratio or random fibers to oriented fibers. Thus an increase in the proportion of random fibers to oriented fibers w' d to increase the cross strength of the bonded Accordingly, we prefer to use a base web containing a substantial although minor proportion of non-oriented fibers. For that reason it is desirable to use a base web that has been cross drafted before being bonded.

The elongation of the fabric is influenced island distances (Y and C, Fig. l) and the dimensions of Energy absorption to rupture is indicative of the amount of work necessary to rupture the fabric and is approximately equal to one-half the breaking load times the elonenergy absorption capacity. The present invention p ermits substantially increasing the properties discussed above.

Development of a uniform lace-like or reticular pattern obtained by uniformly stretching a web bonded in actances.

the extent of openness, The more extendible, the more open the network.

The qualitative textile fabric properties of flexibility, rape, softness, and three-dimensional effect, or loft are enhanced by increasing the inter-resin area distances (Y and C) and by increasing the ratio of the internal diameter (d) to Generally speaking, desirable textile degree only if subbinder may be, and preferably is, used bonded areas covering 5-25% web or sheet. The three-dimensional effect, or loft, is enhanced by the ability of the fabric to be extended crosswise with development of a uniform lace-like structure.

e amount of loft, or three-dimensional trolled by the shape of the reticular fabric structure which is, in turn, controlled by the interannular distances and the ratio of non-oriented to oriented fibers in the web. Increasing the proportion of oriented fibers tends to increase the quilting effect. Increasing the proportion of non-oriented fibers tends to increase the peach fuzz effect.

sparingly, with the of the total area of the render it much simpler to doctor the intaglio print roll that conveniently may be used to imprint the binder pattern on the web.

In carrying the present invention into practice, any of the conventional web-forming, web cross-drafting, web-printing and drying operations, well known in the and any of the conventional binder media of the including the patents mentioned.

Assuming the use of an engraved printing roll of the intaglio type (as described, for example, in the Esther bodying the principles of the present invention may have, for example, the dimensions 7 TABLE Pattern Geometry-Dimensions Basic Type Code No.

Having now described the invention in specific detail and indicated the manner in which it may be carried into practice, it will be readily apparent to those skilled in the art that innumerable variations, applications, modications and extensions of the basic principles involved may be made without departing from its spirit or scope. Thus the fabrics of the presentinvention may be laminated with other fabrics, with paper or with other materials, or employed in a host of ways that will be readily apparent to the skilled artisan. We therefore intend tcl; be limited only in accordance with the appended patent c alms.

The term textile fibers as used herein includes the conventional textile fibers which are capable of being spun into yarn and woven into cloth. Generally speaking, this includes fibers whose average one-half inch or longer.

We claim:

1. A web comprising a major proportion of textile fibers oriented predominantly in one direction and a minor but substantial proportion of random fibers, said oriented and random fibers being bonded together to form a fabric by a uniform binder pattern occupying less than about 35% of the lateral surface of said we and comprising a multiplicity ofannular areas of binder, uniformly separated from each other by substantially unbonded fibers and arranged uniformly in contiguous nonoverlapping columns that are substantially parallel to each other and to the direction of fiber orientation, the individual annuli being interconnected effectively to form interconnected parallelograms that are collapsible on the lazy tongs principle when the fabric is stretched in a direction normal to the direction in which said major proportion of fibers is oriented, the interconnection between said annuli substantially comprising unbonded fiber lengths composed predominantly of the non-oriented fibers of the web.

2. A laterally extensible web of carded fibers containing a major proportion of parallelized fibers and a substantial but minor proportion of non-parallelized fibers, said fibers being bonded together into a laterally but articuextensible fabric by means of a discontinuous binder pattern infused locally into less than 35% of lated multi-annulate the body of the web and occupying the lateral surface thereof, said pattern comprising a multiplicity of annular binder areas uniformly disposed in staggered, non-overlapping relationship with respect to each other, in parallel courses extending substantially normal to said parallelized fibers, each annular area being separated from every other area by substantially unbonded areas of the fabric, but articulated into a lazy tongs structure with the adjacent-most areas in adjacent courses by a group of unbonded fiber lengths composed predominantly of the non-parallelized fibers of the web, said web being characterized by a substantial capacity for elongation when stressed in a direction `normal to said parallelized fibers, with the development of a uniformly open lacelike reticular structure.

References Cited in the file of this patent UNITED STATES PATENTS

Claims (1)

1. A WEB COMPRISING A MAJOR PROPORTION OF TEXTILE FIBERS ORIENTED PREDOMINATLY IN ONE DIRECTION AND A MINOR BUT SUBSTANTIAL PROPORTION OF RANDOM FIBERS, SAID ORIENTED AND RANDOM FIBERS BEING BONDED TOGETHER TO FORM A FABRIC BY A UNIFORM BINDER PATTERN OCCUPYING LESS THAN ABOUT 35% OF THE LATERAL SURFACE OF SAID WEB AND COMPRSING A MULTIPLICITY OF ANNULAR AREAS OF BINDER, UNIFORMLY SEPARATED FORM EACH OTHER BY SUBSTANTIALLY UNBONDED FIBERS AND ARRANGED UNIFORMLY IN CONTIGUOUS NON-OVERLAPPING COLUMNS THAT ARE SUBSTANTILLY PARALLEL

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