MXPA01005738A - Resilient fluid management materials for personal care products - Google Patents

Abstract

There is provided a corrugated nonwoven web where at least 40 percent of the web surface area is made from fusible fibers. The corrugated web is bonded such that no gaps are present between the folds of the web. Such webs provide comparable compression resistance and resiliency to, and greater void volume than, webs having a conventional X-Y plane fiber alignment. There is further provided personal care products having the corrugated nonwoven web as a component where the web is placed in the product in the transverse direction.

Description

ELASTIC FLUID HANDLING MATERIALS FOR PERSONAL CARE PRODUCTS FIELD OF THE INVENTION The present invention relates to a structure in a diaper article for personal care, training underpants, absorbent undergarments, adult incontinence products, bandages, and products for women's hygiene, which can accept the liquid and those which are elastic to maintain, their shape under compression.

BACKGROUND OF THE INVENTION Personal care articles include such items as diapers, underpants, learning products for women's hygiene such as sanitary napkins, linings for panties and plugs, garments and incontinence devices, bandages and the like. The most basic design of all those items typically includes a side-by-side liner, an outer shell and an absorbent core placed between the body-side liner and the outer shell.

Personal care products must accept fluids quickly and without bending under the pressure of the body of the users or of the liquid. The product should be flexible and should have a pleasant feeling on the skin Unfortunately, even when the previous products have filled many of these criteria, a large number has not done so.

The expansion of the layers containing superabsorbents when exposed to body fluids, for example, has been known to block an additional acceptance of the liquid, a phenomenon known as "wet folding". Wet folding eliminates the hollow space so that the fluid enters and can be ineffective to the absorbent core.

Many materials are unable to withstand laterally applied compressive forces, such as that applied by the user's legs in diapers and sanitary napkins, for example. This mechanical action may result in the collapse of the absorbent core of the product, either sagging or bent between the user's legs. This collapse of the nucleus leads to a loss of the void volume tried to make it available to receive and store the fluids of the body. This bulging also results in a diminished absorbent area and a decreased absorbent protection for the user. Finally, this absorent and collapsed core is uncomfortable for the user.

In order to achieve greater integrity and elasticity, a variety of methods and materials of product construction have been tested. These have included gluing the absorbent core layers together, by taping the absorbent core layers, by adding reinforcing materials to the absorbent core and by adding an absorbent core elastic element to support the open structure and retain the hollow space .

Each of these approaches has resulted in some compromise in the absorbent characteristics and / or comfort of the product. Adhesives and adhesives, for example, tend to be hydrophobic and therefore interfere with the absorption of fluids from the body of the product. The gravad increases the integrity of the absorbent core by increasing its density but in doing so reduces the hollow volume needed for fluid intake and retention. The addition of reinforcing materials and elastic in a similar way approved unsatisfactory There is still a need, therefore, for a material which remains flexible and soft while resisting compressive forces and thus maintains its hollow volume for accepting subsequent fluid flows.

It is an object of this invention, therefore, to provide an absorbent structure which can accept menstrual fluids while maintaining its hollow volume resists compressive forces, while at the same time it is also soft and flexible.

SYNTHESIS OF THE INVENTION The objects of the invention are achieved by means of a corrugated non-woven fabric wherein at least 40 percent of the fabric surface area is made of fusible fibers. The corrugated weave is joined so that no separations are present between the folds of the fabric. Tale fabrics provide comparable compressive strength and elasticity and a greater void volume than fabrics that have a fiber alignment in the conventional X-Y plane.

A variety of method can be used to make such fabrics, including spun bonding, bonding and carding, air placement, etc. The fabric is then corrugated and thermally bonded to give a fabric with a perpendicular orientation or in the Z direction of the fibers and which has n separations, channels or valleys between the folds of fabric.

Improved personal care products are also provided which have the corrugated nonwoven fabric as a component where the fabric is placed on the product so that the transverse direction of the fabric is parallel to the transverse direction of the product.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a diagram of a vibratory folder to produce fabrics having fibers positioned perpendicularly (-Z direction).

Figure 2 is a diagram of a rotating folder used to produce fabrics having fibers placed perpendicularly (-Z direction).

Figure 3 shows a bent fiber block (corrugated) 2 and indicates the axes X 12, Y 13 and Z 14.

Figure 4 shows a folded fiber block with non-uniform bending heights.

Figure 5 shows a laminate 15 comprising a folded fiber block 2 and another fabric, foam or other material 16 below.

Figure 6 shows a cross-sectional view of a laminate 15 comprising a bent fibr block 2 with non-uniform heights and another fabric, foam or other material 16 below.

Figure 7 shows the preferred orientation of a folded fiber block 2 in a person care product which is, in this case, a diaper 30.

Figure 8 shows a support 27 used in the compression resistance test procedure.

Figure 9 shows a corrugated fabric having separations between the folds.

Figure 10 shows a corrugated fabric if separations between the folds.

DEFINITIONS "Disposable" includes being discarded after use and not attempting to be washed and reused.

"Front" and "posterior" are used throughout this description to designate relationships with respect to the garment itself, rather than suggesting any position assumed by the garment when it is placed on a user.

"Hydrophilic" describes fibers with the surface of the fibers, which are wetted by n aqueous liquids in contact with the fibers. The degree of wetting of the materials can, in turn, be described in terms of the contact angles and the surface tensions of the liquids and the materials involved. Equipment and techniques suitable for measuring the wettability of particular fiber materials can be provided by the Cahn SFA-222 surface force analyzer system, or by an essentially equivalent system. When measured with this system, the fibers having contact angles of less than 90 ° C designate "wettable" or "hydrophilic" while the fiber having contact angles equal to or greater than 90 ° is designated "non-wetting" or hydrophobic.

The word "layer" when used in the singular may have the dual meaning of a single element or a plurality of elements.

The word "liquid" means a substance not particles and / or a material that flows and can assume the lower form of a container in which it is poured or placed.

"Liquid communication" means that the liquid is capable of moving from one layer to another layer, or from one location to another within the layer.

"Longitudinal" means having the longitudinal ej in the plane of the article and being generally parallel to a vertical plane that divides a user who is standing in the left and right body halves when the article is used. The "transverse" axis lies in the article plane generally perpendicular to the longitudinal axis, for example, so that the vertical plane divides a foot user into the front and rear body halves when the item is being used.

"Conjugated fibers" refers to fibers, which have been formed from at least two extruded polymers of separate extruders but spun together to form a fiber. Conjugated fibers are also sometimes mentioned as multicomponent or bicomponent fibers. The polymers are usually different from one another even though the conjugated fibers can be monocomponent fibers. The polymers are arranged in areas placed essentially constant across the cross section of the conjugate fibers and extend continuously along the length of the conjugate fibers. The confation of such a conjugate fiber may be, for example, one of a sheath / core arrangement where one polymer is surrounded by another or may be a ladder arrangement per side, a cake arrangement or an arrangement of "islands in the sea". "Conjugated fibers teach in U.S. Patent No. 5,108,820 issued to Kaneko et al., And U.S. Patent No. 5,336,552 issued to Strac et al. And in the United States of America patent. No 5,382,400 granted to Pike and others. For fibers of component components, the polymers may be present in proportions of 75/25, 50/50, 25/75 or any other desired proportions. The fibers may also have forms such as those described in the patents of the United States of America. Us 5,277,976 granted to Hogle and others, and 5,069,970 and 5,057.36 granted to Largman and others, incorporated herein by reference in their entirety, which describe fibers with conventional n forms.

"Biconstituent fibers" refer to fiber which has been formed from at least two polymers extruded from the same extruder as a mixture. The term "mixture" is defined below. The biconstituent fibers do not have the various polymer components arranged in different zones placed relatively constant across the cross-sectional area of the fiber and the various polymers are usually not continuous along the entire length of the fiber, instead of this, usually forming protofibril fibrils which start and end at orange blossom. The biconstituent fibers are sometimes also referred to as multi-constituent fibers. Fibers of this general type are also discussed in, for example, U.S. Patent No. 5,108,827 issued to Gessner. Biconstituent and bicomponent fibers are also discussed in the text "Polymer Blends and Compounds" by John A. Manson and Leslie H. Sperling, copyright 1976 by Plenum Press, a division of Plenum Publishing Corporation of New York IBSN 0- 306-30831-2, pages 273 to 277.

As used herein, the term "machine direction" or MD means the length of a fabric in the direction in which it is produced. The term "transverse direction to the machine" or CD means the width of the fabric, for example an address generally perpendicular to the machine direction.

As used herein the term "spunbond fibers" refers to fibers of small diameter which are formed by extruding a melted thermoplastic material as filaments of a plurality of usually circular and fine capillaries of a spinner with the diameter of the extruded filaments then being rapidly reduced as, for example, is indicated in U.S. Patent No. 4,340,563 issued to Appel et al., and U.S. Patent No. 3,692,618 issued to Dorschner et al. and U.S. Patent No. 3,802,817 issued to Matsuki et al., in US Pat. Nos. 3,338,992 and 3,341,394 issued to Kinney, in US Pat. No. 3,502,763 to Hartman and U.S. Patent No. 3,542,615 issued to Dobo et al. Spunbonded fibers are not generally sticky when they are deposited on the collector surface. Spunbonded fibers are generally continuous and have average diameters (of a sample of at least 10) larger than 7 microns, more particularly between about 10 and 35 microns. Fiber may also have forms such as those described in United States of America No. 5,277,976 to Hogle et al., United States of America No. 5,466,410 to Hills and 5,069,970 to 5,057,368 to Largman et al. describes fibers with conventional n-forms.

As used in the term "co-melt blown fibers" means fibers formed by extruding melted thermoplastic material through a plurality of fine, usually circular, capillary matrix vessels with melted threads or filaments into gas streams (e.g. of air), usually hot and high speed which attenuate the filaments of thermoplastic material melted to reduce its diameter which can be a microfiber diameter d. Then, the meltblown fibers are carried by the high velocity gas stream and are deposited on a collecting surface to form a meltblown fiber fabric dispersed at orange blossom. Such a process is described, for example, in the US Pat. No. 3,849,241 issued to Butin et al., The co-melt blown fibers are microfibers which may be continuous discontinuous, are generally smaller than 10 microns in average diameter and They are usually sticky when deposited on a collecting surface.

"Air placement" is a well-known process by which a fibrous non-woven layer can be formed. In the air-laying process, bunches of small fibers having typical lengths ranging from about to about 52 millimeters are separated and taken into a supply of air and then deposited on a forming grid, usually with the help of a vacuum supply. The fibers deposited to the orange blossom are then joined to each other using, for example, hot air or sprayed adhesive. L placement by air is discussed in, for example, U.S. Patent Nos. 4,005,957, 4,388,056, 4,592,708, 4,598,441, 4,674,996, 4,761,258, 4,764,325, 4,904,440, 4,908,175 and 5,004,579 and German Patent DE3508344 Al, in the application of European Patent No. 85300626.0 and in the application British Patent 2,191,793.

As used herein, the term "coform" means a process in which at least one melt blown die head is arranged near a conduit through which other materials are added to the fabric while it is forming. Such other materials may be superabsorbent pulp or other particles, natural polymer fiber (for example, rayon or cotton fibers) and / or synthetic polymer (for example, polypropylene or polyester fibers), for example, where the fibers can be of a basic length The coform processes are shown in the patents of the United States of America commonly assigned No. 4,818.46 granted to Lau and 4,100,324 to Anderson and others. The tissues produced by the coform process are generally referred to as coform materials.

The "carded and bonded fabric" refers to fabric made of basic fibers which are sent through a combing or carding unit, which breaks and separates and aligns the basic fibers in the machine direction to form a fabric fibrous nonwoven generally oriented in the direction of the machine. The tissue is joined by one or more of several methods of union.

The bonding of non-woven fabrics can be accomplished by a number of methods: bonding with dust, where a powdered adhesive is distributed through the fabric and then activated, usually by heating the fabric and adhesive with hot air; pattern bonding, where heated calendering rollers or ultrasonic bonding equipment are used to join the fibers together, usually in a localized bonding pattern, even when the fabric can be bonded across the entire surface if it is it desires, the union through air e where the air which is sufficiently hot to soften at least one component for the fabric is directed through the fabric; chemical bonding using, for example, latex adhesives, which are deposited on the fabric, for example, by spraying; and consolidation through mechanical methods such as drilling and hydroentanglement.

"Placed perpendicularly" or "fabrics in the Z direction" are fabrics in which the fibers are oriented in a direction perpendicular to the predominant plane (X-Y) of the fabric. This predominant plane is usually the MD-CD plane.

Figure 3 indicates the direction of the three axes.

"Personal care product" means diapers, underpants, absorbent undergarments, adult incontinence products, swimming rop, bandages and products for women's hygiene.

The "products for women's hygiene means sanitary napkins, pads and plugs.

"Target areas" refers to the area or position on a personal care product where s normally delivers a download by a user.

TEST METHODS Material Caliber (Thickness) The material gauge is a measure of thickness and is measured at 0.05 pounds per square inch with a Starret type volume tester and millimeter units.

Density: The density of the materials was calculated by dividing the weight by the unit area in a sample in grams per square meter (gsm) by the volume of the sample in millimeters (mm) to 68.9 passages and multiplying the result by 0.001 to convert the value to grams per cubic centimeter (g / cc). A total of three samples were evaluated and averaged against the density values Compression Resistance Test: Personal care items typically find two main modes of compressive strength. The lateral compressive force, for example, is exerted by the user's legs, and the compressive forces "z" are exerted due to the weight of the user by the pressure exerted by the clothes. The lateral compressive elasticity is defined as the behavior of the materials when the force is applied normal to the plane yz, commonly called with pressure in the dimension xy compressive elasticity in the z direction is defined as the behavior of the materials when the force is applied normal to the xy plane, commonly understood as compression thickness of the z-dimension. Figure 3 illustrates the direction of these axes for the fiber block 2 folded typically with the x axis being the number 12, the y axis being the number 13 and e z axis being the number 14.

A single cycle compression was used to characterize the elasticity of the fabric for each mode. The test apparatus used was a computerized material testing system MTS Sintech / 2 Model 3397-139. The pressure test procedure was defined and the data was generated using the Testworks software system version 3.06.

Compression in the Dimension X (Lateral Compression): To measure the compressive elasticity in the dimension x without introducing a bend or twist, a specific sample holder 27 was used. The sample holder 27 is shown in FIG. 8 and was designed to secure the sample. 24 while exposing the face y, z 21 of the sample 24 at the defined height 23 above the surface of the support 27. L sample 24 is placed on the support 27 against the rear clamp 22 and then the adjustable front clamp. is moved to contact the sample 24 by sliding it into the slots 26 and securing it with the bolts 19. This arrangement allows the sample 24 to be held vertically. A slight curvature is placed on the sample 24 by the shape of the support 27 to further minimize bulging and bending. The mounted sample 24 and the support 27 are placed in a compression test machine (not shown) which can be, for example, an MTS Sintech machine. A compression test machine typically has a plate which is moved downward to contact the sample 24 on the face y, z 21. The sample 24 is compressed at 50 percent initial height 23 above the support 27 a a rate of 1.2 centimeters (0.5 inches) per minute. The result of maximum compression for a given sample, it was achieved when the plate reached the lowest displacement point. The load exerted to compress the sample 24 is recorded through the test. The area on which it is applied to the load is defined by the length 24 and the thickness 20 of the total sample in the support 27. Five duplicates were tested for each sample 24. The reference to figure 3 is useful for understanding the size and the application of l shows 24 of the load for this test. The tests were cut to a size of 3.8 centimeters (1.5 inches) along the x-axis 12 and 5.1 centimeters (2 inches) along the axis 13. The height of the clamps (22 and 25) of the support 27 is d 3.1 centimeters (1.22 inches), allowing the height to expose 23 to 0.71 centimeters (0.28 inches).

Sample Calculation: A cloth sample was prepared to the dimensions described above with a thickness of 1.27 centimeters (0. inches). This sample is mounted on a support as described to expose the face and, z to a load. The area over which the load is applied can be calculated as: area (A) = Thickness x length = 1.27 cm (0.5 inches) x 5.08 centimeters (2.0 inches) = 6.45 square centimeters (1 square inch) If the load measured at a maximum compression determined as being 0.079 pounds, the force for compression can be calculated as: force (F) = Load / application area = 0.07 pounds / 1 square inch = 0.079 pounds per square inch.

In general, the data generated during the loading / unloading sequence for the compression tests can be plotted to generate curves showing the thickness against the load of the sample. The area of these curves can then be thought of as a relative measure of compressive area compression hardness under load and discharge curves, can be calculated through an integrating technique, manually determined by weighing the sample cut from the curve or by using software that is specifically designed for the stress testing machine. Whatever the technique, the proportion of the area under a load curve, the area under the discharge curve for a given sample can be thought of as the "compressive hardness ratio". Using this technique it is possible to compare the behavior structure of various materials.

Compression in the dimension -z In order to characterize the compression elasticity in dimension z, no special support was required. The sample was placed on a flat anvil surface which was secured to the lower platform of an MTS Sintech machine. A plate is attached to the upper crossarm and a load is applied as the plate is moved down to contact the fabric.

Circular and pre-weighed samples of the test cloth measuring 5.08 centimeters (2 inches) in diameter were used. The load was applied in a direction that was parallel to the z direction of the sample. The sample was compressed at a rate of 1.27 centimeters / min. (0.5 inches / min) until the measured load was 4.27 kilograms (9.42 pounds), which corresponds to a force of 3 pounds per square inch over the sample of 5.08 centimeters (2 inches) in diameter. The data were collected through this single cycle test to be loaded the sample and when the load was removed. E displacement at load points corresponding to the applied forces of 0.05, 1, 2, 3, 2, 1 and 0-05 pounds per square inch was noted during the sequence of charge discharge. From the data it is possible to generate the loading and unloading curves for the samples, which define the material thickness at any point through a complete compression cycle.

DETAILED DESCRIPTION OF THE INVENTION A personal care product typically has a side-to-body layer, optionally a fluid transfer layer, a fluid retention layer and a garment-side layer acting together as an absorbent system. You can also have a distribution layer or other optional layers to provide specialized functions. This absorbent system for a personal care product composed of layers placed between the side to the body and the layers from side to side, must take and distribute the fluid in a controlled manner away from contact with the body.

The side-to-body layer is sometimes referred to as an upper sheet or side-to-body lining. In the direction of the thickness of the article, the lining material is the layer against the user's skin and in this way the first layer in contact with the liquid or other exudate of the lining user also serves to isolate the user's skin from the liquids maintained in an absorbent structure and should be docile, of soft feeling and not irritating. The side-by-side liner can be treated on the surface with a selected amount of surfactant, or it can be processed in another way to impart the desired level of wettability and hydrophilicity.

The lining layer of the garment side, also referred to as a bottom sheet or an outer cover, is the layer furthest from the wearer. The outer cover has traditionally been formed of a thin thermoplastic film, such as a polyolefin film (eg of polyethylene), which is essentially impermeable to liquid. The outer cover functions to prevent the exudates of the body contained in an absorbent structure from wetting or soiling the user's clothing, bedding or other materials that are put in contact with the personal care product. The outer shell may be, for example, a polyethylene film having an initial thickness of from about 0.5 mils d (0.02 millimeters) to about 0.12 millimeters (5. mils) and a basis weight of from about 10 around 100 grams per square meter, or can comprise synthetic fibers and a binder in a ratio of about 50/50 to about 0/100.

The outer cover can be engraved and / or finished matte to provide a more aesthetically pleasing appearance. Other alternate constructions for the outer shell include the woven or woven fibrous webs or fabrics formed of a woven or non-woven fabric of a thermoplastic film. The outer cover can optionally be composed of a "breathable microporous, permeable to vapor or gas breathable material, which is permeable to vapors or gas, but is essentially impermeable to liquid." Other covers can also serve the function of a hunter member for mechanical fasteners.

The layers of the absorbent system located between the layers from side to body and from side to side, must absorb the liquid from the side layer to the adjacent body in a controlled manner so that the liquid can be filled away from contact with the body. . The inventors have found that corrugated non-woven fabrics, used as the absorbent system in a personal care product such as corrugated nonwoven fibers that are oriented in the direction, provide increased fluid intake. Such fibers oriented in the Z direction facilitate the movement of fluid out of the skin as the fluid flows along the fiber surfaces. These corrugated non-woven materials also provide an increased void volume and divide at hollow volume in an effective manner to allow the taking of larger volumes of liquid than conventional uncorrugated fabrics. This increase in hollow volume is indicated by the lowest densities. The corrugation of the fabric causes the material to act as a spring, opening and closing under the load, but generally returning to its original form.

Corrugated fabrics known in the art and a number of examples can be found in the methods for making such fabrics, in for example, U.S. Patent Nos. 4,111,733, 5,167,740, 5,558,924 and 5,620,545 incorporated herein by reference. A particularly suitable method can be found in the October 1997 issue of the magazine "Industria de los Tejidos" on page 74 in an article by Krema, Jirsak, Hanus and Saunders entitled "What's new in the production of high fluffiness? ? as well as in the Czech patents 235494 titled Fiber Layer, Production Method and Equipment for the Application of Fiber Layer Production Method "granted on May 15, 1995 and 263075 intitulad "Method for the Production of Bulky United Textiles granted on April 14, 1989. The vibratory overlapper (Figure 1) and the rotary overlapper (Figure 2) described therein are commercially available from Georgia Textile Machinery of Dalton, Georgia of the United States of America. In Figure 1, the vibratory overlapper has a reciprocating comb 3 which pulls a carded fabric 1 along a guide board 6 towards the conveyor 7. A fold is formed in the tissue char 1 and is pulled out of the comb 3 by a needle system placed on a reciprocating compressing bar 4. The bent carded weave 1 is pushed by the reciprocating compressor bar 4 to form a block of fiber 2 positioned perpendicularly, the wed is then moved forward between a conveyor belt 7 and a wire guide 5. The conveyor belt 7 carries fiber block 2 to a joining device 8, which typically functions either thermally or mechanically.

The rotary overlap shown in the figure supplies the carded fabric 1 between a supply disk 10 with a supply tray 11 and the working disc teeth 9. The bends are created in the carded fabric 1 as a pas between the teeth 9 producing a fiber block placed perpendicularly 2, which is transported between a conveyor belt 7 and a wire guide 5 towards a joining device 8.

The rotary overlap process and the variants are further described in the European patent application E 0516964 Bl which teaches that the fabrics thus produced are useful primarily in the garment industry such as heat insulating lining materials, in the furniture industry. com elastic fillers, in automotive construction industries as thermal and noise insulators, etc.

The use of the fabrics placed perpendicularly, according to the definition given above, has been known for the production of pads for under the insulated sleeping bag and sound insulation carpets where the basis weight was considered superior to those allowed for personal care products which can be lightweight and comfortable. Fabrics in the Z direction have been previously investigated for personal care products where the fibers provide superior fluid movement. U.S. Patent Nos. 4,578,070 and 4,681,577, for example, teach the alignment of corrugations parallel to the longitudinal axis of a personal care product. U.S. Patent No. 4,886,511 teaches the use of elasticized yarns through the crotch of a diaper to corrugate the product. European Patent EP 0767649 Al discloses a folded front coater layer for a sanitary napkin with longitudinal channels on the surface. U.S. Patent No. 5,695,487 teaches the use of melt blown fabric for such fabrics wherein the fibers were aligned in the longitudinal direction.

In the present invention, the contribution of the fibers oriented perpendicular to the fluid intake as well as the contribution to the compressive strength and therefore to the integrity of the product, of the transversely orienting such fabrics in a product for personal care, Perpendicularly low density oriented fabrics used in the practice of this invention have a higher hollow volume when compared to conventional XY oriented fabrics. The perpendicular orientation of the fibers also results in a comparable mechanical compression elasticity. The inventors have found that by placing the fabrics oriented perpendicularly in a personal care product so that the cross-machine direction of the fabric is in the longitudinal direction it provides the greatest degree of compressive strength.

Fabrics which can be subjected to a perpendicular orientation process can be produced by a variety of processes including air placement, carded and bonded tissue processes, co-bonding, meltblowing and coform processes. Fabrics can be made from a variety of fibers and blends of fibers including synthetic fibers, natural fibers and binders. The fibers in such a fabric can be made of fibers of the same diameter of varying diameter and can be of different shapes, such as 5 lobes, 3 lobes, elliptical, round, etc. The fabric may also include particles, flakes or spheres to impart additional properties to the corrugated absorbent system.

Preferred fibers for inclusion are those having a relatively low melting point as polyolefin fibers. The low melt polymers provide the ability to bond the fabric together at points of fiber crossing with the application of heat. By "lower melted polymers" what is meant is those which have a glass transition temperature of less than about 175 ° C. In addition, fibers having at least one lower melt polymer component, such as conjugate and biconstituent fibers, are suitable for the practice of this invention. Any fiber having a lower melted polymer will be referred to hereafter as "meltable fiber".

Synthetic fibers include those made from polyamides, polyesters, rayon, polyolefins, acrylics, superabsorbents, Lyocel regenerated cellulose and any other suitable synthetic fibers known to those skilled in the art known from synthetic fibers and may also include cosmotropic agents for the degradation of the product. .

Natural fibers include wool, cotton, linen, hemp and wood pulp. The pulps include the standard softwood lumber clasher such as Coos Mills CR-1654 from Coosa, Alabama, the high volume additive formaldehyde-free pulp (HBAFF) available from Weyerhaeuse Corporation available from Tacoma, WA, and is a which is a southern softwood pulp fiber crosslinked with an increased wet modulus, and a chemically crosslinked pulp fiber such as Weyerhaeuse NHB416. The formaldehyde free pulp of high volume additive has a chemical treatment that settles in a twisted curl, besides imparting a rigidity in dry and humid aggregates and elasticity to the fiber. Another suitable pulp is the Buckeye HP2 pulp and yet another one is IP Supersoft from Internationa Paper Corporation. Suitable rayon fibers are the Merge 18453 1.5 denier fiber from Courtaulds Fibers Incorporated of Axis, Alabama.

The binders include fiber, liquid or other binding media which can be thermally activated.

Exemplary binders include conjugated fibers and polyamides, and liquid adhesives. Two such suitable binder are core and sheath conjugate fibers available from KoSA Inc. (formerly Trevira, Inc. and formerly Hoechs Celanese), PO Box 4, Salisbury, North Carolina, 28145-000 under the designation T-255 and T-256, although many suitable binder fibers are known to those skilled in the art and are made by many manufacturers such as Chisso Fibervisions LLC of Wilmington, Delaware. A suitable liquid binder is the Kymene® 557LX binder available from Fibervisions LLC.

Once produced and corrugated, the non-woven fabric must be adequately stabilized and consolidated in order to retain its shape. The inclusion of a sufficient quantity of fusible fibers and subsequent thermal bonding is the preferred method for obtaining adequate stabilization. It is believed that this method allows a proper bond in the center of coarse material as well as on the surface. The inventors have found that such meltable fibers must be at least 40 percent and at most 100 percent of the fiber surface area of the fabric in order to result in a corrugated knit with sufficient resistance to mechanical compression.

The corrugated fabric must also be sufficient for the union of fold to fold so that there are no separations, channels or valleys between each fold and the corrugated fabric. When corrugated fabric is used in a product for personal care absorbent. This construction results in a fluid that necessarily enters the fibrous web of the fabric and that is being guided by the fiber and hollow surfaces. U Corrugated fabric with separations or valleys, in contrast, allows the fluid to move freely along the valley surface without entering the fabric. Allowing the fluid to move freely along the surface can result in a runoff of product fluid for personal care.

The degree of clamping between the required folds to eliminate the separations is best seen in Figures 9 and 10 Figure 9 shows a typical corrugated fabric 40 where the folds 42, 44 are not joined and thus allow the existence of separations 46 between the same. Figure 10 shows a corrugated knit 50 with no separations between the folds 52, 54. Note that even when there is some hollow space between the bending peaks, there is no separation between the parallel portions of the folds. Figure 10 further includes a layer of a fabric 56 attached to corrugated fabric 50 to form a laminate.

The inventors have also found that the desired bend-to-bend attachment results in improvements in compressive strength. These resulting mechanical properties allow for the maintenance of necessary absorbent hollow space while increasing the properties of fluid transmission in the direction of the material. The greatest benefit of the corrugated fabric structure is surprisingly found when the corrugated weave is placed in a personal care product in the transverse direction as shown in Figure 7.

The corrugated fabric may have a uniform or non-uniform bending height clearance required for the final use. Figure 4 shows a fabric 2 with a non-uniform double height. Figure 6 shows a fabric 2 with a non-uniform fold height d which is laminated to another material 16 to produce a laminate 15.

In the case of a laminate, one or more material may be corrugated together or a flat material may be corrugated separately or melted thereto by, for example, thermal bonding and stabilization. Such other layers may be woven or woven fabrics, other nonwovens, films, tissue paper, foamed sheet, etc. and each layer may contain a variety of fibers or particles to impart particular properties. In addition, a layer of non-woven material (eg, melt-blown fiber) may be formed on one or both sides of corrugated fabric resulting in a sandwich-type construction. .

A number of examples of different materials were made that satisfy the purpose of the invention and are described in detail below.

Examples The first and second fabrics (examples 1 and 2) were made with 60 percent by weight of fiber conjugated (binder) sheath / polypropylene core 3 denier d type 233.3 from Chisso Inc., also referred to as Chisso ES and 4 weight percent polyester pentalobal polyester type 295 a 6 denier fiber from KoSa Inc., and processed to final weights of 85 and 112 grams per square meter.

The third and fourth fabrics (examples 3 and 4) made 60 percent by weight of 3 denier d type 233 conjugate fiber (binder) sheath / polypropylene core, from Chisso Inc., also referred to as Chisso, ES 40 percent by weight of 5-lobe polyester type 295, a 6-denier fiber of KoSa Inc. and corrugated using a vibratory perpendicular folding V600 available from Georgia Textile Machinery, Inc., of Dalton, Georgia and thermally stabilized by passing them through a jointer through air at 145 ° C.

A fifth fabric (example 5) of 30 weight percent was made of Chisso ES type 233 fiber, of 3 denier rayon of 40 weight percent, lot 2280 with a wettable jabot finish of Courtaulds Fibers Incorporated of Axis, Alabam and 30 percent by weight of 5-lobed polyester type 295 6-denier fiber from KoSa Inc. This mix was also corrugated using a V600 vibratory perpendicular folder from Georgi-Textile Machinery.

The resulting corrugated fabrics had low densities, for example, usually less than 0.02 g / cc. This compares favorably to the carded and bonded weaving structures, which generally have densities up to 0.025 g / cc.

The results of the compression resistance test in dimension X and in dimension Z according to the method given above and other properties are shown in the Tabl given below where the basis weight is given in grams per square meter (gsm), the thickness in inches (millimeters) and the surface area of meltable fiber is shown as one percent of the entire fibrous surface area present in the fabric.

As can be seen from these results, the structures of this invention have very high hollow volumes and good compressive strength. Comparing the samples 1-2 with samples 3-4, it can be seen that the same strength of dimension X, flat and corrugated materials, comparable base weights of sample at comparable levels of compressive strength, while corrugated fabrics provide the benefit crumbling of the fiber surfaces in the z direction to increase the penetration of the fluid in the structure. In a similar way, the compression results in the z-dimension show that after a cyclic loading sequence, the corrugated structures maintain a greater final tel thickness and therefore a larger hollow volume to accommodate fluid. It should be noted that example 5 with reduced levels of meltable fiber surface area exhibits a poorer compressive strength due to the lack of fiber fiber joints of the internal structure as seen in examples 3 and 4. Such attributes lend themselves to same to the incorporation of personal care products, which must absorb multiple liquid discharges while under compression in more than one direction.

As can be seen from these results, the structures of this invention have very high void volumes, good compression strength. Such attributes lend themselves to incorporation into personal care products, which must absorb multiple liquid discharges while under compression in more than one direction.

Although only a few embodiments of this invention have been described in detail above, those skilled in the art will readily appreciate that many modifications to the example embodiments are possible without departing materially from the novel teachings and the advantages of this invention. Therefore, all those modifications are intended to be included within the scope of the invention as defined in the following claims. In the claims, the media clauses plus function are intended to cover the structures described herein, carrying out the recited function and not only the structural equivalents without also the equivalent structures.

Therefore even when a screw and a nail may not be structural equivalents in the sense that a clav employs a cylindrical surface to secure joints to the wooden parts, while a screw employs a helical surface, in the environment of the fastening Wood parts, a screw and a nail can be equivalent structures.

It should also be noted that any patent applications or publications mentioned herein are incorporated by reference in their entirety.

Claims (16)

R E I V I N D I C A C I O N S

1. A corrugated nonwoven fabric comprising a surface having a surface area, wherein at least 40 percent of said surface area is made of fusible fibers, and wherein said fabric is corrugated to produce folds and is bonded so that there are no separations between the folds.

2. The fabric as claimed in clause 1, characterized in that said fabric is made of a process selected from the group comprising joining with melt blown spinning, air laying, coforming, carded bonding.

3. The fabric as claimed in clause 1, characterized in that said fabric comprises superabsorbent fiber.

4. The fabric as claimed in clause 1, characterized in that said folds are of a uniform height.

5. The fabric as claimed in clause 1, characterized in that said folds are of uniform height n.

6. The fabric as claimed in clause 1, characterized in that said fabric has been corrugated by a method selected from the group consisting of vertical folding and rotating folding.

7. A personal care product comprising the fabric as claimed in clause 1 characterized in that said fabric is aligned in said product in a transverse direction.

8. The personal care product as claimed in clause 7, characterized in that it is a diaper.

9. The personal care product as claimed in clause 7, characterized in that it is a learning underpants.

10. The personal care product as claimed in clause 7, characterized in that it is a product for incontinence.

11. The personal care product as claimed in clause 7, characterized in that it is a bandage.

12. The personal care product as claimed in clause 7, characterized in that it is a product for the hygiene of women.

13. A laminate comprising a corrugated non-woven fabric comprising a surface having a surface area d, wherein at least 40 percent of said surface area d is made of fusible fibers, and wherein said fabric is corrugated to produce folds and it is joined so that n separations are present between said bends, and at least one layer selected from the group consisting of non-woven fabrics, knit fabrics, films, tissue, papers, thin sheet metal and foams.

14. The laminate as claimed in clause 13, characterized in that said folds are of uniform height.

15. The laminate as claimed in clause 13, characterized in that said bends are not uniform in height.

16. The laminate as claimed in clause 1, characterized in that said fabric comprises superabsorbent fiber. E S U M E N A corrugated nonwoven web is provided where at least 40 percent of the woven surface area is made of fusible fibers. The corrugated weave is joined d so that no separations are present between the fabric folds. Such fabrics provide a comparable compression and elasticity resistance, and in addition a larger void volume than that of fabrics having a fiber alignment in the conventional X-Y plane. Personal care products having the corrugated non-woven fabric are also provided with a component where the fabric is placed in the product in the transverse direction.