MXPA01006253A - Materials for fluid management in personal care products - Google Patents

Abstract

There is provided a fluid management material for personal care products which distributes artificial menses according to the gush/distribution test taught herein such that it has a distribution ratio of at least about 0.06. Its preferred that the fluid management material be part of an absorbent materials system having a first fibrous layer, a middle layer adjacent the first layer having hydrophilic oriented surface fibers, and a second fibrous layer adjacent the middle layer. In a personal care product configuration the oriented surface fibers result in a distribution ratio of at least 0.06 where the distribution ratio is a ratio of average of the mass of two end zones of a product divided by the mass of the center zone.

Description

MATERIALS FOR FLUID MANAGEMENT IN PERSONAL CARE PRODUCTS This application claims the priority of the United States of America provisional application No. 60 / 112,902 filed on December 18, 1998.

FIELD OF THE INVENTION The present invention relates to a structure in a personal care article such as diapers, training underpants, absorbent underpants, adult incontinence products, bandages and products for women's hygiene, which can accept an emergence of liquid.

BACKGROUND OF THE INVENTION Personal care articles include such items as diapers, training pants, garments and incontinence devices, bandages and products for women's hygiene such as sanitary napkins, panty liners and plugs and the like. The most basic design of such articles typically includes a side-to-body liner, an outer cover and an absorbent core positioned between the body-side liner and the outer cover.

Women's hygiene products like sanitary napkins, for example, have absorbent cores which have traditionally been designed to take a slow, thick flowing fluid. Women who menstruate, however, often complain of experiencing surges or sudden outbreaks of menstrual discharge which leave the body as a discharge of time fluid to deliver short and high volume. An absorbent core designed to handle the slowly moving flow usually has a very small pore structure to quickly take up these outbreaks or limited fluid surges, and as a result, stagnation of the fluid or puddling of the surface of the product may result . Stagnation on the surface can result in the runoff or staining of clothing and this is acceptable to the wearer. Alternatively, the absorbent material or materials which have a sufficiently large pore structure to rapidly absorb the discharges usually can not redistribute the fluid to the ends of the product, thereby resulting in an emerging fluid accumulating in the center part of the product. the pad where the pressure of the legs can cause draining.

It is an object of this invention, therefore, to provide an absorbent structure which can quickly take up surges or sudden outbreaks of fluid, pull fluid out of the top of the absorbent to achieve a dry feeling for the user, redistribute that fluid along the entire length of the structure and release the fluid to other subsequent absorbent layers.

SYNTHESIS OF THE INVENTION The objects of the invention are achieved by a fluid handling material for personal care products which distribute the artificial menstrual fluids according to the distribution / sprout test here so that it has a distribution ratio of at least around 0.06.

It is preferred that the fluid handling material be part of a system of absorbent materials having a first fibrous layer, a middle layer adjacent to the first layer having the hydrophilic oriented surface fibers, and a second fibrous layer adjacent to the layer half. The density of the first layer is between about 0.02 and 0.14 grams per cubic centimeter. The density of the second layer is greater than that of the first layer and the second layer is preferably homogeneous in its resistance to fluid flow.

In the configuration of the personal care product, the oriented surface fibers result in a distribution ratio of at least 0.06. It is preferred that the products embodying this invention have a minimum of 2.0 square meters of fiber surface area per product in the oriented surface fiber layer arranged in at least one area of oriented surface fibers where the area is at more than 20 millimeters wide and the base weight is at least 50 grams per square meter.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 shows a cross-sectional view of a fiber of capillary surface material suitable for use in the practice of this invention made according to WO 93/02235.

Figure 2 shows a cross-sectional view of a fiber of capillary surface material suitable for use in the practice of the invention made according to PCT / US97 / 14607.

Figure 3 shows cross-sectional views of non-round fibers for use in the practice of this invention made according to U.S. Patent No. 5,458,963.

Figure 4 shows the erased pulp with a longitudinal sine wave pattern and marked in five equal zones along its length.

Figure 5 shows an hourglass-shaped plate for use in the effusion / distribution test.

Figure 6 is a block rate apparatus used in the effusion flow material test.

DEFINITIONS The term "disposable" includes being discarded after a single use and not being rewashed and reused.

The term "frontal" and "posterior" are used throughout this description to designate relationships with respect to the garment itself, rather than suggesting any position that the garment adds when it is placed on a wearer.

"Hydrophilic" describes the fibers or surfaces of the fibers which are wetted by the 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 materials involved. Equipment and techniques suitable for measuring the wettability of the particular fiber materials of the fiber materials can be provided by a Cahn SFA-222 Surface Force Analyzer System, or other essentially equivalent system. When measured with this system, fibers that have contact angles of less than 90 degrees are designated "wettable" or "hydrophilic", while fibers that have contact angles equal to or greater than 90 ° are designated "non-wettable". or hydrophobic "Layer" when used in the singular may have the dual meaning of a single element or a plurality of elements.

"Liquid" means a substance without particles and / or a material that flows and can assume the interior shape of a container into which it is poured or placed.

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

"Particles" in the context of this invention refers to any geometric shape such as, but not limited to, spherical grains, fibers or yarns, flat surfaces, rough surfaces, sheets, ribbons, ropes, threads or similar.

"Spray" and variations thereof include forcibly ejecting the liquid, either as a stream or discrete elements, such as swirl filaments or atomized particles through a hole, nozzle or the like, by means of an applied air pressure. or another gas, by force of gravity or by centrifugal force. Spraying can be continuous or non-continuous.

"Conjugated fibers" refer to fibers which have been formed from at least two extruded polymers from separate extruders but spun together to form a fiber. Conjugated fibers are also sometimes referred to 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 different zones placed essentially constant across the cross section of the conjugated fibers and extend continuously along the length of the conjugated fibers. The configuration of such conjugated fiber can be, for example, a pod / core arrangement where one polymer is surrounded by another or can be a side-by-side arrangement, a cake arrangement or an arrangement of "islands in the sea". Conjugated fibers are taught in U.S. Patent No. 5,108,882 issued to Kaneko et al., In U.S. Patent No. 5,336,552 issued to Strock et al., And in the U.S. Pat. America No. 5,382,400 granted to Pike and others. For the two component fibers, the polymers may be present in proportions of 75/25, 50/50, 25/75 or any other desired proportions. The fibers may also have shapes such as those described in U.S. Pat. No. 5,277,976 to Hogle et al., And 5,06,970 and 5,057,368 to Largman et al., Incorporated herein by reference in their entirety, which describe fibers with unconventional shapes.

The "biconstituent fibers" refer to fibers which have been formed from at least two extruded polymers from the same extruder as a mixture. The term "mix" is as 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 non-continuous along the entire length of the fiber, instead of this usually forming fibrils or protofibrils which start and end at random. Biconstituent fibers are sometimes referred to as multi-constituent fibers. Fibers of this general type are discussed in, for example, U.S. Patent No. 5,108,827 issued to Gessner. Biconstituent and bicomponent fibers are also discussed in John a. Polymer Mixes and Composites textbook. Manson and Leslie H. Sperling, copyright 1976 by Plenum Press, a division of Plenum Publishing Corporation of New York, IBSN 0-306-30821-2 pages 273 to 277.

The "capillary surface materials" or CSM are fibers or groups of such fibers which can spontaneously transport certain fluids on their surfaces .. Fibers of this general type are discussed, in for example, patent application PCT / US97 / 14607 , WO 93/0223, WO 90/12130 and the patents of the United States of America Nos. 5,268,229, 5,611,981 and 5,723,159. Similarly, "capillary channel fibers" offer improved fluid capacity and improved ability to transport and store the fluid. Fibers of this general type are discussed in, for example, U.S. Patent Nos. 5,200,248 and 5,242,644.

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 "cross machine direction" or CD means the width of the fabric, for example, an address generally perpendicular to MD.

As used herein, the term "spunbonded fibers" refers to fibers of small diameter which are formed by extruding the molten thermoplastic material as filaments of a plurality of usually circular and thin capillaries of a spinner with the diameter of the extruded filaments then being rapidly reduced as indicated, for example, in U.S. Patent No. 4,340,563 issued to Appel et al., in U.S. Patent No. 3,692,618 issued to Dorschner et al. , U.S. Patent No. 3,802,817 issued to Matsuki et al., U.S. Patent Nos. 3,338,992 and 3,341,394 issued to Kinney, U.S. Patent No. 3,502,763 issued to Hartman, and U.S. Patent No. 3,542,615 issued to Dobo et al. Spunbond fibers are generally non-sticky when they are deposited on a collecting surface. Spunbonded fibers are microfibers and are generally continuous and have average diameters (from a sample of at least 10) larger than 7 microns, more particularly, between about 10 and 35 microns. The fibers may also have shapes such as those described in U.S. Patent Nos. 5,277,976 issued to Hogle et al., 5,466,410 issued to Hills and 5,069,970 and 5,057,368 issued to Largman et al. Which describe fibers with unconventional shapes.

As used herein, the term "meltblown fibers" means fibers formed by extruding a molten thermoplastic material through a plurality of fine matrix, usually circular, capillaries such as melted filaments or filaments into gas streams (eg. example, of air) usually hot, and at high speed which attenuate the filaments of molten thermoplastic material to reduce its diameter, which can be a microfiber diameter. Then, the melt blown fibers are carried by the high velocity gas stream and deposited. on the collecting surface to form a fabric of melt blown fibers and randomly dispersed. Such a process is described, for example, in United States of America Patent No. 3,849,241 issued to Butin et al. The melt blown fibers are microfibers which may be continuous or discontinuous, are generally smaller than 10 microns in average diameter, and are generally sticky when deposited on the 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 have typical lengths ranging from about 3 to about 52 millimeters and are separated and carried in an air supply and then deposited on a forming grid, usually with the help of a vacuum supply. The randomly deposited fibers are then bonded together using, for example, hot air or sprayed adhesive. Air placement is discussed in, for example, US Patents 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, in the German patent application No. DE 3508344 Al, in the European patent application 85300626.0 and in the British patent application No. 2,191,793.

As used herein, the term "coform" means a process in which at least one melt blown matrix head is arranged near a conduit through which other materials are added to the fabric as it is formed. Such other materials can be, pulp, superabsorbent or other particles, a natural polymer (e.g., rayon or cotton) and / or a synthetic polymer (e.g., polypropylene, polyester, polyamide or acrylic) fibers, e.g. fibers may have typical lengths ranging from about 3 to about 52 millimeters in length. The coform processes are shown in commonly assigned United States of America patents 4,818,464 to Lau and 4,100,324 to Anderson et al. The tissues produced by the coform process are generally referred to as coform materials.

"Carded and bonded fabric" refers to fabrics which are made of basic fibers wherein the typical fiber lengths vary from about 19 to about 52 millimeters in length. The fibers are sent through a carding combing unit, which breaks, separates and aligns the basic fibers in the direction to form a fibrous nonwoven fabric oriented generally in the direction of the machine. The tissue is joined by one or more of several known joining methods.

The union of the non-woven fabrics can be achieved by a number of all; the bonding with powder, wherein a powder adhesive is distributed through the fabric and then activated, usually by heating the fabric and the adhesive with hot air. Pattern bonding, where heated calendering rolls 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 its entire surface if it is want the union, through air, wherein the air which is hot enough to soften at least one component of the tissue is directed through the tissue; chemical bonding using, for example, latex adhesives which are deposited on the fabric by, for example, spraying, and consolidation by mechanical methods such as drilling and hydroentanglement.

The "personal care product" means diapers, training pants, absorbent undergarments, adult incontinence products, women's hygiene products, and wound care products such as bandages and bandages.

The "products for women's hygiene" mean sanitary pads or pads and caps.

The "target area" refers to the area or position on a personal care product where a discharge is normally delivered by a user.

METHODS OF TESTING AND MATERIALS Material gauge (thickness) The gauge of a material is a thickness measurement and is measured at 0.05 pounds per square inch with a Starret-type volume tester, in units of millimeters.

Density The density of the materials is calculated by dividing the weight per unit area of a sample in grams per square meter (gsm) by the volume of the sample in millimeters (mm) to 344.7 pascal and multiplying the result by 0.001 to convert the value in grams per cubic centimeter (g / cc). A total of three samples will be evaluated and averaged for their density values.

Outbreak / distribution This outbreak and distribution trial attempts to simulate the ability of an absorbent material to handle both the slow flow as well as the high and rapid volume outbreak flow. In addition, the test measures the effectiveness of a system of absorbent material to move the fluid along its length.

A piece of absorbent material or system of material to be valued is cut 38 millimeters wide by 152 millimeters lake and marked in 5 equal zones along its length. A desorbent waste material used here is cut into a rectangular piece that measures 76 millimeters wide by 152 millimeters long. The desorbent material used here is a 600 grams per square meter fluff pulp (CR0054 from Coosa Mills of Coosa, Ala), etched with a longitudinal sine wave pattern as shown in Figure 4. The desorbent fluff is also marked at five equal zones along its length. All materials must be weighed before starting the test. The 1.5-inch wide test sample is placed on top of the desorbent material, centered evenly across the width, matching the longitudinal dimensions of each layer. A plate with an hourglass shape as shown in figure 5 (not to scale) is placed on top of the test sample, matching its longest dimension with the longitudinal dimension of the materials. The hourglass plate is 210 millimeters long, 13 millimeters thick, 86 millimeters wide in each end lobe and 76 millimeters wide in the center, has a hole in the center with a diameter of 7 millimeters, weighs about 240 grams and is preferably made of a plastic such as, for example, PLEXIGLÁS® plastic, as it was here.

The most difficult challenge for an absorbent material or material system is to maintain its rapid fluid intake when the absorbent has received some of the fluid as the material did when it was dry and unused. The absorption time of the test shoot using a partially saturated absorbent system is a more challenging criterion than that established by a dry sample. This test procedure begins with a presaturation of the assembled absorbent layers. A slow and continuous flow of 5 milliliters of artificial menstrual fluid is delivered to the absorbent sample. A syringe pump and tube section are used to deliver artificial menstrual fluids (prepared as shown below) to the hole in the center of the hourglass plate at a rate of 10 mis / hour for 30 minutes. The inventors used a 30 cubic centimeter syringe (catalog No. 301626) of Becton Dickinson of New Jersey mounted on a Harvard PHD 200 programmable syringe syringe pump (catalog No. 702002) from Harvard Apparatus, South Natick, Massachusetts of Harvard Apparatus, South Natick, Massachusetts, even when any equivalent delivery means may be adequate. A stretch of TYGON® flexible tubing measuring about 6 to 8 inches from the Northon Performance Plástic Corporation, located in Akron, Ohio (catalog No. AAB00006, 0.125 inches inside diameter, 0.1875 inches outside diameter, 0.03125 inches wall thickness) connects to one end of the syringe and its opposite end is inserted into the hole in the center of the hourglass plate in order to supply the fluid to the absorbent system. If during the 30 minutes the artificial menstrual fluid floods the hole in the hourglass plate, it must be absorbed with a paper towel of known weight. After 30 minutes, the addition of the menstrual fluids was stopped and the weights are recorded for the paper towel containing the overflow, the desorbent material and the test sample.

The desorbent material and the sample (without the hourglass plate) are reassembled in the same orientation as during the 30 minute fluid addition and left undisturbed for 5 minutes. Afterwards, the system is discharged with a fluid outbreak and its absorption time is recorded. Referring to Figure 6, a rate block as shown is placed in the center on the upper part of the test material and its set of strips desorbent. The rate block 10 is 76.2 millimeters wide and 72.9 millimeters deep (on the page) and has an overall height of 28.6 millimeters which includes a central area 19 on the bottom of the rate block 10 which is additionally projected from the main body of the rate block 10 and has a height of 3.2 millimeters and a width of 22.5 millimeters. The rate block 10 has a capillary 12 with an inner diameter of 4.7 millimeters extending diagonally down from one side 15 to the center line 16 at an angle of 21.8 degrees from the horizontal. The capillary vessel 12 can be made by drilling an appropriately sized hole from the side 15 of the rate block 10 to the appropriate angle starting at a point 18.4 millimeters above the bottom of the rate block 10; provided that however, the starting point of the drilling hole on the side 15 must be subsequently submerged so that the fluid test does not escape there. The upper orifice 17 has a diameter of 7.9 millimeters and a depth of 15 millimeters so that it intersects the capillary vessel 12. The upper orifice 17 is perpendicular to the upper part of the rate block 10 and is centered at 7.1 millimeters from the side 15. The upper hole 17 is perpendicular to the upper part of the rate block 10 and is centered 7.1 millimeters from the side 15. The upper hole 17 is the opening in which the funnel 11 is placed. The central hole 18 is for the purposes of viewing the progression of the test fluid and is actually of an oval shape in the plane of Figure 12. The central hole 18 is centered in a widthwise direction on the rate block 10 and has a width of orifice inferior of 8 millimeters and a length of 38.1 millimeters from center to center of semicircles of 8 millimeters of diameter constituting the ends of the oval. The oval is amplified in size above 11.2 millimeters from the bottom of the rate block 10 for ease of observation, to a width of 10 millimeters and a length of 49 millimeters. The upper hole 17 and the central hole 18 can also be made by drilling.

An effusion of 2 milliliters of an artificial menstrual fluid as prepared below was delivered to the orifice in the rate block using a micropipette and a stopwatch was started. The stopwatch was stopped when all the fluid was absorbed into the material or into the material system as observed through the chamber in the test apparatus. The removal of the rate block and the weight of the sample from. test and the desorbent material to determine the fluid placement between each layer. Cut the test sample and the desabsorbent material along the marks, weighing each area. A distribution ratio for each layer can then be calculated as the average mass of the two end zones divided by the mass of the central zone.

The distribution rate can then be seen as: (Fluid in Zone A + Fluid in Zone E) / 2 divided by (Fluid in Zone C) In order to meet the requirements of the present invention, the system of absorbent materials provides an acceptable melt absorption time as well as an acceptable distribution ratio. Penetration time is the absorption time required for a system of partially saturated absorbent materials to absorb a sudden effusion of 2 cubic centimeters of liquid which has been deposited on the uppermost surface. A small absorption time, therefore, indicates that the material system will accept the fluid easily. The rate of distribution is a measure of how a material system also moves the fluid along its length after the effusion discharge. The higher the rate of distribution, the better the fluid material has been distributed along the length of the product.

Preparation of Artificial Menstrual Fluids: the artificial menstrual fluids used were made of blood and egg white (according to the patent of the United States of America No. 5,883,231) by separating the blood-plasma and red blood cells and separating the clear in the thick and thin parts. "Coarse" means that it has a viscosity after homogenization of above 20 centipoise to 150 sec "1, combining the thick egg white with the plasma and mixing completely, and finally adding the red cells and again mixing thoroughly. Blood, in this example, defibrinated heel blood, was separated by centrifugation at 3000 revolutions per minute for 30 minutes, even though other methods or speeds and times can be used if they are effective.The plasma was separated and stored separately, the coating of curd lymph was removed and discarded and the red blood cells packed were stored separately as well.It should be noted that the red blood should be treated in some way so that it can be processed without coagulation.Several methods are known to those skilled in the art. art, such as the defibrinar blood to remove coagulated fibrous materials, the addition of anticoag ulantes and others. Blood should not clot in order to be useful and any method that achieves this without damaging plasma and red blood cells is acceptable.

The large chicken eggs were separated, the yolk and the calabash were discarded and the egg white was retained.

The egg white was separated into the coarse and thin portions by casting the white through a nylon mesh of 1000 micras for about 3 minutes, and the thinnest part was discarded. The thick part of the egg white was retained on the mesh and was collected and pulled into a 60 cubic centimeter syringe which was then placed in a programmable syringe pump and homogenized by ejecting and filling the contents 5 times. The amount of homogenization was controlled by the syringe pump rate of about 100 milliliters / minute and the inner diameter of the tube of about 0.12 inches. After homogenization, the thick egg white had a viscosity of about 20 centipoise to 150 sec "1 and was then placed in the centrifuge and turned to remove debris and air bubbles around 3000 revolutions per minute around 10 minutes.

After the . centrifuged, the homogenized and thick egg white, which contained the ovomucin, was added to a 300 cubic centimeter FENWAL Transfer pack container using a syringe. Then 60 cubic centimeters of pig plasma were added to the FENWAL® transfer pack container. The FENWAL® transfer pack container was held, all air bubbles were removed, and placed in a Stomacher laboratory mixer where they were mixed at a normal (or average) speed for about 2 minutes. The FENWAL® transfer pack container was then removed from the mixer, 60 cubic centimeters of red pig blood cells were added, and the contents were mixed by hand by kneading for about 2 minutes or until the contents appeared homogeneous. A hematocrit of the final mixture showed a red blood cell content of about 30 percent by weight and should generally be within the range of 28-32 percent by weight for artificial menstrual fluids made according to this example. The amount of egg white was around 40 percent by weight., The ingredients and equipment used in the preparation of artificial menstrual fluids are readily available. Below is a list of sources for the items used in the example, although of course other sources can be used provided they are approximately equivalent.

Blood (pig): Cocalico Biologicals, Inc., 449 Stevens Rd., Remsto n, PA 17567, (717) 336-1990.

Fenwal® 300 milliliter transfer vessel with coupler, code, 4R2014: Baxter Healthcore Corporation, Fenwal Division, Deerfield, IL 60015.

Programmable Syringe Pump Harvard Apparatus, model No. 55-4143: 'Harvard Apparatus, South Natick, MA 01760.

Stomacher 400 laboratory macerator model No. BA 7021, series No. 31968: Seward Medical, London, England, United Kingdom. 100 micron mesh, item No. CMN-1000-B: Small Parts, Inc., P.O. Box 4650, Miami Lakes, FL 33014-0650, 1-800-220-4242.

Hemata Stat-II Device for Measuring Blood Cells, Series No. 1194Z03127: Separation Technology, Inc., 1096 Rainer Drive, Altamont Srpings, FL 32714.

DETAILED DESCRIPTION OF THE INVENTION Absorbent personal care articles include such items as diapers, training underpants, incontinence devices and garments, bandages, women's hygiene products, such as sanitary napkins, pant lining and plugs, and the like. The most basic design of all those items typically includes a side-to-body liner, an outer shell and an absorbent core placed between the body-side liner and the outer shell.

Women's hygiene products such as towels, for example, have absorbent cores which have traditionally been designed to take the flow of slow and thick fluid. Women who menstruate, however, usually complain of experiencing surges or sudden effusions of menstrual discharge that leaves the body as a discharge of short delivery time and high volume of fluid. An absorbent core designed to handle the slowly moving flow usually has a small pore size structure to quickly take these effusions or limited emergences of fluid, and as a result, fluid stagnation may occur on the surface of the product . Stagnation on the surface can result in runoff or staining of clothing and is unacceptable to the user. Alternatively absorbent materials which have a pore structure large enough to quickly absorb the bubbles usually can not redistribute that fluid to the end edges of the products as resulting in an accumulation of emergence fluid in the central part of the pad where the pressure of the lateral legs can cause runoff.

What is required and provided by the invention is an absorbent structure which can quickly take fluid effusions or surges, pull the fluid out of the top of the absorbent to achieve a dry feeling for the user, return to distribute the fluid along the entire length of the structure and optionally release the fluid to other subsequent absorbent layers. Although the invention is primarily concerned with feminine hygiene products, the inventors believe that the material of the invention herein can function in the handling of other body fluids such as urine, and will be especially effective for highly viscous fluids such as those of bowel movements (stools) - and exudate from wounds and will be incorporated into diapers, underpants, garments and incontinence devices, bandages and the like.

A personal care product typically has a side-to-body layer, optionally a fluid transfer layer, a fluid retention layer and a side-to-side layer. You can also have a distribution layer or other optional layers to provide specialized functions.

The side-to-body layer is sometimes mentioned as a top sheet facing the body. In the thickness direction of the article, the lining material is the layer against the skin of the wearer and thus the first layer in contact with the liquid or other exudates from the wearer. The lining also serves to isolate the wearer's skin from liquids maintained in the absorbent structure and must be docile, soft-feeling and non-irritating.

The body side liner may be surface treated with a selected amount of surfactant, or may be processed in another manner to impart the desired level of wettability and hydrophilicity. If a surfactant is used, it may be an internal additive or it may be applied to the layer by conventional means, such as spraying, brush coating and the like before depositing the next layer.

The side-to-garment lining layer, also referred to as an outer cover or lower sheet, is the layer farthest from the wearer. The outer cover has traditionally been formed of a thin thermoplastic film, such as a polyethylene film which is essentially impermeable to liquid. The outer cover works to prevent the exudates of the body contained in an absorbent structure from wetting or soiling the wearer's clothing, bedding or other materials that make contact with or are side by side with the personal care product. The outer cover can be engraved and / or finished to provide a more aesthetically pleasing appearance. Other alternate constructions for the outer covering include woven or non-woven fibrous fabrics that have been constructed or treated to impart to them the desired level of liquid impermeability, or to the laminates formed of a woven or non-woven fabric and thermoplastic film. The outer cover may optionally be comprised of a microporous, gas permeable or vapor permeable "breathable" material, which is permeable to vapors or gas but which is still essentially impermeable to liquid. The ability to breathe can be imparted to polymer films by, for example, using fillers in the film polymer formula, in extruding the polymer / filler formula into a film and then stretching the film sufficiently to create gaps around it. of the filler particles, thus making the film capable of breathing. Generally, the more filler is used and the higher the degree of stretch, the greater the degree of ability to breathe. The backs can also serve the function of a matching member for the mechanical fasteners in the case, for example, wherein the non-woven fabric is the outer surface.

The fluid retention layer or layers must absorb the liquid from the side layer to the adjacent body in a controlled manner so that the liquid can be stored out of contact with the body. This can occur even under effusion conditions. A composite structure has been invented which can easily receive sudden surges or effusions of fluid, pull fluid out of the liner from side to body, distribute the fluid along the length of the retention layer and pass the fluid to a bottom layer which will either function as the final fluid destination or will function as a transfer area to move the fluid to another absorbent layer, which may be remote from the discharge area.

The inventive composite structure preferably has at least three fibrous layers; a first fibrous or higher layer of a relatively low density adjacent to and in communication of the liquid with a middle layer or predominantly composed layers of oriented surface fibers which are preferably aligned which in turn are adjacent to and in fluid communication with a second fibrous or lower layer of a relatively higher density. The first low density layer is intended to provide good fluid absorption from a continuous and slow fluid flow as well as a sudden efflux flow. For a relatively low density, what is meant is a density of between about 0.02 and. 0.14 grams per cubic centimeter. In the second fibrous layer, the relatively higher density indicates a density above the density of the upper layer. The second fibrous layer desorbs the layer of oriented surface fibers, regenerating the hollow space between the middle layer and allowing the oriented fibers to continue transporting more fluid along the length of the product. The second fibrous layer with a higher density is preferably homogeneous, in its resistance to liquid flow, for example, the lower layer must not contain areas of high and low resistance to fluid flow.

The upper and lower fibrous layers may be made of predominantly hydrophilic synthetic fibers, natural fibers and binders or a combination of such fibers, according to fibrous tissue making processes known to those skilled in the art, including spunbonding , meltblowing, coformation, carded and bonded weaving processes, tissue formation including wet laying and air placement. The upper and lower fibrous layers can be produced by the same or different methods of forming nonwoven material.

The middle layer interposed between the first layer of low density (or higher) and the second layer of higher density (or lower), works to desorb the top layer, and then distribute the fluid evenly along the length of the product. The oriented surface fibers can be spread evenly across the width of the layer. However, the inventors have found that the most effective use of the fluid transport capacity of the oriented surface fibers occurs when the fibers are aligned in the longitudinal direction of the product, and are spaced apart in one or more tight bunches or bunches to through the width of the material. These bundles reflect the longitudinal strips or zon of higher levels of fiber basis weight and fibrous surface area and small interfiber spacing regions for an increased transport distance and a volume of fluid transported along the product length. The number of bunches and of filament count p bunch will depend on the fluid chemistry of the body that is being transported and the volume presents. More bundles and m filaments will be needed for high fluid volume applications such as diapers, incontinence products and underpants.

The layer or surface layers of oriented fiber may be predominantly hydrophilic synthetic fibers, natural fibr and binders which may be in the form of round or continuous filament fibers or basic fibers and capillary surface materials of continuous filament fibers and channel materials continuous filament capillary continuous filament superabsorbent fibers, stabilized basic fibr tops, and other highly oriented hydrophilic nonwoven fabrics such as bonded carded fabrics, oriented meltblown fabrics and stretched and narrowed woven fabrics or a combination thereof. Such fibers, filaments and layers. The processes for making such layers include those for the production of the first and second fibrous layers. The oriented surface fibers can be monocomponent fibers, biconstituent fibers and conjugated fibr.

The layer containing surface fibers oriented in the practice of the invention may include several denier fibers. The layer can have fibers of a single denier of a denier blend and the range of deniers that works satisfactorily was created by the inventors which is very broad Using a mixture of deniers in the layer can improve transmission performance of the layer and It can add to the structural stability of the coat as well.

In order to produce a successful personal care product using the present invention, it was believed that at least 2 square meters of surface area of the tooth surface fibers are required. Even though this to a prime impression may seem like a large number for relatively small products such as pads for women's hygiene, there is a very large surface area p unit length. Orient fibers must be placed in product in an essentially aligned direction, for example, more than 75% of the hydrophilic fibers are aligned in the same direction, which is about 30% degrees with the direction of fluid movement that is desired . The fibers can be placed in zones or concentrated strips so that they are located close to each other to increase the transmission. These strips or zones can each be up to 20 millimeters wide and must have a minimum basis weight of around d grams per square meter. Multiple strips or zones can be used in a product, depending on its size, physical characteristics or the particular fluid that is being handled as well as the volume of fluid that is being handled.

The conjugated and biconstitute fibers provide the ability to stabilize the tissue through, for example, thermal bonding. With thermal bonding, they function as binders or adhesives, keeping the fibers in place to improve tissue integrity. E fibers also help in the transfer of liquid between layers. Such fibers can be used in any or all layers of a product.

The superabsorbent particles and the fi particles can also be used in the second fibrous layer in order to provide the storage of final fluid. It is important to note, however, that the amount of superabsorbent in the lower layer must be carefully considered since excessive amount can overwhelm and significantly reduce the amount of transmission that occurs in the medium oriented surface fiber layer. A superabsorbent effective amount, in any form, is the quantity c allows the transmission to continue.

The superabosorbents that are useful in present inventions can be chosen from the base classes on the chemical structure as well as the physical form. They include superabsorbents with a gel strength or a high gel strength, superabsorbents bonded in cross-linked surfaces, superabsorbents bonded in uniformly cross-linked or superabsorbents with a varied cross-linked density across the structure. superabsorbents may be based on chemicals including, but not limited to, acrylic acid, maleic anhydride / isobutylene, polyethylene oxide, carboxymethylcellulose, polyvinylpyrrolidone, and polyvinyl alcohol. The superabsorbents can vary in the slow to fast cup. The superabsorbents may be in the form macroporous or microporous foams, particles or fibers, may have a morphology or fibrous or spongy coatings. superabsorbents can be in the form of tapes, fibers, leaves or films. The superabsorbents can be various distributions and sizes of diameter and lengths. superabsorbents can be in various degrees of neutralization Neutralization occurs through the use of ta ions such as Li, Na, K, Ca. These examples of types of superabsorben can be obtained from Stockhausen, Inc. under the trade name FAVOR®880. Examples of these superabsorbent types obtained from Camelot are recognized with FIBERDRI®1241 and FIBERDRI®1161. Examples of these superabsorbent types obtained from Technical Absorbents, Ltd., recognized as Oasis 101 and Oasis 111. Another example including these types of superabsorbents is obtained from Chemdall Inc. designated FLOSORB®60 Lady. Another example included in these ti of superabsorbents is obtained from Sumimoto Seika of Japan and is recognized as SA60N® Type 2. Additional types of superabsorbents not listed here which are commonly available and are commonly known to those skilled in the art may also be useful in the present invention The laminates of this invention can be made by producing each layer separately and then joining together. Alternatively, it is also possible to produce the layers directly on one another in a continuous process. In any case, it is necessary to join the joints together in some way so that the communication of the liquid between the layers is possible.

Such bonding can be made, for example, as a binding through air, thermal bonding, adhesive bonding similar as described above. The online process allows for simple heat bonding between the layers as they are produced, without any additional separate bonding steps. Any method for joining the layers of man that liquid communication is allowed and which is known by those experts in art.

The structures of this invention can make various materials including synthetic fibers, natural fibr, binders and oriented surface fibers.

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

Natural fibers include wood, cotton, linen, hemp and wood pulp. The pulp includes the class of standard soft wood fluff such as Coosa Mills C 1654, the high volume aditi formaldehyde-free pulp (HBAFF) available from Weyerhaeuser Corporation Tacoma, Wa, and which is a soft wood pulp fiber s crosslinked with an increased wet modulus, a pulp fiber chemically crosslinked t as Weyerhaeuser NHB416.

The HBAFF has a chemical treatment curing in a curled and twisted, in addition to imparting an aggregate dryness and a wet stiffness and elasticity to the fiber, ot appropriate pulp is the Buckeye HP2 pulp and yet another is the International Paper's Superso IP Corporation. Suitable ra fibers are Merge 18453 fibers from 1.5 denier from Acor Fiber (formerly known as Courtaulds Fiber Incorporat from axis, Alabama.

Binders include fiber, liquid, other binding media which can be thermally activated. Exemplary binders include conjugated fibrils of polyolefins and / or polyamide and liquid adhesives. Two such suitable binders are the sheath and core conjugate fibers available from KoSA Inc. (formerly Trev Inc. and formerly Hoechst-Celanese), from PO Bos 4. , Salisbu North Carolina 28145-0004 under the designation T-255 and T-2 even though many suitable binder fibers are known to those skilled in the art and made by many manufacturers such as ES FiberVisions Inc. A liquid binder is Kymene® binder. 557LX available from Hercules Inc. Wilmingnton, Dela are.

Surface fibers oriented as capillary surface materials of the preferred case that can spontaneously transport certain fluids are discussed, for example, Patent Application PCT / US97 / 14607, European Patent Application 0 391 814 A2, and Patents of the latter. United States of America numbers 5,200,248, 5,242,644, 5,268.2 5,611,981 and 5,723,159.

Patent PCT / US97 / 14607 discloses a bunch of fibers which comprises at least two fibers that act as individual fibers but are poor fluid carriers, but when they are in a bundle the fibers provide a bundle which is an excellent fluid conveyor. The bundle has a specific volume greater than cubic centimeters per gram (cc / gm), an average fiber capillary width of from 25 to 400 microns and a length greater than one centimeter (cm). At least one of the at least fibers has a non-round cross section, a single fiber volume factor greater than 4.0, a specific capillary volume less than 2.0 cc / gm, and more than 70% of intrafiber channels that have a width of capillary channel greater than 3 microns. Preferably, the cross section defines a first arm having a length greater than 40 microns. The lengths of the cross section of the fibers vary up to around 1000 microns with some having arm lengths that are between 100 and 400 microns. Preferably, the fibers have a denider of between 15 and 250. Figure 2 shows a fiber satisfying the requirements of this patent application.

European Patent Publication 0 391 814 describes fibers which are capable of spontaneously transporting water on their surface. The fiber satisfies the equation: (1-X cos?) = O where? a is the water advance contact angle measured on a flat film made of the same fiber material and having the same surface treatment, any, X is a form factor of the fiber cross section that satisfies the following equation : x = Pw 4r + (p-2) D where Pw is wetted perimeter of the fibr r is the radius of the circumscribed circle circumscribing fiber cross section and D is the smaller axis dimension across the fiber cross section. Figure 3 shows a fiber that meets the requirements of this patent application.

A number of examples of different materials satisfying the purpose of the invention were made and are described in detail below. Note that the comparative examples 1 and 7 are not examples according to this invention.

Example 1 The top layer was a material placed by ai made of 80% by weight of pulp and 20% by weight of fib binder having a basis weight of about 75 grams square meter and a density of about 0.04 grams cubic centimeter. The NB-416 pulp was made from Weyerhaeuser and binder fiber was of the ES-C type made by ES FiberVisi Inc. (formerly known as Danaklon from Varde, Dinamar from Chisso Corporation of Japan, and / or Hercules Inc. from Wilmingt Delaware).

The oriented surface fiber layer is made of polyester fibers formed according to PCT / US97 / 146 having more than 100 filaments per pad and more than denier per filament.

The bottom layer was a material placed by ai made of 90% by weight of pulp and 10% by weight of fib binder having a basis weight of about 75 grams per square meter and a density of about 0.08 grams per cubic centimeter. The pulp was NB-416 made by Weyerhaeuser. The binder fiber was type 255, 2.8 denier made by KoSA Inc., of Charlotte, North Carolina.

Example 2 (comparative) The top layer was a material placed by ai made of 80% by weight of pulp and 20% by weight of fib binder having a basis weight of about 75 grams per square meter and a density of about 0.04 grams cubic centimeter. The pulp was NB-416 made from Wayerhaeuser and binder fiber was of the ES-C type made by ES FiberVisi Inc. There was not a layer of surface fibers oriented in the composite structure.

The lower layer was a material placed by fact of 90% by weight of pulp and 10% by weight of binder having a basis weight of about 75 grams square meter and a density of about 0.08 grams cubic centimeter. The pulp was NB-416 made from Wayerhaeuser and binder fiber was type 255 made by KoSA Inc. Charlotte, North Carolina.

Example 3 The top layer was a material placed by a fact of 40% by weight of pulp, 30% by weight of polyester fiber and 30% by weight of binder fiber having a base p of about 65 grams per square meter and a density of about of 0.04 grams per cubic centimeter. The NB-416 pulp made by Wayerhaeuser, the binder-core conjugate binder fiber was type 255 made by KoSA Inc., Charlotte, North Carolina and the polyester fiber was ti 295 of 6 deniers made by KoSA, Inc.

The oriented surface fiber layer is made of polyester fibers formed according to patent application PCT / US97 / 14607 having more than 100 pillow filaments and more than 60 denier per filament.

The lower layer was a material placed by itself made of 90% by weight of pulp and 10% by weight of binder fiber having a basis weight of about 75 grams per square meter and a density of about 0.08 grams per cubic centimeter. The pulp was NB-416 made by Wayerhaeuser. The conjugate binder fiber sheath and core was type 2 made by KoSA, Inc. of Charlotte North Carolina.

Example 4 The top layer was a woven bonded woven material made of 40% by weight of polyester fiber and 60% by weight of binder fiber having a basis weight of about grams per square meter and a density of about 0.0 grams per cubic centimeter . The polyester fiber was 295 denier 6 and the sheath / core conjugate binder fiber was type 255, both fibers made by KoSA Inc. of Charlotte North Carolina.

The oriented surface fiber layer was made of polyester fibers formed according to PCT / US97 / 146 having more than 100 filaments per pillow and more than deniers per filament.

The lower layer was a material placed by a fact of 86% by weight of pulp and 14% by weight of binder having a basis weight of about 80 grams square meter and a density of about 0.07 grams cubic centimeter. The pulp was NB-416 made by Wayerhaeuse. The binder fiber was type 255 made by KoSA Inc., North Carolina of Charlotte.

Example 5 The top layer was a material placed by ai made of 90% by weight of pulp and 10% by weight of fib binder having a basis weight of about 65 grams per square meter and a density of about 0.03 grams per cubic centimeter. The pulp was NB-416 made by Wayerhaeuser. The binder fiber was type 255 made by KoSA Inc., Charlotte North Carolina.

The oriented surface fiber layer was made of polyester fibers formed according to Paten PCT / US97 / 14607 having more than 100 filaments per pad more than 60 denier per filament.

The lower layer was a shaped material having 50% by weight of pulp and 50% by weight of blown fibers melting polypropylene microfibers having a basis weight around 75 grams per square meter and a density around 0.09 grams per cubic centimeter. The CF405 pulp made by Wayerhaeuser and the polypropylene polymer obtained under the trade name Montell PF-015 from Mont USA., Inc., which has offices in Wilmington, Dela.

Example 6 The top layer was a material placed by a fact of 80% by weight of pulp and 20% by weight of binder having a basis weight of about 65 grams square meter and a density of about 0.04 grams cubic centimeter. The pulp was NB-416 made by Wayerhaeuse the binder fiber was of the ES-C type made by ES FiberVisi Inc. The oriented surface fiber layer was made of round polyester fib having more than 100 pad filaments and more than 3 denier per filament.

The lower layer was a material placed by fact of 90% by weight of pulp and 10% by weight of binder having a basis weight of about 75 grams square meter and a density of about 0.08 grams cubic centimeter. The pulp was NB-416 made by Wayerhaeuse. The binder fiber was type 255 made by KoSA Inc., Charlotte North Carolina.

Example 7 (comparative) This single-ply fabric was an air-laid material made of 90% by weight pulp and 10% by weight of binder having a basis weight of about 250 grams square meter and a density of about 0.14 grams cubic centimeter. The pulp was NB-416 made by Wayerhaeuse. The binder fiber was type 255 made by KoSA, Inc. Charlotte North Carolina.

In the multi-layered examples the ca were joined together by binding through air in the described manner. The materials of the examples were tested according to the effusion / distribution test and the results are shown in Table 1.

Table 1 Penetration Time (Seo.) Distribution Ratio Example 1 10.98 0.238 Example 2 15.00 0.006 Example 3 15.06 0.184 Example 4 9.99 0.183 Example 5 14.94 0.189 Example 6 18.65 0.118 Example 7 27.60 0.001 As can be seen from these results, composite structures of this invention absorb an effus quickly, especially when compared to the example (comparative) as measured by the penetration time. Acceptable penetration times for personal care products should be less than 40 seconds. Distribution ratio results show that materials containing toothed surface fibers in composite material move fluids along their length very well as well, resulting in distribution ratios above 0.06 in all cases. This distribution rate combined with a penetration time below 40 as it produces products which deliver superior performance.

Although only a few exemplary embodiments of this invention have been described in detail to those skilled in the art, it will readily appreciate that many modifications to the exemplary embodiments are possible without departing materially from the novel teachings and advantages of this invention. Therefore, all such modifications are intended to be included within the scope of this invention as defined in the appended claims. In claimsThe media claims more function tries to cover the structures described here as carrying out the recited function and not only the equivalent structure but also the equivalent structures. Therefore, even if a screw and a nail can be structural equivalents the sense that a nail employs a cylindrical surface to secure joints to the wooden parts, while a screw employs a helical surface, in the environment of the fastening of parts of the nail. wood, a screw and a nail can be equivalent structures.

Claims (23)

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

1. A fluid handling material to produce for personal care comprising a fabric that distributes artificial menstrual fluids according to distribution / effusion test results in a rate of distribution of at least about 0.06.

2. The material as claimed in clause 1, characterized in that said material has a penetration of less than 40 seconds.

3. The material as claimed in clause 1, characterized in that said fabric has at least two square meters of surface area of superf oriented fibers.

4. The personal care product comprises the fabric as claimed in clause 3.

5. The personal care product ta as claimed in clause 4, characterized in that oriented surface fibers are essentially aligned

6. The personal care product as claimed in clause 4, characterized in that oriented surface fibers are arranged in at least one area, each zone of at least 20 millimeters wide has a basis weight of at least 50. grams per square me.

7. A pad for the hygiene of the mu comprising the fabric as claimed in the clause

8. The fluid handling material as claimed in clause 1, further characterized by comprising a fibrous absorption layer.

9. The personal care product as claimed in clause 8, further characterized by comprising a second fibrous layer on a side opposite the take-up layer and having a density greater than that of the take-up layer.

10. The personal care product as claimed in clause 9, characterized in that the second layer is engraved.

11. The personal care product as claimed in clause 9, characterized in that the second layer is engraved with a sinusoidal wave pattern.

12. The personal care product as claimed in clause 11, characterized in that the layers are bonded together with an adhesive binder.

13. A fluid handling material as claimed in clause 9, characterized in that at least one layer is made according to the selected process of the gr consisting of joining with spinning, blown with fusi coformación, processes of carded and joined fabric, air placement and tissue formation placed in wet.

14. The personal care product comprises the material as claimed in the clause characterized in that at least one layer is made of materials selected from the group consisting of fibrous cellulose, synthetic fibers and mixtures thereof.

15. A laminate comprising a first fibrous c having a density of between about 0.02 and 0. grams per cubic centimeter, an adjacent middle layer a and communication of liquid with said first layer and which purchases the oriented fiber surface materials and a subsequent fibrous layer adjacent to and in fluid communication with the middle layer and having a density greater than said prime density and said middle layer comprising the surface oriented fibers.

16. The laminate as claimed in clause 15, characterized in that at least one layer is according to a process selected from the group consisting of joining processes with spinning, blowing with fusion, coformació carded and joined fabric, placement by air and formation of you placed in wet.

17. The laminate as claimed in clause 15, characterized in that said fibers of the med layer are essentially aligned.

18. The laminate as claimed in clause 15, characterized in that said fibers of the med layer are not round.

19. The laminate as claimed in clause 15, characterized in that it also comprises superabsorbents.

20. The laminate as claimed in clause 15, further characterized in that it comprises conjugated fibr.

21. The laminate as claimed in clause 15, characterized in that said middle layer comprises superabsorbent fibers.

22. .A personal care product comprises laminate as claimed in clause 1

23. A product for the hygiene of women includes: a first fibrous layer having a density between about 0.02 and 0.14 grams per cubic centimeter; a middle layer adjacent to and in liquid communication with said first layer and comprising at least square meters of surface area of non-round hydrophilic oriented surface fibers essentially aligned at least one area up to 20 millimeters wide and weighing one base of around 50 grams per square meter and, a second fibrous layer adjacent to and communication of liquid with said middle layer and having a density greater than that of said first layer; wherein said product has a penetration time of less than 40 seconds and wherein said product distributes the artificial menstrual fluids according to the effusion / distribution test resulting in a distribution rate of at least about 0.06. SUMMARY A flu handling material is provided for personal care products that distributes artificial menstrual fluids according to an effusion / distribution test taught here so that it has a distribution rate of at least about 0.06. it prefers that the fluid handling material be part of the system of absorbent materials having a first fibrous c, a middle layer adjacent to the first layer that the hydrophilic oriented surface fibers and a second fibrous c adjacent to the middle layer. In a personal care product configuration, oriented surface fibers result in a distribution rate of at least 0.06 where the rate of distribution is an average ratio of the mass of two end zones of a product divided by the mass of the center area.