MXPA98002482A

MXPA98002482A - Method for forming a non-woven frame that shows gradients of energy in the surface and caliber increment

Info

Publication number: MXPA98002482A
Application number: MXPA/A/1998/002482A
Authority: MX
Inventors: William Cree James; Eduardo Ferraz Do Amaral Luis; Ravaglia
Original assignee: The Procter&Ampgamble Company
Priority date: 1995-09-29
Filing date: 1998-03-30
Publication date: 1999-01-11

Abstract

The present invention relates to a method for forming a nonwoven web that exhibits a plurality of surface energy gradients in a preferred embodiment. The method includes the steps of: providing a nonwoven web of fibers exhibiting a surface energy, said nonwoven web having a first surface, a second surface, a gauge, and a plurality of fluid passages that place the first and second surfaces in fluid communication with each other, applying a surface treatment to the first surface of the nonwoven web, the surface treatment having a surface energy less than the surface energy of the fibers of the non-woven web, creating a plurality of surface energy gradients defined by the discontinuous, spaced regions, which are adapted to exert a force on the fluid contacting the first surface, such that the fluid will be directed to the fluid passages for transportation away from the first surface and in the direction of the second surface, and increase the caliber of the non-woven web by feeding the non-woven fabric between a first pressure applicator and a second pressure applicator, each having three-dimensional surfaces, which at least to one degree are complementary to each other. The nonwoven web is particularly well suited to be used as a top sheet in an absorbent disposable article.

Description

METHOD TO FORM A NON-WOVEN FRAME THAT SHOWS ENERGY GRADIENTS ON THE SURFACE AND CALIBER INCREASED FIELD OF THE INVENTION The present invention relates to a nonwoven web with openings, which is suitable for use as a fluid transport mechanism, and a method for making the same. In particular, the non-woven web is designed to facilitate the transport of fluid in a preferential direction from one surface to another surface and resist the transport of fluid in the opposite direction.

BACKGROUND OF THE INVENTION It has been long known in the field of disposable absorbent articles that it is extremely desirable to construct absorption devices, such as disposable diapers, sanitary napkins, incontinence trunks, wound bandages, and the like, which have a dry surface feel to the user to improve the comfort of use and to minimize the potential of developing undesirable skin conditions due to prolonged exposure to moisture absorbed within the article. Accordingly, it is generally desirable to promote the rapid transfer of fluid in a direction away from the wearer and toward a retention structure, while resisting fluid transfer in the reverse direction. A viable solution of the state of the art to the aforementioned problem has been to use a cover or upper sheet on the exposed surface facing the user of the disposable absorbent article, which comprises a nonwoven web. Nonwoven webs formed by extrusion processes of the nonwoven web such as, for example, melt blowing processes and spinning bonding processes can be manufactured into products or product components in a cheap manner that the products can be viewed as Disposable after a single or some uses. Often, the nonwoven webs are used as top sheets in disposable absorbent articles since they exhibit capillary fluid transport characteristics through the three dimensional capillaries formed by the inter-fiber spaces, thus leading the fluid away from the surface of contact with the user and towards the underlying absorbent structure. These nonwoven webs also exhibit a surface appearance and a fabric-like impression, aesthetically pleasing, due to their fibrous nature. Although the nonwoven webs are effective in transporting the fluid, their effectiveness is limited in that these capillary structures can only move the fluid once it reaches the inner capillary. The fluid that moistens and remains on the surfaces of contact with the user contribute to a "wet" feeling or impression, and the point at which this can be colored or dull also contributes to a "stained" visual impression. Surface textures naturally occur in the weft material or imparted to the weave in the formation also increase the likelihood that the residual fluid will be trapped or retained on the contact surface with the body instead of entering the capillary structure for transport away from the surface. Therefore, surface topographies that contribute to desirable visual and tactile impressions when dry, also tend to retain residual fluid on the exposed surface and thus reduced desirable capacity under conditions of use. Accordingly, it would be desirable to provide a nonwoven web with increased effectiveness by transporting the fluid away from a surface that is initially in contact with a fluid. More particularly, it would be desirable to retain the visual and tactile properties of the nonwoven webs, while promoting faster and more complete liquid transport, away from the contact surface with the user and into an absorbent article. associated. As used in this, the term "non-woven weft", refers to a weft having a structure of individual fibers or threads, which are interlaced, but not in any regular, repeating manner. The non-woven webs have, in the past, been formed through a variety of processes, such as, for example, meltblowing processes, spinning bonding processes and bonded carded web processes. As used herein, the term "microfibers" refers to small diameter fibers that have an average diameter no greater than about 100 microns. As used herein, the term "melt blown fibers" refers to fibers formed by extruding a molten thermoplastic material through a plurality of fine die capillaries, usually circular, such as fused filaments or filaments, to through a stream of gas (eg, air) at high speed, which attenuates the filaments of molten thermoplastic material to reduce its diameter, which can be to a microfiber diameter. Then, the fibers blown under melting are carried through the gas stream at high speed and are deposited on a collection surface to form a web of randomly dispersed melt blown fibers. As used herein, the term "spunbonded fiber" refers to fibers of small diameter, which are formed by extruding a molten thermoplastic material such as filaments, from a plurality of thin, usually circular, capillaries of a spinner. with the diameter of the extruded filaments then being rapidly reduced, for example, by means of eductive stretching or other well known splicing mechanisms. As used herein, the term "elastic" refers to any material which, after the application of a diverting force, is stretchable, i.e. stretchable, at least about 60% (i.e. stretched, deflected length, which is at least approximately 160% of its relaxed non-deflected length), and which, will recover at least 55% of its elongation after releasing the stretching force, elongation. A hypothetical example could be a 2.54 cm sample of a material, which can be elongated to at least 4,064 cm, and which, after being lengthened to 4,064 cm and released, will recover to a length of no more than 3.2258 cm. Many elastic materials can be lengthened to more than 60% (ie, much more than 160% of their relaxed length), for example, lengthened to 100% or more, and many of these materials will recover to substantially initial relaxed length. , for example, in a 150% of its initial relaxed length, after releasing the stretching force. As used herein, the term "non-elastic" refers to any material, which does not fall within the definition of "elastic" above. As used herein, the term "extensible" refers to any material that, after application of a diverting force, is extensible, at least approximately 50% without experiencing a catastrophic failure. As used herein, the term "passage" is intended to encompass closed or at least partially enclosed structures or channels, which can communicate fluids. The term fluid passage in this manner is intended to encompass the terms "aperture," "channel," "capillary," as well as other similar terms.

BRIEF DESCRIPTION OF THE INVENTION The present invention relates, in a preferred embodiment, to a method for selectively forming a fluid permeable nonwoven web, which exhibits a plurality of surface energy gradients. The method comprises the steps of: providing a fiber nonwoven web, permeable to the fluid, which exhibits an energy on the surface, the nonwoven web has a first surface or contact with the user, a second surface or which faces the garment, an initial gauge, and a plurality of fluid passages placing the first and second surfaces in fluid communication with each other; applying a surface treatment to the first surface of the nonwoven web, the surface treatment having a surface energy less than the surface energy of the fibers of the non-woven web, thereby creating a plurality of surface energy gradients defined by separate, discontinuous regions, which are adapted to exert a force on the first surface in contact with the fluid, so that the fluid will be directed towards the fluid passages for transport away from the first surface and in the direction of the second surface; and increase the caliber of the nonwoven web so that it is larger than the initial caliber. Preferably the nonwoven web is subjected to mechanical formation to provide the nonwoven web with an increased gauge. The non-woven web is preferably fed between a first pressure applicator and a second pressure applicator, each having three-dimensional surfaces, which at least to one degree are complementary to each other, the first pressure applicator comprises a plurality of separate tooth regions apart by a plurality of grooved regions, the toothed regions comprise a plurality of teeth, the second pressure applicator comprises a plurality of teeth which mesh with the plurality of teeth on the first pressure applicator. As the nonwoven web is fed between the pressure applicators, the part of the non-woven web that passes between the teeth on the first pressure applicator and the teeth on the second pressure applicator is mechanically formed producing high portions in rib shape that provide the nonwoven web with an increased gauge, while the part of the nonwoven web that passes between the grooved regions on the first pressure applicator and the teeth on the second applicator, remains substantially unchanged, is say, its caliber remains substantially unchanged. The nonwoven web is particularly well suited for use as a top sheet on a disposable absorbent article. The first and second surfaces are separated from one another through an intermediate portion. The first surface of the nonwoven web provides a structure which exhibits a surface energy less than the surface energy of the intermediate portion. In a preferred embodiment, the nonwoven web exhibits a plurality of comparatively low surface energy regions., which define gradients of energy on the surface where they interconnect with the surfaces of the energy grid on the upper surface. More particularly, the present invention relates to a fluid pervious nonwoven web having a plurality of small scale surface energy gradients, which are oriented and located in order to effectively transport the fluid away from the first surface or contact with the user. The non-woven web essentially retains its visual, tactile and physical properties of the substrate material, while obtaining the desired surface energy properties. The non-woven webs according to the present invention preferably include discrete, spaced regions, which define energy gradients on the small scale surface on the first surface, to assist the movement of small-scale fluid towards the capillary inlets for transportation away. of the first surface. Said frames also preferably include normal small scale surface energy gradients to the first surface within a capillary strre to aid fluid movement away from the first surface and toward the capillaries for the transport of capillary fluid. The present invention also relates to absorbent articles, which preferably include a topsheet, a backsheet secured to the topsheet, and an absorbent core positioned between the topsheet and the backsheet, wherein the topsheet exhibits gradients. of energy on the surface according to the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS Since the specification concludes with the claims particularly pointing out and distinctly claiming the present invention, it is believed that the present invention will be understood as improvement from the following description taken in conjunction with the accompanying drawings, in which reference numbers identify similar elements, and Figure 1 is a schematic representation of an illustrative method for forming a nonwoven web exhibiting energy gradients on the surface of the present invention; Figure 2 is a perspective illustration, partially broken away, enlarged of a nonwoven web of the present invention; Figure 3 is a partial, enlarged view of the nonwoven web of Figure 2; Figure 4 is an enlarged cross-sectional view of a liquid droplet on a solid surface, wherein the angle A illustrates the contact angle of the liquid with the solid surface; Figure 5 is an enlarged cross-sectional view of a liquid droplet on a solid surface having two different energies on the surface, thus exhibiting two different contact angles A (a) and A (b); Figure 6 is an enlarged cross-sectional view of a drop of liquid located adjacent to a generic capillary exhibiting a gradient of energy at the surface; Figure 7 is an enlarged perspective illustration of a pair of pressure applicators of the present invention; Figure 7A is a segmented, perspective illustration of a nonwoven web of the present invention that has been mechanically formed by a pressure applying system to provide the nonwoven web with an increased gauge; Figure 7B is an enlarged, perspective illustration of another pair of opposing pressure applicators of the present invention; Figure 8 is a top plan view of a sanitary napkin with portions of the sanitary napkin trimmed to more clearly show the construction of the sanitary napkin; Figure 9 is a cross-sectional view of the sanitary napkin of Figure 8 taken along section line 9-9; Figure 10 is a top plan view of the portion of the topsheet of a sanitary napkin embodiment made in accordance with the present invention; Figure 11 is a top plan view of the topsheet portion of another sanitary napkin embodiment made in accordance with the present invention; and Figure 12 is a perspective illustration, amplified, partially segmented, of an absorbent article made in accordance with the present invention.

DETAILED DESCRIPTION OF THE PRESENT INVENTION Referring to Figure 1, a method for selectively forming a nonwoven web with openings exhibiting energy gradients on the surface of the present invention, which is suitable for use as a disposable absorbent article, is schematically illustrated at 20. In accordance with the present invention, a non-woven web 22 is wound from a supply roll 24 and travels in a direction indicated by the arrows associated therewith, as the supply roll 24 rotates in the direction indicated by the arrows associated with it. The non-woven web 22 passes underneath a sprinkler 26, which directs a surface treatment 28 on a surface of the non-woven web 22. The non-woven web 22 can be formed through known nonwoven web extrusion processes, such as, for example, well-known meltblown processes or well-known spin-bonding processes, and passes directly below the sprayer 26 without first being charged with a supply roller. The nonwoven web 22 may be extensible, elastic or non-elastic. The non-woven web 22 may be a spin-linked web, a web blown under melting, or a joined carded pattern. If the non-woven web is a web of blown fibers under melting, it may include microfibers blown under melting. The non-woven web 22 may be made of natural fibers such as wood, cotton, or rayon fibers, or synthetic fibers, such as copolymers of polypropylene, polyethylene, polyester, ethylene, propylene copolymers, and butene copolymers, bicomponent fibers, or combinations of natural and synthetic fibers. The nonwoven web 22 may be a multi-layer material having, for example, at least one layer of a web spun by at least one meltblown layer or web, a bonded carded web, or other material suitable. Alternatively, the non-woven web may be a single layer or material, such as, for example, a spin-linked web, a bonded carded web, or a melt blown web. The non-woven web 22 may also be a composite made from a mixture of two or more different fibers or a mixture of fibers and particles. Said mixtures may be formed by adding the fibers and / or particles to the gas stream where the blown fibers under melting are carried, whereby a matted co-mixture of fibers blown under melting and other materials, for example, wood pulp, discontinuous fibers and particles, occurs before the collection of fibers blown under melting in a collection device to form a coherent branch of randomly dispersed meltblown fibers and other materials. The non-woven web of fibers must be bonded together to form a coherent web structure. Suitable bonding techniques include, but are not limited to, chemical bonding, thermobonding, such as point calendering, hydroentanglement and needling. The surface treatment 28 is applied to a surface of the non-woven web 22 in Figure 1 using the spray 26. The surface treatments can also be applied to a surface of the non-woven web by other techniques known in the art. , such as screen printing, gravure printing, dip coating, etc. Referring now to Figures 2 and 3, a perspective view of a non-woven web 22 according to the present invention is shown, the surface treatment being applied to one of its surfaces. The nonwoven web 22 is a nonwoven web permeable to the fluid composed of individual fibers 60. The nonwoven web 22 preferably has a first or top surface 61 and a second or bottom surface 62. The first surface 61 is separated from the second surface 62 through an intermediate portion 63. The nonwoven web 22 preferably includes a plurality of passages 66 placed on the first and second surfaces in fluid communication with each other. The first surface 61 preferably has a plurality of regions 65, which exhibit a comparatively low surface energy and preferably comprises a surface treatment of energy at the low surface. Preferably, the regions 65 have a relatively low surface energy and a relatively low adhesion work compared to the fibers 60 of the nonwoven web, which have a relatively high surface energy and relatively high adhesion work. Accordingly, the treated nonwoven web 22 exhibits a plurality of surface energy gradients across the boundaries of the regions 65, i.e., the abutting surfaces between the regions 65 and the surrounding fiber surfaces. As illustrated in Figure 3, the relationship of the regions 65 to the topography of the surface (including individual fibers exiting upwardly from the upper surface of the screen) is believed to be an important aspect of the present invention. Observe that intermittent or discontinuous nature, separated from the regions with respect to the surface direction of the weft and the thickness direction of the weft, particularly since the surface treatment, as depicted in Figure 3, is actually a plurality of droplet particles, or discrete globules, which coat the portions of individual fibers instead of binding or masking the fibers that could occlude the pores of the interfibers. This discontinuity results in the generation of a plurality of small scale surface energy gradients, which are believed to be beneficial from a fluid movement point of view. Also clearly shown in Figure 3, is the penetration of the surface treatment towards and below the first surface 61 of the nonwoven web 22. Since most of the regions 65 are concentrated near the same first surface 61, the Treated regions extend down through the weft on a fiber-by-fiber basis to achieve penetration into the intermediate portion 63.Preferably, the regions 65 are concentrated near the first surface 61 and are reduced in frequency (increase in space) with the increase in distance from the first surface, so that more regions of energy on the lower surface, and, for therefore, more surface energy gradients are generated at or near the first surface 61 for a greater effect on the fluids at or near the first surface. On average, therefore, the upper regions of the weft near the first surface could exhibit a lower average surface energy than that exhibited by the lower regions of the weft near the second surface. The non-occlusion of the interfibrillary capillaries is believed to be important, so that sufficient fluid passages remain open for fluid transmission to the underlying structure. If the surface treatment is applied excessively, it tends to occlude the interfibrillary capillaries, thus blocking the transmission of fluid to the underlying structure. Although the foregoing discussion has focused on a true non-woven substrate, it should be understood that the concepts of the present invention can be readily applied to hybrid or nonwoven woven substrates or fabrics in a similar manner. In doing so, it is necessary to recognize the degree of porosity present in the intertwined structure to extrapolate the previous discussion regarding the porosity and separation of interfibrillary capillarity from nonwoven webs to interwoven structures. In addition, the definition of "fiber", as used herein, is also intended to encompass a type of fiber structure commonly referred to as a "capillary channel fiber", that is, a fiber having a capillary channel formed in the same Suitable fibers of this variety are described in greater detail in the U.S. Patents. Nos. 5,200,248, 5,242,644, and 5,356,405, all issued to Thompson et al., On April 6, 1993, September 7, 1993, and October 18, 1994, respectively, the descriptions of which are incorporated herein by reference. The fibrous structures formed of said fibers can exhibit not only capillaries and interfibrillary spaces, but also capillary structures between fibers. According to the present invention, the first user contacting surface 6 of the nonwoven web 22 is relatively non-wettable compared to the relatively wettable intermediate portion 63. A useful wettability parameter is the contact angle that a drop of liquid (adjacent surface of gas-liquid) makes with the solid surface (adjacent surface of gas-solid). Typically, a drop of liquid 110 placed on a solid surface 112 makes a contact angle, A, with the solid surface, as seen in Figure 4. As the wettability of the solid surface by the liquid increases, the Contact angle, A, is reduced. As the wettability of the solid surface by the liquid is reduced, the contact angle, A, increases. The liquid-solid contact angle can be determined from techniques known in the art, such as those described in more detail in Physical Chemistry of Surfaces, second edition, by Arthur W. Adamson 81967), F. E. Bartell and H.

H. Zuidema, J. Am. Chem. Soc., 58, 1449 (1936), and J. J. Bikerman, Ind. Enq. Chem. Anal. Ed. 13, 443 (1941), each of which is incorporated herein by reference. More recent publications in this area include Cheng et al., Colloids and Surfaces 43: 151-167 (1960), and Rotenberg et al., Journal of Colloid and Interface Science 93 (1): 169-183 81983), which also they are incorporated here by reference. As used herein, the term "hydrophilic" is used to refer to surfaces that can be wetted by aqueous fluids (eg, aqueous body fluids) deposited therein. Hydrophilicity and wettability are typically defined in terms of contact angle and surface tension of the fluids and solid surfaces involved. This is discussed in detail in the American publication Chemical Society entitled Contact Anqle, Wettabilitv and Adhesion, edited by Robert F. Gould (Rights 1964), which is incorporated herein by reference. A surface is said to be moistened by a fluid (hydrophilic) when the fluid tends to spontaneously spread across the surface. Conversely, a surface is considered "hydrophobic" if the fluid does not tend to spread spontaneously across the surface. The contact angle depends on the non-homogeneities of the surface (for example, chemical and physical properties, such as roughness), contamination, chemical / physical treatment of or composition of the solid surface, as well as the nature of the liquid and its contamination. The energy at the surface of the solid also has an influence on the contact angle. As the energy on the surface of the solid is reduced, the contact angle increases. As the energy of the surface of the solid increases, the contact angle is reduced. The energy required to separate a liquid from a solid surface (for example a film or fiber) is expressed by equation (1): (1) W = G (1 + cos A) where: W is the adhesion work measured in erg / cm2, G is the liquid surface tension measured in dynes / cm, and A is the liquid-solid contact angle in degrees. With a given liquid, the adhesion work is increased with the cosine of the liquid-solid contact angle (reaching a maximum, where the contact angle A is zero). Adhesion work is a useful tool to understand and quantify the energy characteristics on the surface of a given surface. Another useful method, which can be used to characterize the energy characteristics at the surface of a given surface is the parameter marked "critical surface tension", as discussed in HW Fox, EF Haré and WA Zisman, J. Vcolloid Sci. 8, 194 (1953), and in Zisman, WA, Advan. Chem. Series No. 43. Chapter 1, American Chemical Society (1964), both incorporated herein by reference. Table 1 shows the inverse relationship between the contact angle and the adhesion work for a particular fluid (for example, water), whose surface tension is 75 dynes / cm.

TABLE 1 A (qrados) eos A 1 + eos A W (erq / err 0 1 2 150 30 0.87 1.87 140 60 0.5 1.50 113 90 0 1 00 75 120 -0.5 0.5 38 150 -0.87 0.13 10 180 -1 0 0 As shown in Table 1, as the adhesion work of a particular surface is reduced (exhibiting an energy at the lowest surface of the particular surface), the contact angle of the fluid on the surface increases, and, therefore the fluid tends to "bubble" and occupies a smaller surface contact area. The opposite is also true since the energy on the surface of a given surface is reduced by a given fluid. Therefore, the adhesion work influences interfacial fluid phenomena on the solid surface. More importantly, in the context of the present invention, surface energy gradients or discontinuities have been found useful for promoting fluid transport. Figure 5 illustrates a drop of fluid 110, which is located on a solid surface having two regions 113 and 115 that have different surface energies (indicated by the different stripes for purposes of illustration). In the situation illustrated in Figure 5, the region 113 exhibits a surface energy comparatively lower than the region 115, and, therefore, a reduced wettability for the droplet fluid than the region 115. Accordingly, the drop 110 produces a contact angle A (b) at the edge of the drop contact region 113, which is greater than the contact angle A (a) produced at the edge of the drop contact region 115. It should be noted that although for graphic clarity the points "a" and "b" lie in a plane, the distance "dx" between points "a" and "b" does not need to be linear, rather it represents the degree of drop / surface contact without considering the shape of the surface. The drop 10 thus experiences an imbalance of energy on the surface and, therefore, an external force due to differences in the relative energies on the surface (i.e., the gradient or discontinuity of energy on the surface) between the regions 113 and 115, which can be represented by equation (2): (2) dF = G [eos A (a) - eos A (b)] dx where: dF is the force on the fluid drop, dx is the distance between the reference locations "a" and "b", G? it is as previously defined, and A (a) and A (b) are the contact angles in the "a" and "b" locations, respectively. Solving equation (1) for eos A (a) and eos A (b) and substituting equation (2) for equation (3): (3) dF = G [(W (a) / G-1) - (W (b) / G-1)] dx Equation (3) can be simplified to equation (4): (4) dF = (W (a) - W (b)) dx The importance of the differential in the energy at the surface between the two surfaces is clearly represented in equation (4), since it is the directly proportional effect that changes in the magnitude of the differential in the adhesion work that could have in the magnitude of the strength.

More detailed discussions of the physical nature of surface energy effects and capillarity can be found in Textile Science and Technology, Volume 7, Absorbency, edited by Portnoy K. Chatterjee (1985), and Capillaritv, Theorv and Practice, Ind. Eng. Chem. 61, 10 (1969) by A. M. Schwartz, which are incorporated herein by reference. Therefore, the force experienced by a drop will cause movement in the direction of the energy at the highest surface. For simplicity and graphic clarity, the gradient or discontinuity of surface energy have been represented in Figure 5, as an individual, acute boundary or discontinuity between well-defined regions of energy at the constant but different surface. Surface energy gradients may also exist as a continuous gradient or a step gradient, with the force exerted on any particular droplet (or portions of said droplet) being determined by the energy at the surface in each particular area of contact of the drop. As used herein, the term "gradient" when applied to differences in surface energy or adhesion work, is intended to describe a change in surface energy or adhesion work that occurs over a distance that can be to size. The term "discontinuity" is intended to refer to a type of "gradient" or transition, where the change in energy on the surface occurs over a distance essentially zero. Therefore, as used herein, all "discontinuities" fall within the definition of "gradient". Also, as used herein the terms "capillary" and "capillary" are used to refer to passages, openings, pores or spaces within a structure, which are capable of transporting the fluid in accordance with the principles of capillarity generally represented by equation (5) of LaPlace: (5) p = 2G (eos A) / R where: p is the capillary pressure; R is the internal radius of the capillary (capillary radius); and G and A are as defined above. As noted in Penetration of Fabrics by Emery I. Valko, found in Chapter III of Chem. Aftertreat. Text. (1971). p. 83-113, which is incorporated herein by reference, for A = 90 °, the cosine of A is zero and there is no capillary pressure. For A > 90 °, the cosine of A is negative and the capillary pressure opposes the fluid inlet to the capillarity. Therefore, capillary walls must be hydrophilic in nature (A <90 °) for capillary phenomena to occur. Also, R must be small enough so that p has a significant value, since as R increases (larger opening / capillary structure), the capillary pressure is reduced. Perhaps, at least as important as the presence of energy gradients in the surface, is the particular orientation or location of the same gradients with respect to the orientation and location of the capillaries or fluid passages. More particularly, the gradients or discontinuities of energy on the surface are located in relation to the capillaries, so that the fluid can not reside on the first surface or above without contacting at least a gradient or discontinuity of energy on the surface and thus experience the driving force that accompanies the gradient. Fluid moving to or otherwise present in a capillary inlet will preferably come into contact with at least one gradient or discontinuity of the Z-direction present in the same capillary near the capillary inlet, and thus experience the force of driving the Z direction to drive the fluid towards the capillary, where the capillary forces are presented to move the fluid away from the first surface. In a preferred configuration, the capillaries preferably exhibit an energy input length at the low surface and a wall or capillary surface of energy at the other higher surface, so that the gradient or discontinuity of energy at the surface is a comparatively small but finite distance below the first surface. In said location, the discontinuity or gradient is positioned so that the fluid in contact with the first surface at the capillary edge or on the open end of the capillary will have a lower surface or meniscus, which will extend downward toward the open end of the capillary, where it will be put in contact with the discontinuity. As an additional explanation of this principle, Figure 6 illustrates a drop 110 of a fluid, which is located on a generic capillary or fluid passage. This representation is intended to be generic enough to represent the concept expressed herein without being limited to a particular plot material, design or construction. Analogously to Figure 5, the capillary is formed in order to present the surfaces 113 and 115 with different energies on the surface (indicated by different stripes for purposes of illustration). As shown in Figure 5, the energy of the surface 113 is at a predetermined level, which is comparatively low compared to that of the surface 115, so that the surface 113 is considered to be hydrophobic. Accordingly, the edges of the drop in contact with the surface 113 will exhibit a relatively larger contact angle, A, so that the edges of the drop make a sharp exit from the surface adjacent the surface 113. The surface 115, on the other hand, it has a comparatively larger surface energy compared to the surface 113. In the situation presented in Figure 6, the drop 110 is located on and extends partially towards the capillary inlet in a condition where the Surface tension forces and gravitational forces are sharply in balance. The lower portion of the drop, which is inside the capillary, forms a meniscus 117, with its edges in contact with the capillary wall in region 113 having energy characteristics on the hydrophobic surface. The gradient of surface energy, discontinuity, or transition between the surfaces 113 and 115 is particularly determined to bring the lower portion of the drop into contact near the edge of the meniscus 117. The orientation of the drop and the depth of the meniscus of the Droplets are determined through factors such as fluid viscosity, fluid surface tension, capillary size and shape, and energy at the surface of the upper surface and the capillary inlet. At the moment when the drop is placed by itself on the capillary inlet and the lower edge of the drop makes contact with the energy gradient on the surface in the Z direction, discontinuity or transition between the surfaces 113 and 115, the meniscus 117, which is of a convex shape, is inverted to a concave-shaped meniscus, such as the meniscus 119, presented in a dotted-line shape. When the meniscus changes to a concave shape, such as meniscus 119, the fluid moistens the capillary wall near the upper region of the hydrophilic surface 115 and the fluid undergoes an external force due to the energy in the differential surface described above in equation (3). The energy on the surface and the capillary pressure forces combined in this way act in concert to eject the fluid into the capillary for the transport of capillary fluid away from the first surface. As the fluid droplet moves downward toward the capillary, the nature of the energy at the comparatively low surface of the surface 114 in the upper region of the capillary minimizes the attraction of the fluid to the upper surface and minimizes drag forces on the drop, reducing the incidence of fluid hanging, or residue on or near the top surface. Water is used as a reference liquid only as an example for purposes of illustration, and is taken as limiting. The physical properties of water are well established, and water is readily available and generally has uniform properties whenever it is obtained. The concepts regarding adhesion work with respect to water can be easily applied to other fluids such as blood, menstruation and urine, taking into account the particular surface tension characteristics of the desired fluid. Referring again to Figure 3, since the first surface or contact with the user 61 of the nonwoven web 22 has a relatively low surface energy and a relatively low adhesion work for a given fluid (e.g. water, or body fluids such as menstruation), the intermediate portions 63 of the nonwoven web 22 preferably have a relatively high surface energy and relatively high adhesion work for a given fluid. Since the intermediate portions 63 of the nonwoven web 22 have a relatively higher surface energy, as compared to the first surface 61, the intermediate portions 63 are more wettable than the first surface 61. The second surface 62 of the web is not woven 22 preferably has a higher surface energy and a higher adhesion work for a fluid than those of the first surface 61. The energy on the surface and the adhesion work for a fluid of the second surface 62 may be equal to those of the intermediate portion 63. In a preferred embodiment, the surface energy and adhesion work for the fluid of the second surface 62 are relatively higher than those of the intermediate portion 63. Having a nonwoven web with a energy gradient in the surface formed through structures creating a relatively low surface energy adjacent to the portion of the weft, which will be placed adjacent to and in contact with the skin of the wearer (i.e., the first surface 61), and a portion of energy on the relatively higher surface located away from contact with the wearer's skin (i.e. the intermediate portion 63), the non-woven web 22 will be able to move a drop of liquid from the weft portion by exhibiting the relatively lower surface energy towards the portion of the web by exhibiting the relatively higher surface energy. The movement of the liquid drop is induced by the contact angle differential between the lower surface energy portion and the higher surface energy portion, which results in an imbalance in the surface tension force acting on the contact plane of the solid-liquid. It is believed that this resultant surface energy gradient, which improves the handling properties of the fluid of the weft 22 of the present invention and which makes the weft suitable for use as a topsheet on the absorbent article. In addition to the improved fluid handling propertiesBy designing the nonwoven web so that its relatively lower portion of energy on the surface is placed in contact with the wearer's skin, the adhesion between the skin and the weft is decreased, reducing the capillary force generated by body fluids. Occlusives located between the first surface of the weft and the user's skin. By providing a structure with reduced adhesion between the wearer's skin and the weft, the feeling or impression of stickiness is also reduced. The potential for rewetting is also reduced by having a top sheet with an energy gradient on the surface according to the aforementioned description. Since the forces of use tend to force the collected fluid to rewet or squeeze the absorbent article (for example, compressed by the compression of the absorbent core towards the first surface of the topsheet), said undesirable movement will be resisted by the first surface of the topsheet, which has a relatively low surface energy to repel the fluid as it attempts to make a path out of the pad through the openings in the topsheet. In addition, the fluid is able to enter the topsheet more quickly due to the driving forces of the energy gradients on the surface of the topsheet. The fluid moves in the "Z" direction towards the second surface of the topsheet through the surface energy gradients from the energy on the first surface towards the relatively higher surface energy of the intermediate portions of the surface. upper sheet towards the absorbent core. With respect to the surface energy gradients of the present invention, it is important to remember that the upper and lower limits of any gradient are relative to each other, i.e., the regions of the frame whose abutting surface defines a gradient of Surface energy does not need to be on different sides of the hydrophobic / hydrophilic spectrum. That is, a gradient can be established through two surfaces of varying degrees of hydrophobicity or varying degrees of hydrophilicity, and does not necessarily have to be established with respect to a hydrophobic surface and a hydrophilic surface. Notwithstanding the foregoing, it is preferred that the upper surface of the non-woven web have a comparatively low surface energy, i.e., that it is generally hydrophobic, in order to maximize the driving force imparted to the incoming fluid and minimize the total wettability of the contact surface with the user. It should be noted that with respect to Figure 3, the size and shape of the regions 65 have been exaggerated in resolution and thickness for graphic clarity. The random appearance and irregularity of said depositions or treatments exceeded the limitations of the graphic representation and, therefore, the illustrations herein are intended to be illustrative and not limiting. Accordingly, the regions 65 shown in Figure 3 are preferably also interspersed with even smaller regions, which are too small and random to be adequately illustrated in said illustration. The surface energy gradients of the present invention, therefore, exist in a unique relationship with the surface aspects and / or textures of a fluid permeable web made in accordance therewith. As shown in Figure 3, the surface energy gradients are preferably constructed by forming regions 65 of energy at the low surface, which abuts surrounding regions of the web, which are of a comparatively higher surface energy. . Therefore, each region 65 generates a gradient of energy at the surface at its limit. Therefore, the larger the number of regions 65, the greater the number of energy gradients on the individual surface. The regions 65 are preferably discontinuous (ie, not completely encapsulate the frame) and spaced apart, leaving regions of energy intervention at the highest surface. In each gradient, a drop in contact with both surfaces experiences a driving force, which imparts some degree of movement to the fluid and reduces the likelihood of stagnation or hanging of the fluid, particularly on the topography of the surface. Although the regions 65 can be applied in a predetermined pattern, the regions 65 are preferably randomly oriented on the surfaces of the frame, with the random aspect increasing the probability that the energy gradients on the surface will be appropriately located in order to affect any particular drop or amount of fluid. The random aspect is desirable not only through the first surface of the web, but also within the same fluid passages. Accordingly, any particular capillary or passage may exhibit multiple gradients of surface energy defined by regions 65, which may also be located at different locations in the Z direction from the first surface. Also, the particular fluid passages may exhibit more or less regions than in the other passages, and the regions 65 may also be located with the purpose of residing completely within the fluid passages (i.e., completely located between the first and second passages). second surfaces). The regions 65 are also preferably discontinuous in nature with respect to the directionality of the weft surface. The discontinuity of a hydrophobic surface treatment applied to a less hydrophobic (or more hydrophilic) substrate, such as the surface of the screen results in a pattern of small scale surface energy gradients in the plane of the surface. These gradients are to be distinguished from the large-scale X-Y gradients of a zone nature by their smaller relative size vis-à-vis the average droplet size and the size of the weft surface. Accordingly, as used herein, the term "small scale" is intended to refer to aspects of surface, topography, or surface energy gradients, which are smaller in magnitude than the average size of a drop of fluid on the surface. the surface in question. The average drop size is an easily determinable characteristic, which can be obtained from empirical observations for given fluids and surfaces. Without wishing to be bound by theory, it is believed that improvements in the characteristics of the fluid passage can be achieved through the reduction of the residence time of the fluid on the upper surfaces of the weft, as well as the movement of the fluid from the upper surface towards the capillaries for the transport of the capillary fluid. Therefore, it is believed that it is desirable for the contact surface with the initial fluid of the weft to facilitate the movement of the small scale fluid (as opposed to the larger lateral movement across the surface of the weft) towards the available capillary more close and then quickly down towards the underlying structure. The surface energy gradients of the present invention provide the desired Z-direction driving force, as well as the driving force X-Y to impart the movement of the desired small-scale fluid. The plurality of small scale surface energy gradients exhibited by said frames is believed to be beneficial from a fluid movement point of view. Small-scale gradients help in lateral movement or X-Y of the drops of fluid formed on the surface of the weft. In addition, regions 65, which are smaller in their surface degree than the typical size of the drop, stream, or stream of body fluid incident therein, subject the drop, stream or stream of body fluid to destabilizing forces due to the inevitability of the fluid to which it joins a gradient or discontinuity of energy on the surface. Since the surface energy gradients of the type described herein can be advantageously employed in non-capillary structures, including the surfaces of said structures as two-dimensional ("flat") films, in accordance with the present invention, it is preferred employ both surface energy gradients XY of small scale as energy gradients in the small-scale Z-directional surface of the type described herein to achieve maximum fluid upset and balance of the drop and thereby minimize the residence time of the fluid and the hanging or residue on the upper regions of the frame. Accordingly, the presence of the regions 65 can be limited to the first surface of the screen, and, therefore, provide XY functionality, or limited to the interior of the fluid passages, but preferably are employed as the best advantage over the first surface of the weft and within the fluid passages. Accordingly, in the nonwoven web structures of the present invention, the surface energy gradients provide a synergistic effect in combination with the capillary nature of the structure to provide improved fluid handling and handling characteristics. The fluid on the first surface of the weft encounters two different complementary driving forces on its way away from the first surface and towards the second or opposite surface of the weft, and typically further inwardly inside the absorbent article. These two forces also combine to oppose the movement of the fluid towards the first surface of the weft, thus reducing the incidence of re-wetting and increasing the dryness of the weft surface. A number of physical parameters must be considered in designing a frame according to the present invention, more particularly with respect to properly dimensioning and positioning the energy gradients on the surface for proper fluid handling. These factors include the magnitude of the energy differential in the surface (which depends on the materials used), the migration capacity, the biocompatibility of the materials, porosity or capillary size, total screen size and geometry, surface topography, viscosity of the fluid and tension on the surface, and the presence or absence of other structures on either side of the weft. Preferably, the regions 65 of the non-woven web 22 have an adhesion work for water in the range of about 0 erg / cm 2 to about 150 erg / cm 2, most preferably in the range of about 0 erg / cm to about 100 erg. / cm2, and most preferably from about 0 ergVcm to 75 erg / cm2. Preferably, the remainder of the web surrounding the regions 65 has an adhesion work for water in the range of about 0 erg / cm2 to about 150 erg / cm2, preferably on the scale of about 25 erg / crn to about 150 erg / cm2, and most preferably on the scale of about 50 erg / crrf to 150 erg / cp2. Preferably, the difference in adhesion work for water between the regions 65 and the remainder of the nonwoven web is on the scale of about 5 erg / cm2 to about 145 erg / cm2, preferably on the scale of about 25 erg. / cm2 at about 145 erg / cm2, and most preferably around 50 erg / crn2 at 145 erg / cm2. A suitable surface treatment is a silicone release liner from Dow Corning of Midland, Michigan, available as Syl-Off 7677 to which was added an interlayer available as Syl-Off 7048, in portions by weight from 100 parts to 10 parts, respectively. Another suitable surface treatment is a coating of a UV curable silicone comprising a mixture of two silicones commercially available from General Electric Company, Silicone Products Division, of Waterford, NY, under the designation UV 9300 and UV 9380C-D1, in proportions in weight from 100 parts to 2.5 parts, respectively. The energy at the surface of the silicone release liner on the first surface of the nonwoven web is less than the energy at the surface of the individual fibers 60 that form the nonwoven web 22. Other suitable processing materials include, but are not are limited to fluorinated materials such as fluoropolymers (e.g., polytetrafluoroethylene (PTFEE), commercially available under the tradename TEFLON®) and chlorofluoropolymers. Other materials, which may prove to be suitable for providing regions of reduced surface energy include petrolatum, latex, paraffins, and the like, although silicone materials are currently preferred for use in webs in the context of absorbent article for their properties. biocompatibility As used herein, the term "biocompatible" is used to refer to materials that have a low specific adsorption level for, or in other words a low affinity for, biospecies or biological materials such as glycoproteins, platelets of the blood, and the like. As such, these materials tend to resist the deposition of biological matter to a greater degree than other materials under conditions in use. This property allows them to better retain their surface energy properties necessary for subsequent fluid handling situations. In the absence of biocompatibility, the deposition of said biological material tends to increase the roughness or non-uniformity of the surface, leading to increased tensile force or resistance to fluid movement. Consequently, the biocompatibility corresponds to a reduced tensile force or resistance to the movement of the fluid, and, therefore, a faster access of the fluid to the energy gradient in the surface and capillary structure. The maintenance of substantially equal surface energy also maintains the energy differential at the original surface for subsequent depositions or hardening fluid. However, biocompatibility is not synonymous with low surface energy. Some materials, such as polyurethane, exhibit biocompatibility to some degree, but also exhibit comparatively high surface energy. Some of the low surface energy materials, which may otherwise be attractive to be used here, such as polyethylene, lack biocompatibility. Presently preferred materials, such as silicone and fluorinated materials, advantageously exhibit both low surface energy and biocompatibility. Surfactants to hydrophilize or increase the surface energy of selected regions of the web having a high surface energy include, for example, ethoxylated esters such as Pegosperse® 200-ML, manufactured by Glyco Chemical, Inc. , of Greenwich, Connecticut, ATMER® 645, manufactured by ICI, glucosamides, three-block copolymers of ethylene oxide and propylene oxide such as Pluronic® P103, manufactured by BASF, and silicone and ethylene glycol copolymers such as DC190, manufactured by Dow Corning of Midland, Michigan. Since much of the above discussion has focused on the currently preferred aspect to start with a predominantly hydrophilic web and apply a coating, treatment or overlap layer of material to generate regions of energy on the low surface and to make the upper portions hydrophobic, it should be understood that other aspects for generating surface energy gradients are also contemplated within the scope of the present invention. Such aspects could include applying a hydrophilic material (eg, a hydrophilic latex) to the lower portions of an originally hydrophobic web to generate hydrophilic regions with boundaries on surfaces abutting with hydrophobic web surfaces, forming the web of two or more web materials. various surface energy characteristics with surface energy gradients formed by boundaries between the respective materials, forming the band of a predominantly hydrophobic or predominantly hydrophilic material and altering the chemistry of the surface of its selected regions through mechanical techniques, electromagnetic or bombardment or chemical treatment known in the art, to thereby generate selective surface energy gradients, preferential migration of chemical weft components capable of altering the energy on the surface, treating the hydrophobic regions to be temporarily hydrophilic and to reveal the gradients of energy on the surface during use, etc. After passing under the sprayer 26 where the surface treatment 28 is applied to a surface of the non-woven size 22, the gauge of the weft is then increased. The nonwoven web 22 has an initial gauge which for a flat web is generally the thickness of the web. For example, the caliber of the nonwoven web 22 in the Figure 3 is the dimension between the first surface 61 and the second surface 62, that is, it is the thickness of the nonwoven web. The gauge of a nonwoven web can be determined using a Thwing-Albert low load micrometer model No. 89-1. A preferred method for increasing the gauge of a non-woven web is to subject the non-woven web to mechanical formation, directing the non-woven web through a pressure-applying system 29, shown schematically in Figure 1, employing opposite pressure applicators that they have three-dimensional surfaces, which at least to a degree are complementary to each other. Details of a particularly preferred pressure applying system of the present invention that can be employed as system 29 is set forth in Figure 7. Referring now to Figure 7, there is shown an enlarged, perspective illustration of the pressure applying system. 29 comprising a first pressure applicator 30 and a second pressure applicator 32. The first pressure applicator 30 comprises a plurality of serrated regions 33 spaced apart by a plurality of slotted regions 34. The serrated regions 33 and the slotted regions 34 extend around of the circumference of the first pressure applicator 30 in a direction extending substantially parallel to a longitudinal axis running through the center of the first pressure applicator 30. The toothed regions 33 comprise a plurality of teeth 35. The second pressure applicator 32 includes a plurality of teeth 36 that engage or mesh with the teeth 35 on e the first pressure applicator 30. As the non-woven web is fed between the first and second pressure applicators, the portion of the non-woven web that passes between the teeth in the first pressure applicator and the teeth in the second Pressure applicator will be formed or expanded, producing elevated portions in the form of a rib that provides an increased gauge to the non-woven web. The portion of the non-woven web that passes between the grooved regions on the first pressure applicator and the teeth on the second applicator remains substantially unchanged. A non-woven web that has been mechanically formed by a pressure-applying system similar to system 29 has an increased gauge, as illustrated in Figure 7A. The nonwoven web 22 illustrated in Figure 7A has a first surface 61 and a second surface 62. The non-woven web 22 includes a plurality of raised, rib-shaped portions 70 that are formed as the web passes through. between the teeth in the first pressure applicator and between the teeth on the second pressure applicator. The non-woven web 22 also includes unformed portions 72 corresponding to the portion of the web that passes between the grooved regions in the first pressure applicator and the teeth in the second pressure applicator. Because the portions of the web remain unchanged such as the portion 72, the total width of the non-woven web remains substantially unchanged. The gauge of the mechanically formed non-woven web 22 has increased significantly through the formation of the rib-shaped portions 70. The gauge of the non-woven web is generally shown as 74. The thickness of the non-woven web is generally shown as 75. As can be seen in Figure 7A, the caliper 74 of the nonwoven web is greater than the thickness 75 of the nonwoven web. Preferably, the nonwoven web 22 has an increased caliper which is at least about 1.2 times the initial caliper, more preferably at least about 2 times the initial caliper, and most preferably about 4 times the initial caliper. It should be understood that gauges increased in excess of 4 times are also within the scope of the present invention. An example of a nonwoven web that has been subjected to mechanical formation is described in greater detail in International Patent Publication No. WO 95/03765, filed on February 9, 1975 in the name of Chappell et al., The disclosure of the which is incorporated herein by reference. The pressure applying system 29 shown in Figure 7 can be contrasted with a conventional ring rolling. A conventional ring roll includes a pair of opposed corrugated rolls, each having teeth that are complementary to each other, extending around the total periphery of each roll. A nonwoven web subjected to a conventional ring roll will have an increased overall width, and a reduced overall gauge. This is because the conventional ring rolling has no grooved portion that allows a portion of the nonwoven web passing through it to remain substantially unchanged as the grooved regions 34 on the pressure applicator 30. From representative illustration of the synergism of the present invention, vis-a-vis, the combination of capillary, gauge, and energy effects on the surface, it has been found that the nonwoven webs according to the present invention exhibit a unique combination of properties seen as important from a consumer point of view. More particularly, it has been found that the non-woven capillary webs according to the present invention exhibit good acquisition, dryness and masking characteristics, which will be defined below. In general, the acquisition is a reflection of the degree to which the fluid transport frame interferes or does not interfere with the passage of the fluid. The improved acquisition rates / times reflect a small interference or impedance of the fluid passage, as well as the actual influence of the driving forces such as capillarity and energy gradients on the surface. Dryness is a reflection of the degree to which the structure that carries the fluid resists the transport of fluid in the opposite direction, in essence, the degree to which the structure acts as a one-step valve for fluid flow in a preferential direction. The masking reflects the cleanliness of the surface after the passage of the fluid, also defined as the degree of coloration that remains (with a colored fluid), as well as the size or extent of the decolorised region. To demonstrate the improved functional characteristics exhibited by the non-woven webs of the present invention, a sample of a prior art non-woven web available from Fiberweb under the designation DFPN-127, having a basis weight of about 23 grams per square meter , composed of short carded fibers in a mixture of 60% permanently hydrophilic fiber under the designation T-186, available from Hercules Company, Oxfford GA, and 40% standard hydrophilic fiber T-196, also available from Hercules Company, Oxfford GA , (Example I), a nonwoven web of Example I which is coated with 2.5 grams of cone available from General Electric Company, Silicon Products Divison of Waterford, NY, under the designation UV9300 (example II), and the nonwoven web of Example II which is subjected to mechanical formation, such as that shown in Figure 7, has an increased caliber (example lll. ), were subjected to acquisition, dryness and concealment tests. The analytical or test methods for determining the performance of the frame with respect to these attributes are described in greater detail in the Analytical Methods section below. The results of the tests given in Table II below represent the average value of all the tests actually conducted for each example. Ten tests were carried out for each example.

TABLE I I Example I Example II Example Caliber (thousandth 7.5 7.5 12.9 inch) Acquisition (seconds) 3.70 3.77 3.77 Dryness (grams) 1.10 0.62 0.04 Concealment (gray scale) 72 53 55 From the data in Table I it is evident that all of the three examples exhibited similar adquisitions and concealments, with the concealment of examples II and III which are a bit better than that of example I. Furthermore, it is critical to note that the example lll exhibits a tremendous improvement over examples I and II in terms of dryness, a feature that significantly impacts user comfort. Consequently, the use of example III as a topsheet is highly preferred in structures such as disposable diapers, sanitary napkins and the like, where it is desired to isolate the wearer's skin from absorbed fluids within the absorbent member of the structure. Although Example II exhibited improvements over Example I in terms of dryness, it is believed that the significant improvement in dryness exhibited by Example III was provided by the increased gauge of Example III versus that of Example II. The increased calib exhibited by Example III tends to further isolate the wearer's skin from fluids absorbed in the absorbent element, thus providing improved dryness compared to that of Example II. An enlarged perspective illustration of another suitable pressure applying system 550 comprising first pressure applicator 552 and second pressure applicator 554 is shown in Figure 7B. The pressure applicators 552 each have a plurality of serrated regions 556 spaced apart by a plurality of slotted regions 558. The serrated regions 556 on the applicators 552 and 554 each include a plurality of teeth, such that the teeth on the applicator 552 internally engage or engage with the teeth on the applicator 554. As the nonwoven web is fed between the first and second pressure applicators, 552 and 554, the portion of the non-woven web passing between the teeth in the first applicator of pressure and between the teeth and in the second pressure applicator, will be formed or expanded producing elevated rib-shaped portions that provide an increased gauge to the non-woven tarma. The portion of the nonwoven web that passes between the grooved regions in the first pressure applicator and in the second applicator remain substantially unchanged. Other suitable pressure applicators that may also be used are described in International Patent Publication No. WO 95/03765, published February 9, 1995, in the name of Chappell et al., The disclosure of which is incorporated herein by reference. . The non-woven web 22 is preferably preferably received on an embossing roll 50 and stored. Alternatively, the non-woven web 22 can be fed directly to a production line where it is used to form a topsheet in a disposable absorbent article.

REPRESENTATIVE ABSORBENT ARTICLE As used herein, the term "absorbent article" generally refers to devices used to absorb and contain body exudates, and more specifically refers to devices, which are placed against or close to the body of the user and contain the various exudates discarded from the body. The term "absorbent article" is intended to include diapers, catamenial pads, tampons, sanitary napkins, incontinence pads and the like, as well as bandages and wound dressings. The term "disposable" is used herein to describe absorbent articles, which are not intended to be washed or otherwise restored or reused as an absorbent article (i.e., intended to be discarded after limited use, and, preferably, recirculated, composted or otherwise disposed of in an environmentally compatible manner). A "unitary" absorbent article refers to absorbent articles, which are formed as an individual structure or as separate parts joined together to form a coordinated entity, so that they do not require separate manipulator parts such as a separate bra and pad. A preferred embodiment of a unitary disposable absorbent article made in accordance therewith is the cathemanial pad, sanitary napkin 120, shown in Figure 8. As used herein, the term "sanitary napkin" refers to an absorbent article, which is used by women, adjacent to the pudendal region, generally external to the urogenital region, and which aims to absorb and contain menstrual fluids and other vaginal waste from the user's body (eg, blood, menstruation and urine). Interlabial devices, which reside partially within and partially outside the user's lobby are also within the scope of the invention. However, it should be understood that the present invention is also applicable to other feminine or catamenial hygiene pads, or other absorbent articles such as diapers, incontinence pads, and the like, as well as other wefts designed to facilitate the transport of fluid away from a surface, such as disposable towels, facial tissues and the like. It should be understood that the total size, shape and / or configuration of the absorbent article, if any, in which the fluid transport frames, according to the invention, are incorporated, or used together with, do not have a critical relationship. or functional to the principles of the present invention. Said parameters, however, must be considered together with the intended fluid and the intended functionality when determining the appropriate configurations of the weft and the appropriate orientation of the surface energy gradients, according to the present invention. The sanitary napkin 120 is illustrated as having two surfaces such as the first surface 120a, sometimes referred to as a contact surface or facing the user, a contact or body-facing surface or a "body surface", and a second surface 120b, sometimes referred to as a surface that faces or is in contact with the garment, or a "pledge surface". The sanitary towel 120 is shown in Figure 8, as seen from its first surface 120a. The first surface 120a is intended to be used adjacent to the body of the user. The second surface 120b of the sanitary napkin 120 (shown in Figure 9) is on the opposite side side and is intended to be placed adjacent to the wearer's underwear when the sanitary napkin 120 is used. The sanitary napkin 120 has two centerlines, a longitudinal centerline "L", and a transverse centerline "T". The term "longitudinal", as used herein, refers to a line, axis or direction in the plane of the sanitary napkin 120, which is generally aligned with (eg, approximately parallel to) a vertical axis, which divides a user into left and right halves of body, when sanitary napkin 120 is used. The terms "transverse" or "lateral", as used herein, are interchangeable and refer to a line, axis or direction, which lies within the plane of the sanitary napkin 120 which is generally perpendicular to the longitudinal direction. Figure 8 also shows that the sanitary napkin 120 has periphery moon 130, which is defined by the outer edges of the sanitary napkin 120, in which the longitudinal edges (or "side edges") are designated with 131 and the end edges (or "ends") are designated 132. Figure 8 is a top plan view of a sanitary napkin 120 of the present invention in a substantially flat state, with the portions of the sanitary napkin being cut to show more clearly the construction of the sanitary towel 120 and with the portion of the sanitary towel 120, which looks or is in contact with the user 120a, facing the viewfinder. As shown in Figure 8, the sanitary napkin 120 preferably comprises a liquid permeable top sheet 122, a liquid impermeable backsheet 123 attached to the topsheet 122, and an absorbent core 124 disposed between the topsheet 122 and the top sheet 122. backsheet 123, and a secondary topsheet or acquisition layer 125 positioned between the topsheet 122 and the absorbent core 124. The sanitary napkin 120 preferably includes optional side wings or "wings" 134 that are folded around the crotch portion. of the user's panties. The side flaps 134 can serve a number of purposes, including, but not limited to, helping to keep the towel in an appropriate position, while protecting the wearer's panties from blemishes and keeping the sanitary towel secured to the wearer's pant. Figure 9 is a cross-sectional view of the sanitary napkin 120 taken along the section line 14-14 of Figure 8. As seen in Figure 9, the sanitary napkin 120 preferably includes adhesive attachment means 13. to attach the sanitary towel 120 to the wearer's underwear. Removable release liners 137 cover the adhesive fastening means 136, so that the adhesive does not stick to a surface other than the crotch portion of the wearer's underwear. The topsheet 122 has a first surface 122a and a second surface 122b positioned adjacent to and preferably secured to a first surface 125a of the fluid acquisition layer 125 to promote fluid transport from the topsheet to the acquisition layer. The second surface 125b of the acquisition layer 125 is positioned adjacent to and preferably secured to the first surface 124a of an absorbent core or a fluid storage layer 124 to promote fluid transport from the acquisition layer to the absorbent core. . The second surface 124b of the absorbent core 124 is positioned adjacent to and preferably secured to the first surface 123a of the backsheet 123. In addition to having a longitudinal direction and a transverse direction, the sanitary napkin 120 also has a "Z" direction or shaft, which is the direction that proceeds down through the topsheet 122 and into any fluid storage layer or core 124 that can be provided. The aim is to provide a substantially continuous path between the topsheet 122 and the underlying layer or layers of the absorbent article of the present, so that the fluid is expelled in the "Z" direction and away from the topsheet of the article and towards its final storage layer. The absorbent core 124 may be any of the absorbent means that is capable of absorbing or retaining liquids (e.g., menstruation and / or urine). As shown in Figures 8 and 9, the absorbent core 124 has a body surface 124a, a garment facing surface 124b, side edges and end edges. The absorbent core 124 can be manufactured in a wide variety of sizes and shapes (e.g., rectangular, oval, hourglass, dog bone, asymmetric, etc.) and from a wide variety of liquid absorbent materials commonly used in sanitary napkins and other absorbent articles such as shredded wood pulp, which it is usually referred to as air felt. Examples of other suitable absorbent materials include curled cellulose wadding; meltblown polymers including cc-form; chemically hardened, modified or cross-linked cellulosic fibers; synthetic fibers such as crimped polyester fibers; peat; gauze including gauze wraps and gauze laminates; absorbent foams, absorbent sponges; superabsorbent polymers; absorbent gelling materials; or any equivalent material or combination of materials or mixtures thereof. The configuration and construction of the absorbent core can also be varied (for example, the absorbent core can have a variable gauge zone (for example in order to be thicker in the center), hydrophilic gradient, superabsorbent gradients or density acquisition zones. lower or lower average basis weight, or may comprise one or more layers or structures.The total absorbent capacity of the absorbent core must, however, be compatible with the design load and intended use of the absorbent article. The size and absorbent capacity of the absorbent core can be varied to suit different uses, such as incontinence pads, protective pantyhose, regular sanitary napkins, or night sanitary napkins Illustrative absorbent structures to be used as the absorbent core in the present invention are described in U.S. Patent No. 4,950,264 issued to Osborn on August 21 1990; patent of E.U.A. No. 4,610,678 issued to Weisman et al., September 9, 1986; patent of E.U.A. No. 4,834,735, issued to Alemany et al., May 30, 1989; and European Patent Application No. 0 198 683, Procter & Gamble Company, published on October 22, 1986 in the name of Duenk et al. The descriptions of which are incorporated herein by reference. A preferred embodiment of the absorbent core 124 has a surface energy gradient similar to the energy gradient at the surface of the topsheet 122. The body facing surface 124a of the absorbent core and the portion of the absorbent core 124 immediately adjacent to the absorbent core 124a. body facing surface 124a preferably has a relatively low surface energy compared to the garment facing surface 124b, which has a relatively high surface energy. It is important to note that while there is a gradient of energy at the surface within the absorbent core 124, the energy at the surface of the contact surface with the user or facing the body 124a of the absorbent core is preferably greater than the surface energy of the absorber. the garment facing surface 125b of the acquisition layer 125. This relationship is preferred in order for the fluid to be pulled or propelled from the acquisition layer towards the absorbent core. If the energy on the surface of the surface facing the body 124 of the absorbent core were less than that of the garment facing surface 125b of the acquisition layer, the fluid in the acquisition layer 125 could be repelled by the core. absorbent, thus making the absorbent core unusable. The backsheet 123 and the topsheet 122 are positioned adjacent to the garment facing surface and the body facing surface, respectively of the absorbent core 124 and preferably attached thereto and to each other via attachment means ( not shown) such as those well known in the art. For example, the backsheet 123 and / or the topsheet 122 can be secured to the absorbent core or to each other through a continuous uniform layer of adhesive, an adhesive pattern layer or any arrangement of lines, spirals or separate points. of adhesive. The adhesives that have been found to be satisfactory with manufactured by H.

B. Fuller Company of St. Paul, Minnesota, under the designation HL-1258 and by Findlay of Minneapolis, Minnesota, under the designation H-2031. The attachment means will preferably comprise an open-pattern network of filaments of adhesive as described in U.S. Pat. No. 4,573,986, issued to Minetola et al., March 4, 1986, the description of which is incorporated herein by reference. The illustrative attachment means of an open-pattern filament network comprises several lines of adhesive filaments wound in a spiral pattern as illustrated through the apparatus and method shown in US Pat. No. 3,911, 173, issued to Sprague, Jr., on October 7, 1975; patent of E.U.A. No. 4,785,996, issued to Zeiker et al., November 22, 1978 and the patent of E.U.A. No. 4,842,666 issued to Werenicz on June 27, 1989. The descriptions of which are incorporated herein by reference. Alternatively, the joining means may comprise heat bonds, pressure joints, ultrasonic joints, dynamic mechanical joints, or any other suitable joining means or combinations of these joining means as is known in the art. The backsheet 123 is impervious to liquids (eg, menstruation and / or urine) and is preferably manufactured from a thin plastic film, although other flexible liquid impervious materials may also be used. As used herein, the term "flexible" refers to materials that are comfortable and conform more readily to the shape and general contours of the human body. The backsheet 123 prevents the exudates absorbed and contained in the absorbent core from moistening the articles that are in contact with the sanitary towel 120, such as pants, pajamas and underwear. The backsheet 123 of this form comprises a woven or non-woven material, polymeric films such as polyethylene or polypropylene thermoplastic films, or composite materials such as a film-coated nonwoven material. Preferably, the backing sheet of the polyethylene film has a thickness of about 0.012 mm to about 0.051 mm. The illustrative polyethylene films are manufactured by Clopay Corporation of Cincinnati, Ohio, under the designation P18-1401 and by Tredegar Film Products of Terre Haute, Inidana, under the designation XP-9818. The backing sheet preferably embossed and / or finished in matt to provide a more clothing type appearance. In addition, the backing sheet 123 may allow the vapors to escape from the absorbent core 124 (ie, are breathable), while still preventing the exudates from passing through the backsheet 123. During use, the sanitary napkin 120 may be held in place at through support means or joining means (not shown) well known for such purposes. Preferably, the sanitary napkin is placed in the wearer's underwear or panties and secured thereto through a fastener such as an adhesive. The adhesive provides means for securing the sanitary towel in the crotch portion of the panty. Thus, a portion or all of the outer or garment facing surface 123b of the backsheet 123 is coated with the adhesive. Any adhesive or glue used in the art for such purposes can be used for the adhesive herein, with pressure sensitive adhesives being preferred. Suitable adhesives are manufactured by H. B. Fulller Company of St. Paul, Minnesota, under the designation 2238. Suitable adhesive fasteners are also described in the U.S. patent. 4,917,967. Before the sanitary napkin is placed in place during use, the pressure sensitive adhesive is typically covered with a removable release liner 137 with the purpose that the adhesive will dry or adhere to a different surface than the portion of the sanitary napkin. crotch of the panties before use. Suitable release liners are also described in the US patent. 4,917,697 previously presented. Here, any commercially available release liner can be used. A non-limiting example of a suitable release liner is BL30MG-A Silox 4P / O, which is manufactured by Akrosil Corporation of Menasha, Wl. The sanitary napkin 120 of the present invention is used by removing the release liner and then placing the sanitary napkin in a panty so that the adhesive contacts the panty. The adhesive holds the sanitary napkin in place within the pant during use. In a preferred embodiment of the present invention, the sanitary napkin has two fins 134, each of which is adjacent to and laterally extending from the lateral edge of the absorbent core. The fins 134 are configured to cover the edges of the wearer's panties in the crotch region, so that the fins are disposed between the edges of the wearer's panties and the thighs. The fins serve at least for two purposes. First, the fins help prevent the body and the wearer's panties from being stained by the menstrual fluid, preferably by forming a double-walled barrier along the edges of the pantyhose. Secondly, the fins are preferably provided with attachment means on their garment surface, so that the fins can be folded under the panties and attached to the garment-facing side of the panties. In this way, the fins serve to keep the sanitary towel properly placed in the panties. The fins can be constructed of various materials including materials similar to the topsheet, backsheet, gauze or combination of these materials. In addition, the fins may be a separate element attached to the main body of the towel or may comprise extensions of the topsheet and the back (ie, unitary) sheet. A number of sanitary napkins having suitable or adaptable fins for use with the sanitary napkins of the present invention are described in U.S. Pat. 4,687,478 entitled "Shaped Sanitary Napkin With Flaps", which was issued to Van Tilburg on August 18, 1987; and the patent of E.U.A. 4,589,876 entitled "Sanitary Napkin", which was issued to Van Tilburg on May 20, 186. The description of which is incorporated herein by reference. In a preferred embodiment of the present invention, an acquisition layer (s) 125 may be placed between the topsheet 122 and the absorbent core 124.

The acquisition layer 125 can serve several functions including improving the penetration of the exudates on and into the absorbent core. There are several reasons why improved penetration of the exudates is important, including providing a more even distribution of the exudates through the absorbent core and allowing the sanitary napkin 120 to become relatively thin. The penetration referred to herein may include the transportation of liquids in one, two or all directions (ie, in the x-y plane and / or in the z-direction). The acquisition layer may comprise several different materials including non-woven or woven webs of synthetic fibers including polyester, polypropylene, or polyethylene; natural fibers including cotton or cellulose; mixtures of said fibers; or any of the equivalent materials or combinations of materials. Examples of sanitary napkins having an acquisition layer and a topsheet are more fully described in the U.S.A. 4,950,264, issued to Osborn and the patent application of E.U.A. Series No. 07 / 810,774, "Absorbing Article Having Fused Layers", filed on December 17, 1991, in the names of cree et al. The descriptions of which are incorporated herein by reference. In a preferred embodiment, the acquisition layer may be joined with the topsheet through any conventional means for joining the webs together, most preferably through fusion joints as described more fully in the Cree application presented above. In a preferred embodiment, the acquisition layer 125 preferably has a surface energy gradient similar to that of the topsheet 122 and / or absorbent core 124. In a preferred embodiment, the first surface or facing the user 125a preferably has a relatively low surface energy as compared to the contact surface with the absorbent pad, 125b, Preferably, the energy at the surface of the first surface 125a of the acquisition layer 1255 is preferably greater than the energy at the surface of the second surface of the topsheet 122. In addition, the second surface of the acquisition layer 125b has a relatively low surface energy compared to the energy on the surface of the body-facing surface 124a of the absorbent core 124. Referring to FIG. Now to Figure 10, there is shown another preferred embodiment of a sanitary napkin 220 made in accordance with to present invention. The sanitary napkin 220 is shown in Figure 10 as seen from its first surface or contact with the user, 220a. The sanitary napkin 220 includes a liquid permeable topsheet 222, a liquid impervious backsheet (not shown), bonded to the topsheet 222, an absorbent core (not shown), positioned between the topsheet 222 and the topsheet. backing, and an acquisition layer (not shown) positioned between the topsheet 222 and the absorbent core.

The topsheet 222 preferably includes a plurality of regions and / or zones, such as a first central region 232, a second region 234 adjacent to and contiguous with the first region 232, and a third region 238 adjacent to and contiguous with the second region 234. Preferably, the first surface of the topsheet 222 within the first central region 232 has a relatively higher surface energy than that of the topsheet 222 within the second adjacent region 234. Likewise, the first surface of the sheet upper 222 within second region 234 has a relatively higher surface energy than that of upper sheet 222 within third adjacent region 236. In this manner, fluid deposited on top sheet 122 will be driven from third region 236 to the second region 234 from the second region 234 to the first region 232. Accordingly, the fluid will be directed from the third region 236 to the first region 232 of the topsheet 222 to prevent any runoff of fluids onto the periphery 240 of the sanitary napkin. Since the first surface or contact with the user of the topsheet 222 has an energy gradient on the surface from region to region, which may be discrete or continuous, the topsheet 222 will preferably also have a surface energy gradient. additional between the first surface and the intermediate portions of the topsheet 222. The energy at the surface of the intermediate portions 234 within the respective regions of the topsheet will be greater than the energy at the surface of the contact surface with the user in the first, second and third regions of the topsheet 222. In this manner, the topsheet will also promote the transmission of fluids in the "Z" direction similar to that of the weft 22 described in Figure 4. In some situations , it may be desirable to have a gradient of energy at the surface on the first surface of the topsheet 222, which forces the fluid from the first region to the second region, and from the second region to the third region. In such embodiment, the first surface of the topsheet 222 within the first region 232 has a relatively lower surface energy than that of the topsheet 222 within the second adjacent region 234. Similarly, the first surface of the sheet upper 222 within second region 234 has a surface energy relatively less than that of upper sheet 222 within third adjacent region 236. In this manner, fluid deposited on top sheet 222 will be driven from first region 232. to the second region 234, and from the second region 234 to the third region 236. This type of surface energy gradient may be desirable when it comes to fully utilizing the absorbent capacity of the underlying absorbent core by extending the body fluids through of the first surface of the upper sheet, the fluids will have a much more direct trajectory cta to the peripheral portions of the underlying absorbent core. The regions or zones 232, 234, 236 are shown in Figure 10 generally in an oval configuration. However, regions can be formed in a wide variety of shapes and sizes, such as rectangular, elliptical, hourglass, dog bone, asymmetric, triangular, circular, etc., or even random shapes and sizes. Referring now to Figure 11, a sanitary napkin 280 seen from the first surface 280a is shown. The sanitary napkin 280 includes elements or components similar to those of the sanitary napkin 120 shown in Figures 8 and 9, such as a liquid-permeable topsheet 282, a liquid-impermeable backsheet attached to the topsheet 282, a core absorber positioned between the topsheet 282 and the backsheet, and a secondary topsheet or acquisition layer positioned between the topsheet 282 and the absorbent core. The sanitary napkin 280 has a periphery 290, which is defined by the outer edges of the sanitary napkin 280 where the longitudinal edges (or "side edges") are designated with 291 and the end edges (or "ends") are designated as 292. The topsheet 282 includes a plurality of regions extending generally parallel to the longitudinal axis "L" of the sanitary napkin 280 and includes a first region or center 28 extending parallel to the longitudinal axis from one end of the sanitary napkin towards the another extreme. Adjacent to the first region 284 is a pair of second regions 285, 286, extending essentially parallel to the first region 284. Adjacent to the second regions 285, 286, respectively, there is a pair of third regions 287, 288. Preferably, the first region has a relatively high surface energy as compared to the second regions 285, 286. Similarly, the second regions 285, 286 have a relatively high surface energy as compared to the third regions 287, 288. Alternatively, the first region may have a relatively low surface energy as compared to the second regions 285, 286. The second regions 285, 286 may then have a relatively low surface energy as compared to the third regions 287, 288. It should be noted that the surface energy characteristics of the regions depicted in Figures 10 and 11 are in addition to the surface energy gradients and characteristics of the present invention. Accordingly, within one or more of the regions defined in Figures 10 and 11, the aspects and energy characteristics on the surface described in Figure 4 are included therein as well. A representative embodiment of a disposable absorbent article in the form of a diaper 400, is shown in Figure 12, as used herein, the term "diaper" refers to a garment generally worn by infants and incontinent persons that is worn around the wearer's lower torso. However, it should be understood that the present invention is also applicable to other absorbent articles such as incontinent briefs, incontinent pads, trainers, diaper inserts, sanitary napkins, facial tissues, paper towels and the like. The diaper 400 shown in Figure 12 is a simplified absorbent article that can represent a diaper before being placed on a wearer. However, it should be understood that the present invention is not limited to the particular type or configuration of the diaper shown in Figure 12. Figure 12 is a perspective view of the diaper 400 in a non-contracted state (ie, with full concentration). elastic induced removed) with portions of the structure shown cut away to more clearly illustrate the construction of the diaper 400. The portion of the diaper 400 that is in contact with the wearer looks at the viewfinder. The diaper 400 is shown in Figure 12 and preferably comprises a liquid permeable topsheet 404; a backing sheet impervious to liquid 402 attached to the topsheet 404; and an absorbent core 406 positioned between the topsheet 404 and the backsheet 402. Additional structural aspects, such as elastic members and fastening means to secure the diaper in place to a wearer (such as tape tab fasteners) They can also be included. Since the topsheet 404, the backsheet 402, and the absorbent core 406 can be assembled in a variety of well-known configurations, a preferred diaper configuration is generally described in U.S. Pat. 3,860,003 (Buell), issued on January 14, 1975, the description of which is incorporated herein by reference. Alternatively, the preferred configurations for disposable diapers of the present invention are also described in the U.S.A. 4,808,178 (Aziz et al.), Issued February 28, 1989; patent of E.U.A. 4,695,278 (Lawson), issued September 22, 1987; and the patent of E.U.A. 4,816,025 (Foreman), issued March 28, 1989, the descriptions of which are incorporated herein by reference.

Figure 12 shows a preferred embodiment of the diaper 400 wherein the topsheet 404 and the backsheet 402 are co-extensive and have dimensions of length and width generally greater than those of the absorbent core 406. The topsheet 404 is attached thereto. superimposed on the back sheet 402, thus forming the periphery of the diaper 400. The periphery defines the outer perimeter or the edges of the diaper 400. The periphery comprises the end edges 401 and the longitudinal edges 403. The topsheet 404 is comfortable, soft feeling and non-irritating to the wearer's skin. In addition, the topsheet 404 is permeable to liquid, allowing liquids to easily penetrate through its thickness. A suitable topsheet 404 can be manufactured from a wide variety of materials such as porous foams, cross-linked foams, apertured plastic films, natural fibers (e.g., wood or cotton fibers), synthetic fibers (e.g. polyester or polypropylene) or a combination of natural and synthetic fibers. Preferably, the topsheet 404 is made in accordance with the present invention and includes surface energy gradients therein. A particularly preferred topsheet 404 comprises short polypropylene fibers having a denier of about 1.5, such as polypropylene Hercules type 150 sold by Hercules, Inc. of Wilmington, Delaware. As used herein, the term "short-length fibers" refers to those fibers that have a length of at least about 15.9 mm. There are a number of manufacturing techniques, which can be used to manufacture the topsheet 404. For example, the topsheet 404 can be woven, non-woven, spunbonded, carded, and the like. A preferred top sheet is preferred, thermally bonded through means well known in the art. Preferably, the topsheet 404 has a weight of about 18 to about 25 grams per square meter, a minimum dry tensile strength of at least about 400 grams per centimeter in the machine direction, and a tensile strength. Wetted at least about 55 grams per centimeter in the cross machine direction. Backing sheet 402 is impervious to liquids and is preferably manufactured from a thin plastic film, although other flexible liquid impervious materials may also be used. The back sheet 402 prevents the exudates absorbed and contained in the absorbent core 406 from wetting the articles that are in contact with the diaper 400 such as bedding and underwear. Preferably, backing sheet 402 is a polyethylene film having a thickness of about 0.012 mm to about 0.051 mm, although other flexible, liquid-impervious materials may be used. As used herein, the term "flexible" refers to materials which are comfortable and readily conform to the general shape and contours of the user's body. A suitable polyethylene film is manufactured by Monsanto Chemical Corporation and sold as Film No. 8020. The backsheet 402 is preferably embossed and / or finished in matte to provide a more clothing-like appearance. In addition, the backsheet 402 can allow vapors to escape from the absorbent core 406, while still preventing exudates from passing through the backsheet 402. The size of the backsheet 402 is dictated by the size of the core. Absorbent 406 and the exact diaper design selected. In an alternative embodiment, the backsheet 402 has a modified hourglass shape that extends beyond the absorbent core 406 at a minimum distance of at least about 1.3 cm to about 2.5 cm around the entire periphery of the diaper. The topsheet 404 and the backsheet 402 are joined together through any shape. As used herein, the term "attached" encompasses configurations by which the topsheet 404 is directly attached to the backsheet 402 by attaching the topsheet 404 directly to the backsheet 402, and configurations by which the sheet upper 404 is indirectly attached to back sheet 402 by attaching upper sheet 404 to intermediate members, which in turn are fixed to back sheet 402. In a preferred embodiment, upper sheet 404 and back sheet 402 they are fixed directly to each other at the periphery of the diaper through attachment means (not shown) such as an adhesive or any other attachment means known in the art. For example, a uniform continuous layer of adhesive, an adhesive pattern layer, or a separate line or dot arrangement of adhesive may be used to secure the top sheet 404 to the backsheet 402. Tape tab fasteners are typically applied. (not shown) to the rear waistband region of the diaper 402 to provide fastening means for holding the diaper on the wearer. The tape tab fasteners may be any of those well known in the art, such as the fastening tape described in US Pat. 3,848,594 (Buell), issued November 19, 1974, the description of which is incorporated herein by reference. These tape tab fasteners or other diaper fastening means are typically applied near the corners of the diaper 400. The elastic members (not shown) are disposed adjacent the periphery of the diaper 400, preferably along each longitudinal edge. 403), so that the elastic members tend to stretch and hold the diaper 400 against the wearer's legs. Alternatively, the elastic members may be disposed adjacent either or both of the end edges 401 of the diaper 400 to provide a waistband as well as or rather folds for the legs. For example, a suitable waistband is described in the U.S.A. 4,515,595 (Kievit et al.) Issued May 7, 1985, the disclosure of which is incorporated herein by reference. In addition, a method and apparatus suitable for the manufacture of a disposable diaper having elastically shrinkable elastic members are described in US Pat. 4,081, 301 (Buell), issued March 28, 1978, the description of which is incorporated herein by reference. The elastic members are secured to the diaper 400 in an elastically contractible condition, so that in a normally unrestricted configuration, the elastic members effectively contract or adhere to the diaper 400. The elastic members can be secured in an elastically contractible condition so less in two ways. For example, the elastic members can be stretched and secured while the diaper 400 is in an uncontracted condition. Alternatively, the diaper 400 can be contracted, for example, by folding, and the elastic members are secured and connected to the diaper 400, while the elastic members are in a non-relaxed or undrained condition. The elastic members may extend along a portion of the length of the diaper 400. Alternatively, the elastic members may extend over the entire length of the diaper 400, or any other suitable length to provide an elastically shrinkable line. The length of the members is dictated by the design of the diaper. The elastic members can be in a multitude of configurations. For example, the width of the elastic members can be varied from about 0.25 mm to about 25 mm or more; the elastic members may comprise a single strip of elastic material or may comprise several parallel or non-parallel strips of elastic material; or the elastic members may be rectangular or curvilinear. In addition, the elastic members may be attached to the diaper in any manner known in the art. For example, the elastic members can be ultrasonically bonded, heat-sealed or pressure sealed in the diaper 400 using a variety of bonding patterns or the elastic members can simply be glued to the diaper 400. The absorbent core 406 of the diaper 400 is placed between upper sheet 404 and back sheet 402. Absorbent core 406 can be manufactured in a wide variety of sizes and shapes (e.g., rectangular, hourglass, asymmetric, etc.). The total absorbent capacity of the absorbent core 406 must, however, be compatible with the filler liquid for the intended use of the absorbent article or diaper. In addition, the size and capacity of the absorbent core 406 may vary to suit users ranging from babies to adults. As shown in Figure 12, the absorbent core 406 includes a fluid distribution member 408. In a preferred configuration such as that depicted in Figure 12, the absorbent core 406 preferably further includes an acquisition layer or member 410 in communication. of fluid with the fluid distribution member 408 and located between the fluid distribution member 408 and the topsheet 404. The acquisition layer 410 may comprise several different materials including non-woven and woven webs of synthetic fibers including polyester, polypropylene or polyethylene, natural fibers including cotton or cellulose, mixtures of said fibers or any equivalent materials or combinations of materials. During use, the diaper 400 is applied to a wearer by placing the back waistband region under the user's back, and stretching the remainder of the diaper 400 between the user's legs, so that the front waistband region is positioned. through the user's front. The tape tab fasteners or the like are then preferably secured to face outward from the areas of the diaper 400.

ANALYTICAL METHODS The following are representative analytical methods, which have been found to be suitable and useful for determining the operation of fluid transport frames in accordance with the present invention. The analytical methods described herein are preferably achieved by using a particular normal fluid termed as an artificial menstrual fluid (hereinafter referred to as "AMF"), although similar analytical studies can be taken with other fluids. The formulation and preparation of an artificial menstrual fluid are described in the Test Methods section of the patent application of E.U.A. series No. 08/141, 156, filed on October 21, 1993 in the names of Richards et al., the description of which is incorporated herein by reference. ! _. Acquisition Speed The acquisition speed, as used herein, is a measure of the time required for a given volume of liquid applied to the surface to enter, or "knock", a sheet material superior in an underlying absorbent structure. In the series of tests herein, it is a measure of the time in seconds to completely drain 7.5 ml of an AMF solution having a surface tension of 46-58 dynes / cm from a cavity with a diameter of 2.54 cm and a depth of 1.58 cm, having a multitude of holes in its lower surface. Other suitable volumes of fluid include 17 ml and 5 ml. The cavity is integrally formed in a blow plate of 10.16 x 10.16 cm, which is placed on a complete absorbent article manufactured in accordance with the above description, including the topsheet to be tested. The contact surface of the upper sheet sample is oriented upwards. An electric timer is initiated by the AMF solution in contact with a pair of electrode spaced apart in the cavity described above. The timer automatically turns off when all the AMF solution has been drained from the cavity and into the absorbent element. The times are reported in seconds. 2. Dryness Dryness, as used herein, is a measure of how fluid can easily migrate upward onto the contact surface with the user of the topsheet after fluid acquisition, as well as residual dryness on the surface of the sheet. the upper sheet. Accordingly, 90 seconds after the acquisition of AMF in the previous acquisition test, the strike plate is removed and a pre-sampled filter paper sample of approximately 12.7 cm x 12.7 cm was inserted on the uppermost surface of the top sheet of the absorbent article sample, and a predetermined pressure load of 0.017575 kg / cm2 was applied to the sample for a period of 30 seconds. The filter paper was then removed and reweighed, and the amount of fluid absorbed by the filter paper was termed the "surface dryness" of the sample. The results are expressed in grams of fluid absorbed by the filter paper. Other appropriate time increments include 20 minutes after the end of the acquisition of AMF. Thus it should be evident that a lower "surface dryness" number is indicative of a drier surface sensation. More conveniently, "dryness" can be expressed as 1 / surface moisture, which results in higher dryness values equaling the drier surface sensation. 3. Masking As used herein, the term "masking" is defined as the difference in the intensity of light reflected between a "used" or dirty product and its initial intensity reading before use. The acceptance of a catamenial product strongly depends on the operation of masking of its upper sheet. In fact, good masking not only provides a cleaner, drier top sheet surface, but also reflects better absorbency and less rewetting of the product. Masking can be analyzed by measuring the intensity of reflected light from the surface of the product after it has been moistened, in order to be able to quantify and compare the results between different products. The intensity of light describes the energy of light. The incoming (incident) light beam (for example, sunlight) is reflected by the surface and creates an output beam (reflected) that has a different energy or intensity. The difference of the intensity of the input and output beam is the energy that the surface absorbs. For example, a black surface absorbs significantly more energy or light than a white surface. The energy that is absorbed by the black surface can be transformed into heat. Therefore, black cars tend to be hotter than white cars in the summer. The intensity of the light strongly depends on the light source.

Typically the intensity of the light can be characterized using different levels of grays. Therefore, the target could acquire a value equal to zero (white = 0) and black the value of 255 (black = 225). Any gray (or light intensity) between these two values will be anywhere from 0 and 255. A sample product for evaluation is analyzed before the introduction of any fluid, ie in its unused condition. A measurement area is defined and a group of measurements were taken. The results of 5 measurements were averaged. The samples were then infused with 5 ml of fluid according to the procedure enunciated with respect to the acquisition test to perform the wet measurement. Before removing the blow plate and subjecting the sample to the masking and analysis measurement, 3 minutes were allowed for the fluid to reach the stable state orientation within the sample. A second group of measurements was taken from the same product using the same identified measurement area. The results of 5 measurements were averaged. The numerical difference between the average initial reading and the reading after average use provides a quantification of the difference in reflected light, and therefore, the cleanliness of the product surface. The low numerical differences reflect a small change in the condition before use, and, therefore, an effective "masking", while the higher differences reflect a greater change in the condition before use and, therefore, a "Masking" less effective. The following is a description of the suitable components and of a suitable method for determining the operation of the masking of a fluid transport frame according to the present invention.

Hardware Components The scanner used is a conventional HP Scanner llp connected to an Apple Macintosh computer. The computer must have at least 8 MB of RAM in order to be able to operate the browser software and an NIH image at the same time. The monitor must have at least 256 levels of gray to operate the software.

Software Components Explorer Software (DeskScan 11 2.1) This software is provided by HP and designed to operate with the HP Scanner llp.

NIH Image Version 1.44 This program allows you to analyze an image and determine the density of any color or level of gray and the intensity of reflected light.

Measurement Procedures The following describes in detail the procedure for measuring a catamenial pad or similar object.

Data Determination The flat aspect of the sample surface is very important, in order to obtain consistent results. At this point, a 3.48 cm metal ruler with a weight of 42.8 grams over the length of the catamenial was placed to flatten the sample sufficiently to carry out the measurements without unduly compressing or deforming the sample. After exploring the wet samples, the screen was wiped with a soft gauze impregnated with alcohol. The scanner screen should always be very clean, since dust on the screen can affect the quality of a scanned sample and the measurement.

Using the Scanner You need to follow these steps to scan a sample with an HP llp Scanner.

Preparing the Explorer: 1. Make sure the browser is connected to the computer 2. Turn on the computer 3. Turn on the browser 4. Start the browser software program (DeskScan II 2.1) Scanning images: 5. Place the pad over the center of the screen 6. Place the weight (for example, a metal ruler) on the pad 7. Press PREVIEW on the program menu 8. Select the type of image you want to have (Choose: black and white photo) 9. Select the print path (Choose: Lintronic) 10. Select the area you want to save to a file 11. Adjust brightness and contrast Brightness: 114 Contrast: 115 These values must be set in order to have the same image quality. 12. Make sure you have all the correct fixes 13. Press the END button The system will ask you to define a name and a file to store the file. The file must have a TIFF format. Usually this opinion is pre-established. But make sure you have saved the file in a TIFF format, in order to be able to open this file in NIH Image. 0 The browser will then scan the pad again, this time slower, since it saves the image in a file.

Data Evaluation The following steps describe the procedure to analyze a scanned image.

Analysis of the scanned image using NIH Image Adaptation of the Program 1. Open NIH Image 2. Adapt the program (only when it is used for the first time) a) Menu: OPTIONS ° Check gray scale Preferences: undo memory & Clipboard: set to 1500 K Record preferences in the FILE menu b) Options: - Check area and average density - Digits ... set to 1 c) Restart NIH Image to make all the effective fixings.

Measurement 3. Open the calibration file called CALIBRATION.TIFF 4. Open the scanned file in a TIFF format. ° If the system notifies you that the undo memory is very small. Add memory repeat preferences in step 2a). 0 The measurements for the scanned file will be automatically calibrated, as long as the CALIBRATION.TIFF file is opened at the same time. You can check if the image has been calibrated, if there is a white diamond displayed in the title bar.

. Go to ANALYZE in the menu and select RESET 6. Start measurement a) Select area to be measured (you can choose a square box of approximately 1,016 x 1,016 cm), which is smaller than the area subject to fluid staining. b) Go to ANALYZE in the menu and select RESET. c) Repeat steps 6a) and b) for a total of 5 measurements of different "square boxes" within the region of interest. d) Go to ANALYZE in the menu and select SHOW RESULTS 7. Close the file is save 8. repeat steps 4-7 until the measurement is finished.

Since the particular embodiments of the present invention have been illustrated and described, it may be obvious to those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention.

Therefore, it is intended to cover in the appended claims all these changes and modifications that are within the scope of the invention.

Claims

1. A method for forming a nonwoven web exhibiting a plurality of surface energy gradients, the method comprising the steps of: a) providing a nonwoven web of fibers exhibiting a surface energy, said web nonwoven having a first surface , a second surface, a gauge, and a plurality of fluid passages that place the first and second surfaces in fluid communication with each other; b) applying a surface treatment to the first surface of the non-woven web, the surface treatment having a surface energy less than the surface energy of the fibers of the non-woven web, creating a plurality of surface energy gradients; and c) increasing the caliber of the nonwoven web. The method according to claim 1, wherein said surface energy gradients are defined by discrete, spaced regions, which are adapted to exert a force on a fluid that contacts the first surface, such that the fluid will be directed to the fluid passages for transportation away from the first surface and in the direction of the second surface. 3. The method according to claim 1, wherein the gauge of the nonwoven web is increased by subjecting the non-woven web to mechanical formation. The method according to claim 3, wherein the nonwoven web is fed between a first pressure applicator and a second pressure applicator, the first pressure applicator comprising a plurality of separate serrated regions by a plurality of regions. slotted, said toothed regions comprising a plurality of teeth, said second pressure applicator comprising a plurality of teeth that mesh with the plurality of teeth in said first pressure applicator. 5. The method according to claim 2, wherein the discrete, spaced regions are also located at least partially within the fluid passages. 6. The method according to claim 2, wherein said discrete, spaced regions are randomly distributed over the first surface. The method according to claim 2, wherein said discrete, spaced regions are randomly located between the first and second surfaces. The method according to claim 1, wherein the first surface exhibits a first surface energy and the second surface exhibits a second surface energy which is greater than the first surface energy. The method according to claim 1, wherein said surface treatment comprises a curable silicone material. The method according to claim 1, wherein the non-woven web is a web selected from the group consisting of a woven, bonded web, a web of spunbonded fibers, a web of blown fibers , and a multi-layer material that includes at least one of said frames. The method according to claim 1, wherein the non-woven web comprises a topsheet in an absorbent article.