INTERLABIAL DEVICE ADAPTED FOR THE HANDLING OF MENSTER COMPONENTSFIELD OF THE INVENTION. The present invention relates to absorbent devices, and more particularly to an interlabial absorbent device, adapted to handle the various components of menstruation in a manner that makes the most effective use of the absorbent capacity of the device. These devices are typically used by female users for catamenial purposes.
BACKGROUND OF THE INVENTIONThe development of highly absorbent articles for blood and blood-based fluids such as catamenial products (eg, sanitary napkins, tampons, or interlabial devices), wound dressings, bandages and surgical drapes can be questioned. Compared to water and urine, blood and blood-based fluids such as menses are complex relative mixtures of dissolved and undissolved components (e.g. erythrocytes or red blood cells). In particular, blood-based fluids such as menses are much more viscous than water and urine due to undissolved components and highly viscous mucous components. This higher viscosity hinders the ability of conventional absorbent materials to efficiently and rapidly transport these blood-based fluids to regions remote from the initial point of discharge. For example, undissolved components of blood-based fluids can potentially occlude capillaries of these absorbent materials and highly viscous mucosal components can significantly reduce the absorption rate. This makes the design of absorbent systems suitable for blood-based fluids, such as menses, particularly difficult. In the case of catamenial products, women have come to expect a high level of performance in terms of comfort and fit, fluid retention, and minimal staining. For all the above, leakage of pad fluid on undergarments is considered totally unacceptable. Improving the performance of these catamenial products continues to be a formidable compromise, although a number of improvements have been made in both the catamenial structures and the materials used in these structures. However, the elimination of leaks, particularly along the inside of the thighs, without compromising fit and comfort, has not always met the desired consumer needs. The sanitary napkins of the current art have tried to deal with the absorption of highly viscous body fluids, such as menses, in various ways. For example, U.S. Patent 4,973,325 issued to Sherrod, November 27, 1990, provides such a transfer member to facilitate the movement of bodily fluids downward and outward toward areas distant from the absorbent. The transfer member which is placed per arroba, between and below the absorbers, comprises a material for easily transferring the fluids as well as delivering the fluid to a cellulose absorbent. Although, such a structure may represent an improvement in fluid distribution, the ability to facilitate the movement of fluids towards the distant areas of an absorbent may require a porous network a sufficiently small pore size distribution (for capillary absorption) that It can lead to obstruction by the solid components of menstruation. In another example, U.S. patent application serial number 08 / 382,921, filed in the name of Horney, on February 3, 1995 and published as PCT application WO 96/23474 on August 8, 1996, describes an article absorbent having an acquisition component having a pore size within the range of red blood cells, suspended solids, and the like. The acquisition component traps and stores (ie filters) these body exudate components allowing components with lower viscosity to pass through to be stored in a small pore storage component. Filtering bodily fluids, such as menses, has a clear advantage in making use of absorbent capacity. However, the act of filtering a component means that the pores that filter the component are no longer available for rapid absorption or transport of fluids (ie, the pore is clogged). However, the obstruction is less important for an externally used device, such as that described in Horney's application, which would be for a device that fits close to a source of bodily fluids, such as an interlabial product, because the devices Externally used ones are typically larger than internally used devices and body fluids can flow into a clogged portion for absorption. Interlabial pads have the potential to provide a significantly reduced risk of leakage because they are placed in close proximity to the vaginal introitus allowing them to intercept bodily fluids, such as menstruation, almost immediately after discharge. Numerous attempts have been made in the past to produce an interlabial pad that would combine the best features of tampons and sanitary napkins, while avoiding some of the disadvantages associated with each of these types of devices. Examples of these devices are described in U.S. Patent No. 2,917,049 issued to Delaney on December 15, 1959, and U.S. Patent No. 3,420,235 issued to Harmon on January 7, 1969, United States Patent. No. 4,595,392 issued to Johnson on June 17, 1986, and in U.S. Patent Nos. 5,074,855 and 5,336,208 issued to Rosenbluth on December 24, 1991 and August 9, 1994 respectively, and in the U.S. Patent Number 5,484,429 issued to Vukos on January 16, 1996. A commercially available interlabial device is FRESH'N FIT which is marketed by Athena Medical Corp. of Portland, OR and is described in U.S. Patent Nos. 3,983,873 and 4,175,561 issued to Hirschman. on October 5, 1976 and November 27, 1979, respectively. However, many of these devices have not found great commercial success. There are disadvantages associated with all the previous products. For example, the device described in the Delaney patent does not appear to be capable of easy and convenient insertion due to the possibility of layers of the absorbent material opening during insertion. The commercially available Padette product suffers from the disadvantages that it can not provide protection when a user bends over. In addition, capillaries on or near the surface of these products that is presented to the body may not be able to rapidly absorb the viscous components of body exudates, such as menses, or superficial capillaries may become occluded with particulate material, such as cellular waste. This obstruction can reduce the efficiency of the absorption and result in an increased risk of leakage. In this way, a need exists for a nterlabial device that is small in size and can be easily inserted and that provides protection against incontinence, menstrual discharges, and discharges of bodily exudates across a wide range of movements of the body. the user. A further need exists for an interlabial device that resists clogging by the components of body exudates, such as viscous fluids and cellular debris. The obstruction of the superficial capillaries is not a significant problem for the catamenial devices of the current technique that are not brought interlabially, like sanitary napkins because the fluid can spread over your relatively large surface user by diverting from any of the clogged portions. That is, if a small portion of the surface of a sanitary napkin becomes obstructed by cellular debris or the like, the body fluid can easily move into an unobstructed area for absorption. Also, catamenial devices of the current art frequently do not have sustained body adjustment in such a way that the device can move relative to the body. As a result, body exudates can be deposited on one part of the device at a time and in another position of the device at another time, reducing the risk of obstruction of a given portion. On the other hand, an interlabial device is maintained in relatively the same position with respect to the vaginal introitus and the opening of the user's urethra over a wide range of movements of the wearer. As a result, bodily exudates are continually deposited on the same portion of the interlabel device. This means the risk of obstruction that may be higher for an interlabial device when compared to other catamenial devices of the current art. Therefore, it is an object of the present invention to provide an interlabial absorbent device that is small in size and easy to insert. It is another object of the present invention to provide an interlabial absorbent device that consistently blocks both the vaginal introitus and the opening of the urethra in a manner that provides protection against menstrual discharge, incontinence, and discharges of body exudates. in a wide range of movements of the user.
It is yet another object of the present invention to provide an interlabial absorbent device that "handles" the absorption of high viscosity or insoluble components of bodily fluids such as menses, resisting capillary obstruction by these components. These and other objects of the present invention become more readily apparent when considered with reference to the following description and when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE INVENTIONThe present invention relates to absorbent devices, and, more particularly, to an absorbent device that is insertable within the interlabial space of a female user for catamenial purposes, for the protection of incontinence or both. The interlabial absorbent device of the present invention comprises a main absorbent portion and a stop portion of flexible extensions attached to the main absorbent portion. The main absorbent portion comprises an acquisition member that can rapidly absorb bodily fluids, such as menstruation, without becoming clogged with solid or highly viscous components of these fluids. The main absorbent portion further comprises a storage member that is in effective fluid contact with the acquisition member. The storage member has a pore volume distribution that allows it to suck absorbed bodily fluids from the acquisition member. The interlabial device further comprises a pair of flexible extensions that are attached to the main absorbent portion adjacent to the proximal surface thereof. The proximal surface is that surface of the main absorbent portion that is positioned farther inwardly in the space between the wearer's lips when the interlabial device is inserted. If the insertion occurs, the flexible extensions make contact and tend to adhere to the walls of the user's lips. The flexible extensions are also capable of preferably covering the tip of the user's fingers as the absorbent device is inserted into the user's liplabial space.
BRIEF DESCRIPTION OF THE DRAWINGSAlthough the description concludes with the claims pointing out in a particular way and claiming in a different manner the exposed matter that is considered formant of the present invention, it is believed that the invention will be better understood from the following description taken in conjunction with the drawings that will accompany, in which: Figure 1 is a perspective view of a preferred embodiment of the liplabel absorbent device of the present invention. Figure 2 is an end view of the absorbent device shown in Figure 1. Figure 3 is a perspective view of a preferred alternate embodiment of the interlabial absorbent device of the present invention. Figure 4 is an end view of a preferred alternate embodiment of the present invention having a folded main absorbent portion. Figure 5 is an end view of an alternate embodiment of the folded embodiment shown in Figure 4; Figure 6 is a preferred embodiment of the present invention showing a main absorbent portion having a multiple layer structure.
Fig. 7 is a cross-sectional figure of a body of the wearer encircling and including the labia majora and the labia minora showing the flexible extensions of the present invention covering the tips of the wearer's fingers as inserts the absorbent device of the present invention into the interlabial space of the user. Figure 8 is a cross-sectional view of the same region of the wearer's body shown in Figure 7, showing how the interlabial device of the present invention adjusts when the wearer is standing.
DETAILED DESCRIPTION OF THE INVENTIONGeneral Description of the I nterlabial Absorbent DeviceThe present invention is directed to an interlabial absorbent device. Figure 1 shows a preferred embodiment of the interlabial absorbent structure of the present invention, interlabial device 20. The present invention, however, can be in many other forms, and is not limited to a structure having the particular configuration shown in the drawings. drawings. As used herein the term "interlabial absorbent device" refers to a structure having at least some absorbent components, and is specifically configured to reside at least partially within the interlabial space of a female user during use. Preferably, at least about 30% of the volume of the interlabial absorbent device 20 of the present invention resides within this interlabial space when used, more preferably at least 50% of the volume resides within said interlabial space, still more preferably the volume total of the absorbent device nterlabial 20 residesMost of the women and men who have sex with women are referred to as "older women" and "younger men." For the purposes of this description, however, these differences are not feminine anatomy, attention is directed to Gray's Anatomy, Running Press, 1901 Ed. (1974) at 1025 to 1027. As used herein, the term "solid component of bodily fluids" refers to particles that have an effective radius greater than about 5 microns. The interlabial absorbent device 20 shown in Figure 1 has a longitudinal centerline L which runs along the "x" axis shown in Figure 1. The term "longitudinal", as used herein, refers to a line , axis or direction in the plane of the interlabial device 20 that is generally aligned with (eg, approximately parallel to) a vertical plane that divides a user standing in left and right body halves when the interlabial device 20 is used. The The terms "transverse", "lateral", or "y direction", as used herein, are interchangeable, and refer to a line, axis or direction that is generally perpendicular to the longitudinal direction. The lateral direction is shown in Figure 1 as the "y" direction and is defined by the lateral center line T. The "z" direction, shown in Figure 1, is a direction perpendicular to the plane formed by the longitudinal center line L and the lateral center line T. The term "upper" refers to an orientation in the z direction toward the user's head. "Bottom", or "down", is toward the user's feet. As shown in Figure 1, the interlabial device 20 comprises a main absorbent portion (or "central absorbent"), 22, and a pair of flexible extensions 24 attached to the main absorbent portion 22. The main absorbent portion 22 must be less partially absorbent. The main absorbent portion 22 comprises an acquisition member 26 disposed along the longitudinal center line of the interlabial absorbent device 20 and a storage member 28 disposed laterally on the outside of at least one of the sides of the acquisition member. Preferably, the storage member 28 comprises two portions with a portion that is laterally disposed on the outside of each of the sides (L, plane z) of the acquisition member 26. The flexible extensions 24 are attached to the adjacent main absorbent portion 22. to the proximal end 22A thereof. In use, the proximal end 22A is positioned farther inward in the interlabial space of the wearer. In the preferred embodiment shown in Figure 1, the interlabial device 20 also comprises a back sheet 38 impervious to the liquid to prevent the absorbed liquids from leaking out from the main absorbent portion 22. The interlabial device 20 must be of a size and shape suitable that allow at least a part of it fit comfortably within the interlabial space of the user covering the vaginal orifice of the user, and preferably also the opening of the user's urethra. The interlabial device 20 at least partially blocks and at least preferably completely blocks and intercepts the flow of menses, urine, and other body exudates from the vaginal orifice and the opening of the user's urethra. The size of the interlabial device 20 is also important for the comfort associated with the use of the device. In the preferred embodiment shown in Figure 1, the main absorbent portion 22 of the interlabial device 20 has a length as measured along the longitudinal center line L, between about 35 mm and about 120 mm. Preferably, the length of the interlabial device 20 is between about 40 mm and about 100 mm, and more preferably, it is between about 45 mm and about 90 mm. The dry gauge (or width) of the main absorbent portion 22 of the interiabial device as measured in the transverse direction (or "y" direction) under a confining pressure of 0.25 pounds per square inch (1.7 kPa), is preferably less than or equal to about 15 mm, more preferably the dry gauge is about 10 mm. Even more preferably, the dry gauge is less than about 8 mm. A method for dry gauge measurement is provided in the ABOUT TEST METHODS section. The depth (or dimension in the "z" direction) of the main absorbent portion 22 is preferably between about 8 mm and about 35 mm, and more preferably is about 20 mm. The interlabial device 20 is preferably provided with sufficient absorbency to absorb and retain exudates discharged from the wearer's body. However, the capacity of the product is at least partially dependent on the physical volume of the interlabial absorbent device 20, particularly the main absorbent portion 22 thereof. The main absorbent portion 22 preferably has a capacity of at least about 1 gram of sheep blood as measured in accordance with the Absorbance Capacity test described in the TEST METHODS section below, and may have a capacity of up to about 30. grams using absorbent gels or foams that expand when wet. The capacities can typically vary from about 3 to about 12 grams. Those skilled in the art will recognize that, although they are related, the ability for absorption of body exudates, such as menses, will typically differ somewhat from the absorptive capacity for sheep blood. Since the interlabial space can expand, larger volumes can be stored within the interlabial space, if the fluid is stored as a gel, which adjusts to body pressures. Additionally, if the proximal absorbent device 20 does not reside completely within the interlabial space of the wearer, some of the absorbed exudates may be stored externally to the interlabial space of the wearer.
The Main Absorbent PortionIn the preferred embodiment of the interlabial absorbent device 20 shown in FIGS. 1 and 2, the main absorbent portion 22 comprises an acquisition member 26 and a storage member 28. The acquisition member 26 rapidly acquires the body exudates, such as menstruation or urine, before passing them over the storage member 28 which absorbs and retains the body exudates. Preferably the acquisition member 26 has a ready-made structure for the rapid acquisition of these body fluids and the storage member 28 has a structure made to "suck" at least a portion of the fluids acquired from the acquisition member 26 for storage therein. inside. Although said structures will be discussed in detail below, the acquisition member 26 for a preferred embodiment of the present invention comprises a fibrous assembly having a first density and the storage member 28 comprising a fibrous assembly having a second higher density. The relative densities or the acquisition member 26 and the storage member 28 are such that the acquisition member 26 can rapidly acquire bodily fluids comprising undissolved components (e.g., cellular debris) and components with high viscosity (eg. example, the mucosal components), as well as more fluid components, without substantial obstruction while being able to "deliver" at least a portion of these body fluids to the storage member 28. In other words, the acquisition member 26 it will preferably have a relatively low density (and a relatively large pore volume distribution) and the storage member will have a higher density (and smaller pores).
As clearly shown in Figures 1 and 2, for the preferred embodiment of the present invention, the acquisition member 26 is disposed along the longitudinal center line L where it is in a position to acquire said body exudates as it is discharge from the vaginal introitus or from the urethra. As also shown in Figures 1 and 2, the storage member 28 of this preferred embodiment comprises two partitions, a partition that is laterally disposed on the outside of each side of the acquisition member 26 (one skilled in the art will recognize that a portion individual that is located laterally on the outside of one side of the acquisition member 26 is also suitable). Each of the portions of the storage member 28 is in effective fluid communication with, and preferably attached to, the acquisition member 26. As used herein, the term "fluid communication" is intended to mean that the fluids Bodies can be transferred between two elements of the interlabial absorbent device 20 by capillarity or other means. The main absorbent portion 22 can be manufactured in a wide variety of forms, non-limiting examples include ovoid, trapezoidal, rectangular, rounded rectangular, triangular, cylindrical, hemispherical, or any combination of the foregoing. A rounded rectangular shape is particularly preferred because said shape eliminates pointed corners that may be uncomfortable. Preferably, as shown in Figure 1, the main absorbent portion 22 extends to the total longitudinal length of the interlabial device 20. In an alternate embodiment of the present invention, the main absorbent portion 22 is centered around the lateral centerline T and extends over a part of the longitudinal length of the flexible extensions 24. Such a modality is shown as 120 in FIG. 3 and discussed in more detail in the alternate modes section.
The Acquisition MemberThe acquisition member 26 receives the bodily fluids (e.g., menstruations), as these fluids are released and quickly acquired. The acquisition member 26 of the present invention is particularly capable of acquiring said body fluids over substantially the total cycle of use of the interlabial absorbent device 20 without surface obstruction caused by the solid or high viscosity components of these fluids which would interfere with such rapid acquisition. . In order to allow rapid acquisition without clogging, the acquisition member 26 has larger pores relative to the pores of the storage member 28, such that the acquisition member 26 can acquire the body fluids without being obstructed by the suspended solid components or components with high viscosity of the exudates while "delivering" (partitioning) the remaining fluid portion of the body exudates to the storage member 28. For the acquisition member 26 and the storage member 28 to function in this way, the acquisition member 26 must have a high percentage of pores that are greater than the pore range of the storage member 28. Established otherwise, the average capillary radius of the pore volume distribution of the acquisition member 26 must be greater than the mean capillary radius of the pore volume distribution of the storage member 28. As used herein, the term "capillary radius" is intended to mean an equivalent radius as measured during the desorption stage (increasing hydrostatic pressure) in accordance with the pore volume distribution test described in the TEST METHODS section . To be suitable as the acquisition member 26, a material must have a pore volume distribution such that at least 75% of the pores thereof have a capillary radius greater than about 20 microns. Preferably, at least 75% of the pores have a capillary radius greater than about 30 microns. Even more preferably at least about 75% of the pores have a capillary radius greater than about 50 microns. Particularly preferred materials have a pore volume distribution such that at least 75% of the pores have a capillary radius greater than about 75 microns. Applicants have found that, while the acquisition member 26 has such a capillary radius or greater, the solid and viscous components of menses do not substantially interfere with the acquisition of these body fluids over most of the use cycle of the interlabial absorbent device. As will be discussed in detail below, the smaller pores of the storage member 28 can then acquire components with lower viscosity from the acquisition member 26 because of their superior capillary suction provided by the smaller pores. The acquisition member 26 also preferably possesses number elasticity in order to maintain its ability to acquire the solid and viscous components of the body exudates after the acquisition member wets with the bodily fluids. As used herein, a material "elasticity in number" maintains at least 60% of its initial wet caliper after it is compressed to 50% of its initial wet caliper as described in the methods section of Test below. Preferably, the acquisition member 26 comprises a material having a wet elasticity of at least about 70%. Materials that will acquire the solid and viscous components of body exudates without substantial obstruction include woven materials, non-woven materials, absorbent foams, absorbent sponges. These materials must be either intrinsically hydrophilic or treated so that they are hydrophilic in such a way that water-based body fluids can spread rapidly over them. Suitable woven and nonwoven materials may be composed of natural fibers (e.g., cellulosic fibers), of hydrophilic synthetic fibers (for example, polymeric fibers, such as polyester, rayon, polypropylene or polyethylene fibers, which have been treated to be hydrophilic) or from a combination of natural and synthetic fibers. Fibers useful in the manufacture of materials suitable for use as an acquisition member 26 preferably have a relatively smooth surface so as not to provide "protrusions that may interfere with the rapid absorption of the solid and viscous components of body exudates such as menses. When the acquisition member 26 comprises a foam material, the foam may be either a blown foam (eg, a blown polyurethane foam), an HIPE high internal phase emulsion foam, or other foam as may be known. In the art, suitable cellulosic fibers are the chemically crosslinked, hardened, twisted (crimped) fibers, which are discussed more fully in Moore's U.S. Patent 4,898,642, the disclosure of which is hereby incorporated herein by reference. These fibers can be formed into a suitable weft to be used as an adq. uisition 26 using air placement or wet laying techniques as are familiar in the art. Preferably, the fibers are placed with air as described in commonly assigned U.S. Patent No. 5,607,414 issued to Richards on March 4, 1997, the disclosure of which is hereby incorporated by reference. These fibers are thermally bonded preferably by a thermoplastic material as also described in the aforementioned U.S. Patent No. 5,607,414.
A suitable foam material for the acquisition member 26 is the HIPE foam described in U.S. Patent No. 5,563,179 issued to Stone, on October 8, 1996. Polyurethane foam, marketed by Foamex Corp., is also suitable. from Eddystone, PA as SIF 100. These polyurethane foams will require treatment with a suitable surfactant such that hydrpiphics would be sufficient to be used as an acquisition member 26. A preferred material for the acquisition member 26 comprises a non-woven material of carded rayon, needle punched having a basis weight of between about 65 grams per square meter and about 75 grams per square meter, and a density between about 0.01 grams per cubic centimeter and about 0.05 grams per cubic centimeter, preferably between about 0.02 grams per cubic centimeter and approximately 0.04 grams per centimeter c ubico This material, with a basis weight of approximately 69 grams per square meter and a density of approximately 0.03 grams per cubic centimeter, is available from Sterns Technical Textiles, Inc. of Lockland, OH as the 9290B material. A particularly preferred nonwoven material for the acquisition member 26 comprises a thermally bonded nonwoven material placed with air. A suitable thermoplastic cut fiber for such nonwoven material comprises a polyethylene / polypropylene (18 d-tex x 5 millimeters) two-component material with a hydrophilic finish and which is available from Chisso Corporation of Osaka, Japan. The preferred nonwoven material comprises 100% of said thermoplastic staple fibers. The air bonding and thermal bonding methods described in the aforementioned U.S. Patent 5,607,414 can be used to form a nonwoven web having a basis weight of about 60 grams per meteracquisition member 26) has a substantially vertical orientation. This means that the aravedad and the panilar suction can not be used for the acquisition member 26 is the HIPE foam described in U.S. Patent No. 5,563,179 issued to Stone, on October 8, 1996. Polyurethane foam, marketed by Foamex Corp. of Eddystone, PA as SIF 100, is also suitable. These polyurethane foams will require treatment with a suitable surfactant such that hydrofilics would be sufficient to be used as a acquisition member 26. A preferred material for the acquisition member 26 comprises a needle punched needle-punched rayon nonwoven material having a basis weight of between about 65 grams per square meter and about 75 grams per square meter, and a density between about 0.01 grams per cubic centimeter and about 0.05 grams per cubic centimeter, preferably from approximately 0.02 grams per cubic centimeter and approximately 0.04 grams per cubic centimeter. This material, with a basis weight of approximately 69 grams per square meter and a density of approximately 0.03 grams per cubic centimeter, is available from Sterns Technical Textiles, Inc. of Lockland, OH as the 9290B material. A particularly preferred nonwoven material for the acquisition member 26 comprises a thermally bonded nonwoven material placed with air. A suitable thermoplastic cut fiber for such nonwoven material comprises a polyethylene / polypropylene (18 d-tex x 5 millimeters) two-component material with a hydrophilic finish and which is available from Chisso Corporation of Osaka, Japan. The preferred nonwoven material comprises 100% of said thermoplastic staple fibers. The methods of air placement and thermal bonding described in the aforementioned United States patent 5, 607,414, can be used to form a nonwoven web having a basis weight of approximately 60 grams per square meter and a dry gauge of approximately 2.3 millimeters from these fibers. This nonwoven material has been found to have a pore volume distribution such that at least 75% of the pores have a capillary radius greater than about 200 microns. As can be seen in Figures 1 and 2, the acquisition member 26 is preferably positioned along the longitudinal centerline L of the interlabial absorbent device 20. As can also be seen, the acquisition member 26 extends the longitudinal length substantially total of the main absorbent portion 22. The depth of the acquisition member 26 is also defined by the depth of the main absorbent portion 22. As also shown for the preferred embodiment shown in Figures 1 and 2, the acquisition member 26 is arranged between two parts of storage member 28. Preferably, the acquisition member has a lateral width (dry gauge) of between about 1.0 millimeters and about 4 millimeters. More preferably, the side width is between about 1.5 millimeters and about 2.5 millimeters. The structure shown in Figures 1 and 2 is particularly advantageous for the acquisition and storage of bodily fluids, such as menstruation. As can be seen in Figure 7 when the interlabial absorbent device 20 of the present invention is worn, the main absorbent portion 22 (and, necessarily, the acquisition member 26) has a substantially vertical orientation. This means that gravity and capillary suction cooperate with the acquisition member 26 in acquiring bodily fluids as they are released. This cooperation can cause said bodily fluids, particularly the solid and viscous components thereof, to be drawn down towards the acquisition member 26 and away from the proximal surface 22 A of the main absorbent portion. Because the fluids are drawn away from the proximal surface 22 A, the risk of clogging any of the pores of the acquisition member 26 that are located near that surface is reduced.
The Storage MemberAs noted above, the storage member 28 absorbs and retains body exudates such as menses or urine, and does not need to have much greater absorbent capacity than the amount of total exudate that is absorbed. In particular, the storage member 28 draws fluids from the acquisition member 26 because of its superior capillary suction of the materials comprising the storage member 28. The upper capillary suction of the storage member 28 results from the smaller pores of the same. The storage member 28 should have a pore volume distribution wherein the average capillary radius varies from about 5 microns to about 50 microns, preferably from about 10 microns to about 40 microns, to provide sufficient capillary suction to entrain the components of the fluids from the body exudates from the acquisition member 26 to the storage member 28. It is important to ensure that most of the pores and storage material are small enough to provide sufficient capillary suction. These materials preferably have pore volume distributions such that at least about 75% of the pores of the material have a capillary radius of less than about 80 microns. More preferably these materials have a pore volume distribution so that at least about 75% of the pores of the material have a capillary radius less than about 60 microns. Particularly preferred materials have a pore volume distribution such that at least 75% of the pores of the material have a capillary radius of less than about 45 microns. It is also important that the pore volume distribution of a material suitable for use as a storage member 28 be large enough that the pores thereof are not easily obstructed by the undissolved components of the body fluids (e.g. cell phones). This obstruction may block the flow through the storage member 28 such that a portion of the storage member 28 may not be available for storage of the body fluids. Preferred materials used as a storage member 28 have a pore volume distribution such that less than about 10% of the pores have a capillary radius less than 5 microns. More preferably, the pore volume distribution is such that less than about 15% of the pores have a capillary radius of less than about 5 microns. The storage member 28 of the preferred embodiment shown in Figures 1 and 2 may comprise any type of suitable absorbent structure that is capable of absorbing and / or retaining liquids (e.g., menses and / or urine) and entraining these exudates from the body. acquisition member. The storage member 28 can be manufactured in a wide variety of liquid absorbent materials commonly used in absorbent articles, such as crushed wood pulp, which is generally referred to as an air filter. Examples of other suitable absorbent materials include accreted cellulose wadding; blown polymers in the molten state, including coform; chemically hardened, modified or cross-linked cellulosic fibers; synthetic fibers, such as pleated polyester fibers; peat moss; tissue, including tissue wraps and tissue laminates, absorbent foams; absorbent sponges; superabsorbent polymers; gelling absorbent materials; or any equivalent material or combinations of materials, or mixtures thereof. The storage member 28 may comprise a simple material or a combination of materials, such as a wrapping layer surrounding a central wadding composed of a different absorbent material. A suitable material combination for the storage member 28 comprises a laminate of a fibrous gelling absorbent material disposed between two layers of a tissue placed with air. In this modality, the gelling absorbent material is provided at a level of between about 0.005 grams per square centimeter and about 0.15 grams per square centimeter, preferably between about 0.007 grams per square centimeter and 0.07 grams per square centimeter. A suitable gelling absorbent material is available from Courtaulds Fibers / Allied Colloids, a joint ventura company, West Midlands, England, as OASIS and a suitable tissue which is a placed air tissue from the Fort Howard Tissue Company of Green Bay, Wisconsin. , and that has a base weight of 57 grams per square meter. Alternatively, a combination of air laid cellulosic fibers as is commonly known in the art and a gelling absorbent material is also suitable for use as the storage member 28. For example, applicants have found that such a combination placed with air which has a basis weight of 0.025 grams per square centimeter and which comprises approximately 17% of Fiberdri 1 160 available from Camelot Superabsorbents, Ltd. Cálgari, Alberta, Canada, is particularly suitable. For designs where the use of the gelling absorbent materials is undesirable, a cotton wadding having a basis weight of between about 75 grams per square meter and about 200 grams per square meter and a dry gauge of between about 0.5 millimeters and approximately 3.0 mm, it is preferred. A particularly preferred cotton wadding, having a basis weight of approximately 1d0 grams per square meter and a dry gauge of approximately 1.3 millimeters, is available from REVCO DS, Inc. of Twinsburg, OH as cosmetic cotton boxes (Article 2736) . As shown in Figures 1 and 2 the storage member 28 for this preferred embodiment of the present invention comprises two parts with a part that is located on either side of the acquisition member 26 and laterally on the outside thereof. As also seen each part substantially extends the total longitudinal length of the main absorbent portion 22 and the total depth thereof. The thickness (dry gauge) of each part of the storage member 28 is preferably between about 4% and about 40% of the dry gauge of the main absorbent portion 22. More preferably, the thickness is between about 10% and about 30% of the dry gauge of the main absorbent portion 22. Said structure maximizes the contact area between the acquisition member 26 and the storage member 28. As a result, the interlabial absorbent device 20 of the present invention makes full use of the storage capacity available. As discussed with respect to the acquisition member 26, gravity and capillary suction may cooperate to draw bodily fluids down toward the acquisition member 26. Since the preferred structure shown in FIGS. 1 and 2 provides the vertically oriented contact between the acquisition member 26 and the storage member 28 over an entire major surface of the acquisition member 26, fluids that have been drawn into the acquisition member 26 may be drawn into the storage member 28 at the same depth. This means that the total use of the available storage capacity of the storage member 28 not only depends on the lateral flow through the storage member 28 as would be necessary but had acquisition member 26. As a result the localized portions of the storage member 28 are less likely to saturate before the total absorbent capacity of storage member 28 is used.
The Flexible ExtensionsAs shown in Figures 1 and 2, the interlabial absorbent device 20 also comprises a pair of flexible extensions 24, which are attached to the main absorbent portion 22 adjacent its proximal surface 22A. In a preferred embodiment shown in Figures 1 and 2, the flexible extensions 24 are generally rectangular in shape. Other shapes are also possible for flexible extensions 24 such as semicircular, trapezoidal or triangular? Flexible extensions 24 are preferably from about 40 mm to about 160 mm in length, more preferably from about 45 mm to about 130 mm in length, and most preferably at about 115 mm in length. Although the flexible extensions 24 can have a length that is shorter than the main absorbent portion 22, preferably they have a length that is the same as or greater than the main absorbent portion 22. The width of one of the flexible extensions refers to the distance from the junction of the flexible extension 24 to the main absorbent portion 22 (or the proximal end 24A of the flexible extension 24), toward the distal end (or free end) 24B of the flexible extension 24. The width of an extension flexible 24 is preferably equal to or greater than the depth of the main absorbent portion 22 as described above. The dry gauge of the flexible extensions is preferably less than or equal to about 3 mm, more preferably less than or equal to about 2 mm, and most preferably less than or equal to about 1 mm. Ideally, the dry gauge of the flexible extensions 24 and the main absorbent portion 22 are selected such that the gauge of the overall interlabial absorbent structure 20 is less than or equal to about 8 mm. The flexible extensions 24 can be constructed from any material that has the flexibility and dry gauge required. Suitable materials include: woven and non-woven materials; polymeric materials, such as thermoplastic films formed with openings, plastic films with openings and hydroformed thermoplastic films; porous foams; cross-linked foams; crosslinked thermoplastic films; and thermoplastic canvases. Suitable woven and nonwoven materials may be composed of natural fibers (eg, wood or cotton fiber), synthetic fibers, (eg polymer fibers such as polyester, rayon, polypropylene or polyethylene fibers), or from a combination of natural and synthetic fibers. The flexible extensions 24 can be constructed of a tissue layer. A suitable tissue is a tissue placed with air available from the Fort Howard Tisue Company of Greenbay, Wisconsin, and having a basis weight of 35 pounds / 3000 ft2. Another tissue placed with suitable air is available from Merfin Hygenic Products, Ltd., of Delta, British Columbia, Canada, which has a basis weight of 61 pounds / 3000 ft2, and which has the class designation number 176. Although not necessary for the operation of the present invention, the flexible extensions 24 may preferably be supported by the backsheet 38 as described below. In the preferred embodiments shown in Figures 1 and 3, the pair of flexible extensions 24 may comprise separate sheets of material, independently attached to the main absorbent portion 22 adjacent to the proximal surface 22A thereof. Preferably, the flexible extensions 24 are arranged symmetrically about the longitudinal centerline L of the main absorbent portion 22. The flexible extensions 24 are attached to the proximal surface 22A of the main absorbent portion 22 within approximately 3mm of that surface . The term "attached", as used herein, encompasses configurations in which the element is directly secured to the other element by attaching the element directly to the other element; configurations in which the element is indirectly secured to the other element by fixing the element to a member or intermediate members, which in turn are fixed to the other element; and configurations in which one element is integral with the other element, that is, one element is essentially part of the other element.
The back sheetThe preferred embodiment of the interlabial absorbent device 20 shown in Figures 1 and 2 further comprises a back sheet 38 positioned on and attached to all or a portion of its back surface, including the flexible extensions 24. The back sheet 38 is preferably impermeable or semipermeable to liquids (eg, menses and / or urine), and is preferably flexible. As used herein, the term "flexible" refers to materials that are docile and that will easily conform to the contour and general shape of the human body. The backsheet 38 prevents the exudates absorbed and contained within the main absorbent portion 22 from wetting the articles that are in contact with the interlabial device 20 such as the wearer's undergarments. The backsheet 38 also helps the main absorbent portion 22 prevent the wearer's body from being soiled by the exudates. Additionally, the use of the backsheet may provide an improved (i.e., sanitary) surface for the wearer to hold between the fingers as the proximal absorbent device 20 is inserted, or as the device is optionally removed. the fingers. The backsheet 38 may comprise 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 backsheet is a polyethylene film having a thickness of about 0.012 mm to about 0.051 mm. An exemplary polyethylene film is manufactured by Clopay Corporation of Cincinnati, Ohio, under the designation P18-0401. The backsheet 38 can allow vapors to escape from the main absobent portion 22 (i.e., respirables), while still preventing the exudates from passing through the backsheet.
Optional componentsThe interlabial absorbent device 20 in any of the embodiments shown in the drawings may comprise other optional components.
The Top SheetFor example, the interlabial device 20 may comprise a top sheet placed on and attached to all or a portion of the surface facing the body of the device 20. Preferably, if a top sheet is used, it is attached to at least part of the main absorbent portion 22. Preferably, a top sheet, when used, is disposed on and attached to both of the proximal surface 22A of the main absorbent portion 20 and the body-facing surface of the flexible extensions 24.
If the upper sheet is used, the upper sheet should be docile, soft feeling and not irritating to the wearer's skin. In addition, the top sheet must be permeable to liquid allowing liquids (eg, menses and / or urine) to easily penetrate through its thickness. A suitable top sheet can be manufactured from a wide range of materials such as woven and nonwoven materials; polymeric materials, such as thermoplastic films formed with openings, plastic films with openings and hydroformed thermoplastic films; porous foams; cross-linked foams; crosslinked thermoplastic films; and thermoplastic canvases. Suitable woven and nonwoven materials may be composed of natural fibers (eg, wood or cotton fiber), synthetic fibers, (eg polymer fibers such as polyester, rayon, polypropylene or polyethylene fibers), or from a combination of natural and synthetic fibers. The top sheet may comprise a film formed with openings. Films formed with openings are permeable to body exudates, and, if properly perforated, have a reduced tendency to allow liquids to pass back through and rewet the user's skin. In this way, the surface of the formed film that is in contact with the body remains dry, thus reducing the staining of the body and creating a more comfortable feeling for the wearer. Suitable formed films are described in U.S. Patent No. 3,929,135 entitled "Absorbent structures having tapered capillaries", which was issued to Thompson on December 30, 1975, U.S. Patent No. 4,324,246 entitled "Article Disposable absorbent that has a stain-resistant sheet ", which was issued to Mullane et al. on April 13, 1982; U.S. Patent No. 4,342,314 entitled "Resilient plastic screen exhibiting properties in the form of fiber", which was issued to Radel et al. on August 3, 1982; U.S. Patent No. 4,463,045 entitled "Macroscopically expanded three-dimensional plastic screen exhibiting a non-glossy visible surface and a fabric-like fingerprint", which was issued to Ahr et al. on July 31, 1984; and in U.S. Patent No. 5,006,394"Multilayer Polymer Film", which was issued to Baird on April 9, 1991. The preferred top sheet for the present invention is the formed film described in one or more of the previous patents and that is marketed in sanitary napkins by The Procter & Gamble Company of Cincinnati, Ohio, as the top sheet "DRI-WEAVE". The surface that is in contact with the body of the preferred formed film upper sheet is also hydrophilic to help transfer the liquid through the upper sheet faster than if the surface that is in contact with the body is not hydrophilic, for decrease the likelihood that menstrual fluid will flow out of the topsheet instead of flowing into and being absorbed by the main absorbent portion 22. In a preferred embodiment of said top sheet, surfactant is incorporated into the polymeric materials of the sheet top of formed film. Alternatively, the surface that is in contact with the body of the topsheet can be made hydrophilic by treating it with a surfactant such as is described in U.S. Patent No. 4,950,254 issued to Osborn.
The Body AdhesiveOptionally, the flexible extensions 24 may also be provided with a biocompatible adhesive to assist adhesion of the flexible extensions 24 to the internal surfaces of the wearer's lips. The strength of said adhesive must be selected to assist the interlabial absorbent device to remain in place, while still allowing for reliable and comfortable removal of the device from the interlabial space of the wearer. Suitable adhesives are discussed in U.S. Patent No. 5,336,208 issued to Rosenbluth et al. On August 9, 1994, the disclosure of which is incorporated herein by reference.
The Alternative ModalitiesVarious preferred alternate embodiments of the present invention are also contemplated. Examples of these modalities are discussed below.
Extended Flexible ExtensionsIn an alternate embodiment the interlabial device 120, which is shown in Figure 3, the longitudinal length of the main absorbent portion 122 is only a fraction of the longitudinal length of the flexible extensions 124. Said structure has the advantage of having a smaller volume and, as a result, adopt a smaller portion of the volume of the interlabial space of the wearer than the modality shown in Figures 1 and 2, the interlabial device 20. Conversely, the main absorbent portion 122 of the alternate interlabial device 120 will have a total capacity less than the main absorbent portion 22 of the interlabial device 20. In general, each of the components of the alternate interlabial device 120 comprises the same elements as the interlabial device 20. However, as distinguished above the size ratio between the components differs. In particular, the main absorbent portion 122 of the alternate interlabial device 120 has a longitudinal length less than the main absorbent portion 22 of the interlabial device 20. Depending on the desired ratio between the volume of the device and the absorbent capacity, the main absorbent portion 122 can having a longitudinal length of between about 30% and about 90% of the longitudinal length of the flexible extensions 124. Preferably, the longitudinal length of the main absorbent portion 122 is between about 30% and about 60% of the length longitudinal of the flexible extensions 124. The alternate embodiments (not shown in which the longitudinal length of the flexible extensions is less than the longitudinal length of the main absorbent portion are also contemplated with respect to the present invention.) Preferably, these flexible extensions are centered around of the transverse centerline of said embodiments and extending in the longitudinal direction or at least approximately one third of the longitudinal length of the main absorbent portion. In a variation of this alternate embodiment (not shown), the depth of the main absorbent portion 122 may be greater than the lateral width of one of the flexible extensions 124. Said structure may provide additional absorbent capacity while compensating somewhat for the loss of the volume to the main absorbent portion 122 caused by the decrease in its longitudinal length.
Folded Main Absorbent PortionIn a preferred alternate embodiment, the interlabial device 220, shown in Figure 4, the storage member 228 comprises a folded structure. As shown in Figure 4 the storage member 228 comprises a folded tissue web. The folded tissue web preferably has a strength greater than that of toilet paper with strength in the standard non-wet state. Preferably, the storage member 228 comprises a tissue having a temporary wet strength of greater than or equal to about 50 grams as measured according to the wet break-resistance method described in the TEST METHODS section. down. Preferably, the temporary wet strength is greater than or equal to approximately 100 grams. In a preferred design, this wet strength will decay to about 50% or less of the original strength for about 30 minutes. As shown in Figure 4 the tissue web comprising the storage member 228 is folded into a folded structure comprising a plurality of fold 230 which are arranged in a laterally side-by-side relationship. The tissue web can be folded in such a way that it has any suitable number of folds. Preferably, the tissue web is bent such that the total dry gauge (i.e., width) of storage member 228 of this embodiment is between about 2 millimeters and less than or equal to about 7 millimeters. The folds 230 in the folded tissue web are preferably bent or joined (or retained) in some suitable manner such that the folded sections maintain their folded configuration, and are not able to fully open. The folds may be connected by a variety of means including the use of threads, adhesives, or heat sealed tisus which contain a thermoplastic material, such as polyethylene. A preferred design uses the seam joining joining all the folds 230 simultaneously to the storage member 228. Preferably, the main absorbent structure 222 is provided with 5 sewing locations (4 at the corner and one additional location at about half between). the two lower corners). The alternate preferred embodiment shown in FIG. 4 preferably has a storage member 228 and a flexible extension 224 sized similarly to those described above for the embodiment shown in FIGS. 1 and 2. The width of the storage member 228 of FIG. Interlabial device 220 as measured in the lateral direction (Y direction) is preferably between about 1 millimeter and about 2 millimeters. Preferably, in a preferred embodiment, the width of the main absorbent portion of the interlabial device 20 is approximately 4.5 millimeters. The folded design shown in Figure 4 has the additional benefit of easily providing the flexible extensions 224. The extensions 224 may comprise the same material as the storage member 228, or these may comprise a different material. The extensions 224 are disposed within approximately one millimeter of or, preferably, adjacent to the proximal surface 222A of the main absorbent portion 222 and attached thereto. More preferably, as shown in the embodiment of Figure 4, the extensions 224 are integral parts of the storage member 228 (ie, the extensions 224 comprise integral extensions of the tissue absorbent material that is folded to form the storage member 228. ). The acquisition member 226 and the flexible extensions 224 of the interlabial absorbent device 20 shown in Figure 4 can be constructed from any of the materials discussed with respect to the equivalent members in the embodiment shown in Figures 1 and 2. similar, this alternate preferred embodiment also comprises a rear sheet 238 disposed on the bottom surface thereof. In a variation of the structure of Figure 4, which is shown in Figure 5 as the interlabial device 250, both the acquisition member 226 and the storage member 228 are folded. Said structure has the additional benefit of increased surface contact between the acquisition member 226 and the storage member 228, because the storage folds 203 and the acquisition folds 232 are internally entangled. One skilled in the art will recognize that the dry gauge of the main absorbent portion 222 of this alternate embodiment is determined by the comfort of the user. As a result, the material comprising the acquisition member 226 of this embodiment is thinner (has a lower dry gauge) than the material comprising the embodiment shown in Figure 4. However, because of the folded nature of the folds of acquisition 232, the proximal surface 222A of the interlabial device 250 has a body-contacting area similar to the contact area with the body of the proximal surface 222A of thelabellabel device 220 of Figure 4. In another variation of the folded structure shown in Figure 4, storage member 328 may comprise a plurality of individual layers 332 joined in a face-to-face relationship. This device is shown in Figure 6 as the interlabial device 320. The interlabial device 320 can have all of the same characteristics as described above for the foldable structure 220. One benefit of using a plurality of individual layers 332 is that the various layers can understand different materials with different properties or characteristics. Each of the flexible extensions 324 may be integral with one of the individual layers 332 or may be separately joined to the upper portion 326 of the storage member 328. Preferably, the individual layers 332 are disposed in a side-by-side relationship in such a way that the spaces between the layers are oriented in the z-direction (as shown in Figure 6). As previously discussed, the interlabial absorbent device 20 of the present invention is preferably designed to be placed entirely within the interlabial space of a user. To use the interlabial absorbent device 20 of the present invention, the wearer maintains the main absorbent portion 22 between her fingers. As shown in Figure 7, the flexible extensions 24 are separated to cover the tips of the user's fingers during insertion. This feature provides a hygienic insertion of the proximal absorbent device 20 of the present invention. The proximal surface 22A is inserted first and more towards the labial space. The user can assume a crouched position during insertion to help extend the labial surfaces. Once the proximal absorbent device 20 is inserted, the flexible extensions 24 tend to adhere to the lower surfaces of the lips. When the wearer is standing, the labial walls close more tightly around the interlabial absorbent device as shown in Figure 8. The interlabial device 20 is at least preferably partially retained in place by exerting a slight outwardly oriented pressure so lateral over the internal surfaces of the labia majora, the user's labia minora or both. Additionally, the product is also maintained by traction of the naturally wet labial surfaces to the tissue comprising the flexible extensions 24. The interlabial absorbent device 20 can be used as a "single" product. Alternatively, it can be used as a backing for a tampon, or in combination with a sanitary napkin, pantiliner or incontinence pad for menstrual or incontinence use. If the interlabial absorbent device 20 is used with a sanitary napkin, the sanitary napkin can be of any thickness. Use with a sanitary napkin may be preferred at night to reduce back staining. The interlabial device 20 can be used in conventional panties, or it can be used with menstrual shorts. Numerous alternate embodiments of the interlabial absorbent device of the present invention are possible. For example, these products are designed to be removed by urination, although an alternate extraction cord or loop may be used. These products can also be used with medicinal treatments. These products can be constructed of materials that are biodegradable and / or which will fragment in water with agitation (as in a toilet). The interlabial absorbent device 20 can also be constructed with a plurality of slots in the main absorbent portion 22 to allow the product to be bent in multiple independent directions. This structure allows the product to respond more easily to the tensions associated with body movements. In a preferred version of the modality shown in Figure 4, the ends of the surface of the central absorber that give away from the body can be rounded to reduce the force on the product during sitting. The upper surface of the structure may have one or more slits or have other preferred flexion regions such that the product can easily adjust to vertical pressure against the pelvic surface to help accommodate the nonlinear surface of the pelvic interior surface between the clitoris and the perineum. The flexible extensions 24 of the above absorbent devices can also like a spring in both of the wet and dry conditions such that the sides of the product tend to expand outwardly pressing against the side walls of the labial vestibule, thereby maintaining the product in the place. Furthermore, it is preferred that the flexible extensions 24 maintain the ability to act as a "spring" when wet, such as when the product is saturated with the liquid. Structures, such as polyurethane foams, can provide these properties.
TEST METHODSDry CaliberPrinciple The dry caliber of a sample can be determined using a comparison meter that is tared to provide a predetermined confining pressure.
Apparatus A suitable comparison meter is the Ames, Model 130 with a Disc Indicator Model 482, available from B. O Ames, Company, of Waltham, MA. The comparison meter should have a circular comparison area made of aluminum able to exert a load pressure of 1.7 kPa. It will be recognized that the diameter of the comparison area can be varied to adjust to the different sizes of the samples as long as the loading pressure remains constant.
Operation 1. The comparison meter is set to zero according to the manufacturer's instructions. 2. The comparison area is raised and the sample is placed on the base plate. The sample is placed on the base plate in such a way that when the area is lowered it is in the center of the sample. The comparison area must be at least 5 millimeters from all the edges of the sample. Try to smooth or avoid any wrinkles in the sample. 3. Gently lower the area on the sample.4. Determine the caliber by reading the comparison disc 30 seconds after the area is in contact with the sample. 5. Repeat steps 2 to 4 for a further two samplesCalculations The average of the three readings is the dry caliber of the material.
Absorbent capacityPrinciple The total absorbent capacity of an interlabial absorbent device is measured according to the difference between the dry and loaded weight of the device, where the load fluid is analogous to the menses.
Apparatus Analytical Balance Refined to 0.1 gram Glass Fluid Container, capable of maintaining 1 liter with sufficient depth of wall to ensure no spillage when samples are inserted or removed. The container must have dimensions greater than 150% of the dimensions of the interlabial absorbent device in the x and y directions. Filter Paper Available from Filtration Science Corp., Eaton-Dikeman Division of Mount Holly Springs, PA, as paper # 631.
Test Fluid Defibrinated sheep blood, sterile, which is available from Clevaland Scientific, Inc .; from Bath, OH. Sheep blood is an unstable mat that has a limited shelf life even when stored under appropriate conditions. This comprises a heterogeneous mixture having approximately 15% by weight of hemoglobin and 75-80% by weight of water with low levels of ionic salts, lactic acid, and urea. The blood should be stored in a sealed container at 4 ° C ± 1 ° C before use. This should be discarded after two weeks if it is not used. The test is performed at a temperature of 23 ° C ± 1 ° C. The sheep's blood should be heated in a water bath at that temperature and stirred to ensure uniform distribution of the components before being transferred to the fluid container.
Procedure 1) Condition the test samples by leaving them in an environment of 50% relative humidity and at 23 ° C for a period of two hours before the test. The test must be carried out under similar conditions. 2) Pour about 1 liter of sheep's blood into the fluid container.3) Weigh the test sample in the sheep's blood. 4) Immerse the sample in sheep's blood. 5) Remove the item from the sheep blood after 15 minutes. 6) Place the article on a wire mesh horizontal screen that has square openings of 64 mm x 64 mm and allow it to drain for 5 minutes.7) Weigh the sample to the nearest 0.1 gram and record the weight. 8) Place the sample between two pieces of filter paper and apply a uniform load of 1.7 kPa (0.25 pounds per square inch) to the sample for 35 seconds.9) Weigh the sample to the nearest 0.1 gram and record the weight. 10) Increase the load to 6.8 kPa (1 pound per square inch) and maintain the pressure for 19 seconds. 11) Remove the sample from the filter paper and reweigh the sample to the nearest 0.1 gram to determine the loaded weight.
Calculations and Report The absorbent capacity is defined as the difference between dry and loaded weights.
Distribution of the Pore VolumePrinciple The pore volume distribution for a sample is re-measured for a pore size of approximately 5 microns using the Liquid Porosimeter of the Textile Research Institute (Princeton, NJ). This instrument (i) applies pre-selected hydrostatic air pressures, usually in increment, to a sample pad that can absorb / desorb fluid through a fluid-saturated membrane and (ii) determines the amount of increase and cumulative fluid that it is absorbed / desorbed by the pad at each pressure. A weight is placed on the sample to ensure good contact between the sample and the membrane, and to apply an appropriate mechanical confining pressure. A fluid having a low surface tension (?) Is typically used to ensure wettability (cos (?) = 1) of the fiber surfaces. Each evaluation of the sample includes an absorption / desorption cycle. In the absorption sequence, the accumulated volume absorbed is measured against the hydrostatic decreasing pressure. This is followed by a simple desorption sequence where the accumulated volume desorbed versus the incrementally increasing hydrostatic pressure is measured. The hydrostatic pressures vary from a high pressure corresponding to an equivalent radius:r = 2? cos (?) / Pof about five microns at a pressure of zero or close to zero corresponding to an equivalent radius of at least about 1000 microns or greater. Additional details are provided by the following references: 1. A. Burgeni and O Kapur, Capillary Sorption Equilibria in Fibrous Masses, Textile Research Journal 37, 356 (1967). 2. HG Heilweil, ed., Determining Pore Size Distributions in Fibrous Materials, Research Notes, Textile Research Institute, Number 363 (April) 3. B. Miller and I. Tyomkin, An Extended Range Liquid Extrusion Method for Determining Pore Size Distribution , Textile Res. J. 56, 35 (1986).
Porosimeter Apparatus (available from Textile Research Institute of Princeton, NJ, as Model LP-5) Membrane: GS 90 mm filter with 0.22 μM pore size MILLIPORE (available fromMillipore Corp. of Bedford, MA, as catalog number GSWP 090-25) Porous Plate (available from Fisher Scientific of Pittsburgh, PA) Petri Dish Cap - 90 cm diameter Small soft bristle brush (~ 0.5 inch wide)Test Fluid Tension agent solution: 0.2% by weight of TRITON X-100 solution (available from Rohm and Haas, Philadelphia, PA) in deionized water.
Procedure Sample Preparation Briefly before measuring the pore volume distribution, the sample size is measured (as described here) under the confining pressure of 0.2 psi (1.4 kPa). The density of the sample is calculated from the weight, caliber and area of the sample.
Confinement Pressure A confining pressure of 0.2 psi (1.4 kPa) is used for the measurement of the pore volume distribution. The same weight or equivalent that is used to determine to determine the density of the sample is also used by applying the confining pressure during the measurement of the pore volume.
Configuration of the Instrumentation Arrange the porosimeter according to the instruction manual.
Characteristics of the Absorption / Desorption Cycle An absorption / desorption cycle comprises two stages. The first, a simple absorption sequence where the accumulated volume absorbed is measured against the incrementally decreasing hydrostatic pressure. This is followed by a simple desorption sequence where the accumulated volume desorbed versus the incrementally increasing hydrostatic pressure is measured. The hydrostatic pressures vary from a high pressure corresponding to an equivalent radius of about five microns to a pressure of zero or close to zero that corresponds to a radius equivalent of at least about 1000 microns or more.
Absorption / Desorption Procedure for an Initially Dry Sample 1. The input parameters are entered as described in the equipment instructions and the computer control program is turned on. 2. The upper part of the test cell of the instrument is secured and the vent valve is closed. The fluid flow valve opens to equilibrium. In this step the sample is not yet in the test cell. 3. The control program of the computer is continued. The hydrostatic pressure is adjusted to a pre-set value (ie, STOP RADIO) that is slightly higher than the first inlet pressure used in experiment 4. After the equilibrium is signaled, the liquid valve for the equilibrium, the test cell is opened, the sample is placed on the membrane, the confinement weight is placed on the sample, and the upper part of the test cell of the instrument is secured. The program is continued and the hydrostatic pressure is adjusted to the first inlet pressure. After equilibrium is signaled, the fluid valve opens for equilibrium. 7. The sample is cycled through a series of predetermined pressures corresponding to the specific equivalent pore radii.
Subtraction of the Blank Form. A blank run is recorded, as before, but with the test cell empty. This determines the background of the absorption / desorption response of the system and the membrane. The values are obtained for the cumulative volumes of absorption / desorption versus hydrostatic pressure. These values are used to correct the corresponding values measured for the sample.
Calculations of Normalized Accumulated Volumes Based on the increment volume values, the computer control program calculates the corrected values by the format for the accumulated volume versus the equivalent pore radius. The accumulated volumes are divided by the dry weight of the pad and reported in units of mm3 / mg. Accumulated volumes are divided by volume at saturation (ie, the cumulative volume measured for the equivalent radius greater than the pressure of zero or close to zero) to obtain a normalized accumulated volume (expressed as%) versus the equivalent radius of the volume. pore.
Test the resistance of the ruptureRevision A test specimen, held between annular fasteners, is subjected to the increasing force applied by a polished stainless steel ball of 0.625 inches in diameter. The resistance to rupture is that force that causes the sample to fail. The resistance to rupture can be measured on wet or dry samples. Apparatus Rupture Tester Tension test instrument Intelect-II-STD, No. 1451-24PGB or the Thwing-Albert rupture tester are both suitable. Both instruments are available from Thwing-Albert Instrument Co., Philadelphia, PA. The instruments must be equipped with a 2000 gram load cell. If wet breakage measurements are to be made, the instruments must be equipped with a load cell protection and water protection for the front panel. Room Condition The temperature and humidity must be controlled to remain within the following limits: Temperature: 73 ± 3 ° F (23 ° C ± 2 ° C) Humidity: Relative Humidity of 50 ± 2% Paper Cutter Scissors can be used or another equivalent Tray To soak the samples for wet break, suitable for the sample sizeWater solution to soak the samples for the wet break that must be balanced at the temperature of the conditioned room Stopwatch Suitable for soaking time measurementSample preparation 1) Cut the sample to an appropriate size for the test (minimum sample size 4.5 inches x 4.5 inches). Prepare a minimum of five samples for each condition to be tested. 2) If you are going to make measurements of the break in wet, place an appropriate number of samples cut into a tray filled with water at a balanced temperature.
Equipment layout 1) Arrange the break tester according to the manufacturer's instructions. If a II-STD voltage test instrument is to be used, the following is appropriate: Speed: 12.7 centimeters per minute Breakage sensitivity: 20 grams Peak load: 2000 grams 2) Calibrate the load cell according to the breaking strength expectedMeasurement and Reporting 1) Operate the rupture tester according to the manufacturer's instructions to obtain a measurement of the breaking strength for each sample. 2) Record the breaking strength for each sample and calculate an average and a standard deviation for the breaking strength for each condition. 3) Report the average and standard deviation for each condition in the next gram.
Wet ElasticityPrinciple A test sample, saturated to its free absorbent capacity with 0.9% saline, is compressed to half its caliber before compression. The pressure is then released, and the sample is allowed to recover its thickness in the presence of the expelled fluid. The percent recovery is based on the original wet size of the uncompressed sample.
Test Fluid An aqueous solution of sodium chloride (0.9% salt by weight), obtainable from Baxter Travenol Co., of Deerfield, IL, is used to saturate the samples.
Caliber Gauge Meter: Digital Meter with a 2.54 cm diameter circular base, such as the Ono Sokko Model GS 503, available from Measure-AII, Inc., Fairfield, OH.
Voltage / Compression Tester: Sintech Renew Compression / Voltage running the MTS Sintech 3.04 Software, available from MTS Systems Corporation of Eden Prairie, MN. Cell load 100N, suitable for the Voltage / compression tester. Compression plate: Flat circular plate, 2.54 cm in diameter fixed to the crosshead.
Equipment layout Meter length 4.00 mm Crosshead speed: 5.0 millimeters per minute Turning distance: half the initial caliber of the sampleMethod 1) Cut a square sample of 10 cm x 10 cm from the material to be tested.2) Immerse the sample in the 9% saline solution for 8 minutes. 3) Measure the caliber in the wet using the gauge gauge under a confining pressure of 0.7 kPa (0.1 psi). 4) Set the turning distance (measuring length - 1.5 x caliber in wet) in the tension / compression tester. 5) Place the sample on a circular, flat plate, 140 millimeters in diameter, on the tension / compression tester and turn on the crosshead. 6) Record the distance at a force of 32 grams (that is, at a pressure of 0.1 psi (0.7 kPa)) in the down (distance down) and return (back to distance) cycles of the crosshead.
Calculation:Wet Elasticity = 100 * [(Measured Length) - (Return Distance)] / [(Measured Length) - (Descending Distance)]The disclosure of all patents, patent applications (and any of the patents issued thereon, as well as any of the corresponding published foreign patent applications), and the publications mentioned throughout this description are hereby incorporated by reference here. However, it is not expressly admitted that any of the documents incorporated by reference herein, teach or disclose the present invention. Although the particular embodiments of the present invention have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications may be made without departing from the spirit and scope of the invention.