AU679176B2 - Sanitary napkin having barrier means - Google Patents

Description

CORRECTED

VERSION 'V .1 1Z3 PCT 1 page 1, description; pages 1/5-5/5, drawings, rep-aced by new pages bearing the same number; due to late transmittal by INTERNATIONAL APPLI the. receivin ffice \T N TREATY (PCT) (51) International Patent Classification 5 (1 International Publication Number: WO 93/19711 A61F 13/15 Al (43) International PuDlication Date: 14 October 1993 (14.10.93) (21) International Application Number: (22) International Filing Date: PCT/US93/02448 15 March 1993 (15.03.93) Priority data: 92870052.5 31 March 1992 (31.03.92) EP (34) Countries for which the regional or international application wasfiled: AT et al.

(71) Applicant (for all designated States except US): THE PROC- TER GAMBLE COMPANY [US/US]; One Procter Gamble Plaza, Cincinnati, OH 45202 (US).

(72) Inventors; and Inventors/Applicants (for US only) ROBERTS, John, David [US/IT; Isola 39F1, Via Cassia, 1951, 1-00123 Rome MANCEL, Claude, Paul [FR/BE]; Avenue Bellevue 115, B-1410 Waterloo (BE).

(74) Agents: REED, David et al.; The Procter Gamble Company, 5299 Spring Grove Company, Cincinnati, OH 45202 (US).

(81) Designated States: AU, BB, BG, BR, CA, CZ, FI, HU, JP, KP, KR, LK, MG, MN, MW, NO, NZ, PL, RO, RU, SD, SK, UA, US, European patent (AT, BE, CH, DE, DK, ES, FR, GB, GR, IE, IT, LU, MC, NL, PT, SE), OAPI patent (BF, BJ, CF, CG, CI, CM, GA, GN, ML, MR, SN, TD, TG).

Published With international search report.

679 76 (54)Title: SANITARY NAPKIN HAVING BARRIER MEANS 212 210 1 7 1 225' 224 224 2 2 i I 2 2255 6 5239 107- 107' (57) Abstract 36 A sanitary napkin (210) is provided with a barrier means (107) to provide a bairier against lateral migration of body fluids.

The barrier means (107) can be provided on a sanitary napkin (210) which has no wings and comprises in this core a distal edge (278, 278') which is located within the perimeter of the absorbent core (212) during use of the sanitary napkin. The barrier means (107) can also be provided on a sanitary napkin (210) having wings (224, 224') and can be formed of a unitary part of the napkin's topsheet (214) or can be formed by a separate strip of material.

(Referred to in PCT Gazette No. 08/1994, Section Ii) WO 93/19711 PCT/US93/02448 SANITARY N aPKIN HAVING BARRIER MEANS Field of the Invention The invention relates to a sanitary napkin comprising an absorbent core having a first face, a second face, a perimeter comprising two longitudinal sides and two lateral sides, a liquid-pervious topsheet overlaying the first face of the core, a liquid-impervious backsheet associated with the topsheet, the backsheet overlying the second face of the core, and barrier means located along the longitudinal sides for restricting liquid migration in a direction generally parallel to the lateral sides.

Background of the Invention Such a sanitary napkin is known from the Briti,'h patent application GB 2 168 253.

In this patent application, the barrier means are located outside the perimeter of the core and are formed by an elasticised upstanding part of the topsheet and the backsheet. While lateral liquid migration is reduced by the barrier means, the rate of absorption of liquid entrapped between SUBSTITUTE SHEET (RULE 26) WO 93/19711 PCT/US93/02448 3 of the core, or, for instance when a shaped core is used, is located within the perimeter of the core for the broader parts of the core only.

An embodiment of an absorbent article according to the invention is characterized in that the wall is 'brined by a spacing member located between the topsheet and the backsheet.

The spacing member can be formed by a cantilever of flexible material that is placed between the topsheet and the backsheet outside the perimeter of the core and that presses the topsheet upwards. During use of the sanitary napkin, the napkin is compressed in a direction of the lateral sides and the topsheet is lifted by the cantilever. Preferably the free edge of the wall that is formed by the topslieet and the cantilever is pressed within the perimeter of the core during use of the sanitary napkin, to provide a good absorption of body fluids retained by the cantilever.

The barrier means can also comprise a foam strip which is glued, or otherwise connected, between the topsheet and the core or which is glued on top of the topsheet.

Another embodiment of an absorbent article according to the invention is characterized in that the barrier means comprises the topsheet, the topsheet having a central part overlaying the core and marginal parts forming the wall along the longitudinal sides of the core.

Even though the topshee. is fluid-pervious, the barrier means cause restriction of lateral spread of body fluids. Use of the topsheet to form the wall reduces the need for a separate barrier means and hence keeps the number of components used in the sanitary napkin low, which is desirable during manufacturing. The barrier means can extend along the whole of the perimeter of the core to also prevent fluid migration in a general direction of the longitudinal sides.

Preferably the free edge of the barrier means is contracted before use, so that during use the barrier means is stretched and is pulled away from the topsheet to stand up. The contraction can be caused by the application of an elastic member in its pre-stretched state along the free edge of the 4 barrier means. The free edge of the barrier means, which can be formed by either tLe topsheet, the backsheet or the combination thereof, can also be crimped by application of heat to snorten the free edge of the barrier means.

Shortening of the free edge in this way will also make the barrier means stand up upon longitudinally stretching the sanitary napkin during use.

Brief description of the drawings 'Some embodiments of a sanitary napkin according to the invention will be wgdescribed in detail with reference to the accompanying drawings. In the 0 0 drawings e Figure 1 is a plan view of a sanitary napkin of the present invention, Figure 2 is a cross-sectional view of the sanitary napkin of figure 1 along the line 2-2 of figure 1, the barrier means being formed by the topsheet, Figure 3 is a cross-sectional view of an embodiment of a sanitary napkin, the barrier means being formed by a foam strip, Figure 4 is an embodiment of a sanitary napkin, the barrier means beirg formed by a cantilever, Figure 5 is an embodiment of a sanitary napkin having flaps, the barrier means being formed by a strip which is glued to the flaps, Figure 6 is a front view of a conventional panty in which a sanitary napkin according to the invention can be used, 0 Figure 7 is a cross-sectional view of the panty of figure 6 taken along line 6-6 showing the sanitary napkin of figure 1 disposed therein and Figure 8 is a fragmentary coronal view showing the sectioned senitary napkin and panty of Figure 6 in place on a user.

A preferred embodiment of a sanitary napkin of the present invention is shown in FIGS. 1 and 2 Sanitary napkin 210 comprises an absorbent WO 93/19711 PCT/US93/02448 means represented by central absorbent pad 212 and two flaps 224 and 224'. (In the discussion that follows, unless otherwise noted, the sanitary napkins will have two flaps. While it is not necessary that the flaps be identical, or, more properly, mirror images one of the other, they preferably are. Thus the description of the first will be a description of the second. Discussion of the second will, therefore, be omitted for clarity of exposition. Corresponding elements are indicated in :he drawings by reference numerals and primed reference numerals).

Flap 224 is associated with central absorbent pad 212 along nonlinear line of juncture 226. As used in the coctext of the present specification, the term "nonlinear" refers to any of various curved, as opposed to straight, lines.

Flap 224 has distal edge 278 which is remote from line of juncture226.

In the embodiment illustrated in FIG. 1, line of juncture 226 is concave relative to distal edge 278. That is to say, line of juncture 226 curves away from distal edge 278. In this embodiment, nonlinear lines of juncture 226 and 226' and seam 239 define an absorbent means (central absorbent pad 212) which is narrower in its central region that at its ends.

A sanitary napkin narrower in the center than at the ends is generally perceived by the user as more comfortable than a sanitary napkin of uniform width.

Flap 224 is provided with first imaginary axis of flexibility 256 and second axis of flexibility 234.

FIG. 2, a cross sectional view of sanitary napkin 210 taken along line 2-2, illustrates generally the preferred construction for sanitary napkin 210.

As shown in FIG. 2, central absorbent pad 212 comprises absorbent core 216. Central absorbent pad 212 and flap 224 both comprise topsheet 214.

Backsheet 218 is disposed on the side of absorbent core 216 and flap 224 opposite that of topsheet 214. In effect, topsheet 214 forms one surface of flap 224 while backsheet 218 forms the other surface; topsheet 214 also forms one surface of central absorbent pad 212, backsheet 218 the other.

WO 93/19711 PC/US93/02448 7 In preferred embodiments of the present invention, the outer surface of topsheet 214 is treated with a surfactant. Treating the outer surface of the topsheet with surfactant renders the surface more hydrophilic which results in liquid penetrating the topsheet faster than if the surface were not treated. This diminishes the likelihood that menstrual fluid will flow off topsheet 214 rather than being absorbed by the absorbent core 216. It is preferred that the surfactant be substantially evenly and completely distributed across the outer surface of topsheet 214. This can be accomplished by any of the common techniques well known to those skilled in the art. For example, the surfactant can be applied to topsheet 214 by spraying, by padding, or by the use of transfer rolls.

In preferred embodiments, the inner surface of topsheet 214 is secured in contacting relating to absorbent core 216. This contacting relationship results in liquid penetrating topsheet 214 faster than if it were not in contact with absorbent core 216. Topsheet 214 can be maintained in contact with absorbent core 216 by applying adhesive, preferably in spaced, limited areas, to the inner surface of the topsheet 214. Examples of suitable adhesives used for this purpose include the acrylic emulsion E- 1833BT manufactured by Rohm and Haas Company of Philadelphia, Pa.

and the acrylic emulsion WB3805 manufactured by H.B. Fuller Company of St. Paul, Minn. The adhesives can be applied by the same methods as the surfactant is applied to the outer surface of topsheet 214.

Referring to FIG. 2, it can be seen that absorbent core 216 is positioned between topsheet 214 and backsheet 218. Absorbent core 216 provides the means for absorbing menstrual fluid. Absorbent core 216 is generally compressible, conformable, and non-irritating to the user's skin. It can comprise any material used in the art for such purpose. Examples of suitable materials are layers of tissue (such as wadding) and fibrated comminution pulp (airfelt), with fibrated comminution pulp being preferred.

Backsheet 218 is impervious to liquids and, thus, prevents menstrual fluid which may be expressed from absorbent core 216 from soiling the clothing of the user. Any material used in the art for such purpose can be WO 93/19711 PCT/US93/02448 9 body. Such proximity of central absorbent pad 212 places it precisely where it should: very near the body at the vaginal opening. Central absorbent pad 212 can then absorb the vast majority of the menstrual fluid (menses) before it has an opportunity to flow along central absorbent pad 212.

It is to be observed that lines of juncture 226 and 226' are the lines along which flaps 224 and 224' are associated with the absorbent means (represented by central absorbent pad 212); as such they represent lines of demarcation between the absorbent means and the flaps. It is also to be observed that the lines of juncture are nonlinear in this embodiment, but can also be straight. Preferably, they are concave relative to distal edges 2-8 and 278' and relative to the bulk of central absorbent pad 212. The absorbent means thus takes on a shape in which the width at its center is less than the width at its ends. This contoured shape is closely attuned to anatomical dimensions of the crotch regiun of the user. It makes the sanitary napkin more comfortable to wear while, at the same time, making it more effective as by rendering it less subject to compression by the legs of the user. While nonlinear lines of juncture which are convex relative to the distal edges and to the bulk of the central absorbent pad can be used, they are not preferred.

It is preferred that the width of central absorbent pad 212 between lines of juncture 226 and 226' at their nearest approach be from about 1 to about 8 centimeters. The width of the central absorbent pad 212 at its ends should be from about 2 to about 9 centimeters. Central absorbent pad 212 should be from about 7.6 to about 38 centimeters long.

Central absorbent pad 212 need not have an absorbent capacity much greater than the total amount of menstrual fluid anticipated to be absorbed. Thus, central absorbent pad 212, in addition to being narrow, can be relatively thin. Furthermore, a narrow and thin absorbent means is extremely comfortable to the user. In the embodiment illustrated in FIGS. 1 and 2, topsheet 214 does not serve as a topsheet for flaps 224 and 224'. In general, the flaps do not require a topsheet to enable them to function properly, but the use of a topsheet is preferred. Flap topsheets can be integral with the absorbent means' body contacting surface or they WO 93/19711 PCT/US93/02448 11 Seam 239 is illustrated extending completely around the periphery of sanitary napkin 210; this is a preferred embodiment for ease of construction. (Other means of uniting the various elements of the device can be used).

Topsheet 214 can be secured to backsheet 218 along lines of juncture 226 and 226' by any of the techniques used to form seam 239.

Flap 224 contains first axis of flexibility 256 and second axis of flexibility 234. These two axes of flexibility allow flap 224 to form a wall, in use, as described hereinafter. The axis of flexibility can be formed by a separate hinge line or can be located along a continuous range in the flap 224, which is as flexible so as to bend around any desired line.

First axis of flexibility 256 is so constructed as to allow the flap to bend along first axis of flexibility 256. The direction of the bend of the flap is upward when sanitary napkin 210 is in the configuration of FIG. 2. More generally, the direction of the bend is such that that portion of flap 224 containing distal edge 278 rotates about the first axis of flexibility 256 in an arc beginning generally from its extended position, as shown in FIG.

2, toward the fluid pervious body contacting surface of the absorbent means (as represented in FIG. 2 by that portion of topsheet 214 in register with absorbent core 216) and away from the liquid impervious surface of the absorbent means (as represented in FIG. 2 by that portion of backsheet 218 in register with absorbent core 216).

Second axis of flexibility 234 is so constructed as to allow the flap to bend along second axis of flexibility 234. The direction of the bend is downward when sanitary napkin 210 is in the configuration of FIG. 2.

More generally, the direction of the bend is such that that portion of the flap 224 containing distal edge 278 rotates about second axis of flexibility 234 in an arc generally from its extended position, as shown in FIG. 2, toward the liquid impervious surface of the absorbent means (as represented in FIG. 2 by that portion of backsheet 218 in register with absorbent core 216 as comprising central absorbent pad 212) and away from the fluid pervious body contacting surface of the absorbent means WO 93/19711 PCT/US93/02448 13 degree of flexibility that the flaps can be bent and folded conveniently with manual force, the axes of flexibility can become nonlinear under the influence of external forces.

As illustrated in FIG. 1, first axis of flexibility 256 is in close proximity to line of juncture 226. First axis of flexibility 256 can, in fact, intersect the line of juncture 226 at the point the latter contacts the outer margin of the sanitary napkin (as that margin is represented by seam 239). In the general case, this will be the only situation in which first axis of flexibility 256 and line of juncture 226 touch or coincide. It is to be understood, however, that application of external forces during use can cause the first axis of flexibility to be displaced toward the line of juncture so that, in some instances, the two can touch or coincide.

Sanitary napkins including the central absorbent pad comprising a liquid pervious topsheet, a liquid impervious backsheet, and an absorbent core interposed between the topsheet and the backsheet, and having a flap extending from each longitudinal edge of the central absorbent pad, wherein the line of juncture between each flap and the longitudinal edge of the central absorbent pad is linear, and having each flap provided with a flexible axis located in the body of the flap, can be constructed so that the sanitary napkin preferentially bends at the linear line of juncture of each flap and the longitudinal edge of the central absorbent pad as well as at the flexible axis located within the body of the flap. Such napkins, while distinctly different from those of the present invention, will function in a manner analogous to those of the present invention.

The precise shape of flap 224, as well as the overall shape of sanitary napkin 210, can be selected by those skilled in the art without undue experimentation. In the embodiments illustrated in FIGS. 1 and the flaps are symmetrically disposed along the longitudinal axis of the sanitary napkin; while this is a preferred embodiment, it is not a mandatory design feature. As noted above, the flaps are generally mirror images one of the other; while such a situation is preferred, it is likewise not a mandatory design condition.

r/, WO 93/19711 PCT/US93/02448 Numerous benefits are derived from the use of the sanitary napkin of the present invention. Flaps 224 and 224' are wrapped around each edge 246 and 246' of the crotch portion 244 of the panty as shown in FIG. 8. This encapsulation of the panty crotch assists in preventing the menstrual fluid from coming into contact with the center crotch portion of the panty.

Thus, the center crotch portion of the panty will not be soiled.

There are two other benefits. One is that the portions of the flaps containing the second axes of flexibility, 234 and 234', provide an excellent gasket-like seal against the body. The other is that the central absorbent means, such as central absorbent pad 212, is maintained in excellent contiguous relationship to the body.

The edge of the crotch portion of a panty generally contains an elastic material. When a panty is worn, the elastic of the edge of the crotch portion generates an upward force, i.e. against the body, due to the energy in the elastic and the fit of the panty. The placement of the second axis of flexibility, such as second axes of flexibility 234 and 234', between the body and the edges of the crotch portion of the panty results in the upward force generated by the edge of the crotch portion of the panty pushing the portion of the flaps containing the second axes of flexibility snugly against the body. This results in a gasket-like-seal being formed along the axes of flexibility between the flaps and the body. This is illustrated in FIG. '8 which is a fragmentary coronal view showing the sectioned sanitary napkin and panty of FIG. in place on a user. (A coronal view is the frontal plane that passes through the long axis of the body). The gasket-like seal assists in preventing menstrual fluid from penetrating beyond the second axis of flexibility which, in turn, minimizes soiling of the legs and adjoining clothing. Another benefit derived from the flaps being pushed snugly against the body along the second axes of flexibility is that the absorbent means (central absorbent pad) is forced into close proximity to and into conformity with the body. This, too, is illustrated in FIG. The maintenance of the central absorbent pad against the body is known as "good body contact". Good body contact is beneficial because it provides a barrier to lateral flow of menstrual fluid.

Without such a barrier, menstrual fluid would tend to flow quickly along \1 V r WO 93/19711 PCr/LS93/02448 17 even if the forced bunching is harsh enough to create flow channels, the channels formed will be essentially limited to the central absorbent pad; and even if the forced bunching is so great that flow channels are created in both the central absorbent pad and the flaps, the menstrual fluid is restrained from penetrating beyond the second flexible axes of the flaps.

These four benefits are obtained because the sanitary napkin of the present invention is provided with barrier means or walls 107 and because it bends along the axes of flexibility. The anatomical features of the crotch area of a woman are such that the crotch section is substantially trapezoidal shaped, with the center area of the crotch, which is located at the vaginal opening, being the base of the trapezoid. When a sanitary napkin of the present invention, such as the embodiment shown in FIGS.

1 and 2, is in use, the anatomical features of the crotch area force the sanitary napkin to bend upward at the first axis of flexibility. This results in the sanitary napkin forming a wall at each side of the central absorbent pad; the wall extends from the first axis of flexibility to the second axis of flexibility, as illustrated in FIG. 8 Thus, in use, the sanitary napkin of the present invention has a well-like shape with the plane formed by the second axes of flexibility (234 and 234') that are wrapped around the edge of the crotch portion of the panty (246 and 246') being higher than the plane formed by the first axes of flexibility (256 and 256') when the user is in an upright position.

Inherent bunching in the sanitary napkin of the present invention is substantially limited to the central absorbent pad; essentially no flow channels are formed in the walls. Without being bound by any theory, it is believed that when the flow channels are being formed, the energy creating them is transmitted across the central absorbent pad and the flow channels are extended. This proceeds until the flow channels reach the first axes of flexibility. The flow channels extend no farther than this because, it is believed, the first axes of flexibility relieve the energy extending the flow channels. Thus the flow channels will not reach the gasket-like seal formed between the flap and the body at the second axis of flexibility, and, therefore, the seal will remain intact. The gasket-like h i 4j, if-6 -o WO 93/19711 PCT/US93/02448 19 a preferred way of securing the sanitary napkin in the panty, flap adhesive can contact the edge of the party on only its "inner" surface or both its "inner" and "outer" surfaces so long as a portion of the flap extends around and about the edge of the panty.

The sanitary napkin of this invention has been described as a device which has two flaps which, in use, each form a wall. While those embodiments are highly preferred, devices not having flaps or having only one flap can be envisioned. This one flap would be associated with the central absorbent means along a nonlinear line of juncture. The flap would contain at least two, and preferably at least four, axes of flexibility which would allow it to form both walls described above as it is folded completely around the crotch portion of a panty. The flap would then be associated with the central absorbent means along a nonlinear line of juncture opposite the one mentioned above.

In the embodiments of the sanitary napkin of this invention, illustrated and discussed above, adhesive attachment means were present near the distal edges of the flaps and in register with the central absorbent pad. These elements, designed to hold the sanitary napkin securely in the crotch region of an undergarment, are highly preferred elements. Without detracting from that position, it can be asserted that embodiments of the present invention which effectively lack one or more of the described adhesive attachment means are also useful, novel, effective devices.

The embodiment illustrated in FIGS. 1 and 2 can be readily adapted to function as an embodiment of the present invention which is effectively free of one or more of the adhesive attachment means.

For example, central pad acahesive 220 (and, naturally, its associated central pad release liner 222) can be omitted from sanitary napkin 210 illustrated in FIGS. 1 and 2. In use, this modified embodiment would be placed in the interior crotch region of a panty, just as the unmodified embodiment, except that central absorbent pad 220 is not secured to the interior crotch region of the panty. Flaps 224 and 224' can be secured about the elastic edge of the panty as described above with flap adhesive 236 and 236'. The panty with its associated modified sanitary napkin would then be donned by the user as before. Flap adhesive 236 and 236' in cooperation with the elastic edges of the panty hold the modified sanitary napkin in place.

In a like manner, sanitary napkin 210 can be modified by omitting only flap adhesive 236 and 236' (and release liners 238 and 238'). The modified sanitary napkin would be secured in the crotch region of the panty with central pad adhesive 220 and the flaps would be merely folded about the elastic edges.

0 I In a like -manner, sanitary napkin 210 can be modified by omitting all flap and central pad adhesives. In use, such a modified sanitary napkin would be maintained in position solely by cooperation among the flaps, the elastic edges o of the panty, and the user's body.

In the embodiment as shown in figure 3, the wall 107 is formed by a foam strip 100 which is located underneath the topsheet on top of the core 48. The sanitary napkin of figure 3 is provided with wings 43 for connection to a user's garment as shown in figure seea in the embodiment of figure 4, the wall 107 is formed by a flexible cantilever 102 which is connected between the topsheet 40 and the backsheet 42.

WO 93/19711 PCT/US93/02448 21 FIG. 5 is a fragmentary sectional view and depicts the construction in the crotch region of a further embodiment of a sanitary napkin according to the invention as it is shaped before being applied to the wearer the napkin is subjected to elastic contraction). The absorbent core 44 comprises the absorbent layer 48 that is shown as being completely enveloped by the first and second .issue layers 50 and 52. The absorbent core 44 is disposed between the topsheet 38 and the backsheet 42, both the topsheet 38 and the backsheet 42 extend beyond the side edge 46 of the absorbent core 44 to define the side flap 58. The juxtaposed areas of the topsheet 38 and the backsheet 42 are adhesively secured together by adhesive 88.

The barrier means 62 is shown as being formed by securing an element to the topsheet 38 between the flap's outer edge and the side edge 46 of the absorbent core 44. The proximal edge 64 of the barrier means 62 is formed by securing the barrier means element to the topsheet 38 by adhesive 92. The spacing elastic members 77 are enclosed in a tunnel that is formed when an end of the barrier means element is folded back upon itself; the spacing elastic members 77 being secured in the barrier means 62 by elastic attachments means 94. The distal edge 66 of the barrier means is spaced away from the topsheet top surface 40 by the elastic gathering action of the spacing elastic members 77; a channel 96 thereby being formed by at least the proximal edge 64, the distal edge 66 and the inboard surface 68 of the barrier means 62. The channel 96 is shown as being ready to restrain, contain and hold body fluids until the sanitary napkin 210 is removed from the wearer.

The topsheet 38 is compliant, soft feeling, and non-irritating to the wearer's skin. Further, the topsheet 38 is liquid pervious permitting liquids to readily penetrate through its thickness. A suitable topsheet may be manufactured from a wide range of materials, such as porous foams, reticulated foams, apertured plastic films, natural fibers wood or cotton fibers), synthetic fibers polyester or polypropylene fibers) or from a combination of natural and synthetic fibers. Preferably, it is made of a hydrophobic material to isolate the wearer's skin from liquid in the absorbent core 44.

WO 93/19711 PCT/US93/02448 23 The dimensions, shape, and configuration of the absorbent layer 48 may be varied the absorbent layer may have a varying caliper, or a hydrophillic gradient, or may contain superabsorbent materials or synthetic fibers.

The first and second tissue layers 50 and 52 improve the tensile strength of the absorbent core 44 and reduce the tendency of the absorbent layer 48 to split, lump or ball when wetted. The first and second tissue layers and 52 also help to improve lateral wicking of the absorbed body fluids thereby providing a more even distribution of the body fluids throughout the absorbent layer 48. While a number of materials and manufacturing techniques may be used to manufacture the first and second tissue layers and 52, satisfactory results have been obtained with sheets of tissue paper having a basis weight of about 16 grams per square meter (10 Ibs.

per 3000 square fee) and having an air permeability of about 30.5 cubic meters per minute per square meter (100 cubic feet per minute per square foot) at a pressure differential of about 12.8 millimeters of water inch). While the first and second tissue layers 50 and 52 are preferably coterminous with the absorbent layer 48, they may have different dimensions, a different configuration, or they may be omitted entirely.

The absorbent core 44 is superimposed on the backsheet 42 and is preferably attached thereto by attachments means (not shown) such as those well known in the art. For example, the absorbent core 44 may be secured to the backsheet 42 by a uniform continuous layer of adhesive, a patterned layer of adhesive, or an array of separate lines or spots of adhesive. An adhesive which has been found to be satisfactory is manufactured by Eastman Chemical Products Company of Kingsport, Tenn. and marketed under the tradename Eastobond A-3.

The backsheet 42 is impervious to liquids and is preferably manufactured from a thin plastic film, although other flexible liquid impervious materials may also be used. The backsheet 42 prevents the body fluid absorbed and contained in the absorbent core 44 from weting articles which contact the sanitary napkin such as undergarments. Preferably, the backsheet 42 is a polyethylene film having a thickness of from about 0.012mm (0.5 mil) to about 0.051cm (2.0 mils), although other flexible, WO 93/19711 PCT/US93/02448 be sufficiently spaced away from the topsheet top surface 40 so that a channel 96 is formed to restrain, contain and hold body fluids within the article. The barrier means 62 may be manufactured from a wide variety of materials such as polyester, rayon, nylon, foams, plastic films, formed films, and elastic foams. A number of manufacturing techniques may be used to manufacture the barrier means. For example, the barrier means 62 may be woven, non-woven, carded, or the like. A particularly preferred barrier means 62 comprises a material containing no finish or to render it liquid impermeable. A particularly preferred material manufactured by Crown Zellerbach Company as Celestra.

As shown in FIG. 5, the barrier means 62, and more particularly the proximal edge 64, is disposed inboard of and preferably adjacent to the flap.

The term "inboard" is defined as the direction toward the center line 36 that is parallel to the respective edge (226, 226') along which the particular barrier means 62 is disposed.

The barrier means 62 is disposed to provide a more effective restraint against the flow of body fluids. The barrier means 62 is preferably disposed between the flap's outer edge and the longitudinal center line 36 of the sanitary napkin.

The proximal edge 64 and the distal edge 66 are in spaced relation to each other and define the width of the barrier means 62. The proximal and distal edges 64 and 66 respectively, may be in a parallel, non parallel, rectilinear or relationship. In addition, the barrier means 62 may have a variety of different cross sectional areas including circular. square, rectangular or any other shape. Preferably, the proximal edge 64 is spaced from the distal edge 66 in a parallel and rectilinear relationship to provide a barrier means 62 having uniform widths.

The embodiment of the sanitary napkin shown in FIG 6is provided with the barrier means 62 joined to the topsheet 38. The term "joined" includes any means for affixing the barrier means 32 to the sanitary napkin and includes embodiments wherein the barrier means 62 is a WO 93/19711 PCrT/US93/02448 27 The channel 96 is formed at least along the proximal and distal edges 64 and 66 and the inboard surface 68 of the barrier means 62. The channel 96 forms a barrier to the flow of bodyfluid as they tend to move across the topsheet 38.

The barrier means 62 may additionally be provideu with absorbent means secured to or within the barrier means 62. The absorbent means absorb and contain body fluid which contact the barrier means 61 The absorbent means may be any means which is capable of absorbing and retaining liquid and may have any size, shape, configuration or absorbent capacity. The absorbent means may be positioned to the barrier means 62 along the inboard surface 68 or within the barrier means 62. Preferably, the absorbent means is a layer of airfelt secured within the tunnel formed by the integral barrier means and secured along the entire length and width of the inboard surface 68 of the barrier means 62.

In addition, the barrier means 62 may be rendered liquid impermeable so as to prevent the of bodyfluid. A liquid impermeable barrier means 62 retards the movement of liquid through the barrier means 62, thereby making it more leakage resistant. The barrier means 62 may be rendered liquid impermeable in any manner well known in the art such as selectively treating the barrier means, the barrier means, or by securing a separate material to the barrier means.

The spacing means 76 for spacing the distal edge 66 away from the topsheet top surface 40 is any member which gathers, contracts, stiffens, shortens or otherwise acts on the barrier means 62 so as to cause a channel 96 to be formed along the barrier means 62 to provide a constraint against the leakage of.

As shown in FIG 5 the spacing means 76 preferably comprise spacing elastic member 77 secured adjacent the distal edge 66 inside of the barrier means 62. The spacing elastic member 77 is preferably secured to the barrier means 62 in an contractible condition so that in a normally unrestrained configuration, the spacing elastic member 77 effectively contracts or gathers the barrier means 62.

WO 93/19711 PCT/US93/02448 29 include foams, fabrics, batting, polyethylene film formed films, spray glues, foamed polyester, or a high loft material as is manufactured by Carolina Formed Fabrics.

The spacing means 77 may also comprise means for shortening the length of the distal edge 66 in comparison to the length of the edges of the sanitary napkin. The distal edge 66 can be shortened by making a fold or pleat in the distal edge 66. This fold or pleat is secured by any of the holding means well known to those of ordinary skill in the art, such as adhesives or heat sealing. Alternatively, a section may be cut out of the distal edge and the edges brought together to form a butt or joint. The distal edge 66 may also be shortened by attaching a length of the distal edge 66 to the topsheet 38 at a position different from where the distal edge 66 would lie when the sanitary napkin is in a flattened out condition.

Other shortening techniques as are known in the art may also be used.

The adhesive means for securing end portions of the barrier means 62 closed near the lateral edges of the sanitary napkin provide a more comfortable fit for the wearer and obviate inversion of the distal edges 66 of the barrier means 62 during application and use. Inversion is generally defined as the inboard disposed distal edge 66 turning outwardly when the sanitary napkin is applied to the wearer. In a preferred embodiment such adhesive means are disposed in the front region and the back region of the sanitary napkin. The remaining portions of the barrier means 62 are not secared closed so that the distal edges 66 are left freely.

The adhesive means 78 are preferably glue beads 79 consisting of hot melt adhesives such as marketed by Adhesives Incorporated, Wis., as Adhesives 581.

Claims (18)

1. A sanitary napkin of the type for placement in an undergarment, the sanitary napkin comprising: a central absorbent pad having a body contacting surface, a central region, and a perimeter including a pair of longitudinal edges and a pair of lateral ends, said central absorbent pad comprising: a liquid pervious topsheet; a liquid impervious backsheet joined with said topsheet, and; an absorbent core positioned between said topsheet and said backsheet; a flap extending from each longitudinal edge of said central absorbent pad in said central region, each said flap being joined with said central absorbent pad and being sized and configured to allow each of said flaps to be positioned around the edge of the undergarment at a flexible axis so as to form a first wall, in use, and barrier means for restricting liquid migration in the direction of the lateral sides, each said barrier means comprising a barrier element having a proximal edge joined to said flap, and a free edge spaced from said proximal edge and being free from securement to at least a portion of said flap and said central absorbent paid; 0 wherein said free edge, at least during use of the sanitary napkin, is located within the perimeter of the central absorbent pad and is spaced upwardly about said proximal edge and away from said body contacting surface of said r 'ntral absorbent pad so as to cause said barrier means to form a second wall providing a barrier to the lateral flow of the body fluids.

2. The sanitary napkin of Claim 1, wherein said barrier means comprises spacing means disposed at said free edge of said barrier means for spacing said free edge upwardly about said proximal edge and away from said body contacting surface of said central absorbent pad, said spacing means comprising a spacing elastic member secured to said barrier element in an elastically contractible condition to gather or contract said barrier element adjacent said free edge.

3-24-97 3'40 PM ;WATERMARK 1381 /1 1l3819Q01();f B/13 31 3. The sanitary napkin of claim 2 wherein each said barrier element is liquid impermeable.

4. The sanitary napkin of claim 3 additionally comprising a central pad adhesive means positioned on said backsheet and a flap adhesive means positioned on each of said flaps for securing the sanitary napkin to a wearer's undergarment.

The sanitary napkin of claim 4 wherein said free edges of said barrier element are maintained inboard of said proximal edge by an adhesive means for obviating inversion of said barrier elements.

6. The sanitary napkin of claim 5 wherein said topsheet of said central absorbent pad extends to said flaps and forms a portion of a topsheet for said flaps.

7. The sanitary napkin of claim 2 additionally comprising a central pad adhesive means positioned on said backsheet and a flap adhesive means positioned on each of said flaps for securing the sanitary napkin to a wearer's undergarment.

8. The sanitary napkin of claim 2 wherein said topsheet of said central absorbent pad extends to said flaps and forms a portion of a topsheet for said flaps. a

9. The sanitary napkin ot claim 1 wherein each said barrier element is liquid Impermeable.

10. The sanitary napkin of claim 9 additionally comprising a central pad adhesive means positioned on said backsheet and a flap adhesive means positioned on each of said flaps for securing the sanitary napkin to a wearer's undergarment. 3-24-97 3:40 PM ;WATERMARK 61381 6010; 9/13 32

11. The sanitary napkin of claim 9 wherein said topsheet of said central absorbent pad extends to said flaps and forms a portion of a topsheet for said flaps.

12. The sanitary napkin of claim I additionally comprising a central pad adhesive means positioned on said backsheet and a flap adhesive means positioned on each of said flaps for securing the sanitary napkin to a wearer's undergarment.

13. The sanitary napkin of claim 12 wherein said spacing means comprises a spacing elastic member secured to said barrier element in an elastically contractible condition to gather or contract said barrier element adjacent said free edge.

14. The sanitary napkin of claim 12 wherein said topsheet of said central absorbent pad extends to said flaps and forms a portion of a topsheet for said flaps.

15. The sanitary napkin of claim 1 wherein said flaps additionally comprise a second axis of flexibility within the flap so that the flap is extremely flexible over essentially the whole of its extent. S

16. The sanitary napkin of claim 1 wherein said flaps are formed independently from said central absorbent pad and joined to said central absorbent pad.

17. The sanitary napkin of claim 1 wherein said topsheet of said central absorbent pad extends to said flaps and forms a portion of a topsheet for said flaps. 3-24-97 3:40 PM ;WATERMvARK 813812 33

18. The sanitary napkin of claim 1 wherein said free edge$ of said bardber element are maintained inboard of said proximal edge by an adhesive means for obviating inversion of said barrier elements. DIEM this 24th day of March, 1997. THE PROCTER J! GAMBLE COMEANY 8010;4110/13 WATERMARK PATENT TRADEMARK ATTORNEYS 290 BUR WOOD ROAD HAWTHORN VI!CTORIA 3122 AUSTRALIA VAX DOC 11 AU3812393.WPC LCG./SI:SE 0* C CC C CC C C. C C C CC CCC... C OC Ce C C C PC CC. CCC. C C CC C. CC CC C CCC. CCC. C. a C. C (Y'W. -0 ~~NT 0