ABSORBENT ARTICLE HAVING ELASTICIZED SIDE FLAPS

Abstract: An absorbent article having a liquid permeable topsheet (2), a liquid impermeable backsheet (3) and a liquid absorbent pad (4) for absorbing a liquid exuded from the human body positioned therebetween, and having an elasticized side flap (20) along each side edge of the absorbent article. The sideflap has a loop member (21) formed from either the topsheet or the backsheet, or an optional secondary nonwoven sheet, which extends from and loops back toward the side edge fo the absorbent pad, and an inserted member (30) formed from a layer which extends from the side edge of said absorbent pad. An elastic material (40) is affixed along a portion of the length of the inserted member, and a seal (10) affixes the inserted member inside the loop member at its base end. The absorbent sanitary article provides improved fit and leakage protection with better comfort.

Description: ABSORBENT ARTICLE HAVING ELASTICIZED SIDE FLAPS FIELD OF THE INVENTION This invention relates to a novel absorbent article, and particularly to a sanitary article such as a sanitary napkin or an absorbing sheet. As used herein, the term "absorbent article" refers to devices which absorb and contain body exudates, and, more specifically, refers to 10 devices which are placed against or in proximity to the body of the wearer to absorb and contain the various exudates discharged from the body. BACKGROUND OF THE INVENTION An absorbent article such as sanitary napkins or • *-• ■ * paper diapers requires a good and comfortable fit to the body, in addition to preventing exudates from leaking. There has been conventionally proposed, for example, a curved sanitary napkin in which an elastic material in initial tension is arranged at the longitudinal edge of 2 0 the napkin. If a sanitary napkin is formed into a curved shape by an elastic material, the body fit is enhanced, and an improvement in wearer's feeling of fit as well as the reduction of side leaking can be achieved. Such sanitary napkins are disclosed in U.S. Patent Nos. 25 4,668,230, 4,701,177 and 4,770,657. In the absorbent articles disclosed in the above- mentioned U.S. Patents, an elastic material is directly or indirectly bonded to the edge of a sheet surface which contacts with the body. A seal is provided which divides 30 the elastic material arranged at this edge and an absorbent core positioned at the center. In this conventional constitution, a curved shape is provided to an absorbent article such as a sanitary napkin by wrinkling the surface sheet and the elastic material. • * •• -- However, the above-mentioned conventional absorbent article has a problem that causes an uncomfortable feeling due to a deep wrinkle caused on the surface sheet of the edge and impairs comfort at the time of using the absorbent article in a curved shape, particularly when the surface sheet is a plastic material. Therefore, such sanitary napkins are not completely satisfactory, and there remains a need for improvement in fit, comfort, and containment by sanitary napkins and other absorbent articles. The object of this invention is to provide an absorbent article which can enhance body fit in usage and can achieve an improvement in comfort and reduction of side leakage. SUMMARY OF THE INVENTION This invention provides an absorbent article comprising a wearer-facing, body-contacting liquid permeable topsheet, a garment-facing liquid impermeable backsheet, and a liquid absorbent pad therebetween for absorbing a liquid exuded from the human body, characterized by comprising an elasticized side flap along each side edge of the absorbent pad, the side flap comprising: - a loop member having a base end with an opening positioned toward the side edge of the absorbent pad, a distal end, a garment-facing portion and a wearer-facing portion; - an inserted member which extends through the base end opening into the loop member, and having a distal end and a base end; - an elastic material affixed along a portion of the length of the inserted member outboard of the base end, wherein the elastic material is not affixed to the loop member; and - a seal attaching the inserted member to the garment-facing and wearer-facing portions of the loop member at the respective base ends. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 shows a sanitary napkin of the present invention; Figure 2 shows an alternative sanitary napkin of the present invention; Figure 3 shows a cross sectional view through a lateral centerline of the present invention; Figure 3a shows a partial sectional view through a lateral centerline of another embodiment of the present invention; Figure 3b shows a partial sectional view through a lateral centerline of still another embodiment of the 10 present invention; Figure 4 shows a partial sectional view through a lateral centerline of yet another embodiment of the present invention; Figure 4a shows a partial sectional view through a - • - • -' lateral centerline of still yet another embodiment of the present invention; Figure 4b shows a partial sectional view through a lateral centerline of another embodiment of the present invention; 20 Figure 5 shows a partial sectional view through a lateral centerline of yet another embodiment of the present invention; Figure 5a shows a partial sectional view through a lateral centerline of still yet another embodiment of the present invention; and Figure 6 shows a partial sectional view through a lateral centerline of another embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION 30 As shown in Figure 1, the absorbent article 1 is usually substantially rectangular as a whole, though the end edges can be arc portions 5, respectively. The absorbent member 4 is generally smaller than the backsheet and is substantially rectangular, though both end edges are in the form of an arc portion 6 patterned after the arc portion 5 of the backsheet 3, and both longitudinal sides 7 of the absorbent pad 4 are curved inward so that the center portion becomes slightly narrow. Figure 2 shows an example in which the longitudinal side 7* of an absorbent pad 4 and the heat seal 10' of the elasticized side flap 20 are formed as straight lines. The absorbent article 1 has two centerlines: a longitudinal centerline and a transverse centerline. The term "longitudinal", as used herein, refers to a line, axis or direction in the plane of the absorbent article 1 that is generally aligned with (e.g., approximately parallel to) a vertical plane which bisects a standing wearer into left and right body halves when the absorbent article 1 is worn. The terms "transverse" or "lateral" as used herein, are interchangeable, and refer to a line, axis or direction which lies within the plane of the absorbent article 1 that is generally perpendicular to the longitudinal direction. The topsheet is generally registered to cover completely the wearer-facing surface of the absorbent pad. Preferably, the topsheet extends beyond the periphery of the absorbent pad, or wraps around the lateral edges of the absorbent pad, and is secured to the backsheet to enclose the absorbent pad. One embodiment of an absorbent article 1 according to this invention is shown in Figure 3. The absorbent article 1 comprises a liquid permeable topsheet 2, a liquid impermeable backsheet 3, and a liquid absorbent pad 4 for absorbing a liquid exuded from the human body positioned there between and having a pair of side edges 7, characterized by comprising an elasticized side flap 20 along each side edge 7 of the absorbent pad, the side flap 20 comprising: - a loop member 21 formed from a layer which extends from and loops back toward the side edge 7 of the absorbent pad and is selected from the topsheet 2 and the backsheet 3, the loop member 21 having a base end 22 with an opening 23 proximate the side edge 7 of the absorbent pad, a distal end 24, a garment-facing portion 25, and a wearer-facing portion 26; - an inserted member 30 formed from a layer which extends from the side edge 7 of the absorbent pad and is selected from the backsheet and the topsheet, the inserted member 30 being inserted through the base end opening 23 into the loop member 21 and having a distal end 31 and a base end 32; - an elastic material 40 affixed along a portion of the length of the inserted member 30 outboard of the base end 22 of the inserted member 30, wherein the elastic material is not affixed to the loop member 21; and - a seal 10 attaching the inserted member 30 to the garment-facing portion 25 and wearer-facing portion 26 of the loop member 21 at the base end 22. Elasticized Side Flaps The elasticized side flap 20 is positioned along at least the central portion of each longitudinal side edge, usually symmetrically positioned about the lateral centerline of the article. The side flap 20 can extend to substantially the entire length of the longitudinal side edge of the article, though typically extends from 25% - 100%, preferably 40% - 60%, the length of the longitudinal side of the article. The elasticized side flap comprises a loop member, an inserted member, an elastic material, and a seal, a. Loop member The loop member 21 can be formed from either the topsheet 2 or the backsheet 3. Preferably, the loop member 21 is formed from the topsheet 2 which is more compatible with the skin. When the loop member 21 is formed from the topsheet 2, the backsheet 3 can serve as the inserted member 30. The loop member 21 is formed by extending the layer, in this case the topsheet 2, beyond the edge 7 of the absorbent pad and folding at a distal end 24 inward and back toward the edge of the absorbent core. By "inward" folding is meant folding toward a plane oriented in the x-y direction (or length and width) which passes through the middle of the z-direction (or height) of the absorbent core. When the topsheet (the wearer-facing layer) is the loop member layer, it is folded inward to the garment-facing direction; when the backsheet (the garment-facing layer) is the loop member layer, it is folded inward to the wearer-facing direction. As shown in Figure 3, when the topsheet 2 forms the loop member 21, it can continue to extend and cover the backsheet-side of the absorbent article. The base end 22 of the loop member is proximate to the side edge 7 and has an opening 23 through which the inserted member 30 can be inserted into the inside of the loop member 21. The width of the loop member 21 (from base end 22 to distal end 24) is generally from 10-25 mm, preferably about 15-20 mm. The base end 22 is positioned outboard the edge 7 of the absorbent pad, generally not more than 20 mm, preferably not more than 5 mm. Most preferably, the base end 22 is positioned as close to the absorbent pad edge 7 as possible, along the entire length of the side flap, b. Inserted member The inserted member 30 can be formed by extending the backsheet 3, or the topsheet 2 when the backsheet forms the loop member, beyond the edge 7 of the absorbent pad 4, through the opening 23 and into the loop member 21. The inserted member 30 can also be a distinct layer, extending through the opening 23 and into loop member 21. The distal end 31 of the inserted member can extend to the distal end 24 of the loop member. It can also be folded or curled over inside the loop member 21. Preferably, the portion of the inserted member 30 extending beyond the base end 22 of the loop member has an effective length of at least 5 mm, more preferably about 10-15 mm. The distal end 31 of the inserted member 30 is intended to be free of and not attached to the loop member 21, at least along the center portion thereof. Alternatively, the topsheet or the backsheet can also serve as both the loop member and the inserted member. As shown in Figure 3a, the topsheet 2 forms the loop member 21 as herein before described, and is then folded inward again at the fold 55 located at or near the edge 7 of the absorbent pad. The remaining end portion of the topsheet is then inserted into the loop member. in this embodiment, the edge of the backsheet can extend to and be secured by the side seal 10, and can optionally be inserted into the loop member as an inserted member. Conversely, as shown in Figure 3b, the backsheet, though it is not as compatible with the skin of the wearer, can form both the loop member and the inserted member. In such cases, the seal 10 is made between the distal edge 24 and fold 55 of the folded backsheet 3. c. Elastic member The elastic material 40 provides the elasticity to the elasticized side flap. The elastic material 40 is affixed along at least a portion of the length of the inserted member 30 outboard of the base end 32. Generally, the elastic material 40 is pre-stretched prior to affixment by means 41 (not shown) to the inserted member 30. When the force used to hold the elastic material in the pre-stretched state is released, the elastic material contracts and tends to gather the inserted member. The seal 10 secures the inserted member 30 to the loop member 21 at its base end 32, and prevents the elastic material 40 from contracting completely to its fully relaxed position. Preferably, the elastic material 40 is affixed along at least 25% the length of the inserted member 30, more preferably along 40% - 60% of the inserted member. The elastic member 40 is not attached to the loop member 21. Any stiffness or wrinkling formed in the inserted member 30 as a result of the contraction of the elastic member 40, or due to the elastic material 40 itself, is separated from the skin of the wearer by the loop member 21 layer, thus resulting in no reduction in comfort and skin friendliness. Because the elastic material does not come in direct contact with the skin of the wearer, a broad range of materials and elastic conditions can be used. The elastic material 40 can be elastic strings, strands, or films made from materials including: synthetic or natural rubber, such as LYCRA, elastomeric scrim, elastomeric films (including heat shrinkable elastomeric films), elastomeric woven or nonwoven webs, elastomeric composites such as elastomeric nonwoven laminates, synthetic or natural rubber foams, and the like. A preferred elastic string is a natural rubber commercially available under the designation 9411 produced by Fulflex, Rhode Island. The elastic material can be pre-stretched to any length suitable to gather or contrast the side flaps 20 to the desired shape, without causing significant adverse affect on the skin of the wearer. Generally, the elastic material can be pre- stretched from about 5% to 100% (105% to 200% of the original, relaxed length), more preferably from about 10% to about 30%. The elastic material can be affixed to the inserted member using an affixing means 41, such as a mechanical bond or adhesive bond. Mechanical bonds can include pressure or heat bonds that can bond the inserted member to the elastic. More preferably, an adhesive is used. A suitable adhesive is a hot-melt adhesive such as marketed by Findley Adhesives, Inc., Elm Grove, Wisconsin, as Findley Adhesive H2085 or H2119. The inserted member 30 can be folded or curled around the elastic material 40 to improve the attachment. Alternatively, particularly when it is a stretchable film, the elastic material 40 can be wrapped around the distal end 31 of the inserted member 30. The elastic material 40 is preferably affixed at least about 5 mm from the base end 32 of the inserted member, more preferably about 10-15 mm from the base end. Positioning the elastic material 40 attachment away from the base end 32 of the inserted member provides the contracting elastic material with leverage to gather the distal end of the inserted member and to pull upward the ends of the absorbent article to conform the article to the shape of the wearer, and enables the elasticized side flaps to stand upward and press against the thighs of the wearer for better fit and leakage protection, d. Seal The seal 10 of the side flap 20 is made along the base end 22 of the loop member 21. The seal 10 can be continuous or intermittent; it can be a straight line or curvilinear. Preferably a curvilinear seal is one curved inward toward the absorbent pad and preferably having a curvature of up to 30 degrees. Preferably the seal (and the base end of the loop member) will conform with the shape of the side edge 7 of the absorbent pad. The length of the seal is generally at least as long as the elastic member; and preferably is longer than the elastic means. In a typical sanitary napkin of the present invention, the seal is from about 50-280 mm, more preferably from about 100-160 mm in length. The seal serves to anchor the inserted member 30 and allows the elastic member 40 to pull up the longitudinal ends of the absorbent pad. The seal 10 also helps to prevent leakage from the side of the absorbent pad 4. The seal 10 can be a mechanical energy seal or an adhesive seal. The seal must be sufficient to bond together the garment-facing portion 25 and the wearer-facing portion 26 of the loop member 21 to the inserted member 30 at their respective base ends. Mechanical energy seals are preferred. As used herein, "mechanical energy" includes also thermal energy such as that employed in a heat seal. Such mechanical energy can be applied preferably in the form of an ultrasonic apparatus or pinch roller, which are well known for such purposes. A preferred mechanical seal is a pressure bond seal which bonds together the thermoplastic material of the loop member 21 to the thermoplastic material of the inserted member 30. In one suitable method of sealing the side flap, the assembled article is passed between a rotating anvil roll and a rotating pressure roll which typically exert about 1500- 5000 kilograms force per square centimeter pressure on the sealing area, thereby forming a seal having a width generally from 0.5-6 mm, more preferably from 2-4 mm. Preferably, a temperature below about 80 degrees centigrade is used. It is most preferred to operate the anvil and the pressure roll at their ambient temperature. A higher temperature can be used so long as it is well below the thermoplastic melting temperature of the layers, to avoid damaging or weakening these materials at such temperatures. Another preferred method of forming the seal 40 is a heat seal made by heating the rotating anvil roll and/or the rotating pressure roll at or above the melting temperature of the thermoplastic materials of the elastic panels and chassis, and applying a considerably lower pressure to avoid excessive damage and weakening of the nonwoven fabric layers in the area of the attachment lines. The seal can also be made by using an adhesive or chemical seal to bond the materials of the loop member 21 and the inserted member 30 together. Secondary nonwoven sheet Another preferred sanitary napkin of the present invention is further provided with a secondary non-woven sheet 15 positioned between the topsheet 2 and the absorbent member 4 as a secondary topsheet. The lateral ends of the secondary nonwoven sheet can extend beyond the lateral edges 7 of the absorbent pad, and can serve as either the loop member 21 or as an inserted member 30. In this sanitary napkin, the topsheet 2, backsheet 3, or the secondary non-woven sheet 15 can be the loop member 21 layer; or a combination of these layers can be brought together to form the loop member. Preferably a layer not used to form the loop member 21 is used as an inserted member 30. In Figure 4, the loop member 21 is formed by the topsheet 2 and the inserted member 30 is formed by the secondary non-woven sheet 15 and the backsheet 3. The elastic material 40 is attached to both inserted members. Alternatively, the backsheet 3 only or the secondary non-woven sheet 15 only can be used as the inserted member 30. In Figure 4a the loop member is formed by the secondary nonwoven sheet 15, and the backsheet is extended to form the inserted member 30. The topsheet 2 extends to and is secured along its side edge by the side seal 10. Alternatively as shown in Figure 4b, the side edges of the topsheet can extend beyond the side seal to at least partially cover the loop member 21. in another embodiment, the loop member can be formed by the backsheet 3, and the secondary nonwoven sheet can be extended to form the inserted member. As in the previous embodiments, the topsheet 2 can extend to and be secured along its side edge by the side seal 10, or can be further extended beyond side seal 10 to cover a portion of the wearer-facing portion 26 of the loop member. The topsheet can instead be inserted into the loop member as a second inserted member. In another sanitary napkin of the present invention, the absorbent article 1 has a topsheet 2 having a central portion and a side portion on each lateral side of the central portion, and a non-woven outer sheet 11 positioned on the wearer-facing surface along each side portion of said topsheet. The non-woven outer sheet 11 can be bonded, preferably with a mechanical seal (pressure or heat seal), continuously or in discrete areas, to the topsheet layer to secure its edges from rolling and tearing. The non-woven outer sheet 11 is preferably a soft, comfortable, skin-friendly nonwoven fabric, which preferably forms the loop member 21 of the side flap. In this sanitary napkin, the topsheet 2, backsheet 3, or the non-woven outer sheet 11, or a combination of these, can form the loop member 21 layer. As shown in Figure 5, the non-woven outer sheet 11 also loops back under the topsheet 2 to form the secondary non-woven sheet 15. The topsheet 2 forms the inserted member 30. The backsheet extends beyond the edge of the absorbent pad and is secured to the garment-facing surface 25 of the loop member by seal 10. In another preferred sanitary napkin shown in Figure 5a, the non¬ woven outer sheet 11 forms the loop member 21 and can then extend to cover a portion of the garment-facing surface of the backsheet. In Figure 5a, the backsheet 3 and the topsheet 2 form the inserted members 30; alternatively, the backsheet 3 and the topsheet 2 alone can form inserted member 30. In Figure 6, the inserted member 30 is a distinct layer from any topsheet, backsheet, or other layer that can extend from the side edge 7 of the absorbent pad. In this embodiment, the elastic member can be formed integrally with the inserted member, preferably with the elastic member positioned outboard of the base end 32 of the inserted member. The use of the non-woven outer sheet 11 or the secondary non-woven sheet 15 to form the loop member reduces the amount of topsheet, which is typically a more expensive component, and hence reduces the production cost. Another benefit of the non-woven sheets is an improvement in comfort and skin friendliness. The secondary non-woven sheet 15 and the non-woven outer sheet 11 preferably comprise a non-woven fabric for comfort and skin-feel. Non-woven webs can be made from natural fibers (e.g., wood or cotton fibers), synthetic fibers (e.g., polyester or polypropylene fibers), or a combination of natural and synthetic fibers. Preferably, the non-woven fabric is made of a hydrophilic or a surfactant-treated hydrophobic material. A preferred . non-woven fabric is an air-through non-woven supplied by Fukumura Seishi Kabushiki Kaisha. This non-woven comprises: a first layer which comprises about 50% w/w polyethylene (PE) and about 50% w/w polypropylene (PP) fibers having a denier of about 2, the fibers having a core made of polypropylene and an outer sheath surrounding the core made of polyethylene; and a second layer which comprises 50% w/w polyethylene (PE) and about 50% w/w polyester (PET) fibers having a denier of about 2, the fibers having a core made of polyester and an outer sheath surrounding the core made of polyethylene. The above fibers used in the first and second layers are known in the art as a "bi-component fiber". The sheet can be oriented with either layer facing the wearer. Absorbent pad The absorbent pad 4 is any absorbent means which is capable of absorbing or retaining liquids (e.g., menses and/or urine). As discussed above, the absorbent core 4 can be manufactured in a wide variety of sizes and shapes (e.g., rectangular, oval, hourglass, dog bone, asymmetric, etc.) and from a wide variety of liquid- absorbent materials commonly used in absorbent napkins and other absorbent articles such as comminuted wood pulp which is generally referred to as airfelt. Examples of other suitable absorbent materials include creped cellulose wadding; meltblown polymers including coform; chemically stiffened, modified or cross-linked cellulosic fibers; synthetic fibers such as crimped polyester fibers; peat moss; tissue including tissue wraps and tissue laminates; absorbent foams; absorbent sponges; superabsorbent polymers; absorbent gelling materials; or any equivalent material or combinations of materials, or mixtures of these. The configuration and construction of the absorbent core can also be varied (e.g., the absorbent core can have varying caliper zones (e.g., profiled so as to be thicker in the center), hydrophilic gradients, superabsorbent gradients, or lower density and lower average basis weight acquisition zones; or can comprise one or more layers or structures). The total absorbent capacity of the absorbent core should, however, be compatible with the design loading and the intended use of the absorbent article. Further, the size and absorbent capacity of the absorbent core can be varied to accommodate different uses such as incontinence pads, pantiliners, regular sanitary napkins, or overnight sanitary napkins. Exemplary absorbent structures for use as the absorbent core of the present invention are described in U.S. Patent 4,950,264 entitled "Thin, Flexible Sanitary Naplin" issued to Osborn on August 21, 1990; U.S. Patent 4,610,678 entitled "High-Density Absorbent Structures" issued to Weisman et al. on September 9, 1986; U.S. Patent 4,834,735 entitled "High Density Absorbent Members Having Lower Density and Lower Basis Weight Acquisition Zones", issued to Alemany et al. on May 30, 1989; and European Patent Application No. 0 198 683, The Procter & Gamble Company, published October 22, 1986 in the name of Duenk, et al. Each of these patents are incorporated herein by reference. In a preferred sanitary napkin of the present invention, an acquisition layer(s) can be positioned between the topsheet and the absorbent core. The acquisition layer can serve several functions including improving wicking of exudates over and into the absorbent core. There are several reasons why the improved wicking of exudates is important, including providing a more even distribution of the exudates throughout the absorbent core and allowing the sanitary napkin 1 to be made relatively thin. The wicking referred to herein can encompass the transportation of liquids in one, two or all directions (i.e., in the x-y plane and/or in the z- direction). The acquisition layer can be comprised of several different materials including nonwoven or woven webs of synthetic fibers including polyester, polypropylene, or polyethylene; natural fibers including cotton or cellulose; blends of such fibers; or any equivalent materials or combinations of materials. Examples of sanitary napkins having an acquisition layer and a topsheet are more fully described in U.S. 4,950,264 issued to Osborn and U.S. Patent Application Serial No. 07/810,774, "Absorbent Article Having Fused Layers", filed December 17, 1991 in the names of Cree, et al. Each of these references are incorporated herein by reference. In a preferred embodiment, the acquisition layer can be joined with the topsheet by any of the conventional means for joining webs together, most preferably by fusion bonds as is more fully described in the above-referenced Cree application. In another preferred sanitary napkin of the present invention, a wicking or fluid distribution strip (not shown) can be positioned between the topsheet and the absorbent core. The wicking strip provides permeability and diffusivity of the bodily liquids into and along the longitudinal length of the absorbent core. Preferred wicking strips are melt-blown or spun-bond non-wovens, and provide enhanced fluid distribution in the longitudinal direction of the absorbent article. A particularly preferred wicking strip comprises a series of longitudinally-oriented embossments or compressments, or both, in the non-woven wicking strip, as described in co-pending Japanese Patent Application No. 294665/1991, filed November 11, 1991 (Procter & Gamble Far East Inc.). The longitudinal end edge portion 5 of the absorbent article 1 is typically formed by joining together the topsheet 2 and the backsheet 3, as well as any additional non-woven fabric layer 15, with a suitable seal 8, preferably a heat seal. The backsheet 3 and topsheet 2, and any additional non-woven fabric layer 15 as applicable, can be secured to the absorbent core 4 by attachment means (not shown) such as those well known in the art. For example, the backsheet 3 and/or the topsheet 2 can be attached to each other by a uniform continuous layer of adhesive, a patterned layer of adhesive, or an array of separate lines, spirals, or spots of adhesive. " Adhesives which have been found to be satisfactory are manufactured by H.B. Fuller Company of St. Paul, Minnesota under the designation HL-1258 or H-2031. The attachment means will preferably comprise an open pattern network of filaments of adhesive as is disclosed in U.S. Patent 4,573,986 entitled "Disposable Waste-Containment Garment", which issued to Minetola, et al. on March 4, 1986, and which is incorporated herein by reference. An exemplary attachment means of an open pattern network of filaments comprises several lines of adhesive filaments swirled into a spiral pattern such as illustrated by the apparatus and method shown in U.S. Patent 3,911,173 issued to Sprague, Jr. on October 7, 1975; U.S. Patent 4,785,996 issued to Zieker, et al. on November 22, 1978; and U.S. Patent 4,842,666 issued to Werenicz on June 27, 1989. Each of these patents are incorporated herein by reference. Alternatively, the attachment means can comprise heat bonds, pressure bonds, ultrasonic bonds, dynamic mechanical bonds, or any other suitable attachment means or combinations of these attachment means as are known in the art. Topsheet The topsheet 2 is compliant, soft feeling, and non- irritating to the wearer's skin. Further, the topsheet 2 is liquid pervious permitting liquids (e.g., menses and/or urine) to readily penetrate through its thickness. A suitable topsheet 2 can be manufactured from a wide range of materials such as woven and non-woven materials; polymeric materials such as apertured formed thermoplastic films, apertured plastic films, and hydroformed thermoplastic films; porous foams; reticulated foams; reticulated thermoplastic films; and thermoplastic scrims. Suitable woven and nonwoven materials can be comprised of natural fibers (e.g., wood or cotton fibers), synthetic fibers (e.g., polymeric fibers such as polyester, polypropylene, or polyethylene fibers) or from a combination of natural and synthetic fibers. A preferred topsheet comprises an apertured formed film. Apertured formed films are preferred for the topsheet because they are pervious to body exudates and yet non-absorbent and have a reduced tendency to allow liquids to pass back through and re-wet the wearer's skin. Thus, the surface of the formed film which is in contact with the body remains dry, thereby reducing body soiling and creating a more comfortable feel for the wearer. Suitable formed films are described in U.S. Patent 3,929,135, entitled "Absorptive Structure Having Tapered Capillaries", which issued to Thompson on December 30, 1975; U.S. Patent 4,324,246 entitled "Disposable Absorbent Article Having A Stain Resistant Topsheet", which issued to Mullane, et al. on April 13, 1982; U.S. Patent 4,342,314 entitled "Resilient Plastic Web Exhibiting Fiber-Like Properties", which issued to Radel, et al. on August 3, 1982; U.S. Patent 4,463,045 entitled "Macroscopically Expanded Three-Dimensional Plastic Web Exhibiting Non-Glossy Visible Surface and Cloth-Like Tactile Impression", which issued to Ahr et al. on July 31, 1984; and U.S. 5,006,394 "Multilayer Polymeric Film" issued to Baird on April 9, 1991. Each of these patents are incorporated herein by reference. The preferred topsheet for the present invention is the formed film described in one or more of the above patents and marketed on sanitary napkins by The Procter & Gamble Company of Cincinnati, Ohio as "DRI-WEAVE". In a preferred embodiment of the present invention, the body surface of the formed film topsheet is hydrophilic so as to help liquid to transfer through the topsheet faster than if the body surface was not hydrophilic so as to diminish the likelihood that menstrual fluid will flow off the topsheet rather than flowing into and being absorbed by the absorbent core. In a preferred embodiment, surfactant is incorporated into the polymeric materials of the formed film topsheet such as is described in U.S. Patent Application Serial No. 07/794,745, "Absorbent Article Having A Nonwoven and Apertured Film Coversheet" filed * on November 19, 1991 by Aziz, et al., which is incorporated herein by reference. Alternatively, the body surface of the topsheet can be made hydrophilic by treating it with a surfactant such as is described in the above referenced U.S. 4,950,254 issued to Osborn, incorporated herein by reference. Backsheet The backsheet 3 is impervious to liquids (e.g., menses and/or urine) and is preferably manufactured from a thin plastic film, although other flexible liquid impervious materials can also be used. As used herein, the term "flexible" refers to materials which are compliant and will readily conform to the general shape and contours of the human body. The backsheet 3 prevents the exudates absorbed and contained in the absorbent core 4 from wetting articles which contact the sanitary napkin such as pants, pajamas and undergarments. The backsheet 3 can thus comprise a woven or nonwoven material, polymeric films such as thermoplastic films of polyethylene or polypropylene, or composite materials such as a film-coated nonwoven material. Preferably, the backsheet is a polyethylene film having a thickness of from about 0.012 mm (0.5 mil) to about 0.051 mm (2.0 mils). Exemplary polyethylene films are manufactured by Clopay Corporation of Cincinnati, Ohio, under the designation P18-0401 and by Ethyl Corporation, Visqueen Division, of Terre Haute, Indiana, under the designation XP-39385. The backsheet is preferably embossed and/or matte finished to provide a more clothlike appearance. Further, the backsheet 3 can permit vapors to escape from the absorbent core 4 (i.e., breathable) while still preventing exudates from passing through the backsheet 3. In use, the sanitary napkin 1 can be held in place by any support means or attachment means (not shown) well-known for such purposes. Preferably, the sanitary napkin is placed in the user's undergarment or panty and secured thereto by a fastener such as an adhesive 13. The adhesive 13 provides a means for securing the sanitary napkin in the crotch portion of the panty. Thus, a portion or all of the garment-facing surface of the absorbent article 1 is coated with adhesive. Any adhesive or glue used in the art for such purposes can be used for the adhesive herein, with pressure-sensitive adhesives being preferred. Suitable adhesives are Century A-305-IV manufactured by the Century Adhesives Corporation of Columbus, Ohio; and Instant Lock 34-2823 manufactured by the National Starch and Chemical Company of Bridgewater, NJ. Suitable adhesive fasteners are also described in U.S. Patent 4,917,697. Before the sanitary napkin is placed in use, the pressure-sensitive adhesive is typically covered with a removable release liner 14 in order to keep the adhesive from drying out or adhering to a surface other than the crotch portion of the panty prior to use. Suitable release liners are also described in the above-referenced U.S. Patent 4,917,697. Any commercially available release liners commonly used for such purposes can be utilized herein. Non-limiting examples of suitable release liners are BL30MG-A Silox El/10 and BL30MG-A Silox 4P/0 both of which are manufactured by the Akrosil Corporation of Menasha, WI. The sanitary napkin 1 of the present invention is used by removing the release liner and thereafter placing the sanitary napkin in a panty so that the adhesive contacts the panty. The adhesive 13 assists in maintaining the sanitary napkin in its position within the panty during use. As clearly seen from the above illustration, according to this invention, a sanitary napkin is provided comprising a loop member which stands up and helps the article to form a curved shape, thereby improving fit, comfort, and reducing the risk of side leakage. The elastic material is attached to the inserted member but it is not attached directly to the loop member. Any stiffness or wrinkling formed in the inserted member as a result of the contraction of the elastic member, or due to the elastic member itself, is separated from the skin or the wearer by the loop member layer, thus resulting in no reduction in comfort and skin friendliness. Because the elastic material does not come in direct contact with the skin of the wearer, a broad range of materials and elastic conditions can be used. While 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 can be made without departing from the spirit and scope of the invention. Therefore the appended claims are intended to cover all such changes and modifications that are within the scope of this invention.

Claims: I claim: 1. An absorbent article comprising a liquid permeable topsheet, a liquid impermeable backsheet and a liquid absorbent pad for absorbing a liquid exuded from the human body positioned there between and having a pair of side edges, characterized by comprising an elasticized side flap along each side edge of said absorbent pad, said side flap comprising: - a loop member which extends from and loops back toward said side edge of said absorbent pad, said loop member having a base end with an opening proximate said side edge of said absorbent pad, a distal end, a garment-facing portion, and a wearer-facing portion; - an inserted member which extends through said base end opening into said loop member and having a distal end and a base end adjacent said base end opening; - an elastic material affixed along a portion of the length of said inserted member outboard of said base end of said inserted member, wherein said elastic material is not affixed to said loop member; and - a seal attaching said inserted member to said garment-facing portion and wearer-facing portion of said loop member at said base end. 2. An absorbent article according to Claim 1 wherein said loop member is formed from a layer which extends from and loops back toward said side edge of said absorbent pad and is selected from the group consisting of said topsheet and said backsheet, and said inserted member is formed from a layer which extends from said side edge of said absorbent pad and is selected from the group consisting of said backsheet and the topsheet. 3. An absorbent article comprising a liquid permeable topsheet, a liquid impermeable backsheet, a liquid absorbent pad for absorbing a liquid exuded from the human body positioned there between and having a pair of side edges, and a secondary non-woven sheet positioned between said topsheet and said absorbent pad, characterized by comprising an elasticized side flap along each side edge of said absorbent pad, said side flap comprising: - a loop member formed from a layer which extends from and loops back toward said side edge of said absorbent pad and is selected from the group consisting of said topsheet, said backsheet, said secondary non¬ woven sheet, and a combination thereof, said loop member having a base end with an opening proximate said side edge of said absorbent pad, a distal end, a garment- facing portion, and a wearer-facing portion; .- an inserted member formed from a layer which extends from the group consisting of said side edge of said absorbent pad, and is selected from said backsheet, said topsheet, said secondary non-woven sheet and combination thereof, said inserted member being inserted through said base end opening into said loop member and having a distal end and a base end adjacent said base end opening; - an elastic material affixed along a portion of the length of said inserted member outboard of said base end of said inserted member, wherein said elastic material is not affixed to said loop member; and - a seal attaching said inserted member to said garment-facing portion and wearer-facing portion of said loop member at said base end. 4. An absorbent article comprising, in order, a liquid impermeable backsheet, a liquid absorbent pad for absorbing a liquid exuded from the human body and having a pair of side edges, a liquid permeable topsheet having a central portion and a side portion on each lateral side of the central portion, and a non-woven outer sheet positioned along each side portion of said topsheet, characterized by comprising an elasticized side flap along each side edge of said absorbent pad, said side flap comprising: - a loop member formed from a layer which extends from and loops back toward said side edge of said absorbent pad and is selected from the group consisting of said topsheet, said backsheet, said non-woven outer sheet, and combination thereof, said loop member having a base end with an opening proximate said side edge of said absorbent pad, a distal end, a garment-facing portion, and a wearer-facing portion; - an at least one inserted member formed from a layer which extends from said side edge of said absorbent pad, and is selected from the group consisting of said backsheet, said topsheet said non-woven outer sheet, and combination thereof, said inserted member being inserted through said base end opening into said loop member and having a distal end and a base end adjacent said base end opening; - an elastic material affixed along a portion of the length of said inserted member outboard of said base end of said inserted member, wherein said elastic material is not affixed to said loop member; and - a seal attaching said inserted member to said garment-facing portion and wearer-facing portion of said loop member at said base end. 5. An absorbent article according to Claim 2 or 3 wherein said loop member is the topsheet and said at least one inserted layer is said backsheet. 6. An absorbent article according to Claim 3 wherein said loop member is the topsheet and said at least one inserted layer is selected from said backsheet and said secondary non-woven sheet. 7. An absorbent article according to Claim 6 wherein said elastic material is affixed to said backsheet and said secondary non-woven sheet. 8. An absorbent article according to Claim 3 wherein said loop member is said secondary non-woven sheet and said at least one inserted layer comprises said backsheet. 9. An absorbent article according to Claim 8 wherein said at least one inserted layer further comprises said topsheet. 10. An absorbent article according to Claim 4 wherein said loop member is said non-woven outer sheet and said at least one inserted layer comprises said backsheet. 11. An absorbent article according to Claim 10 wherein said at least one inserted layer further comprises said topsheet. 12. An absorbent article according to any of claims 1-4 further comprising a non-woven embossed wicking strip positioned between said topsheet and said absorbent pad.

Inventors: MORITA YASUKO, MORITA, YASUKO
Applicants: PROCTER & GAMBLE FAR EAST INC, PROCTER & GAMBLE FAR EAST, INC.
Application year: 1992
Main classification: A61F13
IPC codes: A61F13