Applicable absorbent articles

Abstract

An absorbent article is provided having a longitudinal axis and a lateral axis. The article has a topsheet and a backsheet that together form a chassis that is symmetrical about the lateral axis. An absorbent core is disposed between the topsheet and the backsheet, and the periphery of the chassis extends beyond the surface area of ​​the core. The absorbent core is asymmetric about the lateral axis. In one embodiment, less than 50% of the surface area of ​​the absorbent article is mechanically compressed. In another embodiment, the absorbent article has an in-use flexibility of less than 170 mN, preferably less than 130 mN. In a further embodiment, the absorbent article has a flexibilty of less than 0.4 g measured in the core-free area. * It has a stiffness of less than cm.

Description

[Technical Field]

[0001] The present invention relates to an absorbent article having a chassis symmetrical with respect to a transverse axis and an absorbent core asymmetrical with respect to a transverse axis. [Background technology]

[0002] Sanitary napkins are used primarily by women during menstruation to collect and contain menstrual blood and other vaginal discharge, protecting clothing from stains. Similar products also exist for use when experiencing incontinence.

[0003] Panty liners serve almost the same purpose as sanitary napkins, but the main difference lies in their overall size, including thickness. Panty liners are generally less bulky and designed to protect the user's clothing from relatively small amounts of vaginal discharge.

[0004] Many women have developed the habit of wearing absorbent devices during menstruation to protect their clothing from any vaginal discharge, including small amounts of urine, and sometimes from anal discharge. Because sanitary napkins are generally bulky for constant wear, these users typically opt for panty liners.

[0005] Since panty liners can be worn daily by users, users prefer that they have a "subtle presence" feel while still providing adequate protection for their needs. Furthermore, because the shape and style of underwear worn by users changes daily, panty liners intended for daily wear need to be appropriately adaptable.

[0006] Commercially available panty liners are designed for use with so-called thong underwear, which tend to have a crotch area with a wider front section and a narrower back section. Thong underwear, by its nature, also tends to conform to the user's body shape more than conventional underwear. To ensure flexibility when used with thong underwear, existing commercially available panty liners are typically shaped to fit (i.e., with a wider front and a narrower back), or they may be adaptable, typically having an asymmetrical core with a wider front and a narrower back, and a top and back sheet that extend beyond and around the core in a symmetrical dogbone shape. However, in either case, this usually results in a smaller surface area of ​​the absorbent core. Therefore, when designing panty liners for use with thong underwear, there is a trade-off between comfort and protection. The core can be made thinner, but this tends to reduce the rigidity and flexibility of the liner, resulting in a decrease in the overall comfort level, or the panty liner having less absorbency than required.

[0007] Furthermore, today, there are no adaptable panty liners on the market that are truly suitable for use with both regular underwear and thong underwear, or with any shape or size of underwear in between the two. For example, several commercially available adaptable panty liners are offered. However, these panty liners are generally found to be excessively stiff and not adapt to the movement of the user's panties. Moreover, the stiffness, especially in the core-free area, means that it is difficult to fold over the core-free edge. To address this, currently available adaptable panty liners have fold lines on either side of the tapered core, so that the user can only fold the panty liner around the panties along these specific lines. [Overview of the Initiative] [Problems that the invention aims to solve]

[0008] Therefore, there is a need to provide panty liners that offer the desired level of absorbency while remaining comfortable and having the necessary fit. [Means for solving the problem]

[0009] The present invention relates to absorbent articles, such as panty liners, for use with panties having various crotch dimensions and often asymmetrical shapes, such as thong panties, high-cut and low-cut panties.

[0010] In one embodiment, the present invention relates to an absorbent article having a longitudinal axis and a transverse axis, Top sheet and A backsheet, where the top sheet and backsheet together form a chassis for an absorbent material, and the chassis is symmetrical with respect to the lateral axis, the backsheet and An absorbent core disposed between the top sheet and the back sheet, wherein the outer periphery of the chassis extends beyond the surface area of ​​the absorbent core, and the absorbent core is asymmetrical with respect to its lateral axis, comprising: This relates to absorbent articles in which less than 50% of the surface area of ​​the absorbent article is mechanically compressed.

[0011] In another embodiment, the present invention relates to an absorbent article having a longitudinal axis and a transverse axis, Top sheet and A backsheet, where the top sheet and backsheet together form a chassis for an absorbent material, and the chassis is symmetrical with respect to the lateral axis, the backsheet and An absorbent core disposed between the top sheet and the back sheet, wherein the outer periphery of the chassis extends beyond the surface area of ​​the absorbent core, and the absorbent core is asymmetrical with respect to its lateral axis, comprising: It relates to an absorbent article having a flexibility in use of less than 170 mN, preferably less than 130 mN.

[0012] In a third aspect, the present invention is an absorbent article having a longitudinal axis and a transverse axis, a non-woven top sheet, a back sheet, wherein the top sheet and the back sheet together form the chassis of the absorbent article, and the chassis is symmetric about the transverse axis, the back sheet, an absorbent core disposed between the top sheet and the back sheet, wherein the outer peripheral portion of the chassis extends beyond the surface area of the absorbent core, and the absorbent core is asymmetric about the transverse axis, the absorbent core, and comprises, having a rigidity of less than 0.4 g [Figure 5B] measured in the core-free area, which relates to an absorbent article. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The following detailed description of specific forms of the present invention can be more deeply understood when read in conjunction with the drawings enclosed herewith. [Figure 1] It is a view from above of the absorbent article described herein. [Figure 2] It is an exploded view of the absorbent article of FIG. 1 showing each layer. [Figure 3] It is a further exploded view of the absorbent article of FIG. 1 showing the layers of FIG. 2 and additional adhesive layers. [Figure 4] It is a simple plan view of the absorbent article shown in FIG. 1 showing the region where the cross section through the layers shown in FIGS. 5A, 5B, and 5C is shown. [Figure 5A] It is a cross-sectional view of the absorbent article shown in FIG. 4. [Figure 5B] It is a cross-sectional view of the absorbent article shown in FIG. 4. [Figure 5C] It is a cross-sectional view of the absorbent article shown in FIG. 4. [Figure 6] It is a plan view of the absorbent article emphasizing the embossed area of the absorbent core. [Figure 7A] This specification shows the applicable properties of the absorbent articles described herein. [Figure 7B] This specification shows the applicable properties of the absorbent articles described herein. [Figure 7C] This specification shows the applicable properties of the absorbent articles described herein. [Figure 7D] This specification shows the applicable properties of the absorbent articles described herein. [Figure 8A] The process for cutting the absorbent core is schematically shown. [Figure 8B] The process for cutting the absorbent core is schematically shown. [Figure 9] The manufacturing process for the absorbent articles described herein is outlined below. [Figure 10A] The processes for embossing and printing are outlined below. [Figure 10B] The processes for embossing and printing are outlined below. [Figure 11] A schematic diagram of the test apparatus for measuring flexibility during use is shown. [Modes for carrying out the invention]

[0014] The present invention generally relates to feminine hygiene articles, which are typically known as absorbent articles worn externally by women to absorb vaginal discharge and / or urinary incontinence. The term feminine hygiene articles generally encompass articles referred to as pads, panty liners, liners, sanitary napkins, sanitary towels, or interlabial devices. These articles are typically held in place by the user's underwear adjacent to the user's pubic area and may be fixed therein by adhesive or other fastening means.

[0015] As used herein, the term “nonwoven web” refers to a web having a structure in which individual fibers or threads are interwoven but not in a repeating pattern like in woven or knitted fabrics, which typically do not have randomly oriented fibers. The basis weight of a nonwoven is usually expressed in grams per square meter (gsm). The basis weight of a nonwoven web / lamination is the combined basis weight of the constituent layers and any other additive components. Fiber diameter is usually expressed in micrometers, but fiber dimensions can also be expressed in denier, which is a unit of weight per unit length of fiber.

[0016] As used herein, “spunbond fiber” refers to a small-diameter fiber formed by extruding molten thermoplastic material as a filament from a capillary tube, typically circular in shape. Spunbond fibers are generally non-adhesive when deposited on a collection surface. Spunbond fibers are generally continuous and have an average diameter greater than 7 micrometers, more specifically about 8–40 micrometers (from at least 10 samples).

[0017] As used herein, "affinity" and "non-affinity" have the meanings established in the art with respect to a reference liquid contact angle on the material surface. Therefore, materials with a liquid contact angle greater than approximately 75 degrees are considered non-affinity, and materials with a liquid contact angle less than approximately 75 degrees are considered affinity.

[0018] Figure 1 shows a top view of the body-facing surface of an exemplary absorbent article 10. The particular embodiment shown is an example of a panty liner (also called a “liner” or “napkin”), but the present invention is not limited thereto. Such absorbent articles typically have a generally flat body-facing surface, but are generally flexible to adapt to the user’s anatomical structure and movements. They may also be folded and rolled, for example, to facilitate more hygienic transport of individual articles and / or to reduce package size.

[0019] The panty liner shown in Figure 1 has a longitudinal axis YY and a transverse axis XX that intersect at the center point 0 of the panty liner. A front region 12 is provided on one side of the transverse axis, and a rear region 14 is provided on the other side of the transverse axis. The panty liner may have any shape known in the art, but a preferred shape is generally hourglass, tapering inward from a relatively large transverse width in the front and rear regions to a relatively small transverse width in the intermediate region. The panty liner may also have transverse extensions commonly known in the art as "flaps" or "wings" (not shown), which are typically intended to extend over and cover the elastic portion of the panty in the crotch area of ​​the user's underwear.

[0020] Figure 2 is an exploded view of the article of Figure 1, showing the layers from top to bottom, namely a laminated top sheet 20 including a first top sheet 22 and a second top sheet 24, an absorbent core 26, a liquid-impermeable patch 28, and a back sheet 30. A peel-off cover 32, which may be used to cover the adhesive on the clothing-facing surface of the back sheet, is shown in Figure 3. The “top surface” 40 of the article is defined herein as the surface of the article oriented toward the user’s body, and the “bottom surface” 42 is defined herein as the opposite surface of the article, i.e., the surface that is in general contact with the woman’s underwear.

[0021] The panty liner chassis 50, comprising a top sheet (or laminated top sheet, if applicable) and a back sheet, is symmetrical with respect to the longitudinal and transverse axes. The absorbent core is symmetrical with respect to the longitudinal axis but asymmetrical with respect to the transverse axis, with more than 50% of the core located in the front region of the panty liner. Thus, the panty liner comprises a core region 16 and one or more core-free regions 18. The panty liner is intended to be adaptable from a first embodiment ( schematically shown in Figure 7A) in which the panty liner is not folded in any way and has the shape of a top sheet and a back sheet, i.e., symmetrical with respect to both the longitudinal and transverse axes, to a second embodiment for use with various underwear, such as thong panties ( schematically shown in Figures 7B, 7C, and 7D), in which at least a portion of the core-free region of the absorbent article is folded and can be adhered to the underside of the underwear.

[0022] Top sheet The top sheet 20 has a body-facing surface 60 and a clothing-facing surface 62. Typically, the clothing-facing surface 62 is positioned adjacent to the absorbent core 26, or any other layer provided between the absorbent core 26 and the top sheet. Any conventional material may be used to form the top sheet that can be used in the absorbent articles described herein. The top sheet is typically formed from a flexible, smooth, and adaptable porous material that is comfortable against human skin and allows fluids such as urine or vaginal excretions such as menstrual fluid to pass through. Suitable top sheets can be formed from a variety of materials, including woven and nonwoven materials, perforated molded thermoplastic films, perforated plastic films, and perforated film materials including entangled fiber perforated films, hydroformed thermoplastic films, porous foams, mesh foams, mesh thermoplastic films, thermoplastic scrims, or combinations thereof. Non-limiting examples of woven and nonwoven materials suitable for use as a primary top sheet include fibrous materials made from natural fibers, modified natural fibers, synthetic fibers, or combinations thereof.

[0023] The top sheet may also be a laminated top sheet as shown in Figure 2. Such a laminated top sheet may be formed from two layers of different but complementary materials selected from the materials listed above, which are bonded together to form a single layer.

[0024] For example, in a laminated top sheet, the primary top sheet, located on the top surface of the panty liner and in contact with the user's body, may be designed to allow liquid to pass through quickly and easily while still providing a comfortable skin-contact surface. The secondary top sheet may have good fluid-trapping properties. For example, the primary top sheet may be a hydrophobic nonwoven material, such as spunbond polypropylene or multi / bicomponent polyethylene, as well as a polypropylene nonwoven with flexible properties and good re-wetting properties, while the secondary top sheet may be an affinity or semi-affinity material, such as a carded breathable bonded PET material, having a uniform open structure, good elasticity, rapid fluid re-penetration, and fluid distribution. The combination of the two materials may provide a more effective and rapid fluid acquisition from the body-facing surface of the top sheet to the core, and minimal re-wetting, while still providing a comfortable contact surface for the user. The final choice of materials may depend on readily available and cost-effective materials, but the above benefits will still be provided.

[0025] Preferably, as best shown in Figures 2 and 3, the secondary top sheet has the same shape and size as the top sheet so as to extend to the edges of the chassis. The primary and secondary top sheets may be laminated together prior to cutting for molding. In such embodiments, the primary and secondary top sheets are bonded to each other across their entire footprint (as shown by the layer of adhesive 70 shown in Figure 3). Preferably, the laminated top sheet is not embossed, crimped, or mechanically compressed in any other manner. While not bound by theory, mechanical compression in the form of embossing is thought to reduce the flexibility and resilience of the resulting laminated top sheet.

[0026] Preferably, the top sheet has a basis weight of 15gsm to 60gsm, preferably 25gsm to 50gsm, and preferably 35gsm to 45gsm. If the top sheet is a laminated top sheet, the primary top sheet preferably has a basis weight of 5gsm to 25gsm, 10gsm to 20gsm, preferably 15gsm to 18gsm, and preferably 17gsm, and the secondary top sheet preferably has a basis weight of 10gsm to 40gsm, preferably 20gsm to 30gsm, and 22gsm to 26gsm, and preferably 24gsm.

[0027] The top sheet may have several forms of printed patterns intended to be visible to the user from the body-facing surface of the absorbent article. The printed patterns may be used to inform the consumer of the functional areas of the absorbent article. Specifically, in the context of adaptable panty liners, this can help the consumer correctly orient the panty liner (especially when the panty liners are stored in alternating directions within the package) and accurately position the panty liner within the user's panties, ensuring that the portion of the panty liner with the greatest absorbency is positioned within the area of ​​the panties most likely to receive seepage. As described in more detail herein, the printed patterns are preferably applied to the garment-facing surface of the primary top sheet to avoid the risk of ink transfer to the user's body, while still having the necessary intensity to adequately inform the consumer.

[0028] It is worth noting that the discussion regarding laminated top sheets is not limited to the primary top sheet being joined to a secondary top sheet. For example, the primary top sheet 22 may comprise layers of material. For example, a nonwoven fabric and a film may be laminated to form the primary top sheet. Subsequently, the primary top sheet may be laminated to a secondary top sheet. The nonwoven fabric may form a portion of the body-facing surface 60. Alternatively, a film may form a portion of the body-facing surface. The film may be provided with fluid handling holes and micropores. However, when this particular top sheet is used in the context of a panty liner, the rate of liquid soiling may be lower compared to its women's pad or adult incontinence pad counterpart.

[0029] Back seat The backsheet 30 is located on the bottom surface 42 of the absorbent article and provides the clothing-facing surface 44 of the absorbent article. The backsheet may be breathable or not. The backsheet may be impermeable to liquids (e.g., urine) or substantially impermeable, and may be manufactured from a thin plastic film, but other flexible liquid-impermeable materials may be used. As used herein, the term “flexible” refers to a material that is adaptable and readily conforms to the general shape and contours of the human body. The backsheet can prevent, or at least suppress, the exudate absorbed and contained in the absorbent core from wetting clothing articles that come into contact with the panty liner, such as underwear or panties. Alternatively, the backsheet may be, for example, a thin nonwoven fabric material (about 30 g / m²) formed from polyethylene terephthalate or polypropylene fibers. 2 ~40g / m 2 The backsheet may be a liquid-permeable flexible layer formed from a stretchable spunlace nonwoven fabric material having a basis weight, and perforated plastic films, net materials, liquid-permeable foam materials, etc., may be used. If the backsheet is liquid-permeable, preferably a secondary liquid-impermeable patch (such as those described below) is provided to minimize the possibility of leakage.

[0030] The backsheet may be printed on a body-facing surface or a clothing-facing surface. Furthermore, the clothing-facing surface of the backsheet is typically provided with an adhesive to adhere the absorbent article to the user's underwear. The placement and volume of the adhesive may be selected to optimize contact with the user's underwear, depending on the size, shape, and thickness of the absorbent article. Preferably, the adhesive is applied over substantially the entire surface area of ​​the clothing-facing surface 44 of the backsheet (not shown) so that the panty liner moves effectively with the underwear to which it is attached.

[0031] Absorbent core The absorbent core 26 is positioned between the top sheet and the back sheet. As used herein, the term “absorbent core” refers to a material or combination of materials suitable for absorbing, distributing, and containing fluids such as urine, blood, menstrual secretions, and other bodily exudates.

[0032] Absorbent cores can be made from any suitable liquid absorbent material. Non-limiting examples of liquid absorbent materials suitable for use as absorbent cores include crushed wood pulp, commonly known as air felt, crepe cellulose wadding, absorbent gelling materials containing superabsorbent polymers such as hydrogel-forming polymer gelling agents, chemically rigidified, modified, or crosslinked cellulose fiber meltblown polymers including comorphs, synthetic fibers including crimped polyester fibers, tissue paper including tissue paper packaging and tissue paper laminates, capillary fibers, absorbent foams, absorbent sponges, synthetic staple fibers, peat moss, or any equivalent material, or combinations thereof.

[0033] The absorbent core has a relatively smaller surface area than the surface areas of the top sheet and back sheet. As shown in Figure 1, the absorbent core described herein is symmetrical about the longitudinal axis but asymmetrical about the transverse axis, with a larger proportion of the absorbent core located in the front region of the absorbent article. Preferably, at least 50%, 52%, or 54% of the absorbent core is located in the front region of the absorbent article.

[0034] Preferably, the absorbent core has a basis weight of 100 gsm to 170 gsm, preferably 120 gsm to 150 gsm, and preferably 130 gsm to 140 gsm.

[0035] PE patch The liquid-impermeable patch 28 is a layer of impermeable material that may be provided between the backsheet 30 and the garment-facing surface 46 of the absorbent core 26. The liquid-impermeable patch may be used when the backsheet is permeable to provide an additional barrier against potential leakage of seepage from the panty liner, while still allowing air to flow around the outer periphery of the absorbent core. The liquid-impermeable patch may be formed from materials such as a thin plastic film, e.g., polyethylene, and a coating such as a resin, wax, or liquid-tight adhesive.

[0036] Absorbent articles Panty liners, such as those described herein, have an overall chassis consisting of a top sheet and a back sheet, with at least an absorbent core disposed between the top sheet and the back sheet. The chassis has the overall shape of the panty liner and is generally symmetrical about both the longitudinal and transverse axes. As shown in Figures 1, 2, and 3, the chassis may be dogbone shaped, and therefore wider in the front and rear regions and narrower in the central region, although other known shapes may be used. Since panty liners are intended for regular, possibly daily, use and are intended for light flow or backup to other adult incontinence or feminine hygiene devices, they are typically thin and light with a small surface area. Therefore, the chassis preferably has a length of less than 250 mm, preferably less than 230 mm, and preferably less than 200 mm, although it will be understood that different lengths may be chosen for different users, body shapes, or underwear.

[0037] As shown in the exploded view of Figure 3, the top sheet 20 (which is laminated in this case, but may be a single layer) is bonded to the body-facing surface 48 of the core and the area of ​​the back sheet surrounding the core using hot-melt adhesive 72. Preferably, the adhesive is provided around the entire outer periphery of the core and extends to the outer periphery of the chassis, thereby eliminating the need for any other form of fastening (e.g., crimping). Therefore, preferably, the absorbent articles described herein do not have crimped edges. Although not bound by theory, it is thought that when adhesive is provided around the edges of the core, the adhesive provides an additional barrier, thus minimizing the possibility of leakage from the sides of the core to the outside of the panty liner. Furthermore, since crimping around the edges of the liner is not required, overall comfort during use is improved, and the overall rigidity and stretch properties of the panty liner can be made better.

[0038] As described above, an absorbent core, and optionally an impermeable patch, is provided between the top sheet and the back sheet. The panty liner has a thickness through the core of 0.5 mm to 2.0 mm, preferably 0.75 mm to 1.75 mm, preferably 1.0 mm to 1.5 mm. The panty liner further has a thickness of 0.1 mm to 0.7 mm, preferably 0.25 mm to 0.65 mm, preferably 0.35 mm to 0.6 mm, preferably 0.45 mm to 0.55 mm, preferably about 0.5 mm in the core-free region.

[0039] The panty liners described herein are designed to be used with both conventional and non-conventional underwear, and are particularly intended for daily use for adult incontinence. There is always a trade-off between absorbency needs and comfort and flexibility. Therefore, in a particular market for panty liners, it is preferable that the panty liners described herein have an overall absorbency of at least 3g, 5g, 7g, 8g, or 9g, and preferably less than 20g, 15g, 13g, or 12g.

[0040] The absorbent core has a front end 80 and a rear end 82, as shown in Figure 4. The front end of the core is rounded and substantially parallel to the front end 86 of the chassis. Preferably, the outer circumference of the front end of the core is 7 mm or less, preferably 6.5 mm or less, from the outer circumference of the chassis. The sides of the core taper from the front rounded end of the absorbent core to the rear end of the core, and these sides meet at an angle of 3.5° to 9.5°, preferably 5° to 8°, preferably 6° to 7°. Preferably, the rear end of the core is additionally rounded to allow the panty liner to fold around panties of various different shapes and sizes. While not bound by theory, the shape of the illustrated core is thought to provide a balance between absorbent coverage and area around the core so that it can be easily folded around underwear.

[0041] The core occupies at least 50%, 51%, or 52% of the total surface area of ​​the chassis. Preferably, at least 50%, 53%, 55%, 57%, or 60% of the core is provided in the front region of the chassis / panty liner. The asymmetric core described herein is designed to cover a larger portion of the chassis surface area compared to already known adaptable panty liners. In the examples described herein, maximum absorbency is provided in the area where it is most needed (i.e., the front of the panty liner). On the rear side of the panty liner, a core-free area is maximized that is better suited to bending to adapt to various panties.

[0042] Therefore, in the front region of the absorbent article, the absorbent core occupies at least 60%, preferably at least 65% of the surface area between the topsheet and the backsheet, while in the rear region, the absorbent core occupies less than 50%, preferably less than 45% of the surface area between the topsheet and the backsheet. Cross-sections passing through the widest points of the front and rear regions and along the central transverse axis are shown in FIGS. 5A, 5B, and 5C, from which it can be confirmed that the width of the absorbent core varies with respect to the width of the chassis. At the widest point of the rear region of the chassis, the width of the absorbent core is less than 40% of the chassis width. For example, in the example shown in FIG. 5A, the chassis width may be 60-65 mm, and the core width at the same cross-sectional point is 19-21 mm. By reducing the width of the core at this point, a significant degree of freedom is provided to the user for folding the core-free region of the pantiliner over the panty.

[0043] The absorbent article described herein preferably has a rigidity in the core region of 0.5 g * cm to 4 g * cm, preferably 1.5 g * cm to 3.5 g * cm, preferably 2.0 g * cm to 3.0 g * cm, preferably 2.25 g * cm to 2.75 g * cm. This rigidity of the core provides better comfort to the user of the pantiliner during use. In that regard, thong panties, in particular, conform better to the user's body compared to standard underwear. Therefore, by providing a pantiliner with reduced rigidity throughout the core area, the comfort level experienced by the user is improved. Further, in this example, this additional comfort is provided without significantly reducing the overall absorbency provided by the product. Thus, this product functions in a manner comparable to other known adaptable pantiliners, but with additional comfort.

[0044] Preferably, the absorbent articles described herein have a measured flexibility in use of 85 mN to 170 mN, preferably 90 mN to 150 mN, preferably 100 mN to 130 mN, and preferably 105 mN to 120 mN. The flexibility in use test (described below) provides an index of the flexibility of the absorbent article when it is in a adapted form, i.e., when at least a portion of the core-free area is folded around the outer edge of the user's panties. This provides a “real-life” index of the comfort a user may experience when using an absorbent article such as those described herein.

[0045] While not bound by theory, the rigidity and flexibility of the core during use are thought to be at least partially attributable to the thickness of the core layer and to the area of ​​the core that is embossed or mechanically compressed.

[0046] Furthermore, the absorbent article is preferably 0.01 g * cm~0.4g * cm, preferably 0.025 g * cm~0.3g * cm, preferably 0.05 g * cm~0.2g * cm, preferably 0.075 g * cm~0.15g * It has a stiffness in the core-free area of ​​cm. The stiffness in the core area largely determines the ease with which the user can fold the panty liner over the core-free area around the panties. By reducing the stiffness in this area, the described panty liner becomes easier to fold and is therefore purely adaptable around any form or shape of underwear without having any uncomfortable fold points. Although not bound by theory, the stiffness of the absorbent article described herein is considered to be lower than that of other commercially available adaptable panty liners because the absorbent article of the present invention undergoes far less mechanical compression throughout the product and especially in the core-free area. Essentially, mechanical compression forms denser areas of fibers that can increase the stiffness of the absorbent article.

[0047] Therefore, preferably less than 50%, preferably less than 40%, preferably less than 30%, preferably less than 20%, and preferably less than 15% of the total surface area of ​​the absorbent article (i.e., the surface area of ​​the chassis) is mechanically compressed. As used herein, “mechanically compressed” includes, but is not limited to, any known compression method, including scoring, stitching, embossing, crimping, or perforation. Preferably less than 50%, preferably less than 40%, and preferably less than 30% of the core surface area is mechanically compressed. Preferably less than 50%, preferably less than 40%, preferably less than 30%, preferably less than 20%, and preferably less than 10% of the core-free area is mechanically compressed. The core-free area may not substantially include any kind of mechanical compression, such as crimping or embossing.

[0048] To adhere the absorbent article to the user's underwear, an adhesive may be applied to the clothing-facing surface 44 of the backsheet. The adhesive may be any adhesive known in the art. In non-limiting examples, strips, vortices, or waves of pressure-sensitive adhesive may be applied to help keep the absorbent article in place. As used herein, the term “pressure-sensitive adhesive” refers to any peelable adhesive or peelable adhesive means. Suitable adhesive compositions include, for example, water-based pressure-sensitive adhesives such as acrylate adhesives. Alternatively, adhesive compositions may include fast-curing thermoplastics “hot melts,” rubber-based adhesives, double-sided adhesive tapes, and the like.

[0049] The absorbent article may further include a paper release strip 32 (shown in Figure 3) coated on one side, which is applied to the clothing-facing surface 44 of the backsheet. The coating on the paper release strip may be silicone, which reduces the adhesion of the coated side of the release paper to the adhesive. The release strip may be formed from any suitable sheet material, which, when coated, adheres to the adhesive with sufficient tackiness to stay in place before use, but can be easily removed when the absorbent article is used.

[0050] Absorption indicator The panty liners described herein are provided with one or more absorbency indicators. The absorbency indicators help inform consumers of various functions associated with the panty liner. For example, in some embodiments, the absorbency indicator is an embossed pattern 90 (shown in Figure 6) located within the core area of ​​the panty liner, informing the user of where the panty liner's maximum absorbency may be found. Additionally and / or alternatively, printed patterns may be used in the same manner as the embossed pattern, for example, by providing the printed pattern within the core area 26. Printed patterns may also be used to provide the user with an indicator of the panty liner's suitability by, for example, applying a higher density printed pattern in the core area and a lower density in the core-free area. It will be understood that the absorbency indicators may take any form known in the art that can imply the functionality of the panty liner to the user.

[0051] An example of an absorbency indicator is shown in Figure 6 as an embossed pattern 90 provided on the core region 26 of the panty liner. Preferably, the top sheet 20 is embossed together with the absorbent core such that the embossed pattern extends at least over the entire top sheet and absorbent core. As shown in Figure 6, the shape of the embossed pattern is substantially the same as that of the asymmetric absorbent core, and the outer periphery of the embossed pattern 92 is substantially parallel to the outer periphery 94 of the absorbent core. Preferably, the outer periphery of the embossed pattern is located inside the outer periphery of the absorbent core.

[0052] Preferably, the embossed pattern is provided on 10% to 50% of the surface area of ​​the absorbent core. Furthermore, similar to the absorbent core, it is preferable that 50% to 90%, 55% to 85%, 60% to 80%, and 65% to 75% of the embossed pattern be provided on the front region of the absorbent article. Preferably, at least 90%, 93%, 95%, 97%, or 100% of the embossed pattern is provided on the absorbent core without substantially involving embossing or other mechanical compression on the core-free area of ​​the chassis.

[0053] While not bound by theory, the positioning and size of the embossed pattern are thought to serve multiple purposes, namely providing the user with a functional indicator of the area with the greatest absorbency within the absorbent article, and working to improve absorbency by transferring liquid from the top sheet to the absorbent core in the area with the largest volume of absorbent core within the absorbent article.

[0054] Furthermore, by limiting the embossed pattern to areas of the panty liner where it is particularly necessary for functional notification or effectiveness reasons, the overall area of ​​the panty liner that is embossed is reduced. This contributes to a material that is generally more flexible, more elastic, and less rigid compared to a panty liner characterized by embossing across the entire surface area as described above.

[0055] As best shown in Figure 1, a printed pattern visible from the body-facing surface of the absorbent article may be provided. The pattern may be printed on any surface of any layer of the absorbent article, provided that it is visible to the user; however, preferably the pattern is printed on the clothing-facing surface of the top sheet, and the laminated top sheet is preferably provided on the clothing-facing surface of the primary top sheet.

[0056] As shown in the embodiment of Figure 1, two printing patterns are provided. The first printing pattern 110 is provided throughout the core area and has a substantially similar shape on the outer periphery of both the embossed pattern and the absorbent core. The second printing pattern 112 is provided on the outer periphery of the absorbent article and partially overlaps with the absorbent core. A higher proportion of the second printing pattern is provided in the front area of ​​the absorbent article where there is no absorbent core. Preferably, more than 50%, preferably more than 55%, of the second printing pattern is provided in the front area of ​​the absorbent article. Although not bound by theory, the first printing pattern provides the user with visual cues regarding the orientation and maximum absorption area of ​​the absorbent article, thereby enabling the user to correctly position the absorbent article. By concentrating the majority of the second pattern on the front portion of the absorbent article, it becomes easier for the user to identify the core-free area, particularly in the rear area of ​​the panty liner, and thus better recognize where the panty liner may be folded.

[0057] Manufacturing method Figures 8A and 8B show a nested configuration of laterally oriented absorbent cores 150. A continuous web of core material 126 is delivered mechanically to a rotary cutter 152, and asymmetrically oriented cores opposite each other are cut from the continuous web of core material. In embodiments in which the panty liner includes an impermeable patch, the web of the impermeable material may be combined with the absorbent core material before the initial cut so that the absorbent core and the impermeable patch have the same shape and size. However, it will be understood that the impermeable patch may have a different shape and size from the absorbent core.

[0058] The individual absorbent cores form a repeating nesting pattern of absorbent cores that are generally identical in shape and oriented opposite each other. As schematically shown in Figure 9, the body-facing surfaces of the absorbent cores (along with the impermeable patches, if applicable) are then placed on a continuous web of topsheet material 120, with gaps between them in the direction and order in which they were cut. If the topsheet is a laminated topsheet, the primary and secondary topsheet layers may be combined to form a continuous web of laminated topsheets before proceeding to the final assembly process, with the primary topsheet facing the belt and the secondary topsheet receiving the absorbent cores. The continuous web of backsheet material 130 is then applied on the clothing-facing surfaces of the absorbent cores (or, if impermeable patches are present, on the clothing-facing surfaces of the impermeable patches), and the final product form is cut.

[0059] The resulting panty liners are output from the system in alternating directions around the lateral axis, and therefore, the alternately arranged panty liners have opposing front and rear regions, determined by the positioning of the absorbent core.

[0060] This manufacturing system minimizes material waste and improves the speed and efficiency of production. In this regard, the alternating absorbent cores share a boundary wall when cut in the first step, and therefore no material is lost between adjacent absorbent cores. Only a very small amount of absorbent core material is wasted at the top and bottom of each absorbent core. Furthermore, considering the nested cutting of adjacent absorbent cores, it is possible to cut perfectly tapered absorbent cores without wasting a considerable amount of material. This is in contrast to absorbent cores cut parallel to the machine direction, where all material outside the tapered edge is wasted. Similarly, when absorbent cores are placed in the same direction between the continuous webs of the top and back sheets, adjacent panty liners share a boundary wall at the widest parts of the front and rear regions, so that waste between adjacent panty liners is limited to the middle, top, and bottom of the adjacent panty liners. Furthermore, considering the rounded shape of the front region of the absorbent core, it is possible to cover the entire larger surface area of ​​the front region of the panty liner with the absorbent core material, thereby improving the absorbent coverage in the area of ​​the panty liner where it is actually needed.

[0061] Furthermore, although not bound by theory, it is thought that the elasticity of the panty liner in the longitudinal direction will be improved as a result of the manufacturing direction. In this respect, the area of ​​maximum flexibility required by the user is in the longitudinal direction, especially when seen as the greatest variation when sitting / standing. As mentioned above, this is especially true when there is no embossing on the laminated top sheet.

[0062] Preferably, the garment-facing surface of the top sheet is printed before it is placed beneath the absorbent core, or, if a laminated top sheet is provided, the garment-facing surface of the primary top sheet is printed before lamination with the secondary top sheet. By printing on the surface of the top sheet that does not face the user's body, the ink does not come into direct contact with the user's skin. Furthermore, by printing on the garment-facing surface of the primary top sheet (rather than the secondary top sheet), the intensity of the ink seen from the body-facing surface of the top sheet is higher compared to the intensity of the ink seen through either a thicker single top sheet or a combined laminated top sheet. It will be understood that various types of printing processes may be used to create the patterns disclosed herein. For example, in some embodiments, flexographic printing may be used. Specifically, in flexographic printing, a printing plate made of rubber or plastic with a slightly raised image on top may be used. The inked plate is rotated on a cylinder that transfers the image to a sheet. With respect to the panty liners described herein, as shown in Figure 10B, adjacent articles are oriented in opposite directions, and the alternating printing plates on the cylinder are oriented in opposite directions with respect to the transverse axis. This ensures that the orientation of the printing pattern matches the orientation of the asymmetric core. Flexographic printing may be a relatively fast printing process using fast-drying inks. Other embodiments may utilize gravure printing. More specifically, gravure printing utilizes an image etched onto the surface of a metal plate. The etched areas are filled with ink, and the plate is rotated on a cylinder that transfers the image to a sheet.

[0063] Embossing of panty liners is preferably performed after the core is placed on the top sheet, but before the back sheet is placed and before the individual panty liners are cut. Embossing can be achieved using standard techniques such as thermal bonding, ultrasonic bonding, and / or pressure. An example of a preferred process is thermal bonding, in which each layer is passed through two steel rolls, one of which is engraved with a visual pattern and the other is flat. In certain embodiments, one or both of the rolls are heated to a temperature suitable for at least partially melting one or more layers (typically in the range of 90 to 170°C).

[0064] The embossing roll 140 (shown in Figure 10A) may be engraved for most of the embossing patterns using conventional techniques such as machine tools, but it may be desirable to use acid etching or laser engraving to provide finer engravings and thereby finer embossing patterns. The embossing pattern may also be desirable to include relatively thin embossed features that are much thinner than the embossing channels already disclosed in the art, such as in International Publication No. 2003 / 006818. Thin embossed features can give the article an overall feminine and delicate appearance. Therefore, the embossing tool should be capable of high-resolution embossing with a resolution (minimum thickness of the embossed line) of less than about 0.75 mm, but not specifically limited to about 0.35 mm to about 0.60 mm. As shown in Figure 8C, considering the alternating nature of adjacent panty liners as described herein, the embossing roll preferably has an alternatingly oriented embossing pattern pre-engraved on the die.

[0065] When in use Figures 7A, 7B, 7C, and 7D schematically illustrate how the panty liners described herein can be adapted for use with panties of various shapes and sizes according to the user's needs. Figure 7A shows a conventional panty liner on underwear having a narrow central area and wider front and rear areas. When used with such panties, the panty liner described herein may be held in a pre-folded position. In this regard, the top sheet described herein is provided with a certain material and opacity to ensure to the user that the panty liner retains some absorbency outside the core area even when used in this position.

[0066] Figures 7B and 7C schematically illustrate that the panty liners described herein can be folded over the user's panties in a number of different configurations as needed. Because there are no dedicated fold lines, the user has the flexibility to choose how and where to fold the core-free area. Figure 7D schematically illustrates a panty liner used in conjunction with known thong panties, where everything except the core is bonded to the underside of the panties. Various parameters of thickness, stiffness, and flexibility derived from the panty liner structures described herein contribute to the panty liner's suitability (as shown below).

[0067] Test method sample Comparative sample 1: Carefree® Flexiform Fresh (commercially available) liner for slips and thongs.

[0068] Sample 1 of the present invention: Length: 151mm Primary top sheet: Nonwoven spunbond polypropylene - Basis weight = 17 gsm Secondary top sheet: Carded breathable nonwoven polyethylene and polyethylene terephthalate bicomponent fiber - Basis weight = 24 gsm Absorbent core: Airlaid core containing superabsorbent particles - Basis weight = 160 gsm Liquid-impermeable patch: Polypropylene film - Basis weight = 19 gsm Backsheet: Nonwoven spunbond polypropylene - Basis weight = 18 gsm

[0069] Both comparative sample 1 and sample 1 of the present invention are intended to be used as adaptable panty liners having a centrally located core that is asymmetrical with respect to the transverse axis and a chassis that is symmetrical with respect to the longitudinal axis.

[0070] thickness The thickness of the test specimen is measured as the distance between the reference platform on which the test specimen is placed and a press that applies a specific amount of pressure to the test specimen over a specific period of time. All measurements are performed in a laboratory maintained at 23°C ± 2°C and 50% ± 2% relative humidity, and the test specimens are conditioned in this environment for at least two hours prior to testing.

[0071] The thickness is measured using a manual micrometer equipped with a clamp capable of applying a constant pressure of 3.5 kPa ± 0.01 kPa to the test specimen. The manually operated micrometer is a self-weight instrument with accurate readings to the nearest 0.01 mm. A suitable instrument is the Mitutoyo Series 543 ID-C Digimatic, available from VWR International, or an equivalent. The clamp is a flat, grounded, circular movable surface with a diameter smaller than the area of ​​the test specimen being measured and capable of applying the required pressure. A suitable clamp has a diameter of 6.85 mm, but a smaller or larger clamp may be used depending on the size of the area being measured. The test specimen is supported by a horizontal, flat reference platform that is larger than the surface of the clamp and parallel to the surface of the clamp. The system is calibrated and operated according to the manufacturer's instructions.

[0072] A test specimen is obtained by removing it from any individual packaging material present. If folded, gently unfold it to smooth out all wrinkles. If present, remove the release paper to expose the adhesive on the garment-facing side of the test specimen. Lightly apply talcum powder to the adhesive on the backsheet to reduce tackiness. The core area (shown as 16 in Figure 1) is the area of ​​the test specimen that contains the primary absorbent core. The test location in the core area is preferably near the intersection of the longitudinal and transverse centers of the primary absorbent core in an area that does not contain any folds. The core-free area of ​​the test specimen (shown as 18 in Figure 1) is the rear area of ​​the test specimen and does not contain the primary absorbent core. In all cases, the test location to be measured must be wider than the press and must not contain any folds.

[0073] To measure the thickness of the core area, first zero the micrometer against a horizontal, flat reference platform. Place the test specimen on the platform with the top sheet side facing the clamp, centering the test position below the clamp. Gently lower the clamp at a rate of 1.0 mm ± 0.1 mm / sec until the full pressure is applied to the test specimen. Wait 5 seconds, then record the thickness of the core area of ​​the test specimen in 0.01 mm increments. Repeat this process for a total of five duplicate test specimens. Calculate the arithmetic mean of the thicknesses and report it as the core area thickness in 0.01 mm increments.

[0074] Similarly, the thickness of the core-free area is measured for a total of five replicated test samples. The arithmetic mean of the thicknesses is calculated and reported as the core-free area thickness in units of 0.01 mm.

[0075] [Table 1]

[0076] Table 1 shows that the panty liners described herein are generally thinner than the comparison panty liners (comparison sample 1 is also an adaptable panty liner targeting the same / similar user group). Thinner panty liners (preferably without compromising absorbency or other comfort / effectiveness vectors) are generally considered preferable for consumers of such adaptable panty liners, especially those designed for daily use with a variety of different panties and intended to provide the user with a "just there" feel.

[0077] rigidity The stiffness of the core-free area of ​​absorbent materials is measured using a Taber Stiffness Tester (Model 150-B, Taber Industries (North Tonawanda, NY)) equipped with a high-sensitivity attachment (SR, sensitivity range) and 10 unit compensators (both available from Taber Industries). For this setup, each test specimen is measured in the machine direction using a 15-degree deflection to the right. The system is calibrated and operated according to the manufacturer's instructions. All measurements are performed in a laboratory maintained at 23°C ± 2°C and 50% ± 2% relative humidity, and test specimens are conditioned in this environment for at least 2 hours prior to testing.

[0078] To prepare the test specimen, first obtain the test sample and remove it from any existing packaging. If folded, gently unfold it to remove all creases. If present, remove the release paper to expose the adhesive on the clothing-facing side of the test sample. Lightly apply talc powder to the adhesive on the backsheet to reduce tackiness. Obtain the test specimen by removing it from the core-free area of ​​the test sample (shown as 18 in Figure 1), in this case from the rear region of the test sample. When removing the test specimen from the test sample, take care not to impart any contamination or deformation to the specimen during the process. Obtain the test specimen from an area free of folds or creases. An ideal test specimen has a width of 3.81 cm (parallel to the transverse axis) and a length of 3.81 cm (parallel to the longitudinal axis of the test sample). Smaller test specimens may be used to accommodate smaller core-free areas, but the test specimen must have a length of 3.81 cm. The test specimen does not need to be cut from an area parallel to the longitudinal axis of the test sample, but it must have a rectangular shape (e.g., without curved edges) with a width long enough to allow for a core-free area. Calculate the area of ​​the test specimen and record it in units of 0.1 square centimeters. Test results for specimens smaller than the ideal size are normalized based on the area tested.

[0079] Orient the specimen so that the top sheet side faces upward. Insert the specimen into the high-sensitivity attachment so that the second and fourth pins from the left are above the specimen, and the first and third pins from the left are below the specimen, and the length of the specimen is perpendicular to the pins. Ensure that the pins are in contact with the specimen but not applying pressure. Measure the specimen with a 15-degree deflection to the right and record the result in units of 1 Taber Stiffness. Multiply the result by 0.01 (scaling multiplier of SR Attachment + 10 Unit Compensator) and record the result in units of 0.01 Taber Stiffness. Normalize the results for any specimens less than 3.81 cm × 3.81 cm by dividing the result (in Taber Stiffness units) by the area of ​​the specimen (in square centimeters), and then multiply by 14.5 square centimeters (area of ​​the ideal sample size). Note that 1 Taber Stiffness unit is equivalent to 1 gram-centimeter. The result is a core-free area stiffness of 0.01g. * Report in centimeters.

[0080] The same procedure is repeated for a total of five replicated specimens obtained from five substantially identical test samples. The arithmetic mean of the stiffness of the core-free area is calculated as 0.01 g. * Report in centimeters.

[0081] The stiffness of the core-containing region of absorbent articles is measured using a Taber Stiffness Tester (Model 150-B, Taber Industries (North Tonawanda, NY)) equipped to measure test specimens within a test range of 1 to 10 (requires a 10-unit compensator available from Taber Industries). For this setup, each test specimen is measured in the machine direction using 15-degree deflections to the left and right. The system is calibrated and operated according to the manufacturer's instructions. All measurements are performed in a laboratory maintained at 23°C ± 2°C and 50% ± 2% relative humidity, and test specimens are conditioned in this environment for at least 2 hours prior to testing.

[0082] To prepare the test specimen, first obtain the test sample and remove it from any existing packaging. If folded, gently unfold it to remove all creases. If present, remove the release paper to expose the adhesive on the clothing-facing side of the test sample. Lightly apply talc powder to the adhesive on the backsheet to reduce tackiness. Obtain the test specimen by cutting it from the test area of ​​the test sample in an area free from creases or creases. The test area is preferably the intersection of the longitudinal and transverse centers of the primary absorbent core, but the test specimen must contain the largest possible sample of the primary absorbent core. The edges of the test specimen must be parallel to the longitudinal and transverse axes of the test sample. When cutting the test specimen from the test sample, care should be taken not to impart any contamination or deformation to the test specimen during the process. An ideal test specimen has a width of 3.81 cm (parallel to the transverse axis of the test sample) and a length of 3.81 cm (parallel to the longitudinal axis of the test sample). Smaller specimens may be used to accommodate narrow test areas, but they must have a length of 3.81 cm and a rectangular shape (e.g., without curved edges). If the specimen is smaller than the ideal size, its area should be calculated and recorded in units of 0.1 square centimeters. Test results for specimens smaller than the ideal size should be normalized based on the tested area.

[0083] Set up the Taber Stiffness Tester according to the manufacturer's instructions to obtain measurements in the range of 0 to 10. In this setup, the rollers are mounted on the unit in the upper position, and a 10-unit compensator is mounted on the pendulum. Insert the test specimen into the clamp jaws with the length of the specimen vertically aligned. Ensure that the bottom edge of the test specimen rests on the bottom gauge located below the rollers. Use the clamp screws to tighten the test specimen between the clamp jaws, ensuring that the test specimen is centered horizontally and vertically within the fixture. Use the roller adjustment knob to center the test specimen between the rollers and ensure that the pendulum is not deflected during the process. Measure a test specimen with a 15-degree deflection to the left, then a test specimen with a 15-degree deflection to the right, and record the results in 1 Taber Stiffness unit. Calculate the average of the left and right results, then multiply that average by 0.1 (the scaling multiplier for the 10-unit compensator), and record the result in 0.01 Taber Stiffness unit. The results (in Taber Stiffness units) are normalized for specimens smaller than 3.81 cm × 3.81 cm by dividing them by the specimen area (in square centimeters), and then multiplied by 14.5 square centimeters (the area of ​​an ideal sample size). Note that 1 Taber Stiffness unit is equivalent to 1 gram-centimeter. The result is expressed as the stiffness of the core area as 0.01 g. * Report in centimeters.

[0084] The same procedure is repeated for a total of five replicated specimens obtained from five substantially identical test samples. The arithmetic mean of the core area stiffness is calculated to be 0.01g. * Report in centimeters.

[0085] [Table 2]

[0086] Flexibility during use The bending properties of absorbent articles in their adapted form are measured using a constant-speed tensile testing machine with a load cell where the measured force is within 1% to 99% of the cell's limit (a preferred instrument is the MTS Alliance with Testworks 4.0 Software, available from MTS Systems Corp. (Eden Prairie, MN)). All tests are conducted in a room conditioned at 23°C ± 3°C and 50% ± 2% relative humidity, and test specimens are conditioned in this environment for at least two hours prior to testing.

[0087] The bending fixture used in this test is shown in Figure 11. The bottom stationary fixture 3000 consists of a horizontal support platform 3001 having a square edge and mounted on a rail 3002, which allows the horizontal support platform to move horizontally from left to right and lock in place. The bottom fixture 3000 is configured to provide adequate vertical clearance between the top surface of the platform 3001 and the horizontal rail 3002 to prevent contact between the test specimen and any surface below during the test. The support platform 3001 is approximately 10 mm thick and made of polished stainless steel. It has a width wider than the width of the test specimen and a length sufficient to support the test specimen. The edge of the support platform 3001 that is closest to and directly adjacent to the blade 2001 is known as the front edge 3003. The top movable fixture 2000 consists of a blade 2001 with a thickness of 3.0 mm and a height of at least 40 mm, and has a curved bottom edge 2002 (radius of curvature of 1.50 mm). The width of the blade 2001 must be greater than the width of the test specimen. The blade 2001 is made of a lightweight material that allows for maximization of the load cell capacity. Both the bottom fixture 3000 and the top fixture 2000 include integrated adapters 3004, 2004 suitable for fitting into and fixing in place at their respective positions on the tensile testing machine, so that the blade 2001 is perpendicular to the movement of the crossbeam of the tensile testing machine.

[0088] Before testing, the test sample is applied to a standard piece of cotton fabric cut into a triangular shape. The fabric weighs approximately 100 g / m². 2 This is a 100% bleached cotton fabric (Style #429W) available from Testfabrics, Inc. (415 Delaware Avenue, West Pittston, PA 18643). Additional suppliers of this fabric can be found on the Testfabrics website, www.testfabrics.com. Cut a piece of cotton fabric into a triangle with a base of 60.0 mm and a height of 200.0 mm. Mark a line parallel to the base 50.0 mm below the vertex of the triangle to indicate the sample edge line. A separate cotton triangle is needed for each replica.

[0089] To prepare the test specimen, first remove it from any existing packaging. If folded, gently unfold it, smooth out any creases, and determine which end of the test specimen is intended to be the rear side of the product (e.g., it may encompass a narrow core area). If the absorbent core of the test specimen is symmetrical along its transverse center, simply assign one end to the rear side. Place the test specimen on a horizontally flat surface with the top sheet side down. Remove any release paper, if present, to expose the adhesive on the garment-facing side of the test specimen. Attach the prepared cotton triangle to the adhesive side of the test specimen as follows: Ensure that the longitudinal axis of the test specimen and the cotton triangle are aligned. Then, gently place the cotton triangle on the test specimen with the sample edge line on the cotton triangle aligned with the rear edge of the test specimen. Now, fold the test specimen to fit the edge of the triangle, folding the core-free area (shown as 18 in Figure 1) over the cotton triangle at the rear side of the test specimen and securing it with the adhesive. If there is no obvious core-free area on the rear side of the test specimen, then, when folding, fit the test specimen to the edge of the triangle and simply fold the side edge along the rear portion of the test specimen over the cotton triangle. If the test specimen has not been coated with adhesive on the garment-facing side, apply a thin coating of adhesive to the garment-facing side of the test specimen using aerosol adhesive (such as Elmer's Multipurpose Spray Adhesive, or equivalent, available from any convenient source). Then, proceed to attach the cotton triangle to the test specimen as described above. Once the test specimen is attached around the cotton triangle and folded, trim any cotton fabric extending beyond the rear edge of the test specimen along the rear edge of the test specimen. On the garment-facing side of the prepared test specimen, draw a line parallel to the transverse axis of the test specimen and 30.0 mm from the rear edge (narrow end) to indicate the test position. Place the prepared test specimen horizontally and flat on a hard surface, then apply a 5-pound weight (base dimensions approximately 38 mm x 149 mm) to the specimen for at least 5 minutes to ensure adhesion between the specimen and the cotton triangle. When handling the prepared test specimen, take care not to bend or twist it before testing.

[0090] Prepare the tensile testing machine as follows: Position the platform 3001 on its rail 3002 so that the platform 3001 is positioned below the blade 2001. Move the blade 2001 downward until it contacts the platform 3001. Make any necessary adjustments to ensure that the bottom surface of the blade is parallel to the surface of the platform 3001. Now, move the platform 3001 to the left of the blade 2001. Next, lower the blade 2001 and adjust the position of the platform 3001 on its rail so that its leading edge 3003 contacts the blade 2001. Make any necessary adjustments to ensure that the blade 2001 and the leading edge 3003 are parallel and aligned front to back without skew. Now, adjust the position of the platform 3001 so that the distance between the leading edge 3003 and the center of the curved bottom edge 2002 of the blade 2001 is 30.0 ± 0.5 mm, and lock it in place. Raise blade 2001 by approximately 15 mm to avoid interfering with the mounting of the test specimen. Program the tensile testing machine for compression testing so that the crosshead is lowered at an initial speed of 5 cm / min until blade 2001 contacts the specimen with a force of 10 mN. Zero the crosshead. Lower blade 2001 at a speed of 50.0 cm / min with a displacement of 20.0 mm, and collect force (mN) and displacement (mm) data at 400 Hz throughout the test. Then return the crosshead to its original position.

[0091] Place the test specimen on the top surface of the support platform 3001 with the top sheet side facing downwards. Extend the trailing edge of the test specimen over the leading edge 3003 of the support platform 3001 so that the test position is parallel to the leading edge 3003 and laterally centered beneath the blade 2001. During the test, place a weight on the portion of the test specimen remaining on the surface of the support platform 3001 and hold it in place. The weight is heavy enough to secure the test specimen and is positioned so that its leading edge aligns perfectly with the leading edge 3003 of the support platform 3001. Zero the load cell and start the test. Create a force (mN) versus displacement (mm) graph. Read the maximum peak force (mN) from the graph and record it as pad flexibility in units of 0.1 mN.

[0092] Similarly, the entire test is repeated for a total of five substantially similar test specimens. The arithmetic mean of the peak forces is calculated and reported in units of 0.1 mN as the total product flexibility.

[0093] [Table 3]

[0094] Tables 2a and 2b show that the panty liner described herein is less rigid in the core area and more flexible overall than comparable products, while still retaining the same / equivalent or greater volume (as shown in Table 4 below). The lower rigidity level allows the panty liner to adapt and conform to the user's posture, even in the front area of ​​the panty liner where the majority of the core is located. Furthermore, the panty liner described herein is also less rigid in the core-free area compared to comparable adaptable products (comparative sample 1). This is the area of ​​the panty liner intended to be adaptable for use with different panties. The reduced rigidity in this area allows the panty liner described herein to be folded in various different configurations (as shown in Figures 7A to 7D) depending on the needs of the specific panties it is worn with. In comparison, comparative sample 1 is considerably more rigid in this core-free area, and therefore a so-called fold line (described in European Patent No. 1757257B1) is provided to facilitate folding of the core-free area along a specific fold line. Therefore, the panty liners described herein are more suitable than those currently available on the market.

[0095] Chassis stretchability The tensile properties of the core-free area of ​​absorbent materials are measured using a constant-speed stretch tensile testing machine with a load cell that ensures the measured force is within 1% to 99% of the cell's limit (a preferred instrument is the MTS Alliance with Testworks 4.0 Software, available from MTS Systems Corp. (Eden Prairie, MN)). All tests are conducted in a room controlled at 23°C ± 3°C and 50% ± 2% relative humidity, and test specimens are conditioned in this environment for at least two hours prior to testing.

[0096] To hold the test specimen, the same pair of grips are used, one attached to the bottom fixture and the other to the top fixture of the tensile testing machine. The grips must be manually operated and lightweight to maximize the load cell capacity, and must be wider than the test specimen. The bar grips are constructed to allow a single-line gripping force along a line perpendicular to the tensile axis of the tensile testing machine. The top and bottom grips are mounted in a manner that aligns them horizontally and vertically.

[0097] To prepare the test specimen, first obtain the test sample and remove it from any existing packaging. If folded, gently unfold and smooth out all creases. If present, remove the release paper to expose the adhesive on the clothing-facing side of the test specimen. Lightly apply talc powder to the adhesive on the backsheet to reduce tackiness. Obtain a test specimen at least 31.0 mm long, such that a gauge length of 25.0 mm (parallel to the longitudinal axis of the absorbent article) is possible with a width of 10.0 mm (parallel to the transverse axis of the absorbent article). Cut the test specimen from the core-free area of ​​the test sample in an area that does not contain folds or creases. The core-free area (shown as 18 in Figure 1) is the area near the rear of the test specimen that does not contain the primary absorbent core. When cutting the test specimen from the test sample, take care not to contaminate or deform the test specimen during the process.

[0098] The tensile testing machine is programmed for constant-speed uniaxial stretching, and the test specimen is fractured as follows: Using a calibrated gauge block, the gauge length is set to 25.0 mm (L initial Set the machine to 0.00 mm / s and zero the crosshead. Insert the specimen into the grip so that its long side is parallel to the tensile axis of the tensile testing machine. Raise the crosshead at a speed of 1.00 mm / s until the specimen breaks, and collect force (N) and elongation (mm) data at 100 Hz throughout the test. Return the crosshead to its original position. Create a graph of force (N) versus elongation (mm). Read the maximum peak force (N) from the graph and record it as the peak force in units of 0.1 N. Read the elongation (mm) at the maximum peak force from the graph and record it as L peakRecord in units of 0.1 mm. Peak elongation is [(L peak / L initial ) * Calculate using

[100] and record in units of 0.1%.

[0099] The test is repeated using a similar method on a total of five replicated specimens obtained from five substantially identical test samples. The arithmetic mean of the peak force is calculated and reported in units of 0.1 N. The arithmetic mean of the peak extension is calculated and reported in units of 0.1%.

[0100] [Table 4]

[0101] From Table 3, it can be seen that the longitudinal stretch of the panty liner described herein before rupture is approximately twice that of a comparable adaptable panty liner. Therefore, during use, the panty liner described herein conforms much better to the user's normal movements. Furthermore, the force required to stretch the panty liner longitudinally is smaller, and therefore the panty liner responds to small movements as well.

[0102] Absorption capacity - Dunk test method The dunk test determines the theoretical absorption capacity of an absorbent material. The test specimen is immersed in a test fluid for a predetermined length of time, and then a static weight is applied on an inclined platform. The amount of test fluid held by the test specimen represents its absorption capacity. All tests are conducted in a room controlled at 23°C ± 3°C and 50% ± 2% relative humidity, and the test specimens are conditioned in this environment for at least two hours prior to the test.

[0103] The apparatus required to carry out this test includes a liquid reservoir for immersing the test specimen, and an inclined platform and weight assembly for draining excess test fluid. The liquid reservoir is a shallow dish large enough to allow the entire test specimen to lie horizontally flat inside, and deep enough to keep the specimen completely submerged in the test fluid. The inclined platform is made of plexiglass (or equivalent) and is angled 15 degrees to the horizontal. The inclined platform is large enough to support the entire test specimen and weight assembly. Depending on the length of the test specimen, one of two different weight assemblies is used. For test specimens with a longitudinal length of 15.5 cm or less, the weight assembly has a base dimension of 15.5 cm × 5 cm and a mass of 1320 g ± 15 g. For test specimens with a longitudinal length greater than 15.5 cm, the weight assembly has a base dimension of 20.5 cm × 6.5 cm and a mass of 2265 g ± 15 g. The weight assembly, with a foam pad, is constructed as follows: A piece of polyethylene film (from any convenient source) is placed flat on the bench surface. A piece of polyurethane foam (25 mm thick; base dimensions determined by the length of the test specimen as described above, available from Concord-Renn Co. (Cincinnati, OH), density 1.0 lb / ft) is placed. 3 Place the IDL (24 psi) at the center of the top of the film. Stack the plexiglass piece (6.4 mm thick; base dimensions determined by the length of the test specimen as described above) on top of the polyurethane foam. Next, wrap the polyurethane foam and plexiglass plate with polyethylene film and secure it with clear tape. Stack the metal weights with handles on top of the plexiglass plate and tighten them. To prevent the weight assembly from sliding off the inclined platform during testing, use support arms fixed to a ring stand with a non-slip base to keep the weight assembly in place.

[0104] All reagent-grade components required for preparing the test fluid are available from VWR International (or an equivalent source) and include urea (NH2CONH2, CAS No. 57-13-6), sodium chloride (NaCl, CAS No. 7647-14-5), magnesium sulfate hydrate (MgSO47H2O, CAS No. 10034-99-8), anhydrous calcium chloride (CaCl2, CAS No. 10043-52-4), and deionized water. To prepare the test fluid, add 2.0% w / w urea, 0.90% w / w sodium chloride, 0.11% w / w magnesium sulfate sodium sulfate, and 0.06% w / w anhydrous calcium chloride to 96.93% w / w deionized water in a sufficiently large beaker and mix thoroughly.

[0105] To prepare the test specimen, first remove it from any existing packaging. If folded, gently unfold it to remove all creases. If present, leave the release paper in place. Obtain the mass of the test specimen (including the release paper, if applicable) and record it as dry mass in units of 0.01 g.

[0106] Fill the liquid reservoir with a sufficient amount of test fluid and keep the test specimen immersed at least 5 mm below the surface of the test fluid for the entire immersion time. Immerse the test specimen in the test fluid with the top sheet side facing the test fluid and allow it to immerse for 25.0 minutes. After 25.0 minutes, grasp the test specimen by one longitudinal edge and remove it from the test fluid, and drain the test specimen in an upright position for 2.0 seconds. Carefully move the test specimen to the inclined platform with the top sheet side facing the platform surface, taking care not to bend or twist the test specimen. While holding the test specimen in place at one longitudinal end, gently place the weight assembly on the test specimen, ensuring that it is centered on the absorbent core of the test specimen and that both longitudinal axes are aligned. Use the support arm to ensure that the weight does not slide off the inclined surface. Apply the weight assembly to the test specimen for 2.0 minutes. After 2.0 minutes, gently remove the weight assembly. The test specimen is held by one longitudinal edge, and the specimen is drained in an upright position for 2.0 seconds to prevent bending or twisting during the process. The mass of the wet test specimen is obtained and recorded as the wet mass in units of 0.01 g. The amount of liquid held by the test specimen is calculated by subtracting the dry mass from the wet mass and recorded as the absorption capacity in units of 0.01 g.

[0107] Similarly, the test is repeated for a total of five substantially identical test samples. The arithmetic mean of the absorption capacity is calculated and reported to the nearest 0.01 g.

[0108] [Table 5]

[0109] Table 4 shows that the panty liner described herein has the same absorption capacity as comparative sample 1, despite having significantly reduced thickness and rigidity.

[0110] The dimensions and values ​​disclosed herein should not be understood as being strictly limited to the exact numerical values ​​listed. Instead, unless otherwise indicated, each such dimension is intended to mean both the listed value and the functionally equivalent range encompassing that value. For example, a dimension disclosed as "40 mm" is intended to mean "approximately 40 mm."

[0111] All documents referenced in this Application, including any cross-referenced or related patents or patent applications, and any patent applications or patents on which this Application claims priority or benefit thereof, are incorporated herein by reference in their entirety unless explicitly stated to exclude or limit them. No document reference shall be deemed prior art to any invention disclosed or claimed herein, nor shall it be deemed to teach, suggest or disclose any such invention, either alone or in combination with any other reference(s). Furthermore, if any meaning or definition of a term in this Document conflicts with any meaning or definition of the same term in any document incorporated by reference, the meaning or definition given to the term in this Document shall prevail.

[0112] While specific embodiments of the present invention have been illustrated and described, it will be apparent 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, it is intended that all such changes and modifications within the scope of the invention be covered in the appended claims.

Claims

1. An absorbent article having a longitudinal axis and a transverse axis, Top sheet and A back sheet, wherein the top sheet and the back sheet together form the chassis of the absorbent article, and the chassis is symmetrical with respect to the lateral axis, the back sheet and An absorbent core disposed between the top sheet and the back sheet, wherein the outer periphery of the chassis is located outside the surface area of ​​the absorbent core, and the absorbent core is asymmetrical with respect to the lateral axis, Less than 50% (excluding 0%) of the surface area of ​​the absorbent article is mechanically compressed, and the absorbent article has a flexibility in use of 85 mN to 170 mN as measured by a flexibility test in use. The core-free area is an absorbent article having a peak elongation force of 10.39 N to 25 N when measured in the longitudinal direction.

2. The absorbent article measured at 0.5 g in the core area. ＊ cm to 4.0 g ＊ The absorbent article according to claim 1, having a rigidity of cm.

3. The absorbent article measured in the core-free area was 0.01 g. ＊ cm to 0.4 g ＊ An absorbent article according to claim 1 or 2, having a rigidity of cm.

4. The absorbent article according to any one of claims 1 to 3, wherein the absorbent article has a thickness of 0.5 mm to 2 mm as measured in the core area.

5. The absorbent article according to any one of claims 1 to 4, wherein the absorbent article has a thickness of 0.1 mm to 0.7 mm as measured in the core-free area.

6. The absorbent article according to any one of claims 1 to 5, wherein the outer periphery of the absorbent article is substantially free of crimping.

7. An absorbent article according to any one of claims 1 to 6, wherein less than 10% (excluding 0%) of the core-free area is mechanically compressed.

8. The absorbent article according to any one of claims 1 to 7, wherein 10% to 50% of the surface area of ​​the absorbent core is embossed.

9. The absorbent article according to claim 8, wherein the embossed pattern includes a series of intersecting lines.

10. The absorbent article according to any one of claims 1 to 9, wherein more than 50% of the absorbent core is disposed in the front region of the absorbent article.

11. The absorbent article is the absorbent article according to any one of claims 1 to 10, having an absorption capacity of 3 g to 20 g.

12. The absorbent article according to any one of claims 1 to 11, wherein the top sheet is fixed to the back sheet around the outer periphery of the absorbent core using only adhesive.

13. The absorbent article according to any one of claims 1 to 6, wherein the top sheet is a laminated top sheet, and the primary top sheet and the secondary top sheet are fixed together using only an adhesive.

14. The absorbent article according to claim 13, wherein the laminated top sheet is mechanically compressed only in the core region of the absorbent article.

15. The absorbent article according to claim 13 or 14, wherein the laminated top sheet comprises a primary top sheet of spunbond nonwoven fabric and a secondary top sheet of air-carded nonwoven fabric.

16. An absorbent article having a longitudinal axis and a transverse axis, Top sheet and A back sheet, wherein the top sheet and the back sheet together form the chassis of the absorbent article, and the chassis is symmetrical with respect to the lateral axis, the back sheet and An absorbent core disposed between the top sheet and the back sheet, wherein the outer periphery of the chassis is located outside the surface area of ​​the absorbent core, and the absorbent core is asymmetrical with respect to the lateral axis, It has flexibility when used with a load of 85 mN to 170 mN. The core-free area is an absorbent article having a peak elongation force of 10.39 N to 25 N when measured in the longitudinal direction.

17. An absorbent article having a longitudinal axis and a transverse axis, Nonwoven fabric top sheet, A back sheet, wherein the top sheet and the back sheet together form the chassis of the absorbent article, and the chassis is symmetrical with respect to the lateral axis, the back sheet and An absorbent core disposed between the top sheet and the back sheet, wherein the outer periphery of the chassis is located outside the surface area of ​​the absorbent core, and the absorbent core is asymmetrical with respect to the lateral axis, 0.01 g measured in the core-free area ＊ cm to 0.4 g ＊ It has a rigidity of cm, The core-free area is an absorbent article having a peak elongation force of 10.39 N to 25 N when measured in the longitudinal direction.

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