Reusable undergarment with absorbent crotch assembly

Abstract

A reusable undergarment includes an undergarment fabric comprising a continuous waistband and front and back portions extending therefrom a crotch assembly. The crotch assembly includes a fabric topsheet, a barrier sheet, and at least one absorbent layer therebetween. The fabric topsheet has an outer, body-facing surface and an inner surface directed toward a barrier sheet. The outer, body-facing surface may a fibrous material and the inner surface comprises a hydrophobic fibrous material. The barrier sheet is impervious to liquids to prevent leakage therethrough. The at least one absorbent layer has a front edge, a back edge, and two side edges and a perimeter, the at least one absorbent layer being disposed between the fabric topsheet and the barrier sheet. At least a first hydrophobic treatment may be disposed about the perimeter of the at least one absorbent layer at least along the two side edges to inhibit fluid flow to the side edges of the at least one absorbent layer. The crotch assembly has an absorbent capacity of at least about 20 grams, a rate of absorption of at least about 0.1 mL / second, and a rewet % of less than about 20%.

Description

[0001] REUSABLE UNDERGARMENT WITH ABSORBENT CROTCH ASSEMBLY

[0002] BACKGROUND OF THE INVENTION

[0003] Sanitary protections such as napkins and liners are well known articles used by consumers to protect their undergarments from unintentional menstrual discharges or urinal leakage. Traditionally these articles are disposable and discarded after use.

[0004] In the most recent years consumers have become more aware of the environmental impact of single use articles and they are looking for more sustainable options.

[0005] Reusable sanitary protection such as period panties are available on the market. Some period panties contain a detachable absorbent element or insert, which does not fully address the sustainability issue; other period panties with a permanently fixed absorbent core are fully washable and thus offer a more durable option.

[0006] In addition to this sustainability concern, consumers do not want to compromise on the efficacy of their sanitary protection since a stain from menstrual or urinal fluid can be highly embarrassing. The absorbent element of the reusable period panties should be constructed to prevent leakage, have a sufficient absorbency, minimize the humid sensation on the skin (rewet) to avoid irritation and / or discomfort and be thin enough to remain discreet and comfortable to wear.

[0007] All these requirements are hard to meet simultaneously in one product. For example, thin absorbent element with a high absorbency were obtained in the past with superabsorbent polymers mixed in the fibers. However, this type of polymer is incompatible with a washable product as it would lose all efficacy after one laundry cycle. Another solution to increase absorbency is to increase the amount of absorbent material, thus the thickness of the product, which is detrimental for the comfort and discreetness as the product becomes bulkier. Finally, the reusable sanitary protection must be washable at temperature sufficiently high to ensure proper sanitization, this may be incompatible with polymers or glue that are heat sensitive.

[0008] It would be desirable to propose to the consumer a period panty that could meet all the above expectations in term of performance (absorbency, rewet, leakage - proof) while still be comfortable, discreet, and washable at temperature such as 60°C or higher.

[0009] SUMMARY OF THE INVENTION

[0010] We have found a surprisingly effective reusable undergarment may be formed with an undergarment fabric comprising a continuous waistband and front and back portions extending therefrom a crotch assembly having a front edge attached to the front portion of the undergarment fabric, a back edge attached to the back portion of the undergarment fabric to form a crotch portion of the undergarment, and two side edges that, in conjunction with the undergarment fabric, define two leg openings. The crotch assembly includes a fabric topsheet, a barrier sheet, and at least one absorbent layer therebetween. The fabric topsheet has an outer, body-facing surface and an inner surface directed toward a barrier sheet, wherein the outer, body-facing surface comprises a fibrous material and the inner surface comprises a hydrophobic fibrous material. The barrier sheet is impervious to liquids to prevent leakage therethrough. The at least one absorbent layer has a front edge, a back edge, and two side edges and a perimeter, the at least one absorbent layer being disposed between the fabric topsheet and the barrier sheet. The at least a first hydrophobic treatment disposed about the perimeter of the at least one absorbent layer at least along the two side edges to inhibit fluid flow to the side edges of the at least one absorbent layer. The crotch assembly has an absorbent capacity of at least about 20 grams, a rate of absorption of at least about 0.1 mL / second, and a rewet % of less than about 20%.

[0011] In an alternative embodiment, the reusable undergarment includes an undergarment fabric comprising a continuous waistband and front, back, and side portions extending therefrom toward a crotch portion and two leg openings and a crotch assembly attached to the front and back portions of the undergarment fabric, and in conjunction with the undergarment fabric defining the two leg openings. The crotch assembly having a front edge, a back edge, and two side edges and includes a fabric topsheet a barrier sheet and at least one absorbent layer therebetween. The topsheet has an outer, body-facing surface and an inner surface directed toward a barrier sheet, wherein the outer, body-facing surface comprises a fibrous material and the inner surface comprises a hydrophobic fibrous material. The barrier sheet is impervious to liquids to prevent leakage therethrough. The crotch assembly has an absorbent capacity of at least about 20 grams, a rate of absorption of at least about 0.1 mL / second, and a rewet % of less than about 20%.

[0012] In an embodiment, the reusable undergarment includes an undergarment fabric comprising a continuous waistband and front, back, and side portions extending therefrom toward a crotch portion and two leg openings and a crotch assembly attached to the front and back portions of the undergarment fabric, and in conjunction with the undergarment fabric defining the two leg openings. The crotch assembly has a front edge, a back edge, and two side edges and includes a fabric topsheet, a barrier sheet and at least one absorbent layer therebetween. The fabric topsheet has a front edge, a back edge, and two side edges and a perimeter, the body-facing fabric material an outer, body-facing surface and an inner surface directed toward a barrier sheet. The barrier sheet is impervious to liquids to prevent leakage therethrough. The at least one absorbent layer has a front edge, a back edge, and two side edges and a perimeter. At least a first hydrophobic treatment is disposed about the perimeter of the at least one absorbent layer at least along the two side edges to inhibit fluid flow to the side edges of the at least one absorbent layer, and the crotch assembly has an absorbent capacity of at least about 20 grams, a rate of absorption of at least about 0.1 mL / second, and a rewet % of less than about 20%.

[0013] Another aspect of the invention relates to an absorbent crotch assembly for use in a reusable undergarment. The assembly has a front edge, a back edge, and two side edges and includes a fabric topsheet, a barrier sheet, and at least one absorbent layer therebetween. The fabric topsheet has a front edge, a back edge, and two side edges and a perimeter, the body-facing fabric material an outer, body-facing surface and an inner surface directed toward a barrier sheet. The barrier sheet is impervious to liquids to prevent leakage therethrough. The at least one absorbent layer has a front edge, a back edge, and two side edges and a perimeter. At least a first hydrophobic treatment is disposed about the perimeter of the at least one absorbent layer at least along the two side edges to inhibit fluid flow to the side edges of the at least one absorbent layer, and the crotch assembly has an absorbent capacity of at least about 20 grams, a rate of absorption of at least about 0.1 mL / second, and a rewet % of less than about 20%.

[0014] BRIEF DESCRIPTION OF THE DRAWING

[0015] Figure 1 is a front view of one embodiment of a reusable undergarment according to the present invention.

[0016] Figure 2 a back view of the reusable undergarment of Figure 1.

[0017] Figures 3A-3C are plan views of front, back, and crotch fabric sections that can be combined to form the embodiment of Figure 1.

[0018] Figure 4 is an exploded schematic cross-section along line IV- IV of the crotch section of Figure 3C.

[0019] Figure 5 is an exploded schematic cross-section along line I V-IV of an alternate embodiment of the crotch section of Figure 3C.

[0020] Figure 6 is an exploded schematic cross-section along line IV-IV of a second alternate embodiment of the crotch section of Figure 3C.

[0021] Figure 7 is an enlarged cross-section of a fabric topsheet of a crotch section of an alternative embodiment.

[0022] Figure 8 is an alternate embodiment of fabric topsheet of a crotch section of an alternative embodiment.

[0023] Figure 9 is an enlarged view of the outer, body-facing surface of a fabric topsheet of a crotch section of an alternative embodiment.

[0024] Figure 10 is a table of maximum absorbent capacity before leakage of an embodiment of the present invention and commercially available prior art products. Figure 11 is a table of rewet values of an embodiment of the present invention and commercially available prior art products.

[0025] Figure 12 is a table of wicking time of an embodiment of the present invention and commercially available prior art products.

[0026] Figure 13 is a table of wicking speed of an embodiment of the present invention and commercially available prior art products.

[0027] DETAILED DESCRIPTION OF THE INVENTION

[0028] As used in the specification and the claims, the term "microfiber" and variants thereof relate to multifilament synthetic yarns with individual filaments extremely thin (< 1 dtex), which has its yarn count described in dtex, which means a certain weight (grams) in 10 thousand meters of yarn.

[0029] As shown in Figures 1 and 2, the present invention relates to reusable undergarments 100 having an absorbent crotch assembly 200 arranged and configured to capture and absorb bodily fluids, such as menstrual fluid and urine. The reusable undergarments 100 have a front portion 110, a back portion 120, and an absorbent crotch assembly 200. In the embodiment shown in Figures 3A-3C, a reusable undergarment includes a continuous waistband 102 and the front and back portions 110, 120 formed of an undergarment fabric extending therefrom. An absorbent crotch assembly 200 has a front edge 202 attached to the front portion 110 of the undergarment fabric and a back edge 204 attached to the back portion 120 of the undergarment fabric. Two side edges 206 of the absorbent crotch assembly 200 cooperate with the undergarment fabric to define two leg openings 208.

[0030] The undergarment fabric may be made from a multi-direction stretchable fabric such as spandex, cotton, cotton blend, or other material. Often, but not always, these fabrics are knitted fabrics. In an embodiment of the invention, the undergarment fabric may include a blend of polyamide and elastane fibers having a basis weight of between 150 gsm and 300 gsm, optionally, between 200 gsm and 250 gsm.

[0031] The continuous waistband 102, front portion 110, and back portion 120 may be formed by removing portions of a continuous fabric tube folding a portion of the stretchable fabric at the waist portion to form a plurality of layers of this stretchable fabric.

[0032] Alternately, the continuous waistband 102, front portion 110, and back portion 120 may be formed by removing portions of a continuous fabric tube and forming a pocket of fabric at the waist portion and enclosing an elastic material, such as a web, tape, threads, and or cords therein. Preferred elastic material includes a web or tape.

[0033] Alternately, the continuous waistband 102, front portion 110, and back portion 120 may be formed by connecting individual front 110 and back 120 portions and securing them together via side seams. Again, a pocket of fabric may be formed at the waist portion to enclose an elastic material therein, such as a web, tape, threads, and or cords therein. Preferred elastic material includes a web or tape.

[0034] Further, the continuous fabric tube may extend into the crotch portion of the undergarment - a portion of the undergarment corresponding to the absorbent crotch assembly 200.

[0035] The absorbent crotch assembly 200 includes a fabric topsheet 210, a barrier sheet 220 that is substantially impervious to liquids, especially bodily fluids, and at least one absorbent layer 230 disposed between the topsheet 210 and barrier sheet 220.

[0036] In the embodiment of Figure 4, the absorbent crotch assembly 200 includes a fabric topsheet 210, a barrier sheet 220, and an absorbent layer 230 disposed therebetween. Each of the fabric topsheet 210, a barrier sheet 220 and absorbent layer 230 have a front edge, back edge, and two side edges corresponding to the front edge 202, back edge 204, and side edges 206 of the absorbent crotch assembly 200. This absorbent crotch assembly 200 may also include a layer of undergarment fabric 104. This layer of undergarment fabric 104 may be formed as a part of the absorbent crotch assembly 200, or it may be a continuation of the undergarment fabric from the front and back portions 110,120 described above.

[0037] The absorbent layer 230 of the embodiment of Figure 4 has at least a first hydrophobic treatment disposed about the perimeter of the absorbent layer along the two side edges thereof, e.g., side margins 234 and optionally, the front edge 202 of the absorbent layer 230. The hydrophobic treatment inhibits fluid transport into and / or fluid absorption into the side margins 234 of the absorbent layer material. A representative, non-limiting list of useful hydrophobic treatments includes hydrophobic thermoplastic construction tape, permanent hydrophobic fiber finish, hydrophobic material impregnation, over-compression of the material forming the absorbent layer 230, and the like.

[0038] Hydrophobic thermoplastic construction tapes may be used to attach adjacent layers of the absorbent crotch assembly together and may also impart fluid inhibiting and / or barrier properties to the side margins 234 and optionally, the front edge 202 of the absorbent layer 230. Preferred hydrophobic thermoplastic construction tapes maintain laminate integrity above 40 °C, and more preferably, above 60 °C. A representative, non-limiting list of useful hydrophobic thermoplastic construction tapes includes polyurethane, natural and synthetic rubber, styrene-isoprene-styrene block copolymers, polyolefins (such as polyethylene), and the like . In an embodiment of the invention, the polyurethane tape is a thermoplastic polyurethane tape having a thickness between about 0,025 mm and about 0,150 mm, preferably between about 0,05 mm and about 0,10 mm, with an adhesive softening point of greater than about 125°C, preferably greater than about 140°C and less than 200°C. Permanent hydrophobic fiber finishes render hydrophilic and / or absorbent elements of the absorbent layer hydrophobic to impart fluid inhibiting and / or barrier properties to the side margins 234 and optionally, the front edge 202 of the absorbent layer 230. Preferred hydrophobic fiber finishes are heat resistant and are not dissipated or removed during laundering process above 40 °C, and more preferably, above 60 °C.

[0039] Hydrophobic materials may also be impregnated into the side margins 234 and optionally, the front edge 202 of the absorbent layer 230. Preferred hydrophobic impregnation materials are heat resistant and are not dissipated or removed during laundering process above 40 °C, and more preferably, above 60 °C. A representative, non-limiting list of useful hydrophobic impregnation materials includes waxes, including paraffin, beeswax and plant-based waxes, hydrocarbon-based polymers, siloxane-based polymers, fluorocarbons, and the like.

[0040] In addition, the absorbent crotch assembly 200 further includes elastic piping bands 240 enclosing the side edges of the fabric topsheet 210, barrier sheet 220 and absorbent layer 230, and the elastic piping bands preferably continue beyond the side edges 206 of the absorbent crotch assembly 200 to the undergarment fabric and encircle each leg opening 208. These components are secured together via at least one sewn seam 250 along the side edge of the absorbent crotch assembly 200. Specifically, the at least one seam 250 is sewn through the side margin 234 of the absorbent layer 230.

[0041] In the embodiment of Figure 5, the absorbent crotch assembly 200 includes a fabric topsheet 210, a barrier sheet 220, and two absorbent layers 230a, 230b disposed therebetween. Each of the fabric topsheet 210, a barrier sheet 220 and two absorbent layers 230a, 230b have a front edge, back edge, and two side edges corresponding to the front edge 202, back edge 204, and side edges 206 of the absorbent crotch assembly 200. A first absorbent layer 230a is disposed adjacent to the fabric topsheet 210, and a second absorbent layer 230b is disposed below the first absorbent layer 230a. The second absorbent layer 230b is wider than the first absorbent layer 230a, and side edges of the second absorbent layer 230b extend outwardly beyond the corresponding side edges of the first absorbent layer 230a. Thus, the portion of the second absorbent layer extending outwardly beyond the first absorbent layer 230a defines side margins 234 of the second absorbent layer 230b. This absorbent crotch assembly 200 may also include a layer of undergarment fabric 104. This layer of undergarment fabric 104 may be formed as a part of the absorbent crotch assembly 200, or it may be a continuation of the undergarment fabric from the front and back portions 110,120 described above.

[0042] The first and second absorbent layers 230a, 230b of the embodiment of Figure 5 have at least a first hydrophobic treatment disposed about the perimeter of the first and second absorbent layers 230a, 230b along the two side edges thereof, e.g., side margins 234 and optionally, the front edge 202 of the second absorbent layer 230b. The hydrophobic treatment inhibits fluid transport into and / or fluid absorption into the side margins 234 of the absorbent layer material. A representative, nonlimiting list of useful hydrophobic treatments includes hydrophobic thermoplastic construction tape, permanent hydrophobic fiber finish, hydrophobic material impregnation, over-compression of the material forming the absorbent layer 230, and the like.

[0043] Hydrophobic thermoplastic construction tapes may be used to attach adjacent layers of the absorbent crotch assembly together and may also impart fluid inhibiting and / or barrier properties to the side margins 234 and optionally, the front edge 202 of the second absorbent layer 230b. In the embodiment of Figure 5, the hydrophobic thermoplastic construction material 236 may be disposed to adhere the first and second absorbent layers 230a, 230b together. Preferred hydrophobic thermoplastic construction tapes maintain laminate integrity above 40 °C, and more preferably, above 60 °C. A representative, non-limiting list of useful hydrophobic thermoplastic construction tapes includes polyurethane, natural and synthetic rubber, styrene-isoprene-styrene block copolymers, polyolefins (such as polyethylene), and the like . In an embodiment of the invention, the polyurethane tape is a thermoplastic polyurethane tape having a thickness between about 0,025 mm and about 0,150 mm, preferably between about 0,05 mm and about 0.10 mm, with an adhesive softening point of greater than about 125°C.

[0044] Permanent hydrophobic fiber finishes render hydrophilic and / or absorbent elements of the absorbent layer hydrophobic to impart fluid inhibiting and / or barrier properties to the side margins 234 and optionally, the front edge 202 of the second absorbent layer 230b. Preferred hydrophobic fiber finishes are heat resistant and are not dissipated or removed during laundering process above 40 °C, and more preferably, above 60 °C.

[0045] Hydrophobic materials may also be impregnated into the side margins 234 of the second absorbent layer 230b and optionally, the front edge 202. Preferred hydrophobic impregnation materials are heat resistant and are not dissipated or removed during laundering process above 40 °C, and more preferably, above 60 °C. A representative, non-limiting list of useful hydrophobic impregnation materials includes waxes, including paraffin, beeswax and plant-based waxes, hydrocarbon-based polymers, siloxane-based polymers, fluorocarbons, and the like.

[0046] In addition, the absorbent crotch assembly 200 further includes elastic piping bands 240 enclosing the side edges of the fabric topsheet 210, barrier sheet 220 and absorbent layer 230, and the elastic piping bands preferably continue beyond the side edges 206 of the absorbent crotch assembly 200 to the undergarment fabric and encircle each leg opening 208. These components are secured together via at least one sewn seam 250 along the side edge of the absorbent crotch assembly 200. Specifically, the at least one seam 250 is sewn through the side margin 234 of the absorbent layer 230. In the embodiment of Figure 6, the absorbent crotch assembly 200 includes a fabric topsheet 210, a barrier sheet 220, and two absorbent layers 230a, 230b disposed therebetween. Each of the fabric topsheet 210, a barrier sheet 220 and two absorbent layers 230a, 230b have a front edge, back edge, and two side edges corresponding to the front edge 202, back edge 204, and side edges 206 of the absorbent crotch assembly 200. A first absorbent layer 230a is disposed adjacent to the fabric topsheet 210, and a second absorbent layer 230b is disposed below the first absorbent layer 230a. The second absorbent layer 230b is wider than the first absorbent layer 230a, and side edges of the second absorbent layer 230b extend outwardly beyond the corresponding side edges of the first absorbent layer 230a. Thus, the portion of the second absorbent layer extending outwardly beyond the first absorbent layer 230a defines side margins 234 of the second absorbent layer 230b. This absorbent crotch assembly 200 may also include a layer of undergarment fabric 104. This layer of undergarment fabric 104 may be formed as a part of the absorbent crotch assembly 200, or it may be a continuation of the undergarment fabric from the front and back portions 110,120 described above.

[0047] The first and second absorbent layers 230a, 230b of the embodiment of Figure 6 are joined by at least two sewn seams 252, one disposed towards the left side edge and one toward the right side edge.

[0048] The first and second absorbent layers 230a, 230b of the embodiment of Figure 5 have at least a first hydrophobic treatment disposed about the perimeter of the first and second absorbent layers 230a, 230b along the two side edges thereof, e.g., side margins 234 and optionally, the front edge 202 of the second absorbent layer 230b. The hydrophobic treatment inhibits fluid transport into and / or fluid absorption into the side margins 234 of the absorbent layer material. A representative, nonlimiting list of useful hydrophobic treatments includes hydrophobic thermoplastic construction tape, permanent hydrophobic fiber finish, hydrophobic material impregnation, over-compression of the material forming the absorbent layer 230, and the like.

[0049] Hydrophobic thermoplastic construction tapes may be used to assist in attaching adjacent layers of the absorbent crotch assembly together and may also impart fluid inhibiting and / or barrier properties to the side margins 234 and optionally, the front edge 202 of the second absorbent layer 230b. In the embodiment of Figure 6, the hydrophobic thermoplastic construction material 236 may be disposed to reinforce the attachment of the first and second absorbent layers 230a, 230b. Preferred hydrophobic thermoplastic construction tapes maintain laminate integrity above 40 °C, and more preferably, above 60 °C. A representative, non-limiting list of useful hydrophobic thermoplastic construction tapes includes polyurethane, natural and synthetic rubber, styrene-isoprene-styrene block copolymers, polyolefins (such as polyethylene), and the like . In an embodiment of the invention, the polyurethane tape is a thermoplastic polyurethane tape having a thickness between about 0,025 mm and about 0,150 mm, preferably between about 0,05 mm and about 0.10 mm, with an adhesive softening point of greater than about 125°C.

[0050] Permanent hydrophobic fiber finishes render hydrophilic and / or absorbent elements of the absorbent layer hydrophobic to impart fluid inhibiting and / or barrier properties to the side margins 234 and optionally, the front edge 202 of the second absorbent layer 230b. Preferred hydrophobic fiber finishes are heat resistant and are not dissipated or removed during laundering process above 40 °C, and more preferably, above 60 °C.

[0051] Hydrophobic materials may also be impregnated into the side margins 234 of the second absorbent layer 230b and optionally, the front edge 202. Preferred hydrophobic impregnation materials are heat resistant and are not dissipated or removed during laundering process above 40 °C, and more preferably, above 60 °C. A representative, non-limiting list of useful hydrophobic impregnation materials includes waxes, including paraffin, beeswax and plant-based waxes, hydrocarbon-based polymers, siloxane-based polymers, fluorocarbons, and the like.

[0052] In addition, the absorbent crotch assembly 200 further includes elastic piping bands 240 enclosing the side edges of the fabric topsheet 210, barrier sheet 220 and absorbent layer 230, and the elastic piping bands preferably continue beyond the side edges 206 of the absorbent crotch assembly 200 to the undergarment fabric and encircle each leg opening 208. These components are secured together via at least one sewn seam 250 along the side edge of the absorbent crotch assembly 200. Specifically, the at least one seam 250 is sewn through the side margin 234 of the absorbent layer 230.

[0053] In an alternative embodiment, the barrier sheet 220 is wrapped around at least the side edges of the absorbent layer(s) in the side margin 234 of the absorbent layer(s) 230.

[0054] In an embodiment shown in Figure 7, the fabric topsheet 210 has an outer, body-facing surface 212 and an inner surface 214 directed toward the barrier sheet 220 in the absorbent crotch assembly 200. The outer, body-facing surface 212 comprises a fibrous material 216 and the inner surface 214 comprises a hydrophobic fibrous material 218.

[0055] The fabric topsheet 210 provides a body-facing surface that is preferably comfortable to the wearer and has desirable fluid transport qualities. Thus, the fabric topsheet may be formed of fibers selected from the group consisting of natural and synthetic cellulosic fibers, polyamide fibers, polyester fibers, acrylic fibers, and combinations thereof.

[0056] In certain embodiments, the fabric topsheet 210 is formed of at least two different fibers, at least one of which is hydrophobic. We have found that knitted fabrics provide moderate levels of stretchability that is desired to enable the absorbent crotch assembly 200 to move with the user. A particularly useful knitted fabric is a double face knitted fabric, such as described in Vasconcelos, FB et al. "Moisture Management Evaluation in Double Face Knitted Fabrics with Different Kind of Constructions and Fibers," Journal of Fashion Technology & Textile Engineering (2017). However, unlike the goal of this reference, the present invention places a hydrophilic material, preferably a natural or synthetic cellulosic fibrous material in contact with the wearer's skin and the hydrophobic fibrous material on the opposite surface to distribute to the absorbent layer(s) 230.

[0057] In an embodiment shown in Figure 8, the fabric topsheet 210 comprises a double face knitted fabric. The outer, body-facing surface 212 comprises a fibrous material 216 and the inner surface 214 comprises a hydrophobic fibrous material 218.

[0058] In another embodiment, the fibrous material 206 comprises a fibrous cellulosic material, preferably cotton, and the hydrophobic fibrous material 218 comprises a hydrophobic polymeric fibrous material, preferably polyester.

[0059] In particularly preferred embodiments, the fibrous material 206 comprises a natural fibrous cellulosic material, preferably organic cotton, and the hydrophobic fibrous material 218 comprises a hydrophobic polymeric fibrous material, preferably polyester.

[0060] In an embodiment shown in Figure 9, the double face knitted fabric topsheet 210 comprises an elongated mesh knitted fabric. The elongated mesh includes a repeating pattern of yarns intersecting in an acute angle a, and the bisect of the angle a defines a major axis X of the elongated mesh. The major axis X of the elongated mesh extends between the front edge and the back edge of the absorbent crotch assembly. Orienting the elongated mesh substantially longitudinally (between the front and back edges of the absorbent crotch assembly appears to minimize lateral movement (between the leg openings) of fluids deposited on the fabric topsheet, thereby minimizing side leakage.

[0061] In an embodiment of the invention, the fabric topsheet may have a basis weight of about 100 gsm to about 200 gsm, optionally about 150 gsm to about 200 gsm.

[0062] The absorbent layer(s) 130 of the absorbent crotch assembly 200 may be formed of fabrics arranged and configured to absorb bodily fluids such as menses and / or urine and which are capable of releasing such bodily fluids during household washing conditions. Preferably, absorbent crotch assembly 200 and the reusable undergarment 100 are washable at up to about 40 °C, preferably up to about 60 °C for at least 30 washes without deteriorating, such as through delaminating or other degradation of the article's integrity.

[0063] The absorbent layer(s) 130 include may be formed of fibers selected from the group consisting of natural and synthetic cellulosic fibers, polyamide fibers, polyester fibers, acrylic fibers, and combinations thereof.

[0064] In an embodiment of the present invention, the absorbent layer(s) 130 is fabric including hydrophilic fibers such as natural and synthetic cellulosic fibers and / or polyamide fibers. Additional fibers may also be incorporated into the absorbent layer(s) 130, and these additional fibers may also include hydrophobic fibers, such as polyester. For example, a terry knitted fabric or microfiber fabric formed of polyamide and polyester has produced a desirable absorbent crotch assembly 200, either as a single layer, or more preferably in a multi-layered construction. For enhanced durability, a multilayered construction may be unitized by seams 252. The barrier sheet 220 may be any useful washable, liquid-resistant (preferably liquid impervious) sheet. Useful barrier sheets include, without limitation, polymeric films and laminates of polymeric films and fabric sheets.

[0065] In an embodiment of the present invention, a blended fiber fabric useful in the absorbent layer(s) includes 70-90 wt-%, optionally 80-85 wt-% polyester fibers and 10-30 wt-%, optionally 15-20 wt-% polyamide fibers. The absorbent layer(s) may have a thickness of at least about 3.5 mm, optionally at least about 4 mm, or at least about 5 mm. Preferred layer(s) may have a thickness of between about 4 mm and 5 mm. The absorbent layer(s) may have a basis weight of about 250 gsm to about 500 gsm, optionally between about 300 gsm and about 450 gsm, or between about 350 gsm and about 400 gsm.

[0066] In an embodiment of the present invention, the barrier sheet 220 comprises a laminate of a fabric and a continuous polymeric film. A representative, non-limiting list of useful fabrics includes woven, nonwoven, and knitted fabrics.

[0067] In one example, a breathable laminate of polyester fabric and a polyurethane film having a basis weight of at least about 50 grams / meter2("gsm") may be used, optionally at least about 100 gsm, or 125 gsm or 150 gsm. The barrier sheet preferably has a basis weight of less than 300 gsm, optionally less than 250 gsm or 200 gsm.

[0068] In an embodiment of the invention, the polymeric film is directed toward the absorbent layer(s). This orientation is believed to enable the fluid that contacts the film to be easily absorbed by the absorbent layer(s).

[0069] In an alternative embodiment, the fabric layer is i directed toward the absorbent layer(s). This orientation is believed to enable the fluid that contacts the fabric to be distributed to less saturated portions of the absorbent layer(s).

[0070] The laminate may include a woven or nonwoven polyester fabric and a thermoplastic polyurethane film. Alternatively, the laminate may include a polyester microfiber terry knitted fabric and a thermoplastic polyurethane film.

[0071] Various types of stitching and thread may be used in the various illustrative undergarments disclosed herein, including that of Figures 1 and 2. Persons of ordinary skill in the art will recognize appropriate stitching patterns, such as straight stitch, triple straight stitch, two-needle cover stitch, zigzag stitch, three step zigzag, lightning bolt stitch, honeycomb stitch, overlock / overedge stitch, feather stitch, or combination thereof.

[0072] In an embodiment of the present invention, hydrophobic thread, preferably polyester thread is used to attach the various components together and to finish edges by serging, etc. EXAMPLES est method

[0073] Performance measurement reported in table 1 below were performed by Hohenstein Laboratories GmbH & Co. KG. according to the protocol disclosed in "Femtech Standards publication. Reusable Absorbent undergarment Testing Protocol" FEMTECHMAS-6513-l:2022 A copy of the protocol can be requested from FemTech at MAS at this address: https: / / femtech.twinery.co / #download-form

[0074] Results

[0075] Inventive examples 1, 2 and 3, in table 1, correspond to absorbent articles according to the present invention. Inventive examples 1, 2 and 3 absorbent structures are as follow:

[0076] Example 1

[0077] Undergarment fabric: a polyamide / elastane blend (87% / 13%) knit fabric.

[0078] Absorbent crotch assembly:

[0079] Fabric topsheet: a double face knitted fabric formed of organic cotton (64%) and polyester (36%) in which the outer, body-facing surface is formed of cotton, and the inner surface is formed of polyester. The double face knitted fabric has an elongated mesh wherein the elongated mesh defines a major axis extending between the side edges of the crotch assembly.

[0080] Absorbent layer: two layers of Polyester (85%) + Polyamide (15%), thickness: 4.4 mm per layer, available from Kukuroglu, Pinarkent Mahallesi 208 sokak No:l Pamukkale / Denizli (Turkey).

[0081] Barrier layer: Polyester / polyurethane laminate (polyester micro terry knitted fabric / polyurethane film laminate, available as BREEZE PES LIGHT from AKBEZ Tekstil Sanayi ve Ticaret A.§., Merkez Mah. Eski Edirne Asfalti No:42 / K 34245 Gaziosmanpaja, Istanbul, TURKEY)

[0082] The barrier layer extended into the back portion of the undergarment to the waistband. Example 2

[0083] Undergarment fabric: a polyamide / elastane blend (87% / 13%) knit fabric.

[0084] Absorbent crotch assembly:

[0085] Fabric topsheet: a double face knitted fabric formed of organic cotton (64%) and polyester (36%) in which the outer, body-facing surface is formed of cotton, and the inner surface is formed of polyester. The double face knitted fabric has an elongated mesh wherein the elongated mesh defines a major axis extending between the side edges of the crotch assembly.

[0086] Absorbent layer: two layers of Polyester (85%) + Polyamide (15%), thickness: 5.2 mm per layer, available from Kukuroglu, Pinarkent Mahallesi 208 sokak No:l Pamukkale / Denizli (Turkey).

[0087] Barrier layer: Polyester / polyurethane laminate (polyester micro terry knitted fabric / polyurethane film laminate, available as BREEZE PES LIGHT from AKBEZ Tekstil Sanayi ve Ticaret A.§., Merkez Mah. Eski Edirne Asfalti No:42 / K 34245 Gaziosmanpaja, Istanbul, TURKEY)

[0088] The barrier layer extended into the back portion of the undergarment to the waistband.

[0089] Example 3

[0090] Undergarment fabric: a polyamide / elastane blend (87% / 13%) knit fabric.

[0091] Absorbent crotch assembly:

[0092] Fabric topsheet: a double face knitted fabric formed of organic cotton (64%) and polyester (36%) in which the outer, body-facing surface is formed of cotton, and the inner surface is formed of polyester. The double face knitted fabric has an elongated mesh wherein the elongated mesh defines a major axis extending between the front and back edges of the crotch assembly.

[0093] Absorbent layer: two layers of Polyester (85%) + Polyamide (15%), thickness: 4.4 mm per layer, available from Kukuroglu, Pinarkent Mahallesi 208 sokak No:l Pamukkale / Denizli (Turkey).

[0094] Barrier layer: Polyester / polyurethane laminate (polyester micro terry knitted fabric / polyurethane film laminate, available as BREEZE PES LIGHT from AKBEZ Tekstil Sanayi ve Ticaret A.§., Merkez Mah. Eski Edirne Asfalti No:42 / K 34245 Gaziosmanpaja, Istanbul, TURKEY)

[0095] The barrier layer was limited to the absorbent crotch assembly and did not extend into the back portion of the undergarment.

[0096] Comparative examples 4 to 19 are commercial products available on the market. These products are sold by the following brands (by alphabetical order, no relation with the order the comparative examples are appearing in Table 1):

[0097] ALWAYS, DIM, ESSITY, FACELLE natural, INTIMY, JESSA, MODIBODY heavy-overnight, NOBLOOD.FR, NUR DIE, OOIA, SCHIESSER, SELENACARE 25 ml, SELENACARE 35 ml, SKIN UP FREEDOM (ERGOTEKS), THE FEMALE COMPANY, UNIQLO.

[0098] Table 1 As can be seen from the results in table 1, the articles according to the present invention have a maximum absorbent capacity before leakage superior or equal to 25ml of fluid. The higher the absorbent capacity before leakage is, the more desirable it is for the consumer. This absorbency performance compared to competition products is better illustrated in Figure 10. Only competitor products related to comparative examples 10, 15 and 17 showed similar absorbent capacity before leakage.

[0099] The articles according to the present invention also showed a rewet below 4 g, when considering the mass of fluid released from the article absorbent structure; or blow or equal to 13% when considering the % of fluid released from the article absorbent structure. The lower the rewet is, the more desirable it is for the consumer. This rewet performance compared to competition products is better illustrated in Figure 11, showing the rewet %. No comparative example showed a rewet % similar or lower than the present invention. This is an important benefit of the present invention over the prior arts since it provides an increased comfort to the user by minimizing the unpleasant sensation of skin contact with a wet surface when the absorbent article is used.

[0100] The articles according to the present invention also showed a wicking time for 3 ml of fluid below 28 seconds. The lower the wicking time is, the more desirable it is for the consumer. This wicking time performance, for 3ml of fluid, compared to competition products is better illustrated in Figure 12. Only competitor products related to comparative examples 4, 5, 6, 10, 12 and 16 showed similar wicking time for 3 ml of fluid. This observation was confirmed by the wicking speed expressed in ml / s. The articles according to the present invention also showed a wicking speed superior to 0.1 ml / s. The higher the wicking speed is, the more desirable it is for the consumer. This wicking speed performance compared to competition products is better illustrated in Figure 13. Only competitor products related to comparative examples 4, 5, 6, 10, 12 and 16 showed similar wicking speed, confirming the results presented in Figure 3 about the wicking time for 3 ml of fluid.

[0101] When analyzing the results obtained it is relevant to put in perspective the absorbency, rewet and wicking speed, since all these features are desirable simultaneously in a reusable absorbent article. It is worth noting that only comparative example 10 performs similarly to the present invention in both absorbency (maximum absorbent capacity before leakage) and wicking (wicking time for 3 ml of fluid or wicking speed). However, the rewet (g or %) of comparative example 10 is much higher than the rewet of the articles according to the present invention.

[0102] It is difficult to obtain simultaneously appropriate performances in absorbency, rewet and wicking speed, however such performances were achieved by the articles according to the present invention.

Claims

1. A reusable undergarment with an absorbent crotch assembly comprising:(a) an undergarment fabric comprising a continuous waistband and front and back portions extending therefrom;(b) a crotch assembly having a front edge attached to the front portion of the undergarment fabric, a back edge attached to the back portion of the undergarment fabric to form a crotch portion of the undergarment, and two side edges that, in conjunction with the undergarment fabric, define two leg openings, the crotch assembly comprising: i. a fabric topsheet having an outer, body-facing surface and an inner surface directed toward a barrier sheet, wherein the outer, body-facing surface comprises a fibrous material and the inner surface comprises a hydrophobic fibrous material; ii. the barrier sheet is impervious to liquids to prevent leakage therethrough; ill. at least one absorbent layer having a front edge, a back edge, and two side edges and a perimeter, the at least one absorbent layer being disposed between the fabric topsheet and the barrier sheet; and iv. at least a first hydrophobic treatment disposed about the perimeter of the at least one absorbent layer at least along the two side edges to inhibit fluid flow to the side edges of the at least one absorbent layer; wherein the crotch assembly has an absorbent capacity of at least about 20 grams, a rate of absorption of at least about 0.1 mL / second, and a rewet % of less than about 20%.

2. The reusable undergarment of claim 1 wherein the crotch assembly further comprises a layer of the undergarment fabric adjacent the barrier sheet and the front edge of the crotch assembly is sewn to the front portion of the undergarment fabric, the back edge of the crotch assembly is sewn to the back portion of the undergarment fabric, and elastic trim is wrapped around edges of the leg openings and sewn to the undergarment fabric and to the crotch assembly through the hydrophobic thermoplastic construction tape.

3. The reusable undergarment of any previous claim wherein the fabric topsheet comprises a double face knitted fabric.

4. The reusable undergarment of claim 3 wherein the double face knitted fabric comprises an elongated mesh knitted fabric wherein the elongated mesh defines a major axis extending between the front edge and the back edge of the crotch assembly.

5. The reusable undergarment of claim 4 wherein the body-facing surface of the double face knitted fabric comprises a fibrous cellulosic material and the inner surface comprises a hydrophobic polymeric fibrous material.

6. The reusable undergarment of claim 5 wherein the fibrous cellulosic material comprises cotton and the hydrophobic polymeric fibrous material comprises polyester.

7. The reusable undergarment of any previous claim wherein the crotch assembly further comprises a layer of the undergarment fabric adjacent the barrier sheet.

8. The reusable undergarment of any previous claim wherein the first hydrophobic treatment is selected from the group consisting of hydrophobic thermoplastic construction tape, permanent hydrophobic fiber finish, hydrophobic material impregnation, compression, and combinations thereof.

9. The reusable undergarment of any previous claim wherein the undergarment is washable at up to about 40 °C, preferably up to about 60 °C for at least 30 washes without delaminating.

10. The reusable undergarment of any previous claim wherein the at least one absorbent layer comprises a first absorbent layer adjacent to the fabric topsheet, and a second absorbent layer adjacent to the barrier sheet, and the second absorbent layer extends beyond the side edges of the first absorbent layer.

11. The reusable undergarment of claim 10 wherein the first absorbent layer is sewn to the second absorbent.

12. A reusable undergarment with an absorbent crotch assembly comprising:(a) an undergarment fabric comprising a continuous waistband and front, back, and side portions extending therefrom toward a crotch portion and two leg openings;(b) a crotch assembly attached to the front and back portions of the undergarment fabric, and in conjunction with the undergarment fabric defining the two leg openings, the crotch assembly having a front edge, a back edge, and two side edges and comprising: i. a fabric topsheet having an outer, body-facing surface and an inner surface directed toward a barrier sheet, wherein the outer, body-facing surface comprises a fibrous material and the inner surface comprises a hydrophobic fibrous material; ii. the barrier sheet is impervious to liquids to prevent leakage therethrough; and ill. at least one absorbent layer disposed between the fabric topsheet and the barrier sheet; wherein the crotch assembly has an absorbent capacity of at least about 20 grams, a rate of absorption of at least about 0.1 mL / second, and a rewet % of less than about 20%.

13. The reusable undergarment of claim 12 wherein the fabric topsheet comprises a double face knitted fabric.

14. The reusable undergarment of any of claims 12-13 wherein the double face knitted fabric comprises an elongated mesh knit fabric wherein the elongated mesh defines a major axis extending between the front edge and the back edge of the crotch assembly.

15. The reusable undergarment of any of claims 12-14 wherein the body-facing surface comprises a fibrous cellulosic material and the inner surface comprises a hydrophobic polymeric fibrous material.

16. The reusable undergarment of claim 15 wherein the fibrous cellulosic material comprises cotton and the hydrophobic polymeric fibrous material comprises polyester.

17. The reusable undergarment of any of claims 12-16 wherein the crotch assembly further comprises a layer of the undergarment fabric adjacent the barrier sheet.

18. The reusable undergarment of any of claims 12-17wherein the at least one absorbent layer comprises a first absorbent layer adjacent to the fabric topsheet, and a second absorbent layeradjacent to the barrier sheet, and the second absorbent layer extends beyond the side edges of the first absorbent layer.

19. The reusable undergarment of claim 18 wherein the first absorbent layer is sewn to the second absorbent.

20. A reusable undergarment with an absorbent crotch assembly comprising:(a) an undergarment fabric comprising a continuous waistband and front, back, and side portions extending therefrom toward a crotch portion and two leg openings;(b) a crotch assembly attached to the front and back portions of the undergarment fabric, and in conjunction with the undergarment fabric defining the two leg openings, the crotch assembly having a front edge, a back edge, and two side edges and comprising: i. a fabric topsheet having a front edge, a back edge, and two side edges and a perimeter, the body-facing fabric material an outer, body-facing surface and an inner surface directed toward a barrier sheet; ii. the barrier sheet is impervious to liquids to prevent leakage therethrough; ill. at least one absorbent layer having a front edge, a back edge, and two side edges and a perimeter, the at least one absorbent layer being disposed between the fabric topsheet and the barrier sheet; and iv. at least a first hydrophobic treatment disposed about the perimeter of the at least one absorbent layer at least along the two side edges to inhibit fluid flow to the side edges of the at least one absorbent layer; wherein the crotch assembly has an absorbent capacity of at least about 20 grams, a rate of absorption of at least about 0.1 mL / second, and a rewet % of less than about 20%.

21. The reusable undergarment of claim 20 wherein the reusable undergarment is washable at up to about 40 °C, preferably up to about 60 °C for at least 30 washes without delaminating.

22. The reusable undergarment of any of claims 20-21 wherein the fabric topsheet comprises a double face knitted fabric.

23. The reusable undergarment of claim 22 wherein the double face knitted fabric comprises an elongated mesh knit fabric wherein the elongated mesh defines a major axis extending between the front edge and the back edge of the crotch assembly.

24. The reusable undergarment of any of claims 20-23 wherein the body-facing surface comprises a fibrous cellulosic material and the inner surface comprises a hydrophobic polymeric fibrous material.

25. The reusable undergarment of claim 24 wherein the fibrous cellulosic material comprises cotton and the hydrophobic polymeric fibrous material comprises polyester.

26. The reusable undergarment of any of claims 20-25 wherein the crotch assembly further comprises a layer of the undergarment fabric adjacent the barrier sheet.

27. The reusable undergarment of any of claims 20-26 wherein the first hydrophobic treatment is selected from the group consisting of hydrophobic thermoplastic construction tape, permanent hydrophobic fiber finish, hydrophobic material impregnation, compression, and combinations thereof.

28. The reusable undergarment of any of claims 20-27 wherein the at least one absorbent layer comprises a first absorbent layer adjacent to the fabric topsheet, and a second absorbent layer adjacent to the barrier sheet, and the second absorbent layer extends beyond the side edges of the first absorbent layer.

29. The reusable undergarment of claim 28 wherein the first absorbent layer is sewn to the second absorbent.

30. An absorbent crotch assembly for use in a reusable undergarment, the assembly having a front edge, a back edge, and two side edges and comprising:(a) a fabric topsheet having a front edge, a back edge, and two side edges and a perimeter, the body-facing fabric material an outer, body-facing surface and an inner surface directed toward a barrier sheet;(b) the barrier sheet is impervious to liquids to prevent leakage therethrough;(c) at least one absorbent layer having a front edge, a back edge, and two side edges and a perimeter, the at least one absorbent layer being disposed between the fabric topsheet and the barrier sheet; and(d) at least a first hydrophobic treatment disposed about the perimeter of the at least one absorbent layer at least along the two side edges to inhibit fluid flow to the side edges of the at least one absorbent layer; wherein the crotch assembly has an absorbent capacity of at least about 20 grams, a rate of absorption of at least about 0.1 mL / second, and a rewet % of less than about 20%.

31. The absorbent crotch assembly of claim 30 wherein the absorbent crotch assembly is washable at up to about 40 °C, preferably up to about 60 °C for at least 30 washes without delaminating.

32. The absorbent crotch assembly of any of claims 30-31 wherein the fabric topsheet comprises a double face knitted fabric.

33. The absorbent crotch assembly of claim 32 wherein the double face knitted fabric comprises an elongated mesh knit fabric wherein the elongated mesh defines a major axis extending between the front edge and the back edge of the crotch assembly.

34. The absorbent crotch assembly of any of claims 30-33 wherein the body-facing surface comprises a fibrous cellulosic material and the inner surface comprises a hydrophobic polymeric fibrous material.

35. The absorbent crotch assembly of claim 34 wherein the fibrous cellulosic material comprises cotton and the hydrophobic polymeric fibrous material comprises polyester.

36. The absorbent crotch assembly of any of claims 30-35wherein the crotch assembly further comprises a layer of the undergarment fabric adjacent the barrier sheet.

37. The absorbent crotch assembly of any of claims 30-36wherein the first hydrophobic treatment is selected from the group consisting of hydrophobic thermoplastic construction tape, permanent hydrophobic fiber finish, hydrophobic material impregnation, compression, and combinations thereof.

38. The absorbent crotch assembly of any of claims 30-37 wherein the at least one absorbent layer comprises a first absorbent layer adjacent to the fabric topsheet, and a second absorbent layer adjacent to the barrier sheet, and the second absorbent layer extends beyond the side edges of the first absorbent layer.

39. The absorbent crotch assembly of claim 38 wherein the first absorbent layer is sewn to the second absorbent.

Images