WASHABLE SANITARY PRODUCT

Abstract

The present inventive concept relates to a washable sanitary product. The sanitary product comprises a liquid impermeable back sheet, a liquid retaining pad, having an outer surface area adapted to reside nearest the skin of the user and an inner surface resting against the back sheet, wherein a peripheral portion of said back sheet extends radially outside a perimeter of said liquid retaining pad. The sanitary product further comprises a liquid impermeable annular liner being sealingly attached to the outer surface of the liquid retaining pad along the peripheral portion of the liquid retaining pad by a first seal and to the peripheral portion of the back sheet by a second seal, such that the peripheral portion of the liquid retaining pad is sandwiched between the back sheet and the liner. The annular liner and the back sheet together form a liquid impermeable container for said liquid retaining pad. The liquid retaining pad comprises least one element of spacer fabric that serves as both liquid distribution layer and as liquid retaining layer.

Claims

1. A washable sanitary product comprising: a liquid impermeable back sheet, a liquid retaining pad, having an outer surface area adapted to reside nearest the skin of the user and an inner surface resting against the back sheet; wherein a peripheral portion of said back sheet extends radially outside a peripheral portion of said liquid retaining pad; and characterized by a liquid impermeable annular liner being sealingly attached to the outer surface of the liquid retaining pad along said peripheral portion of the liquid retaining pad by a first seal and to said peripheral portion of said back sheet by a second seal, such that said peripheral portion of the liquid retaining pad is sandwiched between the back sheet and the liner, wherein said annular liner and said back sheet together form a liquid impermeable container for said liquid retaining pad, wherein said liquid retaining pad comprises at least one element of spacer fabric that serves as both liquid distribution layer and as liquid retaining layer.

2. The washable sanitary product according to claim 1, wherein said spacer fabric is a three-dimensional fabric made of an upper layer, a lower layer, and an interconnecting layer of pile filaments that serve as spacer yarns.

3. The washable sanitary product according to claim 2, wherein said upper layer has a lower flow resistance than said lower layer.

4. The washable sanitary product according to claim 2, wherein said spacer fabric is a three-dimensional warp knit fabric.

5. The washable sanitary product according to claim 1, wherein said spacer fabric element is located on said back sheet without any intermediate liquid absorbing materials.

6. The washable sanitary product according to claim 1, wherein said liquid retaining pad comprises an outer spacer fabric element, intended to be facing the skin of a user and at least one intermediate spacer fabric element sandwiched between said outer spacer fabric element and said back sheet.

7. The washable sanitary product according to claim 1, wherein said at least one intermediate spacer fabric element has a smaller surface area than the surface area of said outer spacer fabric element and is located such that said outer spacer fabric element covers said at least one intermediate spacer fabric element.

8. The washable sanitary product according to claim 1, proceeding claims, wherein a spacer fabric element residing closest to the back sheet is attached to the back sheet.

9. The washable sanitary product according to claim 1, said sanitary product further comprises an undergarment, wherein said back sheet, said liquid retaining pad and said annular liner is integrated in said undergarment.

10. A method of manufacture of a washable sanitary product, the method comprising: providing a spacer fabric element, sealingly attaching a liquid impermeable annular liner to a peripheral portion of the spacer fabric element such that a radially extending portion of said annular liner extends radially outside the perimeter; sealingly attaching aid radially extending portion to a liquid impermeable back sheet, such that the perimeter of the spacer fabric element is sandwiched between the back sheet and the liner, wherein said annular liner and said back sheet together form a liquid impermeable container for said spacer fabric element.

11. The method according to claim 10, wherein said annular liner is attached to said spacer fabric element and to said back sheet by means of heat lamination.

12. The method according to claim 10, wherein said spacer fabric element is an outer spacer fabric element and wherein said method further comprising: providing an inner spacer fabric element, attaching said inner spacer fabric element to said back sheet before said step of sealingly attaching said radially extending portion of said annular liner to said back sheet.

13. The method according to claim 12, further comprising: providing at least one intermediate spacer fabric element on said inner spacer fabric element before said step of sealingly attaching said radially extending portion of said annular liner to said back sheet, such that said at least one intermediate spacer fabric element is sandwiched between said outer spacer fabric element and said inner spacer fabric element.

14. The method according to claim 12, wherein said inner spacer fabric element is thicker than said outer spacer fabric element and/or said at least one intermediate spacer fabric element.

15. The method according to claim 10, wherein said annular liner is provided as at least two sections and wherein said step of sealingly attaching the annular liner to the extending portion of said spacer fabric element comprises: attaching a first annular liner section; and attaching a second annular liner section such that said first and second annular liner sections together form an annular liner.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The inventive concept, some non-limiting embodiments, and further advantages of the inventive concept will now be described with reference to the drawings in which:

[0040] FIG. 1a illustrates, in an exploded view, a washable sanitary product according to a first embodiment of the invention, having a single spacer fabric element.

[0041] FIG. 1b is a cross section of the sanitary product of FIG. 1a.

[0042] FIG. 2a illustrates, in an exploded view, a washable sanitary product according to a second embodiment of the invention, having two spacer fabric elements.

[0043] FIG. 2b is a cross section of the sanitary product of FIG. 2a.

[0044] FIG. 3a illustrates, in an exploded view, a washable sanitary product according to a third embodiment of the invention, having three spacer fabric elements.

[0045] FIG. 3b is a cross section of the sanitary product of FIG. 3a.

[0046] FIG. 4 illustrates a flow chart of a process for the manufacturing of the sanitary product in FIG. 3a-b.

[0047] FIG. 5 illustrates, in an exploded view, a washable sanitary product that is integrated in an undergarment.

DETAILED DESCRIPTION OF THE DRAWINGS

[0048] In the following description, the present inventive concept is described with reference to a washable sanitary product 100.

[0049] FIG. 1a-b illustrate a sanitary product 100 that is made of an annular liner 10, a liquid retaining pad 70, and a back sheet 30 (counting from the upper part of the sanitary product 100). The sanitary product 100 of FIG. 1a additionally has an underlying layer 40 that is meant to adhere to an undergarment.

[0050] The liquid retaining pad 70 is located on top of the back sheet 30. The back sheet 30 is liquid impermeable and covers the entire lower layer of the spacer fabric in the retaining pad 70 such that it makes the underside of the sanitary product 100 liquid impermeable. Preferably, the back sheet 30 is flexible such that it promotes comfort to the user. It can for example be made of an adhesive film comprising thermoplastic materials such as polyolefines, polyesters, polyamides or combinations thereof. The back sheet 30 is, as illustrated in FIG. 1a, typically attached to an underlying layer 40 that is meant to adhere to an undergarment. However, it can also be attached directly to an undergarment without any underlaying layer (see FIG. 5).

[0051] As illustrated in FIG. 1b, the back sheet 30 extends radially outside a peripheral portion 72 of the liquid retaining pad 70. This extending portion 32 of the back sheet 30 is sealed to the annular liner 10. Similar to the back sheet 30, the annular liner 10 is preferably made of an adhesive material as described above, such that it adapts to the user. The annular liner 10 is preferably made of the same material as that of the back sheet 30.

[0052] As illustrated in FIG. 1b, the annular liner 10 is attached to an upper side of a peripheral portion 72 of the liquid retaining pad 70 along a first seal 15a. Further, the annular liner 10 is attached to a peripheral portion 32 of the back sheet 30 along a second a seal 15b. In the illustrated example, the first seal 15a is 3-5 mm wide, while the second seal 15b is 2-4 mm wide.

[0053] Hereby, the peripheral portion 72 of the liquid retaining pad 70 is sandwiched between the back sheet 30 and the annular liner 10 such that the back sheet 30 and the annular liner 10 together form a sealed flexible container 13 for the liquid retaining pad 70. It is important that the seals 15a, 15b extend along the entire peripheral portion 72 of the liquid retaining pad 70 in order to prevent any liquid held inside the pad 70 from leaking out at the edges.

[0054] The seals 15a, 15b also protect the liquid retaining pad 70 from tearing during laundering. The sealed flexible container 13 thus has two functions; it prevents the liquid kept inside the liquid retaining pad 70 from leaking out and it protects the liquid retaining pad 70 from tearing during laundering.

[0055] The liquid retaining pad 70 includes at least one element of spacer fabric, and in the example in FIG. 1a it includes only one spacer fabric element 20. A spacer fabric is understood as a three-dimensional fabric that comprises a first, upper layer 22 that is connected to a second, lower layer 23 by an intermediate spacer layer 24. The spacer fabric element 20 has a thickness sufficient to provide the required liquid retaining capacity, and may for example be in the range 2-10 mm, typically in the range 3-5 mm. As a specific example, the spacer fabric element in the illustrated embodiment may be 3 mm, 4 mm or 5 mm thick.

[0056] An example of a commercially available spacer fabric is disclosed in WO2014/101928, hereby incorporated by reference, in which case the spacer fabric is warp knitted.

[0057] The upper and lower layers 22, 23 here have openings 25 to improve liquid permeability. The openings of the lower layer are preferably smaller than the openings of the upper layer, such that the lower layer 26 is denser and has higher flow resistance than the upper layer 22. Because of this, the liquid kept inside the liquid retaining pad 70 is spread more in the lower layer 23 than in the upper layer 22, which means that the liquid is more concentrated in the lower layer 23 than in the upper layer 22. The upper layer 22, having an open hole structure, is thus preferably located such that it resides nearest the skin of the user and the lower layer 23 facing the back sheet 30. Hereby, the liquid is rapidly guided into the spacer fabric and leaves a sense of dryness to the user.

[0058] The yarn in the layers 22, 23, 24 of the spacer fabric 20 is preferably made of thermoplastic fibers having low or negligible amount of absorption. Examples of such fibers are polyolefines, polyesters, polyamides or combinations thereof. Hereby, the liquid that enters the sanitary product 100 is spread at the surface of the fibers by wicking and not absorbed into the fibers. Wicking is the ability of a textile fiber to carry moisture along the surface of the fiber.

[0059] Preferably, the spacer fabric itself does not include any absorbing fibers, i.e. fibers made of absorbing materials. Instead, the spacer fabric may consist of thermoplastic fibers such as polyesters, polyamides or polyolefines.

[0060] On the contrary, for thermoplastic fibers, instead of the liquid being absorbed by the fiber, it sits in droplets on the fiber's surface and moves around by wicking. Thermoplastic fibers thus facilitate both washability and time for drying.

[0061] Absorption capacity is calculated by weight of absorbed liquid divided by the weight of the absorbing material defined at a certain time of exposure. In the sanitary industry, in addition to calculation of absorption capacity, liquid absorption is often measured by strike trough/penetration time, i.e. the speed at which liquid is absorbed by the product or by wetback (or rewet), i.e. the amount of liquid that is released by the product to the skin after absorption when pressure is applied to the product. In the case of the spacer fabric used in the invention, the spacer yarns prevent pressure to apply on the liquid retaining pad and therefore helps to lower the amount of wetback.

[0062] FIG. 2a-b illustrate a sanitary product 101 having a liquid retaining pad 70 that consists of two elements of spacer fabric; an outer spacer fabric element 20 and an inner spacer fabric element 26. The outer spacer fabric 20 is located on top of the inner spacer fabric element 26 and is here slightly larger than the inner spacer fabric element, so that it extends beyond the outer edge of the inner element 26, as illustrated most clearly in FIG. 2b. This means that only the peripheral portion 72 of the outer spacer fabric element 20 is sandwiched between the annular liner 10 and the back sheet 30, thereby improving the functionality of the sealed container 13.

[0063] The outer and the inner spacer fabric 26 in FIG. 2a-b have the same thickness, e.g. about 3 mm respectively. However, it is also possible that the outer spacer fabric 20 is either thicker or thinner than the intermediate spacer fabric 24.

[0064] Similar to the outer spacer fabric element 20, also the inner spacer fabric element preferably has larger openings in its upper layer, so as to have lower flow resistance facing the user.

[0065] FIG. 3a-b illustrate a sanitary product 102 having liquid retaining pad 70 that contains three elements of spacer fabrics; an outer spacer fabric 20, an inner spacer fabric 26, and an intermediate spacer fabric 28. Alternatively, the sanitary product 100 may include two or more intermediate spacer fabric elements 28 depending on the desired absorption capacity of sanitary product 100.

[0066] Similar to the product in FIG. 2a, the outer spacer fabric element 20 is slightly larger than the inner spacer fabric element 26, so that it extends beyond the outer edge of the inner element 26, as illustrated most clearly in FIG. 3b. This means that only the peripheral portion 72 of the outer spacer fabric element 20 is sandwiched between the annular liner 10 and the back sheet 30, thereby improving the functionality of the sealed container 13.

[0067] The size of the intermediate spacer fabric element(s) 28 may be even further reduced compared to the inner and outer spacer fabric elements 20, 26. This makes the liquid retaining pad 70 thicker in a central part than e.g. in the front and rear edges.

[0068] FIG. 3a illustrates that the outer spacer fabric 20 may be of a different material than the that of the intermediate spacer fabric 28 and the inner spacer fabric 26. The outer spacer fabric 20 here has bigger openings 25 in the upper layer than the two others. The bigger openings 25 have several advantages. It facilitates for the liquid pass into the liquid retaining pad 70 and makes the surface of the liquid retaining pad 70 feeling dry. It also promotes circulation of air between the user and the sanitary product 100. In addition, washing and drying is improved since water and air better can penetrate the liquid retaining pad 70. However, since the lower layer of the spacer fabric is adapted to collect more liquid than the upper layer, the lower layer of each spacer fabric element in the sanitary product 100 is advantageously equally dense with the same sizes of openings 25.

[0069] FIG. 4 illustrates a flow chart for manufacturing of a sanitary product 100 as shown in FIG. 3a. First, in step 51, an annular liner 10 is attached to the outer spacer fabric element 20. To facilitate the process, the annular liner 10 may be separated into two sections 11a, 11b. Each section 11a, 11b of the annular liner 10 is attached to a perimeter 72 of the element 20 such that a portion of the annular liner 10 extends radially outside the element 20. The liner 10 may be attached by heat lamination, e.g. by applying pressure at a temperature between 130-150° C. for a duration of between 50-100 sec.

[0070] Then, in step S2, the inner spacer fabric element 26 is attached to the back sheet 30, again preferably by heat lamination. As illustrated in FIG. 3a, the thickness of the inner element 26 may be thicker than the outer element 20. For example, the inner element 26 maybe a few mm thicker, e.g. 5 mm instead of 3 mm. As a consequence of the pressure applied during step S2, the thickness of the inner element 26 in the finished product may be substantially the same as the outer element 20.

[0071] Then, in step S3, any intermediate spacer fabric elements 28 are arranged (not necessarily attached) on the inner element 26.

[0072] Finally, in step S4, the outer spacer fabric element 20, having the annular liner 10 attached thereto, is arranged on the stack of spacer fabric elements 26, 28, and the liner 10 is attached to the peripheral portion 32 of the back sheet 30.

[0073] By means of pressure and heat, applied only to the annular liner 10 and the portion 32 of the back sheet 30, a seam 15b is created between the annular liner 10 and the back sheet 30 with the peripheral portion 72 of the element 20 sandwiched in between.

[0074] FIG. 5 illustrates a sanitary product 103 that is integrated in an undergarment 50. The sanitary product 100 in FIG. 5 is identical to the sanitary product 100 in FIG. 1 except from the difference that the back sheet 30 is attached to an undergarment 50 and not an underlaying layer. The back sheet can be attached to the undergarment by sewing or by glue.