WO2009106899A1

WO2009106899A1 - Multi-layered nappy

Info

Publication number: WO2009106899A1
Application number: PCT/GB2009/050204
Authority: WO
Inventors: Magnus Drever Smyth; Fiona King
Original assignee: Tots Bots Ltd
Current assignee: Tots Bots Ltd
Priority date: 2008-02-28
Filing date: 2009-02-27
Publication date: 2009-09-03
Anticipated expiration: 2010-08-28
Also published as: GB0803716D0

Abstract

A multi-layered nappy having a central absorbent core layer attached to a honeycomb-knit polyester wicking barrier layer, which provides good moisture retention and which largely prevents or greatly reduces leakage or seepage of moisture from the nappy.

Description

IMPROVED NAPPY

Technical Field

The present invention relates to an improved nappy. In particular, the present invention relates to an improved reusable nappy that prevents or greatly reduces leakage or seepage of moisture therefrom. The invention also relates to an improved reusable nappy with increased comfort for the wearer.

Background Art

Nappies, or diapers, have been known for many years. Originally, nappies were fashioned from absorbent cloth or fabric, and were reusable. In more recent history, disposable nappies came to the fore; their use being widespread. However, disposable nappies typically include a large degree of modern synthetic materials, which are not biodegradable. Therefore the use of disposable nappies is now considered environmentally unsound. In view of this, there has been resurgence in the use of reusable nappies, and a decline in the use of disposable nappies.

Modern reusable nappies are much improved when compared to their traditional counterparts, being prepared from modern absorbent materials, and being shaped to fit babies and/or toddlers. However, despite the advances in reusable nappy technology, commonly used materials can feel uncomfortable against the skin when wet. Furthermore, the modern materials used in such nappies must be very absorbent, and therefore can be very thick, making modern reusable nappies bulky and thus impeding the mobility of the wearer. In addition, whilst modern synthetic materials are very absorbent, in use they tend to allow moisture to transfer from the inside to the outside of the nappy. As a result, these nappies can feel damp to the touch, and clothing worn on top of such nappies can become wet.

Therefore, it is an object of the present invention to overcome at least some of the drawbacks associated with the prior art.

A further object of the invention is to provide a reusable nappy that has increased comfort for the wearer.

Disclosure of the Invention

According to first aspect of the present invention there is provided a multi- layered nappy comprising an absorbent layer, the absorbent layer comprising first and second sides, wherein the first side of the absorbent layer is for contacting the body of a wearer; and an outer layer housing the absorbent layer and for securing the absorbent layer onto the body of the wearer, said outer layer comprising a barrier layer which comprises a wicking material, said barrier layer located immediately adjacent to the second side of the absorbent layer, wherein the barrier layer prevents or greatly reduces the flow of moisture from the absorbent layer.

Known reusable nappies are associated with leakage or seepage of moisture, resulting in moisture leaking out of the nappy, wetting the clothes or skin surrounding the nappy causing discomfort, and promoting the development of nappy rash.

Leakage or seepage of moisture from the nappy of the present invention is largely prevented through the provision of a barrier layer around the second side of the absorbent material wherein the second side of the absorbent material faces away from the body of the user. Moisture is retained in the absorbent material as the flow of moisture through the barrier material is largely prevented. Accordingly, the nappy of the present invention provides good moisture retention, and leakage of moisture therefrom is largely prevented.

The outer layer houses the absorbent layer insofar as the absorbent layer over-lies the outer layer such that in use the absorbent layer is held against the body of the wearer by the outer layer.

The barrier material of the nappy of the present invention comprises a wicking material. Typically the wicking material comprises a first side formed from plain woven material, and a second side formed from a multicellular material comprising a plurality of holes or depressions, said multi- cellular material having a surface area at least 20% greater than that of the plain woven material; typically at least 30% greater; generally at least 40% greater. The multi-cellular material is generally at least 20 % more absorbent than the plain woven material, typically at least 30% more absorbent; generally at least 40% more absorbent.

The multi-cellular material may be located immediately adjacent to the second side of the absorbent layer.

Generally the multi-cellular material comprises a repeating pattern of holes or depressions. The multi-cellular material is commonly referred to as a "honey-comb" material due to its repeating pattern of holes or depressions. Typically the wicking material is a polyester, cotton or silk wicking material. Generally the wicking material is a polyester wicking material. Such wicking material is known in the art.

It is known that if the plain woven side of such wicking material is placed immediately adjacent a material retaining moisture, the moisture is transferred from the material into or through the wicking material, evaporating from the multi-cellular side of the wicking material. In this way, moisture is transferred away from the material, with little or no moisture being absorbed in the wicking material. The plain woven side of the wicking material remains substantially dry to the touch.

Surprisingly, if the multi-cellular side of such wicking material is placed immediately adjacent a material retaining moisture, the wicking material acts as a barrier to the moisture, and the moisture is substantially prevented from being transferred through the wicking material. Although some moisture is absorbed and retained in the multi-cellular side of the wicking material very little or none of the moisture is able to flow through the wicking material. It is surprising that such wicking material can act as a barrier to the flow of moisture in this way as such wicking material is typically used to aid the transfer and evaporation of liquid away from an absorbent material.

The nappy of the present invention includes a barrier material comprising a wicking material. The wicking material typically has a first plain woven side and a second multi-cellular side. The second multi-cellular side is advantageously located immediately adjacent to the second side of the absorbent layer, wherein the second side of the absorbent layer faces away from the body of the user. The absorbent material typically comprises terry towelling, cotton, bamboo fibre, polyester, cellulose, and/or viscose. According to one embodiment of the present invention, the absorbent material may comprise an absorbent core of super-absorbent material and a surrounding absorbent material. Typically the absorbent core is at least two times more absorbent than the surrounding absorbent material. The absorbent core may be formed from the same material or a different material from the rest of the absorbent layer. Typically the absorbent core is formed from a polyester microfiber terry material. Generally, cellulose fibres (cotton, viscose, bamboo fibres) are used to form the surrounding absorbent material (the absorbent surface layer).

Whilst the polyester microfiber core typically has two times the fluid retention capacity per gram than cellulose fibres, the absorbency rate is not as high. Combining layers of polyester microfiber terry with layers of cellulose terry gives both improved rate of absorption and capacity when compared to either material functioning on its own. The polyester fabric also releases moisture more easily than the cellulose fabrics, thus improving the drying time of the nappy without compromising the absorbent performance.

The nappy is shaped to accommodate the wearer. The outer layer typically comprises a crotch portion which extends into a front portion to accommodate the stomach of the wearer in use and a back portion to accommodate the bottom of the wearer in use. The front and back portions may be attachable by a waist portion which typically comprises flaps extending from the back portion to the front portion to be secured, typically through the use of known fastening mechanisms such as Velcro or poppers. The waist portion may therefore be configured to facilitate removable attachment of the front portion to the back portion. Generally the absorbent layer extends from the front portion to the back portion along the crotch portion. The barrier layer is typically secured to the absorbent layer and extends from the front portion to the back portion along the crotch portion.

Advantageously the barrier material comprising a wicking material extends around the waist portion. Generally the barrier material is secured to the outer layer around the waist portion. This prevents or greatly reduces leakage from the waist portion.

The barrier material is generally secured all around the second side of the absorbent material that faces away from the body of the user.

Optionally there is included a further layer of wicking material comprising a first side formed from plain woven material, and a second side formed from a multi-cellular material, the further layer arranged such that in use the first side thereof is located towards the body of the wearer for contact therewith.

Typically the outer layer is formed from the barrier layer. Alternatively the outer layer may comprise an additional layer located around the barrier layer. The additional layer can be located immediately adjacent to the barrier layer, such that said additional layer forms an outermost layer of the nappy.

The additional layer may be permeable or impermeable to liquid. Typically the additional layer is formed from water permeable materials such as polyester wicking fibres, or water-impermeable materials. The additional layer may be removeably attached to the barrier layer. The additional layer may comprise a water repellent material. The water repellent material may be attached to the waist portion, and in particular the water repellent material may be attached to the waist portion at the section securing the front portion to the back portion. The water repellent material may comprise polyurethane laminate (PUL).

The layers of the multi-layered nappy of the present invention may be assembled with or without the use of securing means such as stitching, gluing, hook and loop fastening. The absorbent layer may be detachable from the outer layer, aiding more frequent washing thereof relative to the outer layer.

According to another aspect of the present invention there is provided a multi-layered nappy comprising an absorbent layer and a barrier layer, wherein the barrier layer comprises a wicking material, said wicking material extending at least to a waist portion.

According to a further aspect of the present invention there is provided a multi-layered nappy comprising an absorbent layer for contacting the body of a wearer, and an outer layer located adjacent the absorbent layer, said outer layer comprising a crotch portion, a front portion, a back portion and a waist portion, said waist portion being configured to secure the front portion to the back portion, wherein at least the waist portion of the outer layer comprises a barrier layer comprising a wicking material, said barrier layer for locating towards the body of the wearer, wherein the barrier layer prevents or greatly reduces the flow of moisture through the waist portion.

The nappy of the present invention includes a barrier layer comprising a wicking material. The wicking material typically has a first plain woven side and a second multi-cellular side. The second multi-cellular side is advantageously located towards the body of the wearer and the first plain woven side is preferably facing away from the wearer.

The waist portion may comprise a further layer of wicking material comprising a first side formed from plain woven material, and a second side formed from a multi-cellular material, the further layer arranged such that in use the first side thereof is located towards the body of the wearer for contact therewith.

Brief Description of the Drawing

The present invention will now be described by way of example only with reference to the accompanying figure in which: Figure 1 shows one embodiment of the nappy of the present invention in plan view.

Modes for Carrying out the Invention

Referring to Figure 1 there is shown at 1 a nappy having a central absorbent bamboo fibre layer 2, attached to a honeycomb-knit polyester wicking barrier layer 3. Within the absorbent layer 2 there is located a core layer of polyester microfiber material (not shown) which has approximately twice the absorbent capacity as the bamboo fibre material of the absorbent layer 2. An outer layer 7 houses the absorbent layer 2 and the barrier layer 3. The outer layer 7 and the barrier layer 3 extend beyond the absorbent layer 2 to form a front waist band 4 and a rear waist band 5a, 5b. Attached to the front waist band 4 are hook and loop fasteners (not shown), for securing the front waist band to the hook and loop fasteners 6a, 6b attached to the rear waist band 5a, 5b. In use, the nappy is placed on an individual with the absorbent layer placed against the skin, in the crotch region. The nappy is folded towards the individual's body and the front waist band is secured to the back waist band using the hook and loop fasteners.

The layers are assembled by stitching together as is conventional. Alternatively, the layers may be glued together or can be assembled using any other methods known in the field. For example, the core layer may be held between the wicking layer and the central layer without additional fixing.

Whilst in the example given, there is a core region within the central region, it will be understood that a suitable nappy may be provided having a central absorbent bamboo fibre layer attached to a honeycomb-knit polyester wicking layer only. Also, in the above example, the wicking material wholly covers one side of the central layer and extends beyond the dimensions thereof. It will be appreciated that in an alternative arrangement, the wicking layer attaches to upper and lower regions of the central region to form waist bands only, the material of the central region being exposed on both sides, or being covered on one side by an alternative material.

The central regional is designed to come into contact with an individual at a region where absorbance of body fluids is most critical, whereas the waist bands are designed to contact the waist region of an individual. As the waist bands are made from a wicking material, which is much less absorbent than the bamboo or polyester terry fibres, they do not draw moisture from the central region of the nappy. Therefore, any absorbed moisture remains primarily in the central layer of the nappy. Also, the wicking material may "breathe", and can promote the transfer of moisture from the waist bands to the environment, should the waist bands become wet.

In one embodiment, the nappy comprises a polyester wicking layer having a substantially smooth side and a honeycomb side. The wicking layer is attached to the central layer such that the honeycomb side is in contact with (or at least juxtaposed) the central layer. In this embodiment, the wicking layer effectively works "in reverse" in that the arrangement discourages moisture from seeping from the central layer to the flat side of the wicking layer. In use, this has the advantageous effect of suppressing the transfer of moisture from the central layer to the flat side of the wicking layer, which of course would conventionally come into contact with the individual's clothing. Therefore, in use, this embodiment has the added advantage of mitigating seepage of moisture from the inside to the outside of the nappy.

The inventors have unexpectedly found that placing the wicking material in this particular orientation inhibits the transfer of water from the central region to the furthest-most surface of the wicking layer. Ordinarily, such wicking materials are used with the flat side placed next to the "wet" article (or most often the skin), the honeycomb-surface being exposed to the air to increase the evaporation of any moisture. It appears that having the pores (so-formed by the honeycomb-surface) in direct contact with the water absorbent layer can act to reduce the amount of moisture transferred through the wicking material.

In a further embodiment, the nappy as described in Figure 1 further comprises an outer layer comprised of polyurethane laminate (PUL), which acts as a waterproof membrane. The outer layer is attached to the wicking fabric at the extremities of the waist band regions thus providing an air gap between the main body of the nappy (comprising the central, core and wicking layers), and the PUL. Thus the wicking layer and the waterproof membrane are juxtaposed. This aids drying of the nappy after washing, as it allows air to circulate the main body of the nappy. In this particular embodiment, hook and loop fasteners are attached to both the wicking material and the waterproof membrane.

Whilst in the embodiment described above the waterproof membrane is polyurethane laminate, it will be appreciated that alternative suitable waterproof laminates known in the art can also be used. In this embodiment, the outer layer is stitched to the extremities of the waist bands, but it will be understood that alternatively, it may be detachable from the main body of the nappy. Furthermore, in another alternative the outer layer may simply be a separate waterproof cover that does not attach to the main body of the nappy.

In an alternative to the embodiments described above, the waist band comprises a further layer of wicking material such that the waist band has two layers of wicking material, effectively providing two barrier layers.

Whilst one of the wicking material layers is arranged as described above, the further wicking material layer is arranged such that in use the plain woven material is located towards the body of the wearer. This provides a waist band in which the two wicking material layers have their the plain woven material sides exposed, the multi-cellular material sides facing each other such that they are not visible. The two layers of wicking material are attached to each other using sewing, gluing or other techniques known in the art. Waist bands as described above mitigate the transfer of moisture from the absorbent layer of the nappy to the waist band, thereby providing an increased degree of comfort to the wearer.

The materials chosen above have the added advantage of providing a very absorbent, yet dry to the touch, nappy which has less bulk than would be necessary with traditional reusable nappies. This is achieved by the unique combination of the relatively thin wicking layer, the highly absorbent bamboo fibre and optionally the superior absorbent capacity of the polyester microfiber terry containing layer. In addition, the unique design described herein, wherein the waist bands are primarily wicking material only, affords a comfortable and stretchy, yet non-bulky nappy.

Industrial Applicability

The present invention provides an improved reusable nappy that prevents leakage or seepage of moisture therefrom. This provides a better degree of comfort for the wearer.

Various modifications and variations to the described embodiments of the invention will be apparent to those skilled in the art without departing from the scope and spirit of the invention. Although the invention has been described in connection with specific preferred embodiments, it should be understood that the invention as claimed should not be unduly limited to such specific embodiments. Indeed, various modifications of the described modes of carrying out the invention which are obvious to those skilled in the art are intended to be covered by the present invention.

Claims

1. A multi-layered nappy comprising an absorbent layer, the absorbent layer comprising first and second sides, wherein the first side of the absorbent layer is for contacting the body of a wearer; and an outer layer housing the absorbent layer and for securing the absorbent layer onto the body of the wearer, said outer layer comprising a barrier layer which comprises a wicking material, said barrier layer located immediately adjacent to the second side of the absorbent layer, wherein the barrier layer prevents or greatly reduces the flow of moisture from the absorbent layer.

2. A multi-layered nappy as described in claim 1 , wherein the wicking material comprises a first side formed from plain woven material, and a second side formed from a multi-cellular material comprising a plurality of holes or depressions.

3. A multi-layered nappy as described in claim 2, wherein the multicellular material is located immediately adjacent to the second side of the absorbent layer.

4. A multi-layered nappy as described in claims 2 or 3, wherein the multi-cellular material has a surface area at least 40% greater than that of the plain woven material.

5. A multi-layered nappy as described in claims 2 to 4, wherein the multi-cellular material is at least 40 % more absorbent than the plain woven material.

6. A multi-layered nappy as described in claims 2 to 5, wherein the multi-cellular material comprises a repeating pattern of holes or depressions.

7. A multi-layered nappy as described in claim 6, wherein the repeating pattern of holes or depressions forms a honey-comb pattern.

8. A multi-layered nappy as described in any preceding claim, wherein the wicking material is a polyester wicking material.

9. A multi-layered nappy as described in any preceding claim, wherein the absorbent layer comprises terry towelling, cotton, bamboo fibre, cellulose, and/or viscose.

10. A multi-layered nappy as described in any preceding claim, wherein the absorbent layer comprises a core of super-absorbent material and a surrounding absorbent material.

11. A multi-layered nappy as described in claim 10, wherein the super- absorbent core material is at least two times more absorbent than the surrounding absorbent material.

12. A multi-layered nappy as described in claims 10 or 11 , wherein the absorbent core material is formed from a polyester microfiber terry containing material.

13. A multi-layered nappy as described in any preceding claim, wherein the nappy is shaped to accommodate the wearer.

14. A multi-layered nappy as described in any preceding claim, wherein the outer layer comprises a crotch portion which extends into a front portion to accommodate the stomach of the wearer in use, and a back portion to accommodate the bottom of the wearer in use.

15. A multi-layered nappy as described in claim 14, wherein the absorbent layer extends from the front portion to the back portion along the crotch portion.

16. A multi-layered nappy as described in claims 14 or 15, wherein the front and back portions are attachable by a waist portion.

17. A multi-layered nappy as described in claim 16 wherein the waist portion is configured to facilitate removable attachment of the front portion to the back portion.

18. A multi-layered nappy as described in claims 16 or 17, wherein the barrier layer comprising a wicking material extends around the waist portion.

19. A multi-layered nappy as described in claim 18, wherein the waist portion comprises a further layer of wicking material comprising a first side formed from plain woven material, and a second side formed from a multi-cellular material, the further layer arranged such that in use the first side thereof is located towards the body of the wearer for contact therewith.

20. A multi-layered nappy as described in any preceding claim, wherein the outer layer comprises an additional layer located immediately adjacent to the barrier layer, such that said additional layer forms an outermost layer of the nappy.

21. A multi-layered nappy as described in any claim 20, wherein the additional layer comprises a water repellent material.

22. A multi-layered nappy as described in any claim 21 , wherein the water repellent material comprises polyurethane laminate (PUL).

23. A multi-layered nappy as described in any claims 20 to 22, wherein the additional layer is removeably attached to the barrier layer.

24. A multi-layered nappy comprising an absorbent layer and a barrier layer, wherein the barrier layer comprises a wicking material, said wicking material extending at least to a waist portion.

25. A multi-layered nappy comprising an absorbent layer for contacting the body of a wearer, and an outer layer located adjacent the absorbent layer, said outer layer comprising a crotch portion, a front portion, a back portion and a waist portion, said waist portion being configured to secure the front portion to the back portion, wherein at least the waist portion of the outer layer comprises a barrier layer comprising a wicking material, said barrier layer for locating towards the body of the wearer, wherein the barrier layer prevents or greatly reduces the flow of moisture through the waist portion.

26. A multi-layered nappy as described in claim 25, wherein the wicking material has a first plain woven side and a second multi-cellular side.

27. A multi-layered nappy as described in claim 26, wherein in use the second multi-cellular side is located towards the body of the wearer.

28. A multi-layered nappy as described in claims 25 to 27, wherein the waist portion comprises a further layer of wicking material comprising a first side formed from plain woven material, and a second side formed from a multi-cellular material, the further layer arranged such that in use the first side thereof is located towards the body of the wearer for contact therewith.