GB2292526A

GB2292526A - Sanitary product

Info

Publication number: GB2292526A
Application number: GB9514624A
Authority: GB
Inventors: Hayley Gabb
Original assignee: Smith and Nephew PLC; Smith and Nephew Inc
Current assignee: Smith and Nephew PLC; Smith and Nephew Inc
Priority date: 1994-07-16
Filing date: 1995-07-17
Publication date: 1996-02-28
Anticipated expiration: 2015-07-17
Also published as: GB2292526B; GB9514624D0

Abstract

The product, which may be a tampon, sanitary towel, diaper or incontinence product, comprises at least in part a "spacer" fabric, i.e. a fabric having first and second (preferably knitted) spaced apart surfaces with a plurality of fibrous members extending between such surfaces and secured thereto by e.g. knitting, weaving, welding or use of adhesive. The spaces between the fibrous members may be filled, e.g. with chitosan, alginate or activated charcoal. The fabric may be rolled up in a tightly wound coil, secured by a tie cord 60 and covered by a perforate coverstock 90 to form a tampon, the interior of the spacer fabric being filled with cotton/rayon fibres. Alternatively, the fabric may form the absorbent pad 150 of a sanitary towel, optionally with an infill of superabsorbent. <IMAGE>

Description

SANITARY PRODUCTS The present invention relates to sanitary products and in particular to such products comprising fabrics having spaced apart surfaces.

In the field of upholstery it is known to use fabrics comprising first and second opposed surfaces, which surfaces are joined together by a large number of filaments, typically formed of resilient material. Since the filaments cause the opposed surfaces to be spaced apart from one another, such fabrics are sometimes known as "spacer fabrics".

Such fabrics are generally constructed to be capable of deforming in a resilient manner so that after having been deformed they return substantially to the shape they were in before deformation.

According to the present invention there is provided a sanitary product at least a portion of which comprises a fabric characterised in that at least a portion of said fabric consists of a spacer fabric.

The sanitary products of the present invention can be easily manufactured and yet still demonstrate good absorbency. They are particularly advantageous in that the spacer fabrics can be used to incorporate a wide variety of filler materials so that the product can be tailored for different customer requirements. Since spacer fabrics are generally resiliently deformable, they can conform to body contours and can also provide a degree of cushioning.

The term "sanitary product" is used herein to include fabric products intended to absorb secretions or excretions from the body.

These include feminine hygiene products (e.g. tampons, towels etc.), diapers, incontinence products etc.

Such sanitary products may consist mainly or only partially of a spacer fabric, for example in a tampon where all of the product bar a coverstock and tie cord may comprise spacer fabric. In a diaper only the fluid absorbing region may comprise spacer fabric and the major portion may comprise cover layers, nets, backing layers of which some or all may extend beyond the spacer fabric and may be used to provide means for fitting the sanitary product and extra comfort.

The term "spacer fabric" when used herein refers to a fabric having first and second generally spaced apart surfaces, which surfaces are spaced from one another by a plurality of fibrous members. The surfaces are desirably opposed to one another.

The term "fibrous member" when used herein refers to all or part of a fibre used as a spacer. The term includes yarns and filaments (or parts thereof).

Thus according to the present invention there is provided a sanitary product wherein said spacer fabric comprises first and second opposing surfaces in a spaced apart relationship wherein a plurality of fibrous members extend between said first and second surfaces thereby to maintain them in a spaced apart relationship.

Preferably the spacing between the first and second surfaces is at least 0.5mm. This may be across all or a substantial portion of the spacer fabric e.g. across at least 50%, of the volume thereof.

The spacing may be as large as desired for the particular sanitary product for which the spacer fabric is intended but is typically no more than 50mm (across all or a substantial portion of the spacer fabric).

In a preferred embodiment of the present invention the spacer fabric is characterised in that the first and second opposing surfaces of said spacer fabric are spaced apart from 0.5mm to 50mm more preferably from 1 mum to 30mm and most preferably from 2mm to 20mm.

The surfaces may be substantially planar and may be substantially parallel to one another over all or a substantial part of the spacer fabric. In some embodiments however it may be desirable that one or more edge portions of the fabric are compressed relative to the rest of the fabric. Thus, the fabric may have one or more tapered edges. The edges may be held together by stitching, welding, adhesive or tape for example.

The first and second opposing surfaces may be present as surfaces of first and second opposing sheets of knitted, woven or non-woven material. The surfaces may be formed of the same or different material.

Preferably however both the first and second opposing surfaces are knitted. Any desirable knit may be used for forming the first and second sheets, for example warp knit, weft knit, and may also be patterned (e.g. with a waffle pattern).

Most preferably warp knitting (e.g. using Raschel warp knitting machinery) is used.

The fibrous members may be formed from one or more fibres which interconnect the first and second surfaces. They may be secured to the first and second opposing surfaces by any appropriate means e.g. by knitting, weaving, the use of adhesives or welding (which is particularly apt for thermoplastic materials).

Desirably knitting is used.

Thus, in a most preferred embodiment, the spacer fabric comprises knitted first and second opposing surfaces and a plurality of fibrous members which interconnect said opposing surfaces.

The spatial relationship between the fibrous members and the two opposing surfaces is that the majority of the fibrous members may be perpendicular or oblique to the two opposing surfaces but are preferably not parallel to the opposing surfaces.

Desirably the spacer fabric is formed as a unit in a single process. An apt process for forming such a fabric is disclosed in US Patent No. 4601940 (Fischer) in which a padded fabric suitable for forming brassieres is disclosed. This fabric is a type of spacer fabric which can advantageously be used in medical support products of the present invention. The fabric can be made by using a warp or tricot or Raschel knitting machine having at least three guide bars and two rows of spaced needles. Two of the guide bars feed thread which is knitted to form two surfaces which are held spaced apart from one another. Simultaneously with forming the two surfaces, fibrous members, (which in US Patent No. 4601940 are referred to as filler threads), are used to interconnect the two surfaces by knitting.The filler threads are produced from a fibre fed through a third guide bar which is located between the two guide bars feeding the thread to form the knitted surfaces.

Another apt process for forming such a fabric is disclosed in EP-A-0529671, in which a Raschel warp knitting machine with two needle bars and six thread guide bars are used to form a fabric which is said to provide a cushion, suitable for use in car seat upholstery. The knitted fabric may comprise opposed surfaces formed using the same or a different knitting construction. Both may have two threads on the front and back needle bars. The fibrous members (referred to in EP-A-0529671 as "pile") may also have two thread guides, but alternatively may have only one. Cord, tricot, atlas or satin tricot lapping may be used.

Although in EP-A-0529671 there is disclosed the laminating of the knitted (spacer) fabric to another material suitable for forming a seat cover, such lamination is not a requirement of the present invention.

According to the present invention there is provided the use of a spacer fabric in the manufacture of a sanitary product.

The fibrous members in whatever fabric they are used should be sufficiently resilient to maintain the first and second opposed surfaces in spaced relation to one another when pressure is not applied to the spacer fabric. Thus the spacer fabric should be selfsupporting.

Preferably the fibrous members are arranged so as to prevent the opposed surfaces contacting one another when a compressive force of up to 0.5 N/m2 more preferably of up to 2.5 N/m2 is applied to the fabric in a direction opposing the force exerted by the spacer elements to keep the opposed sheets apart.

Therefore in a preferred embodiment of the invention there is provided a sanitary product wherein that said opposing surfaces can withstand between 0.5N/m2 and 2.5N1m2 of force in a direction substantially perpendicular to said opposing surfaces.

It is also preferred however that the fibrous members are capable of deforming (e.g. bending) so as to provide a cushioning effect. Thus in a further embodiment the fibrous members are desirably formed of resiliently deformable material.

By varying the material, diameter, length and/or the number of fibrous members per unit volume the characteristics of the spacer fabric (resilience, compressibility, etc.) can be tailored for different applications.

Different fibrous members and different materials for the opposing surfaces and fibrous members may be used within the same spacer fabric.

Apt fibrous members may be formed from polyester, polyamide (e.g. nylon TM), polypropylene, polyethylene, cotton or other fibrous materials. Elastomeric materials may also be used (e.g. LycraTM, SpandexTM or elastomeric polyurethanes) and may be incorporated together with non-elastomeric fibrous members.

Permeable/hollow fibres may also be used such as Celgard available from Hoechst-Celanese.

By using fibrous members, spacer fabrics can be provided with a substantial void volume which can then be filled with any desired filler material which may be advantageous in for sanitary protection.

The number of fibrous members per unit volume determines the void volume available between fibrous members and the void volume may vary across the spacer fabric.

Typically the void volume comprises at least 50%, advantageously at least 80% of the total volume between the opposing surfaces. Thus pharmaceutically active agents may be provided (e.g. antimicrobial agents, such as chlorhexidine) and may be used together with pharmaceutically acceptable carrier materials.

Any conventionally known filler materials may be used.

Chitosan or alginates may be used as a filler material. Other possible filler materials include odour absorbing materials (e.g.

activated charcoal) and absorbent materials (e.g. superabsorbents).

The filling material may occupy substantially all or part of the available void volume. When the filling material occupies part of the available void volume, the filling material may fill some of the voids substantially, partially or a mixture thereof.

In a further embodiment of the present invention there is provided a sanitary product wherein void volumes exist between fibrous members characterised in that a filling material is contained within the void volumes.

Ways of incorporating filler materials include forcing the materials into the spacer fabric by blowing or by the use of suction, as is frequently used for forming air laid textile materials.

The sanitary product desirably comprises an outer cover of water pervious material. This may be a net or perforate film forming a coverstock.

Therefore there is provided a sanitary product characterised in that said sanitary product comprises said spacer fabric and a water pervious cover. Said water pervious cover may also be a partial cover. When said water pervious cover is a partial cover the cover is preferably on one surface of the sanitary product and most preferably on the body facing surface.

Such covers include coverstocks, nets, backing layers and similar materials The spacer fabric will generally be enclosed within the coverstock and can be in any desired configuration. In tampons it may be in the general form of a cylindrical shape produced by coiling a sheet. Preferably said sheet is a substanially rectangular sheet.

In a further embodiment of the present invention there is provided a sanitary product wherein said sanitary product is a tampon, where said tampon comprises a substantially cylindrically shaped coiled sheet of said spacer fabric. Preferably said tampon is substantially enclosed by a coverstock.

According to the present invention there is provided a spacer fabric for use in sanitary protection wherein the materials comprising said spacer fabric are flexible.

In sanitary towels or diapers said spacer fabric may be generally planar or may be curved for example in a convex or concave manner to conform to body contours. In these products a non water pervious material may be incorporated at a region of the product, (e.g. as a sheet located between the spacer fabric and the coverstock) to prevent liquid passing completely across the product at this region. The products may be provided with elasticated edges and/or fasteners to aid in securing them in position on a user.

Adhesives may also be utilised for this purpose.

The spacer fabric should be flexible enough for the intended sanitary product, for example in a tampon the spacer fabric must be flexible enough to allow coiling of a sheet for example a rectangular sheet, and for a diaper or sanitary towel must be flexible enough to mould to body curves.

Preferably the spacer fabric is less flexible than the water pervious cover.

Thus in a preferred embodiment of the present invention there is provided sanitary protection wherein said spacer fabric is curved to conform to body contours, and in yet another embodiment said sanitary protection is characterised in that a portion of said sanitary protection consists of non water pervious material.

A sanitary product as herein before described can be manufactured using conventional techniques and processes wherein at least a portion of said sanitary product comprises a spacer fabric.

The present invention will now be described by way of example only with a reference to the accompanying drawings, wherein: Fig. 1 shows a spacer fabric (perspective view) Fig. 2 shows the spacer fabric in Fig. 2 when coiled up (transverse section).

Fig. 3 shows a tampon which can incorporate a spacer fabric (perspective view) Fig. 4 shows a transverse section through a sanitary towel which incorporates a spacer fabric and Fig. 5 shows a plan view of the sanitary towel shown in Fig. 4.

Turning now to Fig. 1, there is shown in perspective view a spacer fabric of J-910 Fukui City, Japan or from Karl Meyer Textilmaschinenfabrik of D-63166 Obertshausen, Germany.

The fabric 10 comprises upper and lower opposed knitted fabric surfaces 20 and 30, which are interconnected by fibrous spacer members 40.

Fabric 10 can be wrapped into a tight coil by rolling it as indicated by arrow 50.

Fig. 2 shows a cross-section through fabric 10 when rolled up in a tightly wound coil and secured in this shape by a tie cord 60, and substantially covered by a coverstock 90.

This type ofarrangement can be used to form a tampon by coiling the fabric 10 into a generally cylindrical shape of appropriate dimensions and providing a coverstock material over the coiled up fabric 10. The tie 60 may also function as a removal cord for the tampon or a separate removal cord for the tampon may be provided.

In this embodiment the interior of the spacer fabric 70 is filled with an appropriate non-toxic absorbent infill material - eg.

cotton/rayonTM fibres.

Fig. 3 shows a typical digital tampon which has a removal cord 80 and optionally a coverstock 90. The coverstock is perforate and lies over an absorbent inner core. Longitudinal grooves 100 are optionally provided to aid in insertion/removal.

In Fig. 4 a sanitary towel 110 is shown in transverse section.

Sanitary towel 110 comprises an inner absorbent pad 150, formed of a spacer fabric material optionally filled with an infill of superabsorbent material. An outer layer of perforate coverstock material 120 is provided which allows body fluids to pass across it.

On the non-body contacting surface of the coverstock 120 an adhesive 140 is provided to secure the sanitary towel in position.

Body fluid passes across coverstock 120 and into absorbent pad 150. In order to prevent break-through of fluid an impermeable sheet 130 is provided.

150. In order to prevent break-through of fluid an impermeable sheet 130 is provided.

A plan view of the sanitary towel 110 illustrated in crosssection in Fig. 4 is shown in Fig. 5.

The towel 110 is provided with a peripheral seal 160 provided by heat sealing and has a raised area, the periphery of which is illustrate by dotted line 170. The raised area corresponds to the area where the absorbent pad 120 (shown in Fig. 4) is present.

Other types of sanitary towel may be provided utilising the present invention eg. the sanitary towel may have conformable wings. Sanitary pads may also be provided.

Claims

1. A sanitary product at least a portion of which comprises a fabric characterised in that at least a portion of said fabric consists of a spacer fabric.

2. A sanitary product as claimed in claim 1 characterised in that said spacer fabric comprises first and second opposing surfaces in a spaced apart relationship wherein a plurality of fibrous members extend between said first and second surfaces thereby to maintain them in a spaced apart relationship.

3. A sanitary product as claimed in claim 1 characterised in that the first and seeend surfaces of said spacer fabric are spaced apart at least 0.5mm.

4. A sanitary product as claimed in claim 2 characterised in that said spacer fabric comprises first and second opposing surfaces and a plurality of fibrous members which interconnect said opposing surfaces.

5. A sanitary product as claimed in claim 2 characterised in that said opposing surfaces can withstand between 0.5N/m2 and 2.5N1m2 of force in a direction substantially perpendicular to said opposing surfaces.

6. A sanitary product as claimed in claim 2 wherein void volumes exist between the fibrous members characterised in that a filling material is contained within the void volumes.

7. A sanitary product as claimed in claim 1 characterised in that the materials comprising said spacer fabric are flexible.

8. A sanitary product as claimed in claim 1 characterised in that said sanitary product comprises said spacer fabric and a water pervious cover.

9. A sanitary product as claimed in claim 8 characterised in that said water pervious cover is a partial cover.

10. A sanitary product as claimed in claim 1 characterised in that said sanitary product is a tampon.

11. A sanitary product as claimed in claim 10 characterised in that said tampon comprises a substantially cylindrically shaped coiled sheet of said spacer fabric.

12. A sanitary product as claimed in claim 11 where said tampon comprises a substantially rectangular coiled sheet of said spacer fabric.

13. A sanitary product as claimed in claim 11 where said tampon is characterised in that said coiled spacer fabric is substantially enclosed by a coverstock.

14. A sanitary product as claimed in claim 1 characterised in that said sanitary product is a towel.

15. The use of a spacer fabric in the manufacture of a sanitary product as claimed in claim 1.

16. A sanitary product as claimed in claim 1 characterised in that said spacer fabric is curved to conform to body contours.

17. A sanitary product as claimed in claim 1 characterised in that a portion of said fabric consists of non water pervious material.

18. A process for the manufacture of a tampon as claimed in claim 10 which comprises coiling said spacer fabric to a substantially cylindrical shape and providing said shaped spacer fabric with a cover stock and a tie cord.

19. A sanitary product substantially as described herein with reference to Figures 1-5 of the accompanying drawing.