WO2008090562A1

WO2008090562A1 - Tampon covers

Info

Publication number: WO2008090562A1
Application number: PCT/IL2008/000116
Authority: WO
Inventors: Theodor Stern
Original assignee: Rostam Ltd.
Priority date: 2007-01-25
Filing date: 2008-01-27
Publication date: 2008-07-31

Abstract

The present invention provides a tampon for insertion into a body cavity for absorption of fluid therein. The tampon has an introduction end, a withdrawal end and a longitudinal axis therebetween and comprises an absorbent core having an outer surface and a cover with apertures, to facilitate passage of fluid from the body cavity into said absorbent core. According to one aspect of the invention, the cover is made of a fibrous material and the apertures are non-throughgoing. According to another aspect, the cover may be made of any suitable material and the apertures are essentially through-going and are oriented such that their outer end is closer to the introduction end of the tampon than their inner end.

Description

TAMPON COVERS

FIELD OF THE INVENTION

This invention relates to tampon covers, in particular apertured tampon covers, and their manufacturing.

BACKGROUND OF THE INVENTION

Examples of use of apertured materials in absorbent articles are disclosed in WO 02/070026, WO 02/056810, WO 02/49686, EP 1244402, EP 1056423, WO 2005/048901, WO 2004/080362, WO 02/056811, WO 01/01910, WO 01/01909, US 6465713, US 6570055, US 6743965, WO 01/01905, US 6860874.

In particular WO 2007/114742 discloses a non-woven fabric used as a top sheet material on an absorbent article, the fabric has through-going apertures for obtaining a quick inlet time and a low rewet. EP 1171070 discloses the use of apertured material to provide a breathable layer for absorbent articles such as baby diapers, sanitary napkins or pantiliners.

SUMMARY OF THE INVENTION

According to one aspect of the present invention there is provided a tampon for insertion into a body cavity for absorption of fluid therein, the tampon having an introduction end, a withdrawal end and a longitudinal axis therebetween, the tampon comprising: an absorbent core having an outer surface; a cover at least partially encompassing said absorbent core and having a first surface adapted for facing said body cavity and a second surface at least partially in contact with the outer surface of the absorbent core; a plurality of apertures formed in said cover at least over the majority of its area, at least a majority of said apertures being in the form of ducts having an outer end in the form of a first opening in said first surface, an inner end in the form of a second opening spaced from the second surface in the direction of the absorbent core, and a side wall extending between the first and second openings, which is oriented so that the first opening is located closer to the introduction end of the tampon than the second opening. By virtue of the specific orientation of the apertures in the tampon cover, passage of fluid from the body cavity into said absorbent core is facilitated. The cover may be made of a fluid-impervious polymeric material or a fluid- pervious fibrous material.

The plurality of apertures may be arranged at any desired pattern over the cover and may be grouped or distanced as desired.

The ducts may have any desired cross-sectional geometrical shape in both cross- sections, along their central lines (i.e. lines connecting the centers of the first and second openings) and perpendicular thereto, and such cross-sectional shapes may be different for different ducts.

For example, the ducts' shape may be circular, rectangular, triangular or the like in the cross-section taken perpendicular to their central lines, and they may converge from the first opening towards the second opening, e.g. may be frusto-conical in the cross-section taken along their central lines. Furthermore, the ducts' walls in such longitudinal cross-section may be straight, curved, wavy or the like.

According to another aspect of the present invention, there is provided a method for producing a tampon having a cover as described above, comprising: providing an absorbent core; providing a cover material and encompassing thereby at least partially said absorbent core so that a first surface of the material is adapted for facing a body cavity and a second surface is at least partially in contact with the outer surface of the absorbent core; forming in said material, when said absorbent core is encompassed thereby, a plurality of apertures at least over the majority of its area, at least a majority of said apertures being in the form of ducts having an outer end in the form of a first opening in said first surface, an inner end in the form of a second opening spaced from the second surface in the direction of the absorbent core, and side wall extending between the first and second openings, which is oriented so that the first opening is located closer to the introduction end of the tampon than the second opening. According to yet another aspect of the present invention, there is provided a tampon for insertion into a body cavity having an introduction end and a withdrawal end, the tampon comprising: an absorbent core having an outer surface; a cover made of a fibrous material comprising a three-dimensional web of intersecting fibers defining at their intersections web holes, allowing the material to be fluid-permeable, the cover having a first surface adapted for facing said body cavity and a second surface at least a part of which is in contact with the outer surface of the absorbent core and a material body therebetween; a plurality of apertures formed in said material at least over the majority of its area, at least a majority of said apertures each having an opening at a first surface, a side wall extending inwardly from said opening and terminating at a distance from the second surface inside said material body, whose portion between the second surface and the aperture constitutes the aperture's web-like base, an average characteristic cross sectional diameter of one opening at least at the first surface being greater than that of one web hole at least at the first surface.

The fluid-permeable material may be a woven or non- woven fibrous material. The thickness of the web-like base of the apertures, i.e. the distance from the first surface to the side location at which the side walls of the apertures terminate, may be different for different apertures, and at least for the majority of the apertures this distance at least does not exceed the longitudinal extension of the side walls thereof along the thickness of the material body.

When the cross sectional geometry of the web hole is circular, the characteristic diameter is that of the circle's diameter. In the event the cross sectional geometry of the web hole is of a polygonal shape, the characteristic diameter refers to the diameter of the circle inscribed within that polygon.

Among advantages of the cover according to both aspects of the present invention are: a) enhanced surface smoothness and ease of insertion and retrieval of the tampon, as in other known tampons having apertured cover, as a consequence of having openings in the surface of the cover facing the body cavity; c) the prevention or at least reduction of the outward flow of exudates from the tampon; and d) in case the absorbent core of the tampon is made of fibrous material, the prevention of fibers of such material from protruding through the apertures. According to yet another aspect of the present invention, there is provided a method for producing a cover for a tampon having an absorbent core, comprising: providing fibrous material comprising a three-dimensional web of intersecting fibers defining at their intersections web holes, allowing the material to be fluid permeable, the material having a first surface, a second surface and a material body therebetween; forming a plurality of apertures in said material at least over the majority of its area, at least a majority of said apertures each having an opening on said first surface, a side wall extending inwardly from said opening and terminating at a distance from the second surface inside said material body, whose portion between the second surface and the aperture constitutes the aperture's web-like base, an average characteristic cross sectional diameter of one opening at least at the first surface being greater than that of one web hole at least at the first surface; and forming from said material the cover on the absorbent core so that at least a part of said second surface of the material is in contact with the outer surface of the absorbent core.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to understand the invention and to see how it may be carried out in practice, embodiments will now be described, by way of non-limiting examples only, with reference to the accompanying drawings, in which:

Fig. 1 is a schematic illustration of one example of a tampon for insertion into a body cavity, in which a tampon cover according to the present invention, may be used;

Fig. 2A is an enlarged cross-sectional view taken along longitudinal axis of the tampon shown in Fig. 1 , of a portion of the tampon designated as II, illustrating one example of a tampon cover according to the present invention;

Fig. 2B is a view similar to that shown in Fig. 2A, illustrating another example of a tampon cover according to the present invention;

Fig. 3 is a schematic planar view of a material from which the tampon covers illustrated in Figs. 2A and 2B are made; and Fig. 4 is a view similar to that of Figs. 2A and 2B, illustrating a still further example of a tampon cover according to the present invention. DETAILED DESCRIPTION OF EMBODIMENTS

As used herein, the term "tampon" refers to devices that absorb and contain body exudates such as e.g. blood, menses and/or vaginal discharges, dental and nasal tampons, and that are adapted for the introduction into a corresponding cavity inside the body.

Fig. 1 illustrates a tampon 10 which has an introduction end 12, a withdrawal end 14, and a longitudinal axis of symmetry X. The tampon 10 comprises an absorbent core 15 having an outer surface 16 and a cover 18 at least partially wrapping the core 15. As seen in Figs. 2A and 2B the cover 18 has a first surface generally designated

22 adapted for facing a body cavity (not shown) and a second surface 24 in contact with the outer surface 16 of the absorbent core 15. The thickness of the cover 18 between the two surfaces measured perpendicularly to the axis X may be in the range of 20 - 2000 microns. The cover 18 has a plurality of three-dimensional apertures 25 formed therein and spread essentially over its entire area (seen in Fig. 3).

The apertures 25 are constituted by ducts 27 in protuberances 19 formed in the cover 18, each protuberance having a proximal end 19' at the first surface 22 of the cover, a distal end 19" protruding from the second surface towards and at least partially into the absorbent core 15, and a side wall 23 extending therebetween and oriented so that the proximal end 19' of the protuberances 19 is closer to the introduction end 12 of the tampon than the distal end 19".

The protuberances 19 with the ducts 27 are formed in the cover 18 so that the inner surface 29 of the side wall 23 of the protuberances 19 is essentially an extension of the first surface 22, and the outer surface 30 of the side wall 23 is an extension of the second surface 24 of the cover 18.

Each duct 27 extends between a first opening 26 at the proximal end 19' of the protuberance in the first surface 22 of the cover 18, and a second opening 28 at the distal end 19" of the protuberance 19, being thus slanted and having the first opening 26 located closer to the introduction end 12 of the tampon 10 than the second opening 28, to facilitate the passage of fluid from the exterior of the tampon via through the apertures 25 into said absorbent core 15. The three dimensional apertures 25 seen in Figs. 2A and 2B are of a slanted funnel shape and have circular shape in the cross-section taken parallel to the axis X.

The apertures 25 are orientated such that their central lines C passing through the centers of the openings 26 and 28 form an angle different from 90° with the longitudinal axis X. This angle may for example be in the range of 30°-60°.

As seen in Figs. 2A and 2B, the side walls 23 of the apertures 25 may be parallel

(side walls 23a and 23b in Fig. 2A) or non-parallel (side walls 23a and 23b in Fig. 2B) to their central lines C. In the example shown in Fig. 2B, the apertures 25 are frusto- conical so that the diameter of the second opening 28 of the aperture 25 is smaller than that of the first opening 26. Moreover, in the example shown in Fig. 2B, the apertures

25 are not symmetrical relative to their central lines C so that the side wall's portions

23a and 23b thereof have different lengths, i.e. the side wall portion 23a which is closer to the introduction end 12 of the tampon 10 is longer than the wall 23b closer to the withdrawal end 14. Optionally, the ducts 27 may have a curved shape such that their central lines C are at least partially curved.

The cover 18 shown in Figs. 2A and 2B may be made of a fluid impervious polymeric film or fluid pervious fibrous fabric (e.g. a woven or non-woven material) material or combination of these. Generally, the three-dimensional apertures in the film or fibrous material may be thermo-formed, or may be obtained by any other means, e.g. pressure, vacuum, perforation, as part of a material manufacturing process, or as an integral part of the tampon assembly line.

The polymeric film may consist of any polymer or mixture of polymers. The polymeric film may be composed of a thermoplastic synthetic polymer, including (but not limited to) polyolefin, polyester, polyanhydride, polyether, polyamide, polyimide, polyurethane, polyacrylic, halogenated polymers, etc. or coplymers of two or more of the above. The film may consist of a blend of (but not limited to) the above listed or a laminate. The blend may be homogeneous or phase-separated.

The polymer may also be a thermoset, if the degree of crosslinking permits the necessary processing for obtaining the three-dimensional apertures 25. The film may contain various additives such as fillers, plasticizers, dyes or pigments, etc. and/or various surface treatments such as surfactants, lubricants, etc.

The aperture forming method in a polymeric film may include any mechanical or thermal means or combination of both, including (but not limited to) thermoforming, piercing (e.g. by heat, water or air jet, vacuum etc.), in-calendering processes, casting, etc or a combination thereof, as part of a material manufacturing process, or as an integral part of the tampon assembly line.

When the cover 18 is made of a fluid-pervious material, the material may be a fibrous fabric (e.g. a woven, knitted, or non-woven material). The fibers may be (but not limited to) natural (e.g. cellulose-based - cotton, etc. or protein-based- wool, silk, etc.), regenerated (synthetic), cellulose fibers (e.g. viscose, rayon, lyocell) including cellulose derivates, synthetic fibers based on synthetic polymers including (but not limited to) polyolefin, polyester, polyether, polyamide, polyimide, polyurethane, polyacrylic, etc. The polymers may include copolymers and/or polymer blends.

Also, the fibers may be bi-component or multi-component. The fibers may have any form of cross-section including trilobal or multi-lobal. The fabric may be composed of one or a mixture of two or more of the above listed types of fibers. The fibers may include different finishes, additives, surface treatments, bonding agents, surfactants, active agents, etc. The fibers may be hydrophobic, hydrophilic, or a mixture of both.

The cover 18 may be formed on the absorbent core 15 by first encompassing the core by non-apertured cover material and subsequently forming in this material the apertures 25. The apertures 25 may be formed by any mechanical or thermal means or combination of both, including (but not limited to) thermoforming, in-calendering processes, fiber shifting/dislocation, etc. or a combination thereof, as an integral part of the tampon assembly line.

Alternatively, the apertures may be formed in the cover material before wrapping thereby the absorbent core, i.e. as part of a material manufacturing process.

Fig. 4 illustrates another cover 38 for use in the tampon 10 shown in Fig. 1. The cover 38 is made of a fibrous material (e.g. woven or non- woven material) comprised of a three-dimensional web of intersecting fibers defining at their intersections web holes such as to allow the material to be fluid permeable. The cover 38 has a first, outer surface 42 adapted for facing a body cavity (not shown), a second, inner surface 44 in contact with the absorbent core 15 and a material body 43 therebetween. The cover 38 has non-through going apertures 45 extending inwardly from openings 48 in the first, outer surface 42 of the cover towards the second surface 44, terminating inside the material body 43 at a distance D from the second surface. A portion between the second surface 44 and the aperture 45 constitutes the aperture's web-like base portion 49, whose thickness corresponds to the distance D. The distance D is clearly less than the thickness T of the cover and it may for example be in the range between a minimum thickness of a single layer of material fibers up to 75% of material thickness T. More particularly, the distance D may be between 20% and 50% of the thickness T, and still more particularly, between 25% to 40% of the thickness T. In one particular example, the thickness T may be about 150 microns and the distance D may be about 50 microns.

Each aperture 45 has a side wall 46 which may have the same geometry as that of the apertures 25 in the tampon cover 18 described above. Moreover, the apertures 45 may also be inclined in the same or similar way as the apertures 25. The openings 48 in the first surface 42 have an average area of one opening greater than an average area of one web hole of the fibrous material, at least at its first surface (the web holes not being seen in the Figures). To simplify the comparison, average or characteristic diameters, rather than areas, of the web holes and the openings may be compared, and those of the openings exceed those of the web holes, respectively.

The cover sleeve 38 described above may be produced by the following steps: providing fibrous material comprising a three-dimensional web of intersecting fibers defining at their intersections web holes, the material having the first surface 42, the second surface 44 and a material body 43 therebetween; forming the apertures 45 in said material such that said apertures extend inwardly from the openings 48 at the first surface 42 and terminate inside the material body at a distance from the second surface such that the material body forms the web- like base portion 49; and forming from said material the cover 38 on the absorbent core 15 so that the second surface 44 of the material is in contact with the outer surface 16 of the absorbent core.

The three-dimensional apertures 45 in the fibrous material may be formed by any means including any mechanical or thermal means or combination of both, including (but not limited to) ultrasonic aperturing, pressure, vacuum, partial perforation, thermoforming, in-calendering processes, fiber shifting/dislocation, etc. or a combination thereof. In any case, the process of forming the apertures should be such as not to close at least a part, and preferably, a majority of the web holes of the material at the base portion 49 of the apertures 45 or the wall 46 thereof, i.e. such as to keep the porous nature of the fibrous material. Moreover, the process may be such that some of the fibers in the web-like base portion 49 of the apertures 45 may be ruptured during the production, in view of which the web holes' dimensions in the base portion may be different from those in the remainder of the material body and in the first surface of the cover.

The cover 38 may be formed from any number of types of fibrous materials (e.g. a woven or non-woven material). The fibers may be (but not limited to) natural (e.g. cellulose-based - cotton, etc. or protein-based- wool, silk, etc.) regenerated (synthetic) cellulose fibers (e.g. viscose, rayon, lyocell) including cellulose derivates, synthetic fibers based on synthetic polymers including (but not limited to) polyolefϊn, polyester, polyether, polyamide, polyimide, polyurethane, polyacrylic, etc. The polymers may include copolymers and/or polymer blends.

Those skilled in the art to which this invention pertains will readily appreciate that numerous changes, variations, and modifications can be made without departing from the scope of the invention, mutatis mutandis.

Claims

CLAIMS:

1. A tampon for insertion into a body cavity for absorption of fluid therein, having an introduction end, a withdrawal end, and a longitudinal axis therebetween, the tampon comprising: • an absorbent core having an outer surface;

• a cover made of a fibrous material comprising a three-dimensional web of intersecting fibers defining at their intersections web holes, allowing the material to be fluid permeable, the cover having a first surface adapted for facing said body cavity and a second surface at least part of which is in contact with the outer surface of the absorbent core and a material body therebetween; and

• a plurality of apertures formed in said material at least over the majority of its area, at least a majority of said apertures each having an opening at a first surface, each aperture having a side wall extending inwardly from said opening and terminating at a distance from the second surface inside said material body whose portion between the second surface and the aperture constitutes the aperture's web-like base, an average characteristic cross-sectional diameter of one web hole does not exceed that of the aperture at least at the first surface.

2. A tampon according to Claim 1, wherein the distance from the first surface to the location at which the side walls of said apertures terminate at least does not exceed the longitudinal extension of the side wall thereof along the thickness of the material body.

3. A tampon according to Claim 2, wherein said distance is essentially less than said longitudinal extension.

4. A method for producing a cover for a tampon having an absorbent core, comprising:

• providing fibrous material comprising a three-dimensional web of intersecting fibers defining at their intersections web holes, allowing the material to be fluid permeable, the material having a first surface, a second surface and a material body therebetween;

• forming a plurality of apertures in said material at least over the majority of its area, at least a majority of said apertures each having an opening on said first surface, a side wall extending inwardly from said opening and terminating at a distance from the second surface and inside said material body , whose portion between the second surface and the aperture constitutes the aperture's web-like base, an average characteristic cross- sectional diameter of one web hole at least not exceeding that of the aperture at least at the first surface; and

• forming from said material the cover adapted to essentially encompass a majority of absorbent core so that at least part of said second surface of the material is in contact with an outer surface of the absorbent core.

5. A method according to Claim 4, wherein the step of forming a plurality of apertures does not close at least a part of the web holes of the material at the base or the side wall of each aperture.

6. A tampon for insertion into a body cavity for absorption of fluid therein, having an introduction end, a withdrawal end, and a longitudinal axis therebetween, the tampon comprising:

• an absorbent core having an outer surface;

• a cover, at least partially encompassing said absorbent core, having a first surface adapted for facing said body cavity and a second surface at least partially in contact with the outer surface of the absorbent core; • a plurality of apertures formed in said cover at least over the majority of its area, at least a majority of said apertures being in the form of ducts having an outer end in the form of a first opening in said first surface, an inner end in the form of a second opening spaced from the second surface in the direction of the absorbent core, and side wall extending between the first and second openings, which is oriented so that the first opening is located closer to the introduction end of the tampon than the second opening.

7. A tampon according to Claim 6, wherein the ducts, in their longitudinal cross- section, converge towards the second surface.

8. A tampon according to Claim 6, wherein ducts are orientated such that at their longitudinal cross section taken along their central lines passing through the centers of the first opening and the second opening, said central lines form an angle with said longitudinal axis, which is less than 85°.

9. A tampon according to Claim 8, wherein the angle is in the range 30°-60°.

10. A tampon according to Claim 8, wherein in a cross section taken along the central lines, the side walls of the ducts are non-parallel to said central lines.

11. A tampon according to any one of Claims 6 to 10, wherein the ducts converge in the direction from the first surface to the second surface so that the cross-sectional diameter of the second opening is smaller than that of the first opening.

12. A tampon according to any one of Claims 6 to 11, wherein at a cross section taken through the central lines of the ducts, the ducts are not symmetrical relative to their central lines so that the side wall's portions thereof have different length and the side wall portion closer to the introduction end of the tampon is longer than the wall closer to the withdrawal end.

13. A method for producing a tampon having a cover of any one of Claims 6 to 12, comprising:

• providing an absorbent core; • providing a cover material and encompassing thereby at least partially said absorbent core so that a first surface of the material is adapted for facing a body cavity and a second surface is at least partially in contact with the outer surface of the absorbent core; and

• forming in said material, when said absorbent core is encompassed thereby, a plurality of apertures at least over the majority of its area, at least a majority of said apertures being in the form of ducts having an outer end in the form of a first opening in said first surface, an inner end in the form of a second opening spaced from the second surface in the direction of the absorbent core, and side wall extending between the first and second openings, which is oriented so that the first opening is located closer to the introduction end of the tampon than the second opening.