MXPA99009437A - Tampon - Google Patents

Abstract

Se provee un tampón con una capa de barrera permeable o soluble interpuesta entre un núcleo absorbente y una sobrecubierta, que permite sustancialmente de manera completa, el mojado uniforme que se obtiene aún bajo condiciones de flujo ligero. La barrera impide el flujo inmediato del fluido hacia el núcleo, dando tiempo para que el fluido sea llevado por la sobrecubierta alrededor de la superficie externa del tampón, antes de ser arrastrado hacia el núcleo absorbente.

Description

TAMPON BACKGROUND OF THE INVENTION The present invention relates to tampons. The tampons can be formed from two types of absorbent compressed masses, a rolled absorbent mass, formed to provide a specific length section of an absorbent material, for example, a non-woven web, having a width approximately corresponding to length of the tampon, and winding or winding the section on itself to form an absorbent compressed mass, or uncoiled absorbent compressed masses, formed by providing a fibrous block of absorbent material having a width corresponding approximately to the length of the tampon. In both cases, the absorbent mass is compressed radially to form a finished buffer. The term "absorbent compressed mass" as used herein, refers to both absorbent masses rolled or uncoiled. Buffers are often provided with a dust jacket, ie, an outer cover of a liquid permeable material, for example a thermoplastic nonwoven material, to improve the smoothness of the surface of the tampon, to reduce the insertion and removal forces, and preventing fibers from the non-woven material from stripping (recessed from the fiber ") during insertion and removal.A common problem in both types of tampons is non-uniform or incomplete wetting of the buffer surface, particularly during flow conditions light menstrual.Incomplete or non-uniform wetting tends to result in the drying of the vaginal epithelium, in part due to the rapid initial uptake of vaginal secretions in the dry areas of the tampon to balance the relative humidity contents of these areas of the tampon and vaginal epithelium The drying of vaginal epithelium can cause discomfort, because the vaginal wall is dry It will resist the removal of the tampon, potentially causing abrasions to the epithelium. This phenomenon tends to confuse users of tampons, and can make the tampon difficult and uncomfortable to remove.

BRIEF DESCRIPTION OF THE INVENTION The inventors have found that by providing a buffer with a semipermeable or soluble barrier layer interposed between an absorbent core and a dust jacket, the substantially uniform wetting around the outer surface of the absorbent core can be obtained even under conditions of light menstrual fluid. buffer, for example, a smaller flow of one gram of fluid, provided there is a minimum volume of fluid sufficient to substantially wet the total external surface. The barrier prevents immediate fluid flow to the core, allowing time for the fluid to be transported via capillary action within the jacket around the outer surface of the tampon, before being drawn into the absorbent core. The jacket conveys the fluid around the external surface of the tampon to improve the uniformity of wetting, without significantly reducing the absorbent capacity of the tampon. The invention gives importance to a tampon including an absorbent core, an insertion end dimensioned for insertion into a body cavity, an extraction end, an extraction cord extending from the extraction end, and a body that is extends between the insertion end and the extraction end. The tampon further includes a dust jacket covering at least a portion of the absorbent core, and a barrier layer interposed between the dust jacket and the surface of the absorbent core. Preferably, the absorbent core comprises a rolled, radially compressed absorbent mass. The dust jacket can cover the total absorbent core, or it can cover only a part of the absorbent core, for example, the dust jacket can cover the body but be open at the insertion end and / or the extraction end. The barrier layer preferably protects the total surface of the absorbent core, but in some embodiments it may be open at the insertion end and / or the extraction end. The barrier layer preferably covers at least the surface area of the tampon that is in contact with the wall of the vagina during use. If the barrier layer is open at the insertion end, it is preferred that the insertion end of the tampon be covered by, or coated with, a second barrier material, to prevent fluid from being drawn into the core through the end. of insertion before substantially completely wetting the outer surface of the tampon. In a first embodiment, the barrier layer is semipermeable to initially retard and then eventually allow the flow of menstrual fluid through the barrier layer once the outer surface of the tampon has been wetted. The barrier layer can be a porous, perforated or scored film, or it can be a fluid permeable membrane. A preferred barrier layer is a cellophane grooved film. Preferably, the barrier layer includes from about 1 to 10% of fluid permeable area. It is preferred that the orientation of the grooves of the grooved film be selected from the group consisting of: parallel to the longitudinal axis of the tampon (the axis extending between the ends of insertion and removal of the body), perpendicular to the longitudinal axis of the tampon, and diagonal to the longitudinal axis of the tampon. In a second embodiment, the barrier layer is initially impermeable to the fluid but is highly soluble in water. When the tampon is inserted, the fluid is momentarily prevented by the barrier layer from being drawn into the absorbent core, allowing the fluid to instead travel around and wet the surface of the tampon, carried by the dust jacket. Then after insertion, the barrier layer dissolves in the menstrual fluid, allowing the fluid to flow into the absorbent core. Preferred water-soluble barrier layers, waterproofs include but are not limited to films of polyvinyl alcohol, polyvinyl pyrrolidone, polyethylene oxide and polyethylene glycol. Preferably, the barrier layer has a solubility coefficient (i.e., the time required for a fluid to pass through the film) of about 1 to 30 minutes in physiological saline (1%). The porosity and / or solubility of the barrier layer is selected to allow the surface of the tampon to be substantially completely wetted even under conditions of low menstrual flow, while also allowing the fluid to flow into the absorbent core almost immediately after of which fluid makes contact with the dust jacket. Preferably, the compressed absorbent mass has a cylindrical, smooth outer surface, rather than a groove shape as is conventional for digital buffers. The smooth surface provides an uninterrupted continuous path for the flow of fluid on the surface of the absorbent mass. Other features of the invention will be apparent from the following description of the preferred embodiments, the claims, and the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a side view of a tampon according to an embodiment of the invention, with a part of the jacket cut away to show the underlying barrier layer.

Figure 2 is a cross-sectional side view of the tampon of the Figure 1.

DESCRIPTION OF THE PREFERRED MODALITIES Referring to Figures 1 and 2, a preferred tampon 10 includes an absorbent mass 12 having an insertion end 14, a body 16, an extraction end 18, and an extraction cord 20. The tampon 10 further includes a layer of barrier 22 adjacent the surface of the absorbent mass 12, and a jacket 26 surrounding the barrier layer. Preferably, the barrier layer has a thickness of about 10 to 50 microns, more preferably about 18 to 25 microns. In the embodiment shown in Figure 1, the barrier layer is a cellophane film having a plurality of substantially parallel slots 24. Instead of grooves, the barrier layer can have any pattern of pores, perforations or other openings, desired. Alternatively, instead of the cellophane film with slots, the barrier layer 22 may be another type of perforated or slotted, porous, semipermeable material, which is either soluble or insoluble in the menstrual fluid. Moreover, the barrier layer 22 may be any suitable impermeable material that is sufficiently soluble in the menstrual fluid to allow it to dissolve at a controlled rate upon contact with the menstrual fluid. Suitable water soluble films include polyvinyl pyrrolidone, polyethylene oxide, polyethylene glycol and polyvinyl alcohol. Other suitable barrier layers include coatings of paraffin-free synthetic waxes. Suitable coverings are permeable, hydrophilic sheet materials, which will be absorbed by capillary action or will entrain menstrual fluid on the surface of the absorbent mass during the period of time prior to absorption of the fluid in the core, ie, the time before the dissolution of the barrier layer or passage of the fluid through the slots or perforations in the barrier layer. Suitable dust jacket materials include, but are not limited to, chemically bonded rayon, nonwoven materials, thermally bonded nonwoven materials, nonwoven materials with hydrophilic treatments, spunbonded webs, and hydroentangled webs. Preferred fibers for use in the jacket include, but are not limited to, chemically bonded rayon, polypropylene and bicomponent fibers treated with hydrophilic treatments. The preferred base weight of the jacket is about 15 to 30 g / m2, more preferably 30 g / m2. Preferably, the barrier layer covers at least the surface area of the tampon that contacts the end of the vagina wall of the tampon. When this is the case, the insertion end of the tampon is preferably covered with a separate barrier layer or material, for example, a coating of a water soluble polymer such as a synthetic wax. A preferred coating is polyethylene glycol, more preferably a degree of polyethylene glycol having a molecular weight of about 20,000 to 100,000. Any conventional absorbent material is suitable for use in the buffer of the invention. Preferred absorbent materials are selected from the group consisting of cellulosic fibers, cotton fibers, rayon fibers and mixtures thereof. More preferred are mixtures of cotton and rayon fibers. Preferably, the compressed absorbent mass has a smooth outer surface, instead of a fluted surface, as shown in Figure 1. The smooth outer surface facilitates the movement of the fluid on the surface of the tampon.

For ease of manufacture, it is preferred that the jacket and the barrier layer be laminated together to form a single laminate sheet that can be applied to the absorbent core in a single step. Other embodiments are within the claims. For example, while grooves of the grooved film are shown as being substantially parallel and straight, they can have any desired shape and orientation, for example, these can be L-shaped, S-shaped, or straight but not arranged parallel to each other.

Claims (21)

1. A tampon comprising: an absorbent core, an insertion end dimensioned for insertion into a body cavity, an extraction end, an extraction cord attached to the extraction end, and a body extending between the insertion end and the extraction end, a jacket covering at least part of the absorbent core, and a first barrier layer interposed between the jacket and the surface of the absorbent core.

The tampon according to claim 1, wherein the absorbent core comprises a radially compressed, rolled absorbent mass.

The tampon according to claim 1, wherein the barrier layer covers the body of the absorbent core and the surface of the absorbent core and the insertion end is covered by a second barrier layer to prevent the flow being drawn into the core through the insertion end before substantially completely wetting the surface of the tampon.

4. The buffer according to claim 3, wherein the second barrier layer comprises a water soluble polymer.

5. The buffer according to claim 4, wherein the water-soluble polymer is a polyethylene glycol.

6. The buffer according to claim 5, wherein the polyethylene glycol has a molecular weight of about 20,000 to 100,000.

The buffer according to claim 1, wherein the barrier layer is a water-impermeable, water-soluble film.

8. The buffer according to claim 7, wherein the film is selected from the group consisting of polyvinyl alcohol films, polyvinyl pyrrolidone films, polyethylene oxide films and polyethylene glycol films.

The buffer according to claim 7, wherein the barrier layer has a solubility coefficient of about 1 to 30 minutes in physiological saline solution (1%).

The tampon according to claim 1, wherein the barrier layer is a fluid permeable film.

The tampon according to claim 10, wherein the barrier layer is a perforated film.

The tampon according to claim 10, wherein the barrier layer is a grooved film.

The tampon according to claim 12, wherein the tampon has a longitudinal axis extending between the insertion and extraction ends, and the slotted film includes a plurality of substantially parallel slots having an orientation selected from the group which consists of: parallel to the longitudinal axis of the tampon, perpendicular to the longitudinal axis of the tampon, and diagonal to the longitudinal axis of the tampon.

The tampon according to claim 11, wherein the barrier layer is a cellophane film.

15. The tampon according to claim 11, wherein the barrier layer includes from about 1 to 10% of the fluid-permeable area.

16. The buffer according to claim 10, wherein the barrier layer is a semipermeable membrane, permeable to the fluid.

17. The buffer according to claim 1, wherein the barrier layer has a thickness of about 10 to 50 microns.

18. The tampon according to claim 17, wherein the barrier layer has a thickness of about 18 to 25 microns.

19. The tampon according to claim 1, wherein the dust jacket is made of a hydrophilic nonwoven material. The tampon according to claim 1, wherein the tampon has a cylindrical, smooth outer surface, to provide a continuous path for fluid flow over the surface of the tampon. The tampon according to claim 1, wherein the barrier layer and the dust jacket are laminated together to form a single laminate sheet.