Surgery – Means and methods for collecting body fluids or waste material – Absorbent pad for external or internal application and...
Reexamination Certificate
1997-11-12
2001-11-13
Ruhl, Dennis (Department: 3761)
Surgery
Means and methods for collecting body fluids or waste material
Absorbent pad for external or internal application and...
C604S904000
Reexamination Certificate
active
06315763
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to tampons.
Tampons may be formed from two types of pledgets, a rolled pledget, formed by providing a section of specific length of an absorbent material, e.g. a nonwoven web, having a width corresponding approximately to the length of the tampon, and winding or rolling the section upon itself to form a pledget, or non-rolled pledgets, formed by providing a batt of absorbent material having a width corresponding approximately to the length of the tampon. In both cases, the pledget is compressed radially to form a finished tampon. The term “pledget”, as used herein, refers to both rolled and non-rolled pledgets.
Tampons are often provided with an overwrap, i.e. an outer covering of a liquid permeable material, for example a thermoplastic nonwoven, to improve the smoothness of the tampon surface, reducing insertion and withdrawal forces, and to prevent fibers of the nonwoven from being detached (“fiber fluff-off”) during insertion and withdrawal.
One problem common to both types of tampons is uneven or incomplete wetting of the surface of the tampon, particularly during conditions of light menstrual flow. Incomplete or uneven wetting tends to result in drying of the vaginal epithelium, in part due to the rapid initial uptake of vaginal secretions into dry areas of the tampon to equilibrate the relative moisture contents of these areas of the tampon and the vaginal epithelium. Drying of the vaginal epithelium may cause discomfort, because the dry vaginal wall will tend to resist withdrawal of the tampon, potentially causing epithelial abrasions. This phenomenon tends to be disconcerting to tampon users, and can make tampon withdrawal difficult and uncomfortable.
SUMMARY OF THE INVENTION
The inventors have found that by providing a tampon with a semi-permeable or soluble barrier layer interposed between an absorbent core and an overwrap, substantially uniform wetting around the outer surface of the tampon can be obtained even under light menstrual fluid conditions, e.g., a flow of less than one gram of fluid, provided there is a minimal volume of fluid sufficient to wet substantially the entire outer surface. The barrier prevents immediate flow of fluid into the core, allowing time for fluid to be transported via capillary action within the overwrap around the outer surface of the tampon, prior to being drawn into the absorbent core. The overwrap transports the fluid around the outer surface of the tampon to improve evenness of wetting, without significantly reducing the absorbent capacity of the tampon.
The invention features a tampon including an absorbent core, an insertion end dimensioned for insertion into a body cavity, a withdrawal end, a withdrawal cord extending from to the withdrawal end, and a body extending between the insertion end and the withdrawal end. The tampon further includes an overwrap covering at least a portion of the absorbent core, and a barrier layer interposed between the overwrap and surface of the absorbent core. Preferably, the absorbent core comprises a rolled, radially compressed pledget. The overwrap may cover the entire absorbent core, or may cover only a portion of the absorbent core, e.g., the overwrap may cover the body but be open at the insertion end and/or withdrawal end. The barrier layer preferably covers the entire surface of the absorbent core, but in some embodiments may be open at the insertion end and/or withdrawal end. The barrier layer preferably covers at least the area of the tampon surface that contacts the vaginal wall 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 insertion end prior to substantially complete wetting of the outer surface of the tampon.
In a first embodiment, the barrier layer is semipermeable to initially retard and then eventually allow flow of menstrual fluid through the barrier layer once the outer surface of the tampon has been wetted. The barrier layer may be a porous, perforated or slit film, or may be a fluid-permeable membrane. A preferred barrier layer is a slit cellophane film. Preferably the barrier layer includes about 1 to 10% fluid-permeable area. It is preferred that the orientation of the slits of the slit film be selected from the group consisting of: parallel to the longitudinal axis of the tampon (the axis extending between the insertion and withdrawal ends 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 fluid impermeable but is highly water soluble. When the tampon is inserted 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 overwrap. Shortly after insertion, the barrier layer dissolves in the menstrual fluid, allowing fluid to flow into the absorbent core. Preferred impermeable, water soluble barrier layers include but are not limited to films of polyvinyl alcohol, polyvinyl pyrrolidone, polyethylene oxide and polyethylene glycol. Preferably, the barrier layer has a solubility rate i.e., the (time required for a fluid to pass through the film) of from about 1 to 30 min. in physiological saline solution (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 fluid to flow into the absorbent core almost immediately after fluid contact with the overwrap.
Preferably, the compressed pledget has a smooth, cylindrical outer surface, rather than a fluted shape as is conventional for digital tampons. The smooth surface provides a continuous uninterrupted path for fluid flow over the surface of the pledget.
Other features of the invention will be apparent from the following description of preferred embodiments, from the claims, and from the drawings.
REFERENCES:
patent: 2340311 (1944-02-01), Donovan
patent: 2440141 (1948-04-01), Donovan
patent: 3340874 (1967-09-01), Burgeni
patent: 3523535 (1970-08-01), Croon
patent: 4211225 (1980-07-01), Sibalis
patent: 4226237 (1980-10-01), Levesque
patent: 4276338 (1981-06-01), Ludwa et al.
patent: 4305391 (1981-12-01), Jackson
patent: 4335722 (1982-06-01), Jackson
patent: 0 685 215 A1 (1995-05-01), None
Albright Mark
Sanger Nigel
Taylor Fiona
Whyte Carolyn
Cummings Theodore P.
Fitzpatrick Matthew P.
Johnson Kevin C.
Ruhl Dennis
Tambrands Inc.
LandOfFree
Tampon does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Tampon, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Tampon will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2577335