Title:
HYDRO-DISSOCIATIVE AGGLOMERATE TAMPON
United States Patent 3812856
Abstract:
A tampon having an absorbent body which is an agglomerate of pieces of absorbent foam, said agglomerate being held together by an overwrap which has water frangible closures that are maintained before use and in vivo but open up when the tampon is agitated in an excess of water such as a standard sewage disposal system.
US Patent References:
Catamenial appliance and composition
Mosier - February 1964 - 3121427
WATER-SOLUBLE CELLULOSE ETHER OR STARCH COMPOSITIONS
Ganz - December 1969 - 3485651
MICROORGANISM GROWTH INHIBITING FIBER PRODUCTS
Gander et al. - July 1970 - 3521624
/3616797.html
Champaigne, Jr. et al. - November 1971 - 3616797
SANITARY NAPKIN
Morane - June 1972 - 3669114
Catamenial appliance and composition
Mosier - February 1964 - 3121427
WATER-SOLUBLE CELLULOSE ETHER OR STARCH COMPOSITIONS
Ganz - December 1969 - 3485651
MICROORGANISM GROWTH INHIBITING FIBER PRODUCTS
Gander et al. - July 1970 - 3521624
/3616797.html
Champaigne, Jr. et al. - November 1971 - 3616797
SANITARY NAPKIN
Morane - June 1972 - 3669114
Inventors:
Duncan, Robert Campbell (Cincinnati, OH)
Kokx, Darrel Dayfield (Cincinnati, OH)
Kokx, Darrel Dayfield (Cincinnati, OH)
Application Number:
05/254055
Publication Date:
05/28/1974
Filing Date:
05/17/1972
View Patent Images:
Export Citation:
Assignee:
The Procter & Gamble Company (Cincinnati, OH)
Primary Class:
Other Classes:
604/904, 604/369, 604/378, 604/372, 604/370
International Classes:
A61F13/24; A61F13/20; A61F13/20
Field of Search:
128/156,284,285,287,29W,296
US Patent References:
Primary Examiner:
Rosenbaum, Charles F.
Attorney, Agent or Firm:
Aylor V, Robert Gorman John Witte Richard B. C.
Claims:
What is claimed is
1. A catamenial device comprising an absorbent body, said body being an agglomerate of discrete pieces of three-dimensional cellular absorptive material, a flexible, fluid-permeable overwrap encasing said body, and means of egress in said overwrap for said pieces, said means being discrete and localized in the overwrap, said means being substantially closed to the passage of the pieces before and during use and said means being water frangible upon disposal in a water bath, whereby said pieces remain encased before and during use and, upon disposal of the device in a water closet, an opening forms in the overwrap and the pieces disgorge through the opening and separate from the overwrap.
2. The device of claim 1 wherein said means comprises a closure of the overwrap.
3. The device of claim 2 wherein said closure is maintained by a water frangible adhesive operatively associated with the closure, said adhesive having an inverse temperture-water solubility property and a threshold temperature between about 95°F. and 70°F.
4. The device for claim 2 wherein said overwrap is essentially tubular and said closure comprises a longitudinal seam in the overwrap.
5. The device of claim 2 wherein said overwrap is tubular and the closure comprises a gathering of a terminal longitudinal end of said overwrap.
6. The device of claim 5 wherein said overwrap is tubular and said closure also comprises a longitudinal seam extending to the gathered longitudinal end, the seam being secured by a water frangible adhesive, whereby when the device is placed in a water bath, said overwrap opens both along the saem and at the gathered longitudinal end to disgorge the pieces of absorptive material.
7. A catamenial device comprising an absorbent body, said body being an agglomerate of pieces of three-dimensional cellular absorptive material, a flexible, fluid-permeable overwrap encasing said body, and means of egress in said overwrap for said pieces, said means being a reentrant portion of the overwrap, said reentrant portion being an end portion of the overwrap turned inwardly around the end of and through the agglomerate of pieces, said agglomerate in the region of the reentrant portion being between the outer portion of the overwrap and the reentrant portion, said reentrant portion extending at least to about the midpoint of the device, whereby before and during use of said device said pieces remain encased by said overwrap an upon deposition of said device in a water bath said reentrant portion opens outwardly and said pieces can exit and be separated from the overwrap.
8. The device of claim 7 wherein said means comprises a reentrant portion at both longitudinal ends of the device.
9. The device of claim 7 wherein the terminal end of said reentrant portion is gathered into a closure and said closure is maintained with a water-frangible adhesive.
10. The device of claim 7 wherein the terminal end of the reentrant portion is adjacent the opposite terminal end of the overwrap.
11. The device of claim 7 wherein the terminal end of the reentrant portion is adjacent to and attached to the opposite terminal end of the overwrap with a water-frangible adhesive.
12. The device of claim 7 wherein said overwrap is tubular and said means also comprises a longitudinal seam extending to the terminal end of the reentrant portion, said seam including a water-frangible adhesive betwen the adjacent edges of the overwrap forming the seam, whereby upon exposure to an excess of water, both the seam and the reentrant portion open to disgorge the pieces of absorptive material.
13. The device of claim 12 wherein said adhesive has an inverse temperature-water solubility property and a threshold temperature between about 95°F. and 70°F.
1. A catamenial device comprising an absorbent body, said body being an agglomerate of discrete pieces of three-dimensional cellular absorptive material, a flexible, fluid-permeable overwrap encasing said body, and means of egress in said overwrap for said pieces, said means being discrete and localized in the overwrap, said means being substantially closed to the passage of the pieces before and during use and said means being water frangible upon disposal in a water bath, whereby said pieces remain encased before and during use and, upon disposal of the device in a water closet, an opening forms in the overwrap and the pieces disgorge through the opening and separate from the overwrap.
2. The device of claim 1 wherein said means comprises a closure of the overwrap.
3. The device of claim 2 wherein said closure is maintained by a water frangible adhesive operatively associated with the closure, said adhesive having an inverse temperture-water solubility property and a threshold temperature between about 95°F. and 70°F.
4. The device for claim 2 wherein said overwrap is essentially tubular and said closure comprises a longitudinal seam in the overwrap.
5. The device of claim 2 wherein said overwrap is tubular and the closure comprises a gathering of a terminal longitudinal end of said overwrap.
6. The device of claim 5 wherein said overwrap is tubular and said closure also comprises a longitudinal seam extending to the gathered longitudinal end, the seam being secured by a water frangible adhesive, whereby when the device is placed in a water bath, said overwrap opens both along the saem and at the gathered longitudinal end to disgorge the pieces of absorptive material.
7. A catamenial device comprising an absorbent body, said body being an agglomerate of pieces of three-dimensional cellular absorptive material, a flexible, fluid-permeable overwrap encasing said body, and means of egress in said overwrap for said pieces, said means being a reentrant portion of the overwrap, said reentrant portion being an end portion of the overwrap turned inwardly around the end of and through the agglomerate of pieces, said agglomerate in the region of the reentrant portion being between the outer portion of the overwrap and the reentrant portion, said reentrant portion extending at least to about the midpoint of the device, whereby before and during use of said device said pieces remain encased by said overwrap an upon deposition of said device in a water bath said reentrant portion opens outwardly and said pieces can exit and be separated from the overwrap.
8. The device of claim 7 wherein said means comprises a reentrant portion at both longitudinal ends of the device.
9. The device of claim 7 wherein the terminal end of said reentrant portion is gathered into a closure and said closure is maintained with a water-frangible adhesive.
10. The device of claim 7 wherein the terminal end of the reentrant portion is adjacent the opposite terminal end of the overwrap.
11. The device of claim 7 wherein the terminal end of the reentrant portion is adjacent to and attached to the opposite terminal end of the overwrap with a water-frangible adhesive.
12. The device of claim 7 wherein said overwrap is tubular and said means also comprises a longitudinal seam extending to the terminal end of the reentrant portion, said seam including a water-frangible adhesive betwen the adjacent edges of the overwrap forming the seam, whereby upon exposure to an excess of water, both the seam and the reentrant portion open to disgorge the pieces of absorptive material.
13. The device of claim 12 wherein said adhesive has an inverse temperature-water solubility property and a threshold temperature between about 95°F. and 70°F.
Description:
FIELD OF THE INVENTION
This invention relates generally to absorbent pads designed to be disposed of in a sewage system. More particularly, it concerns absorbent devices wherein the absorbent body is an agglomerate of distinct and separable pieces of foam or sponge encased by an overwrap.
DESCRIPTION OF THE PRIOR ART
Convenient disposal of single-use absorptive products has always presented a problem. These absorptive products are generally disposed of with the ordinary solid garbage or in a water closet. The mode of disposal generally considered most convenient is flushing in a water closet, but some absorptive products, such as disposable diapers, sanitary napkins and large tampons not properly prepared, can clog water closet systems when excessive bulk is employed.
Many different absorptive materials are used in the single-use absorptive products, various fibers being the most commonly used. Although fibrous products present some water closet disposal problems, sponge, sponge-like, and plastic foam products present greater water closet disposal problems due to the fact that they do not readily break down in a water closet system, and thus are more prone to clog water closet systems.
OBJECTS OF THE INVENTION
It is one object of the present invention to provide a highly absorbent, effective, catamenial tampon which can be disposed of readily in a water closet.
It is another object of this invention to provide a comfortable, effective, catamenial tampon which is hydro-dissociative.
More paticularly, it is a further object of this invention to provide an overwrapped agglomerate absorbent device which is hydro-dissociative and thereby convenient to dispose of.
SUMMARY OF THE INVENTION
In accordance with the present invention, there is provided a catamenial device comprising an absorbent body which is an agglomerate of pieces of three-dimensional cellular absorptive material, a fluid-permeable overwrap encasing the absorbent body, and means of egress from the overwrap for the pieces of absorptive material. The means of egress is closed to the passage of the pieces of absorptive material before and during use and adapted to be opened upon disposal in water, whereby the pieces remain encased before and during use and are disgorged and separated from the overwrap upon disposal in a water closet.
BRIEF DESCRIPTION OF THE DRAWINGS
While the specification concludes with claims particularly pointing out and distinctly claiming the subject matter which is regarded as forming the present invention, it is believed that the invention will be better understood from the following description which taken in connection with the accompanying drawing, in which the thickness of some of the materials are exaggerated for clarity and in which:
FIG. 1 is a fragmentary perspective of a tampon of this invention;
FIG. 2 is a cross-sectional elevational view of the tampon of FIG. 1 during one stage of its formation;
FIG. 3 is a cross-sectional elevational view of an alternate embodiment tampon at one stage of its formation;
FIG. 4 is a fragmentary perspective of a fully formed tampon of FIG. 3; and
FIG. 5 is a fragmentary perspective view of another tampon of this invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to FIG. 1, tampon 20 is shown as an absorbent device of this invention. The tampon 20 has an absorbent body 21 which is an agglomerate of pieces 22 of three-dimensional cellular absorptive material encased by overwrap 23 which can be made from a rectangular piece of overwrap material which is folded over edge to edge and held in the tubular-shape thus formed by longitudinal seam 26. The overwrap 23 has means of egress for the pieces 22, one form of the means of egress being an opening end 28. A withdrawal string 24 can be attached to the closed end 29 of the tampon 20 in any manner well known in the tampon art, for example, threading a double string through the closed end 29 to form a loop and passing the free ends of the string 24 through the loop or fixing the string 24 to the overwrap 23 by sewing it or bonding it thereto sufficiently to withstand forces encountered during withdrawal.
The opening end 28 is a closure formed by gathering the terminal end of the overwrap and holding the gathered overwrap together with a water frangible (i.e., that which is opened, broken, or destroyed by water) adhesive in order that the closure is maintained before and during wearing of the tampon 20 and is opened when tampon 20 is deposited in a standard water closet.
The water frangible closures described herein, such as opening end 28, are means of egress from the overwrap 23 for the pieces 22 and are substantially closed to the passage of pieces 22 before and during use of the tampon. The water frangible closure is opened by the swirling water in a flushed water closet or by a repeated dunking of the tampon 20 in the body of water in a water closet.
The expression "gathering" as used above is intended to include any bringing together of the overwrap at a longitudinal end to form a closure of the overwrap at that end, e.g., a closure in which the overwrap is omnidirectionally gathered radially inwardly as if drawn by a draw string; a fin seal wherein the terminal end is flattened to a single plane by forces perpendicular to the plane; a lap joint wherein the terminal end is folded inwardly and diametric portions of the end overlap, etc. A terminal end of the overwrap or any portion of the overwrap can be any extremity or margin of the overwrap, such as is indicated by end 36 in FIG. 4.
The water frangible closure can be formed with a water frangible adhesive 25. The tampon 20 at one stage of its formation can be such as shown in FIG. 2 where the overwrap 23 is tubularly shaped and has a closed end 29 which can be, but need not necessarily be, water frangible. If not water frangible, the closed end 29 can be formed by any convenient means such as sewing that end shut or, if desired, by bonding it with non-water soluble adhesives. An agglomerate of pieces 22 of absorptive material comprising an absorbent body 21 is placed within the bag-shaped overwrap and the opening end 28 is gathered to form a closure which is maintained by the water frangible adhesive 25 shown in FIG. 1. The overwrap 23 can be loose about the agglomerate, i.e., it does not have to form a tightly fitting overwrap with tensile forces therein. In fact, it can be advantageous to make the overwrap 23 oversized so that it is loose about the absorbent body 21 and essentially unstressed. An oversized overwrap tends to give the tampon a fluffy, soft feel and impression. An oversized overwrap also provides room for expansion of the absorptive material should it happen to be wet-swelling so that its absorptive capacity may be maintained.
In another embodiment such as is shown in FIG. 3, an overwrap 30 is slightly longer than that required for the embodiment of FIG. 1 so that a portion of the overwrap can be made reentrant, i.e., folded around one end of the agglomerate and inwardly through a portion of the agglomerate. Broadly speaking, that part of the overwrap which is not reentrant is the outer portion of the overwrap. In this embodiment the overwrap also can be tubularly shaped and have a closed end 29. The absorbent body 21 is placed within the bag-shaped overwrap and the agglomerate of pieces 22 is shaped to form therein a cavity 31 wherein the reentrant portion 34 of the overwrap 30 is placed such that the terminal end 36 of the overwrap 30 is the innermost end of the reentrant portion 34 of the overwrap 30 as is shown in FIG. 4. Folding the reentrant portion 34 into the cavity 31 forms an opening end 28 of the tampon of FIG. 4. When the reentrant portion 34 is folded inwardly, the absorbent body 31 is enclosed by the overwrap 30; when the reentrant portion 34 is unfolded as in FIG. 3, a means of egress is provided by the opened end. It is desirable that the reentrant portion extend to at least approximately the midpoint of the device.
The opening end 28 of the tampon of FIG. 4 has no proclivity toward opening before emersion in a water bath due to the fact that the overwrap itself is flexible and does not tend to "spring back" and the forces exerted on the tampon before and during use are primarily radially inward. When a tampon of this embodiment is introduced to a water bath, the reentrant portion 34 works outwardly, thereby providing the means of egress, so that the pieces 22 of absorptive material are free to exit the overwrap. The opening and dissociative proclivities of any of the embodiments of this invention are enhanced by a swirling or agitated water bath and it is thought to occur because the pieces 22 move with the water currents and/or have inertial forces which create forces within the overwrap tending to open the overwrap and remove the pieces 22.
Although it is not necessary to form a glued closure at the terminal end 36 of the embodiment of FIG. 4, an adhesive such as water frangible adhesive 25 of FIG. 1 can be used, if desired, to assist in closing the terminal end 36. A glued closure at the terminal end 36 would be reassuring to an inquisitive comsumer examining the tampon in that the consumer would note that the agglomerate of pieces 22 is encased during use by a sealed overwrap.
Another embodiment of a closure which will open to form a means of egress is shown in FIG. 5 wherein the overwrap 30 is long enough such that the leading end, i.e., terminal end 37 of the overwrap 30 is adjacent the closed end 29, i.e., the reentrant portion 35 extends through the agglomerate of pieces 22. In this embodiment, as in that of FIG. 4, the terminal end 37 can be either glued or unglued. If glued, a water frangible adhesive 33, similar to the water frangible adhesive 25 of the embodiment in FIG. 1, can be used. Also, terminal end 37 can be, but need not be, attached to closed end 29. If the terminal end 37 is attached to the closed end 29, a water frangible adhesive 33 may be used. The tampon of FIG. 5 thus is a completely encased hydro-dissociative agglomerate tampon having an opening end 28 which provides a means of egress.
In an alternate embodiment to that shown in FIG. 4, both ends, rather than only one end, of the overwrap can be reentrant on the absorptive body 21 with the terminal ends of the reentrant portions being adjacent at the approximate midpoint of the tampon. The terminal ends may be, but need not necessarily be, glued with a water frangible adhesive and each provides a means of egress from the overwrap. Also, the adjacent terminal ends of the two reentrant overwrap portions may, if desired, be attached to each other with a water frangible adhesive.
An alternative tampon structure to that shown in FIG. 1 which would provide a means of egress for the pieces of absorptive material is one wherein the overwrap is essentially tubular with closed ends and has a water frangible longitudinal seam, such as seam 26 of FIG. 1 or seam 32 of FIG. 4, which opens upon exposure to an excess of water. This seam can be of any of the well known types, such as one wherein the opposite edges forming the seam are overlapped and glued together with a water frangible adhesive 27, see FIG. 1, which will release when the tampon is flushed or dunked in a water closed. Thus, in this embodiment the means of egress is the water frangible longitudinal seam.
The water frangible longitudinal seam can, of course, be combined with the other described means of egress to enhance the opening capabilities of the overwrap. The opening capabilities are enhanced by including such a seam in the structure of the overwrap because both the longitudinal seam and the end open to thereby allow the pieces 22 forming the absorbent body 21 to escape radially as well as longitudinally from the overwrap.
In the preferred embodiment of a tampon of this invention, the overwrap is a nonwoven fabric; the absorbent body is an agglomerate of individual and separable pieces 22 of a hydrophilic, wet swellable, polyurethane foam, and the water frangible adhesive is one having an inverse temperature-water solubility relationship. Although not critical for the purpose of this invention, the tampon can have an outside diameter of approximately 2 1/4 inches and a length of about 2 1/4 inches. The form forming the absorbent body weighs about 2.5 grams and is cut into pieces which are about three-eighths inch across and smaller, i.e., pieces which will pass through a screen having a three-eighths inch mesh. Although the three-eighths inch and smaller size pieces have been found to work well, the size of the pieces can vary widely. The smallest acceptable size is determined by whether the piece will absorb and whether it will be retained by the overwrap. The largest acceptable size is determined by whether the piece will be disgorged from the overwrap and whether it will pass through a sewage system. The agglomerate of pieces 22 need not be coherent in and by itself because the overwrap will maintain the agglomerate, but it is contemplated that a water frangible cohesion between adjacent pieces can be used if desired.
This preferred embodiment can be inserted into a vagina via a telescoping tube type inserter, as is well known to those of ordinary skill in the tampon art. The tampon is resiliently compressed and maintained in that condition before and during insertion by placing it in the outer tube of the inserter. The outer tube is inserted into the vagina and the tampon is ejected from the outer tube by pushing the inner tube so that it telescopes within the outer tube. The inserter is removed from the vagina after the tampon has been ejected from the outer tube.
Absorptive materials which work well as the absorbent body for the tampon of this invention are polyurethane foams described in detail in the commonly owned, copending U.S. patent application entitled "Compliant Conformable Tampon," Ser. No. 172,694, filed Aug. 18, 1971. One of those polyurethane foams is available commercially as Scott Hydro-Foam TM from Scott Paper Company, Foam Division, Eddystone, Pennsylvania. The Hydro-Foam TM is hydrophilic and wet swelling. It was found to have a cell count of approximately 80 cells per inch, a density of about 1.9 to 2.3 pounds per cubic foot and a dry modulus of compression (as defined in ASTM Test D1564, Compression Load Deflection Text [suffix D] modified in that the samples were cubes 2 inches on a side) of about 0.4 pound per square inch. Other three-dimensional cellular absorptive materials, such as other gas blown foams, natural sponges, and cellulose sponges, can also be used as the absorptive material of this tampon.
The material used as the overwrap is a smooth, soft, non-pilling, flexible, fluid-permeable non-woven fabric. A biodegradable material for the overwrap is desirable. Two non-wovens which have functioned well as the overwrap and are believed to be biodegradable are: Dexter 2149, a non-woven fabric consisting of approximately a 60:40 cotton:rayon blend, saturation bonded with a mixture of HA8 and HA24, Rohm and Hass acrylic binders, said fabric having a measured weight of about 0.6 to 0.7 ounce per square yard and being hydrophobic and available from C. H. Dexter & Sons Co., Windsor Locks, Connecticut; and Viskon, which is a 100 percent rayon, non-woven, line-bonded material, is hydrophilic, has a measured weight of about 0.47 ounce per square yard, and is available from Chicopee Mills, 1450 Broadway, New York, N.Y. Reemay, which is a hydrophobic, spun bonded, low basis weight, polyester non-woven fabric having a measured weight of about 0.4 ounce per square yard and is available from E. I. Du Pont de Nemours, Wilimington, Delaware, is another non-woven which has performed satisfactorily as an overwrap.
The water frangible adhesive which can be used in the preferred embodiment of the tampon of this invention preferably has an inverse temperature-water solubility property, that is, it is insoluble at temperatures above a threshold temperature but is soluble at temperatures below that theshold. Any such physiologically safe adhesive having a threshold temperature lower than normal body temperature and higher than the sewage water temperture would work satisfactorily, but preferably the threshold temperature should be between about 95°F. and 70°F. In a satisfactory specific application of the present invention the adhesive used had a threshold temperature of about 85°F. so that the adhesive was insoluble while it was within the vagina where it would become wetted with menses and the temperature is about 98°F., i.e., above the threshold temperature, but was soluble in water used in an ordinary sewage system which is about 70°F. or less. The adhesive used was Klucel and is available from Hercules, Inc., Wilmington, Delaware. Klucel is a non-ionic, water soluble, thermoplastic cellulosic material formed by reacting alkali cellulose with propylene oxide to give hydroxypropylcellulose (ether link) and having a molecular weight of about 60,000 to 1,000,000. Below is an idealized structure of a hydroxypropylcellulose molecule with a molar substitution of 3.0. ##SPC1##
Other water frangible adhseives which can adhesives used to form the water frangible closures of the tampon of this invention, even though they do not have an inverse temperature-water solubility property, are Elvanol available from E. I. Du Pont de Nemours, Wilmington, Delaware, and Carbowax available from Union Carbide, 270 Park Ave., New York, N.Y. 10017. Elvanol is a water soluble polyvinyl alcohol having a typical structure as follows: ##SPC2##
Elvanol is generally 2with a plasticizer such as gylcerin to give it a low solution viscosity. Carbowax is an ethylene oxide polymer (called polyethylene glycol) having a typical structure as follows:
HO -- CH 2 -- (CH 2 -- O -- CH 2 ) n -- CH 2 -- OH
n = average nmber of oxyethylene groups per molecule. Carbowax 1000 to Carbowax 6000 are waxy water soluble solids suitable for some hot metal applications.
A material which has worked well as a withdrawal string is a waterproof cotton string having a 5/3 ply and a 9 pound tensile strength. Such a string is available from Bibb Manufacturing Company, Macon, Georgia under the name of 5/3 ply Sno-Spun bleach 108 cotton. The waterproofing on the string is to prevent wicking within the string which could lead menses outside the vagina and soil the user's clothing.
Thus it is apparent that there has been provided, in accordance with the invention, an absorptive device that fully satisfies the objects, aims, and advantages set forth above. While the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications, and variations with be apparent to those skilled in the art in light of the foregoing description. Accordingly, it is intended to embrace all such alternatives, modifications, and variations which fall within the spirit and broad scope of the appended claims.
This invention relates generally to absorbent pads designed to be disposed of in a sewage system. More particularly, it concerns absorbent devices wherein the absorbent body is an agglomerate of distinct and separable pieces of foam or sponge encased by an overwrap.
DESCRIPTION OF THE PRIOR ART
Convenient disposal of single-use absorptive products has always presented a problem. These absorptive products are generally disposed of with the ordinary solid garbage or in a water closet. The mode of disposal generally considered most convenient is flushing in a water closet, but some absorptive products, such as disposable diapers, sanitary napkins and large tampons not properly prepared, can clog water closet systems when excessive bulk is employed.
Many different absorptive materials are used in the single-use absorptive products, various fibers being the most commonly used. Although fibrous products present some water closet disposal problems, sponge, sponge-like, and plastic foam products present greater water closet disposal problems due to the fact that they do not readily break down in a water closet system, and thus are more prone to clog water closet systems.
OBJECTS OF THE INVENTION
It is one object of the present invention to provide a highly absorbent, effective, catamenial tampon which can be disposed of readily in a water closet.
It is another object of this invention to provide a comfortable, effective, catamenial tampon which is hydro-dissociative.
More paticularly, it is a further object of this invention to provide an overwrapped agglomerate absorbent device which is hydro-dissociative and thereby convenient to dispose of.
SUMMARY OF THE INVENTION
In accordance with the present invention, there is provided a catamenial device comprising an absorbent body which is an agglomerate of pieces of three-dimensional cellular absorptive material, a fluid-permeable overwrap encasing the absorbent body, and means of egress from the overwrap for the pieces of absorptive material. The means of egress is closed to the passage of the pieces of absorptive material before and during use and adapted to be opened upon disposal in water, whereby the pieces remain encased before and during use and are disgorged and separated from the overwrap upon disposal in a water closet.
BRIEF DESCRIPTION OF THE DRAWINGS
While the specification concludes with claims particularly pointing out and distinctly claiming the subject matter which is regarded as forming the present invention, it is believed that the invention will be better understood from the following description which taken in connection with the accompanying drawing, in which the thickness of some of the materials are exaggerated for clarity and in which:
FIG. 1 is a fragmentary perspective of a tampon of this invention;
FIG. 2 is a cross-sectional elevational view of the tampon of FIG. 1 during one stage of its formation;
FIG. 3 is a cross-sectional elevational view of an alternate embodiment tampon at one stage of its formation;
FIG. 4 is a fragmentary perspective of a fully formed tampon of FIG. 3; and
FIG. 5 is a fragmentary perspective view of another tampon of this invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to FIG. 1, tampon 20 is shown as an absorbent device of this invention. The tampon 20 has an absorbent body 21 which is an agglomerate of pieces 22 of three-dimensional cellular absorptive material encased by overwrap 23 which can be made from a rectangular piece of overwrap material which is folded over edge to edge and held in the tubular-shape thus formed by longitudinal seam 26. The overwrap 23 has means of egress for the pieces 22, one form of the means of egress being an opening end 28. A withdrawal string 24 can be attached to the closed end 29 of the tampon 20 in any manner well known in the tampon art, for example, threading a double string through the closed end 29 to form a loop and passing the free ends of the string 24 through the loop or fixing the string 24 to the overwrap 23 by sewing it or bonding it thereto sufficiently to withstand forces encountered during withdrawal.
The opening end 28 is a closure formed by gathering the terminal end of the overwrap and holding the gathered overwrap together with a water frangible (i.e., that which is opened, broken, or destroyed by water) adhesive in order that the closure is maintained before and during wearing of the tampon 20 and is opened when tampon 20 is deposited in a standard water closet.
The water frangible closures described herein, such as opening end 28, are means of egress from the overwrap 23 for the pieces 22 and are substantially closed to the passage of pieces 22 before and during use of the tampon. The water frangible closure is opened by the swirling water in a flushed water closet or by a repeated dunking of the tampon 20 in the body of water in a water closet.
The expression "gathering" as used above is intended to include any bringing together of the overwrap at a longitudinal end to form a closure of the overwrap at that end, e.g., a closure in which the overwrap is omnidirectionally gathered radially inwardly as if drawn by a draw string; a fin seal wherein the terminal end is flattened to a single plane by forces perpendicular to the plane; a lap joint wherein the terminal end is folded inwardly and diametric portions of the end overlap, etc. A terminal end of the overwrap or any portion of the overwrap can be any extremity or margin of the overwrap, such as is indicated by end 36 in FIG. 4.
The water frangible closure can be formed with a water frangible adhesive 25. The tampon 20 at one stage of its formation can be such as shown in FIG. 2 where the overwrap 23 is tubularly shaped and has a closed end 29 which can be, but need not necessarily be, water frangible. If not water frangible, the closed end 29 can be formed by any convenient means such as sewing that end shut or, if desired, by bonding it with non-water soluble adhesives. An agglomerate of pieces 22 of absorptive material comprising an absorbent body 21 is placed within the bag-shaped overwrap and the opening end 28 is gathered to form a closure which is maintained by the water frangible adhesive 25 shown in FIG. 1. The overwrap 23 can be loose about the agglomerate, i.e., it does not have to form a tightly fitting overwrap with tensile forces therein. In fact, it can be advantageous to make the overwrap 23 oversized so that it is loose about the absorbent body 21 and essentially unstressed. An oversized overwrap tends to give the tampon a fluffy, soft feel and impression. An oversized overwrap also provides room for expansion of the absorptive material should it happen to be wet-swelling so that its absorptive capacity may be maintained.
In another embodiment such as is shown in FIG. 3, an overwrap 30 is slightly longer than that required for the embodiment of FIG. 1 so that a portion of the overwrap can be made reentrant, i.e., folded around one end of the agglomerate and inwardly through a portion of the agglomerate. Broadly speaking, that part of the overwrap which is not reentrant is the outer portion of the overwrap. In this embodiment the overwrap also can be tubularly shaped and have a closed end 29. The absorbent body 21 is placed within the bag-shaped overwrap and the agglomerate of pieces 22 is shaped to form therein a cavity 31 wherein the reentrant portion 34 of the overwrap 30 is placed such that the terminal end 36 of the overwrap 30 is the innermost end of the reentrant portion 34 of the overwrap 30 as is shown in FIG. 4. Folding the reentrant portion 34 into the cavity 31 forms an opening end 28 of the tampon of FIG. 4. When the reentrant portion 34 is folded inwardly, the absorbent body 31 is enclosed by the overwrap 30; when the reentrant portion 34 is unfolded as in FIG. 3, a means of egress is provided by the opened end. It is desirable that the reentrant portion extend to at least approximately the midpoint of the device.
The opening end 28 of the tampon of FIG. 4 has no proclivity toward opening before emersion in a water bath due to the fact that the overwrap itself is flexible and does not tend to "spring back" and the forces exerted on the tampon before and during use are primarily radially inward. When a tampon of this embodiment is introduced to a water bath, the reentrant portion 34 works outwardly, thereby providing the means of egress, so that the pieces 22 of absorptive material are free to exit the overwrap. The opening and dissociative proclivities of any of the embodiments of this invention are enhanced by a swirling or agitated water bath and it is thought to occur because the pieces 22 move with the water currents and/or have inertial forces which create forces within the overwrap tending to open the overwrap and remove the pieces 22.
Although it is not necessary to form a glued closure at the terminal end 36 of the embodiment of FIG. 4, an adhesive such as water frangible adhesive 25 of FIG. 1 can be used, if desired, to assist in closing the terminal end 36. A glued closure at the terminal end 36 would be reassuring to an inquisitive comsumer examining the tampon in that the consumer would note that the agglomerate of pieces 22 is encased during use by a sealed overwrap.
Another embodiment of a closure which will open to form a means of egress is shown in FIG. 5 wherein the overwrap 30 is long enough such that the leading end, i.e., terminal end 37 of the overwrap 30 is adjacent the closed end 29, i.e., the reentrant portion 35 extends through the agglomerate of pieces 22. In this embodiment, as in that of FIG. 4, the terminal end 37 can be either glued or unglued. If glued, a water frangible adhesive 33, similar to the water frangible adhesive 25 of the embodiment in FIG. 1, can be used. Also, terminal end 37 can be, but need not be, attached to closed end 29. If the terminal end 37 is attached to the closed end 29, a water frangible adhesive 33 may be used. The tampon of FIG. 5 thus is a completely encased hydro-dissociative agglomerate tampon having an opening end 28 which provides a means of egress.
In an alternate embodiment to that shown in FIG. 4, both ends, rather than only one end, of the overwrap can be reentrant on the absorptive body 21 with the terminal ends of the reentrant portions being adjacent at the approximate midpoint of the tampon. The terminal ends may be, but need not necessarily be, glued with a water frangible adhesive and each provides a means of egress from the overwrap. Also, the adjacent terminal ends of the two reentrant overwrap portions may, if desired, be attached to each other with a water frangible adhesive.
An alternative tampon structure to that shown in FIG. 1 which would provide a means of egress for the pieces of absorptive material is one wherein the overwrap is essentially tubular with closed ends and has a water frangible longitudinal seam, such as seam 26 of FIG. 1 or seam 32 of FIG. 4, which opens upon exposure to an excess of water. This seam can be of any of the well known types, such as one wherein the opposite edges forming the seam are overlapped and glued together with a water frangible adhesive 27, see FIG. 1, which will release when the tampon is flushed or dunked in a water closed. Thus, in this embodiment the means of egress is the water frangible longitudinal seam.
The water frangible longitudinal seam can, of course, be combined with the other described means of egress to enhance the opening capabilities of the overwrap. The opening capabilities are enhanced by including such a seam in the structure of the overwrap because both the longitudinal seam and the end open to thereby allow the pieces 22 forming the absorbent body 21 to escape radially as well as longitudinally from the overwrap.
In the preferred embodiment of a tampon of this invention, the overwrap is a nonwoven fabric; the absorbent body is an agglomerate of individual and separable pieces 22 of a hydrophilic, wet swellable, polyurethane foam, and the water frangible adhesive is one having an inverse temperature-water solubility relationship. Although not critical for the purpose of this invention, the tampon can have an outside diameter of approximately 2 1/4 inches and a length of about 2 1/4 inches. The form forming the absorbent body weighs about 2.5 grams and is cut into pieces which are about three-eighths inch across and smaller, i.e., pieces which will pass through a screen having a three-eighths inch mesh. Although the three-eighths inch and smaller size pieces have been found to work well, the size of the pieces can vary widely. The smallest acceptable size is determined by whether the piece will absorb and whether it will be retained by the overwrap. The largest acceptable size is determined by whether the piece will be disgorged from the overwrap and whether it will pass through a sewage system. The agglomerate of pieces 22 need not be coherent in and by itself because the overwrap will maintain the agglomerate, but it is contemplated that a water frangible cohesion between adjacent pieces can be used if desired.
This preferred embodiment can be inserted into a vagina via a telescoping tube type inserter, as is well known to those of ordinary skill in the tampon art. The tampon is resiliently compressed and maintained in that condition before and during insertion by placing it in the outer tube of the inserter. The outer tube is inserted into the vagina and the tampon is ejected from the outer tube by pushing the inner tube so that it telescopes within the outer tube. The inserter is removed from the vagina after the tampon has been ejected from the outer tube.
Absorptive materials which work well as the absorbent body for the tampon of this invention are polyurethane foams described in detail in the commonly owned, copending U.S. patent application entitled "Compliant Conformable Tampon," Ser. No. 172,694, filed Aug. 18, 1971. One of those polyurethane foams is available commercially as Scott Hydro-Foam TM from Scott Paper Company, Foam Division, Eddystone, Pennsylvania. The Hydro-Foam TM is hydrophilic and wet swelling. It was found to have a cell count of approximately 80 cells per inch, a density of about 1.9 to 2.3 pounds per cubic foot and a dry modulus of compression (as defined in ASTM Test D1564, Compression Load Deflection Text [suffix D] modified in that the samples were cubes 2 inches on a side) of about 0.4 pound per square inch. Other three-dimensional cellular absorptive materials, such as other gas blown foams, natural sponges, and cellulose sponges, can also be used as the absorptive material of this tampon.
The material used as the overwrap is a smooth, soft, non-pilling, flexible, fluid-permeable non-woven fabric. A biodegradable material for the overwrap is desirable. Two non-wovens which have functioned well as the overwrap and are believed to be biodegradable are: Dexter 2149, a non-woven fabric consisting of approximately a 60:40 cotton:rayon blend, saturation bonded with a mixture of HA8 and HA24, Rohm and Hass acrylic binders, said fabric having a measured weight of about 0.6 to 0.7 ounce per square yard and being hydrophobic and available from C. H. Dexter & Sons Co., Windsor Locks, Connecticut; and Viskon, which is a 100 percent rayon, non-woven, line-bonded material, is hydrophilic, has a measured weight of about 0.47 ounce per square yard, and is available from Chicopee Mills, 1450 Broadway, New York, N.Y. Reemay, which is a hydrophobic, spun bonded, low basis weight, polyester non-woven fabric having a measured weight of about 0.4 ounce per square yard and is available from E. I. Du Pont de Nemours, Wilimington, Delaware, is another non-woven which has performed satisfactorily as an overwrap.
The water frangible adhesive which can be used in the preferred embodiment of the tampon of this invention preferably has an inverse temperature-water solubility property, that is, it is insoluble at temperatures above a threshold temperature but is soluble at temperatures below that theshold. Any such physiologically safe adhesive having a threshold temperature lower than normal body temperature and higher than the sewage water temperture would work satisfactorily, but preferably the threshold temperature should be between about 95°F. and 70°F. In a satisfactory specific application of the present invention the adhesive used had a threshold temperature of about 85°F. so that the adhesive was insoluble while it was within the vagina where it would become wetted with menses and the temperature is about 98°F., i.e., above the threshold temperature, but was soluble in water used in an ordinary sewage system which is about 70°F. or less. The adhesive used was Klucel and is available from Hercules, Inc., Wilmington, Delaware. Klucel is a non-ionic, water soluble, thermoplastic cellulosic material formed by reacting alkali cellulose with propylene oxide to give hydroxypropylcellulose (ether link) and having a molecular weight of about 60,000 to 1,000,000. Below is an idealized structure of a hydroxypropylcellulose molecule with a molar substitution of 3.0. ##SPC1##
Other water frangible adhseives which can adhesives used to form the water frangible closures of the tampon of this invention, even though they do not have an inverse temperature-water solubility property, are Elvanol available from E. I. Du Pont de Nemours, Wilmington, Delaware, and Carbowax available from Union Carbide, 270 Park Ave., New York, N.Y. 10017. Elvanol is a water soluble polyvinyl alcohol having a typical structure as follows: ##SPC2##
Elvanol is generally 2with a plasticizer such as gylcerin to give it a low solution viscosity. Carbowax is an ethylene oxide polymer (called polyethylene glycol) having a typical structure as follows:
HO -- CH 2 -- (CH 2 -- O -- CH 2 ) n -- CH 2 -- OH
n = average nmber of oxyethylene groups per molecule. Carbowax 1000 to Carbowax 6000 are waxy water soluble solids suitable for some hot metal applications.
A material which has worked well as a withdrawal string is a waterproof cotton string having a 5/3 ply and a 9 pound tensile strength. Such a string is available from Bibb Manufacturing Company, Macon, Georgia under the name of 5/3 ply Sno-Spun bleach 108 cotton. The waterproofing on the string is to prevent wicking within the string which could lead menses outside the vagina and soil the user's clothing.
Thus it is apparent that there has been provided, in accordance with the invention, an absorptive device that fully satisfies the objects, aims, and advantages set forth above. While the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications, and variations with be apparent to those skilled in the art in light of the foregoing description. Accordingly, it is intended to embrace all such alternatives, modifications, and variations which fall within the spirit and broad scope of the appended claims.