Sanitary Tampon

Abstract

An absorbent material and method of constructing such material is disclosed. The absorbent material includes at least two united constituents, one of which contains filaments with a portion of such filaments transferred through openings in the other constituent. The transference may be effected through the use of transfer needles, which not only transfers filaments but additionally provides the openings through which the filaments extend. The absorbent material is particularly adapted for use in a tampon or other other catamenial device. Other uses, such as in disposable diapers or in other products where a relatively high degree of absorbency in a relatively economical product is desirable are also contemplated.

Description

The present invention relates to an absorbent material and the methods of making the same. While various applications for such absorbent material are contemplated, the present invention finds specific application for use in catamenial devices such as tampons.

Tampons enjoy a wide acceptance and various catamenial devices have been developed, employing various material compositions which must provide a relatively high degree of absorbency in a product which is relatively compact and economical to manufacture.

Aside from its absorbent characteristics, the material employed must be comfortable so as to allow ready insertion into the vaginal canal; have a strength sufficient to retain its integrity in use; and further have the ability to expand once subjected to the moisture in the vaginal canal so as to conform to the space between the walls of the canal to prevent leakage of the menstrual discharge and still allow for easy withdrawal.

The materials employed must also be adapted to be made economically both with respect to material cost and manufacture processes.

Present catamenial devices generally employ fibrous materials such as cellulosic structures, principally rayon, cotton, paper or mixtures or blends thereof depending principally upon the absorptive capacities of the bulk of the materials to increase absorbency. Aside from varying the type of raw materials employed, by and large developments to increase and/or enhance absorptive capacity has been dealt with by either adding to the bulk of the material and/or the compression of the materials so as to add quantitatively to the mass of absorbent material within a given volume.

As hereinafter more specifically described, a method has been found to increase the absorbency levels of more economical, lesser absorbent raw materials so as to enable the substitution of such materials, in, for example a catamenial device, with the finished product having an absorptive capacity which is at least at a parity with a product of equal weight heretofore constructed of more expensive, greater absorbent raw materials.

According to the present invention it has been found that absorptive capacity is increased through the use in a tampon of an absorptive material having at least two layers where at least one of the layers has absorptive capabilities and at least one of the layers includes filaments, wherein a portion of the filament of the filament bearing layer has been transferred completely through openings in the other companion layer.

It has been determined that particularly desirable results are obtained if the two layers are dissimilar and where both layers are absorbent materials. Further, one of the layers preferably is adapted to act as a matrix with the filaments of the other of the layers extending through openings in the matrix layer.

For example, a tampon having absorbent material weighing 2.2 grams, 50 percent of which is rayon and 50 percent of which is cellulose crepe wadding normally has an absorbency equal to only 80 percent of an identically constructed, more expensive all rayon tampon having absorbent material weighing 2.2 grams.

If however, the same rayon and cellulose crepe wadding constituents are modified in accordance with the present invention to provide openings through the cellulose crepe wadding, and a plurality of the filaments of the rayon are transferred through such openings the tampon will have an absorbency level equal to the more expensive all rayon tampon.

The absorptive composite of the present invention is preferably formed by juxtaposing in substantially superimposed relationship, two constituent materials; at least one of such materials being of an absorptive substance, and at least one of such materials including filaments; forming openings through at least one of such materials, and transferring filaments from such filament bearing material through the other of such materials.

Preferably the formation of the openings and the filament transference steps are accomplished in a single operation by the use of barbed needles, such as the type commonly referred to as "felting needles" with a least portion of the barbs oriented along the shank of the needle in the direction of the desired filament transference.

In a tampon it is preferably that the transference of filaments be of a degree such that the number of filaments on either face of the matrix layer be substantially equal.

It is believed that the increase in absorbency of the material of the present invention is due to alteration in the interstitial spacing effected during transference, the increase of the surface area effected in the creation of the openings, and/or the wicking or capillarity between layers along the transferred through filaments. The transferred through filaments act not only to maintain the integrity of the united constituent materials but further serve to maintain the integrity of the openings through the layers. This latter feature has special pertinency in the use of the absorbent material in catamenial devices where the forming machinery generally exerts a crimping pressure on the material being processed to shape and "set" the tampon.

Although such novel feature or features believed to be characteristic of the invention are pointed out in the claims, the invention and the manner in which it may be carried out may be further understood by reference to the description following and the accompanying drawings.

FIG. 1 is a top elevational view of an absorbent material of the present invention, with a corner of one of the layers folded back to indicate the manner in which the filaments of one layer are transferred through the openings provided in the other layer.

FIG. 2 is a cross sectional view taken along lines 2--2 of FIG. 1 with dimensions exaggerated for clarity.

FIG. 3 is a cross sectional view, also exaggerated for clarity, of another embodiment of the present invention.

FIG. 4 is a cross sectional view, similarly exaggerated for clarity, of an alternate embodiment of an absorbent material of the present invention.

FIG. 5 is a schematic illustration of an apparatus for constructing an absorbent material in accordance with a method of the present invention.

FIGS. 6 a- c are side elevations illustrating the sequential filament transference of the present invention; FIG. 6a illustrating superimposed layers of constituent material before the entry of the transfer needle; FIG. 6b illustrating a transfer needle as it transfers filaments; and FIG. 6c illustrating the transfer needle as it is withdrawn from the united constituent layers with the transferred filaments extending through the openings.

FIGS. 7-9 are side elevational views of various transferring needles which may be employed.

FIG. 10 is a sectionalized perspective of a portion of a tampon employing absorbent material of the present invention.

FIG. 11 is a side elevation illustrating the absorbent material of the present invention formed as a tampon and disposed within a tampon insertion device, partially cut-away.

Referring now to the figures in greater detail, where like reference numbers denote like parts in the various figures.

Illustrated in FIGS. 1 and 2 is one form of an absorbent composite 1 of the present invention. While various materials may be employed, the particular composite shown comprises two dissimilar constituents 2,3, both of which are absorbent, and at least one of which (2) contains relatively long filaments. For example, one of the constituents 2 is a fibrous substance, such as rayon and its companion constituent 3 is an absorbent paper such as cellulose crepe wadding.

As shown in FIGS. 1 and 2 the absorbent composite is provided with a plurality of openings 4 extending through the cellulose crepe wadding layer 3 through which the filaments 2' of the rayon fibrous material 2 pass, such that filaments 2' and 2" extend on opposite faces of the crepe wadding layer 3.

For clarity, the constituents 2,3 may be referred to as "layers" although as illustrated in FIGS. 1 and 2, the transference of the fiber filaments 2' of the fibrous material 2 through the companion layer 3 has been accomplished in a manner so as to substantially equalize the number of transferred filaments 2' and non-transferred filaments 2" at the opposed faces of the companion layer 3.

In FIG. 3 the absorbent composite 5 illustrated also includes dissimilar constituents with a fibrous layer 6 and a companion matrix layer 7. However, a lesser portion 8 of the filaments of the fibrous layer 6 are transferred through the openings 9 in the companion matrix layer 7 so as to be exposed on the outer face of the companion layer 7.

Whereas FIGS. 1-3 illustrate embodiments including two starting "layers," various other combinations of multi-layers of material are possible. In FIG. 4 for example there is illustrated an absorbent composite 10 including an inner layer of fibrous material 11 and a pair of outer matrix layers 14. A portion of the filaments 12 of the inner layer 11 have been transferred through openings 13 in both outer superimposed layers 14.

It is to be appreciated that the "layers" of the absorbent composite illustrated in FIGS. 1-4 are not necessarily as clearly defined as illustrated. In the manufacture of such material the filament transference is such that while the constituent materials retain their respective identities a selective union of the materials results visually integrating the constituents.

The amount of openings and filaments transferred per unit, can vary depending upon the degree of increased absorbency desired ranging from a small number of openings to that degree of openings which would destroy the matrix layer. Since it is desired to have at least some filaments passing through each of the openings to maintain the integrity of the openings, a particularly favorable union would be a uniting such as illustrated in FIG. 2 where there is a substantial equalization of filaments on opposite faces of the matrix layer. There is thus provided substantially equalized wicking on both faces of the matrix with filaments extending through all of the openings.

Referring to FIG. 5 there is illustrated an apparatus for processing an absorbent composite in accordance with the present invention.

A web of fibrous material 15 is fed such as from a spool 16 to a needle punching machine 17. A second web of material 18 is also fed, such as from a spool 19 so as to lie in superimposed relationship with the fibrous material 15 when the two webs 15,18 are positioned at the work station area 20 of the needle punching machine 17.

The needle punching machine 17 depicted is but a schematic representation encompassing in a broad sense the basic operation of needle punch equipment, it being understood that various apparatus are available to perform the fiber filament transference and hole punching functions requisite in forming the absorbent material of the present invention. As illustrated, the needle punching machine 17 includes an reciprocally driven piston 21 adapted to drive a needle beam 22 carrying a plurality of vertically oriented barbed needles 23 so as to vertically actuate the needles 23 to vertically reciprocate them into needle receptacles 24 in the bed 25. A transference of the filaments and a union of the webs 15, 18 also occurs and the so processed resultant absorbent material 27 is taken up, such as by take-up spool 28.

As is more clearly illustrated in FIGS. 6a- c, the needles 23 pass through the webs 15,18 effecting openings. The barbs 26 effect a fiber filament transference from the fibrous web 15 through the formed openings in the second web 18.

The orientation of the barbs and the stroke of the needles must be such as to effect a transference, that is the barbs must pass completely through the webs. The sequential steps are illustrated in FIGS. 6a through 6c wherein the barbs 26 engage a portion of the filaments on the web 15. The point of the needle 23 punctures the web 18 and the filaments engaged by the barbs 26 are transferred through the openings so made. The needle 23 is then retracted with the filaments disengaged from the barbs, such filaments remaining within the openings and extending through the web 18.

Various needle configurations are possible. In FIG. 7 for example the needle 29 is constructed having barbs 30 disposed along its shank 31 such that the barbs 30 would engage filaments and transfer them in the direction of the arrow A. Such a needle configuration would be employed where the shank 31 would first pass through the fibrous material and then the transferee web such as is shown in FIG. 5 and FIGS. 6a-c.

Were the web superimposition of FIG. 5 reversed, such as by having the transferee web first subjected to the needle shank, a needle 32 such as illustrated in FIG. 8 would be suitable. The barbs 33 on the needle 32 are aligned so as to engage a portion of the fiber filaments on the fibrous web and draw such filaments through the needle made openings in the transferee web. Or, in the alternative in lieu of the unidirectional fiber filaments transference of FIG. 5, transference between webs can be accomplished from both above and below the webs employing various combinations of needles 29,32 and 34 illustrated in FIGS. 7,8 and 9 respectively.

Further this multi-station, above and below technique may be employed, where multiple webs are employed, such as the three webs which initiate the absorbent material 10 shown in FIG. 4.

An alternative method of constructing a multi-layered composite such as the composite of FIG. 4 may be accomplished by use of needles, such as illustrated by the needle 34 of FIG. 9. The needle 34 of FIG. 9 includes along its shank 31, both barbs 36 for transference in one direction and barbs 37 for transference in the opposite direction. The downward stroke of the needle through the multiple webs would transfer filaments in the direction of the stroke through the bottom web. The reciprocal retracting motion of the needle would transfer filaments from the central web of fibrous material through the upper web.

Filament transference including the provision of openings has resulted in increased absorbency and this has been found to be of particular value in the construction of tampons. As illustrated in FIG. 10, a typical tampon structure of the present invention is shown.

The tampon illustrated may be constructed in a variety of ways using various manufacturing techniques. For example, a multiphase linear flow machine such as depicted in U.S. Pat. No. 3,465,390 to Mooney may be employed.

The tampon 43 shown includes two layers of superimposed absorbent material 38 constructed in accordance with the present invention. A gauze layer 44 for strong securement is positioned between the two absorbent material layers 38 and a withdrawal string 39 extends through the layers 38, 44.

While a gauze layer 44 has been illustrated such gauze layer 44 may be dispensed with in embodiments where the matrix layer of the absorbent material 38 is of a sufficient strength to maintain the string 39 securely even after the absorbent material 38 has been subjected to moisture.

Illustrated in FIG. 11 is the tampon of FIG. 10 loaded into a telescoping tube inserter device 40 such as those presently available in the art. It might further be noted that as formed the openings 41 and fibers 42 extend transversely with respect to the body portion of the tampon thus facilitating not only the absorption of menstrual fluid, but further present a network of openings for the menstrual discharge.

As will be seen from the examples which follow, combined absorbent and non-absorbent materials can be employed in the formation of an acceptable starting material for use as a tampon and the non-absorbent constituents may be chosen for both strength and selective functionality. Further, enhancement of absorbent characteristics is also provided in an all rayon combination.

The following test results are believed indicative of the enhanced properties of an absorbent material constructed in accordance with the present invention.

So as to provide more definitive results all of the following samples were formed into tampons and absorbency levels were determined in such condition. Each of the tampons tested had a weight of approximately 2.4 grams with 2.2 grams being of absorbent material and the remaining .2 grams including the intermediate gauze layer. It is of note that in the making of the tampons pressure is applied to the material surface to close some of the openings in those samples (such as samples V and VI infra, where the shortness of the filaments of the cellulose crepe wadding prevented such filaments from maintaining the integrity of the openings, thus accounting in some degree for the relatively minor increment in absorbency levels.

Absorbency levels were tested employing the Syngyna Method. A summary of the Syngyna Method may be found in a paper entitled "A Comparison of the Absorptive Efficiency of the Commercial Catamenial Tampons" written by Professor G.W. Rapp and published in June 1958 (Dept. of Research, Loyola Univ., Chicago, Ill.)

The Syngyna Method basically consists of applying to a properly positioned tampon an adaptation pressure of physiological magnitude and then allowing a fluid of proper consistency to flow at its tip at a controlled rate. The test is concluded when the first drop of fluid begins to fall from the open end of the "Syngyna" regardless of whether the tampon seems saturated or not.

Using as a control an all rayon tampon [weighing 2.4 grams] which has a Syngyna absorbency level in grams of 11.2, the following tests are exemplary of the present invention. The examples are given by way of illustration and are not intended to limit the invention. --------------------------------------------------------------------------- I

Material Transference Employed Method Results __________________________________________________________________________ 50% rayon 3 Barbed needles, Syngyna absorbency denier, 1 9/16 triangular shank, of 11.2 grams fiber length 15 gauge (0.072 50% cellulose inch) diameter crepe wadding 800 needle holes 10 lb. per 3,000 per square inch sq. feet (10 9 barbs per plies) needle __________________________________________________________________________ --------------------------------------------------------------------------- II

Material Transference Employed Method Results __________________________________________________________________________ 50% rayon 3 NONE Syngyna absorbency denier, 1 9/16 of 9.0 grams fiber length 50% cellulose crepe wadding 10 lb. wgt. per 3,000 sq. feet (10 plies) __________________________________________________________________________

The 50 percent rayon, 50 percent cellulose crepe wadding sample exhibited progressively enhanced absorbency levels as the needle transferring operation progressed as can be seen from the chart below:

SYNGYNA ABSORBENCIES IN GRAMS

NO 100 400 800 Punches Punches Punches Punches Control 9.0 9.9 10.4 11.2 11.2

A further desirable result of the above two samples was discovered. A single layer of cellulose crepe wadding (10lb. wgt. per 3,000 sq. feet - 10 ply) alone was needle punched by the same needle punching equipment of sample I. Such sampling started to loose its integrity at approximately 800 punches per square inch whereas the same material maintained its integrity when subjected to the same amount of needle punches as part of the rayon-cellulose crepe wadding union of sample I.

As can be noted from sample I above a more economical material, that is cellulose crepe wadding has been substituted for a substantial portion of the rayon in the tampon. Normally, as shown in sample II this substitution would effect a 20 percent loss in absorbency. However, as illustrated the material of sample I was brought to the level of absorbency of an all rayon tampon of equal weight. --------------------------------------------------------------------------- III

Material Transference Employed Method Results __________________________________________________________________________ 40% rayon 3 Barbed needles, Syngyna absorbency denier, 1 9/16 triangular shank, of 10.40 grams fiber length 15 gauge (0.072 60% cellulose inch diameter) crepe wadding 800 needle holes 10 lb. wgt. per per square inch 3,000 sq. feet 9 barbs per needle (10 plies) --------------------------------------------------------------------------- IV

Material Transference Employed Method Results __________________________________________________________________________ 25% rayon 3 Barbed needles, Syngyna absorbency denier, 1 9/16 triangular shank. of 9.30 grams fiber length 15 gauge (0.072 75% cellulose inch) diameter crepe wadding 800 needle holes 10lb. wgt. per per square inch 3000 sq. feet 9 barbs per needle (10 plies) __________________________________________________________________________ --------------------------------------------------------------------------- V

Material Transference Employed Method Results __________________________________________________________________________ 100% cellulose Barbed needles Syngyna absorbency crepe wadding triangular shank, of 8.8 grams 10 lb. wgt. per 15 gauge (0.072 3,000 sq. feet inch) diameter (10 plies) 800 needle holes per square inch 9 barbs per needle __________________________________________________________________________

It should be noted that a 100 percent cellulose crepe sampling constituted of exactly the same materials of sample V. but not subjected to the needle punching has a Syngyna absorbency of 8.6 grams. It is of interest to note that the fibers on such cellulose crepe wadding are relatively short and non-elastic and thus difficult to transfer through to another surface in great numbers. --------------------------------------------------------------------------- VI

Material Transference Employed Method Results __________________________________________________________________________ 20% polyurethane Barbed needles, Syngyna absorbency 1/8 inch sheet triangular shank of 10.10 grams (non-absorbent) 15 gauge (0.072 80% cellulose inch diameter) crepe wadding 10 lb. 800 needle holes wgt. per 3,000 sq. per square inch feet (10 plies) 9 barbs per needle. __________________________________________________________________________

A polyurethane (non-absorbent) and cellulose crepe wadding sampling containing no openings for filament transference exhibited an absorbency level from 2 to 3 percent less than the sample VI sampling above. It is also of note that where a sampling of 80 percent rayon [3 denier 1 9/16 fiber length] was combined in a 20 percent polyurethane [ 1/8 inch sheet non-absorbent] there was a 5 percent increment in absorbency where openings and filament transference was effected by barbed needles of the type indicated in the examples. --------------------------------------------------------------------------- VII

Material Transference Employed Method Results __________________________________________________________________________ 15% cheese cloth Barbed needles, Syngyna absorbency 100% cotton; 85% triangular shank of 9.30 grams cellulose crepe 15 gauge (0.072 wadding 10 lb. wgt. inch diameter) per 3,000 sq. feet 800 needle holes (10 plies) per square inch 9 barbs per needle __________________________________________________________________________

A sampling of cheese cloth - cellulose crepe wadding similar to example VII above not subjected to needle punching exhibited 25 percent less absorbency than the sample VII material.

As may be noted from the above, not only is there increased absorbency (Samples I,III,IV,V) but materials heretofore not generally employed in the manufacture of absorbent material, especially as a constituent material, for a rather inexpensive item such as a tampon (Sample VII) can be made to reach acceptable absorbency levels for use in such products.

It has also been found that it is possible to increase the absorbency of an all rayon tampon. Where the constituents are layers weighing 2.2 grams of rayon, it has been found that the needle punching operation (i.e., 800 strokes p.s.i. using a 15 gauge 0.072 diameter needle) spreads the filaments and realigns the filament orientation with a resultant increase in absorbency levels.

While all of the tests above were conducted employed 800 openings per square inch, tests were conducted at varying levels from 10 openings per square inch to over 1,000 openings per square inch, it being found that on the materials tested a range of between 600-850 punches per square inch gave best results.

In addition, increased absorbency occurs both in instances where the constituent materials are the same and to a much greater degree where the constituent materials are dissimilar. Similarly while positive results have been obtained employing absorbent and non-absorbent combinations, enhanced results occur where all of the constituent materials are absorbent. All that is required however, is that at least one of the layers be absorbent and at least one of the layers contain filaments having a length sufficient to be effectively transferred through the openings in one of the constituent materials, at least to a sufficient degree to retain the integrity of the openings.

Hence, the absorbency levels of the absorbent composite is a function of:

a. the constituent materials

b. the size of the openings

c. the number of openings,

d. the number of filaments transferred

e. the denier of filaments, and

f. specific gravity (density) of filaments

By selectively varying any of the above such as by increasing the needle size, and/or the number of barbs per needle, or increasing the number of openings, or by otherwise affecting any of the above variables, selective grading of absorbency levels can be accomplished.

The only major limiting factor (aside from raw material cost) would appear to be the ability of the constituents to withstand the needle punching filament transference operation. As such, it is desirable that the transferee layer be of a material which will act well as a matrix to retain openings having filaments extending therethrough.

While the present invention has been described with particularity in terms of its application to a tampon various other uses are possible. It is to be further appreciated that the terms and expressions which have been employed are used for purposes of illustration, it is recognized though that various modifications are possible within the scope of the invention as claimed.

Claims

Having thus described certain forms of the invention in some detail, what is claimed is:

1. A tampon comprising at least two constituent absorbent layers, one of said layers having absorbent filaments, the other of said absorbent layers having plurality of openings therethrough; a portion of said absorbent filaments extending through the openings in said other layer to form an integrated absorbent composite; said absorbent composite oriented in said tampon whereby the major portion of said openings having filaments extending therethrough extend in a direction transverse to the body of said tampon.

2. A tampon comprising, a first strip of an absorbent composite, a second strip of an absorbent composite, each of said strips including superimposed layers of absorbent rayon and absorbent crepe paper; said rayon layer having a plurality of filaments; said crepe paper having a plurality of openings; said rayon and paper layers united such that a portion of the filaments of said rayon layer extend through the openings in said paper layers to form an integrated composite; said first and second strips of absorbent composite in superimposed relationship and formed into a substantially cylindrical compressed body such that the major portion of said opening in said paper layers extend in a direction transverse to said cylindrical body.

3. The tampon as claimed in claim 2 wherein the number of openings in each of said paper layers is in the order of 100 to 1,000 openings per square inch and each of said openings has a diameter of at least 0.072 of an inch.