Title:
ABSORBENT TAMPON
United States Patent 3683912
Abstract:
An absorbent tampon having a fluid pervious layer of polypropylene fibers disposed on its outer surface. Insertion force for such tampons is reduced more than 50 percent when compared with the insertion force required for conventional tampons.
US Patent References:
Sanitary napkin
Bletzinger et al. - September 1959 - 2902038
Cellulosic product
Burger, Jr. et al. - March 1960 - 2926667
Non-adherent bandage pad
Yeremian - December 1968 - 3416526
INTERLABIAL PAD
Harmon - January 1969 - 3420235
BANDAGING AND DRESSING MATERIAL
Wicker et al. - December 1970 - 3545442
Sanitary napkin
Bletzinger et al. - September 1959 - 2902038
Cellulosic product
Burger, Jr. et al. - March 1960 - 2926667
Non-adherent bandage pad
Yeremian - December 1968 - 3416526
INTERLABIAL PAD
Harmon - January 1969 - 3420235
BANDAGING AND DRESSING MATERIAL
Wicker et al. - December 1970 - 3545442
Inventors:
Olson, Virginia A. (Oshkosh, WI)
Townsend, Bruce A. (Oshkosh, WI)
Townsend, Bruce A. (Oshkosh, WI)
Application Number:
05/029776
Publication Date:
08/15/1972
Filing Date:
04/28/1970
View Patent Images:
Export Citation:
Assignee:
Kimberly-Clark Corporation (Neenah, WI)
Primary Class:
Other Classes:
604/904, 604/370, 604/379
International Classes:
A61F13/20; A61F13/20
Field of Search:
128/263,270,285,296
Primary Examiner:
Rosenbaum, Charles F.
Parent Case Data:
REFERENCE TO RELATED APPLICATION
This application is a continuation of application Ser. No. 708,575 filed Feb. 27, 1968 now abandoned.
Claims:
What is claimed is
1. In a compressed tampon for intravaginal use comprising an absorbent body enclosed in a fluid pervious fiber overlay with the entire structure compressed to a self-sustaining cylindrical form of a size for insertion into the vaginal canal, the improvement in which the fluid pervious overlay of said compressed structure consists of non-absorbent polypropylene fibers, said tampon being characterized by substantially reduced frictional resistance to insertion into the vagina compared to the frictional resistance to insertion of intravaginal tampons having an absorbent surface.
2. The tampon of claim 1 in which said overlay is a web wrapper of non-woven fibers.
3. The tampon of claim 2 in which the fibers in said non-woven web are spot-bonded together in spaced areas comprising minute heat embossments.
4. The tampon of claim 2 in which the fibers in said non-woven web are bonded together at their crossing points by chemical adhesion.
5. The tampon of claim 1 in which said overlay is adhered to a scrim of cross-laid low twist threads bonded together at their intersections.
6. The tampon of claim 2 in which said web is in the weight range of 1 to 25 grams per square yard.
7. The tampon of claim 2 in which said web is in the weight range of 5 to 16 grams per square yard.
8. The tampon of claim 1 in which the exposed polypropylene fibers disposed on the compressed tampon surface have a glazed finish.
1. In a compressed tampon for intravaginal use comprising an absorbent body enclosed in a fluid pervious fiber overlay with the entire structure compressed to a self-sustaining cylindrical form of a size for insertion into the vaginal canal, the improvement in which the fluid pervious overlay of said compressed structure consists of non-absorbent polypropylene fibers, said tampon being characterized by substantially reduced frictional resistance to insertion into the vagina compared to the frictional resistance to insertion of intravaginal tampons having an absorbent surface.
2. The tampon of claim 1 in which said overlay is a web wrapper of non-woven fibers.
3. The tampon of claim 2 in which the fibers in said non-woven web are spot-bonded together in spaced areas comprising minute heat embossments.
4. The tampon of claim 2 in which the fibers in said non-woven web are bonded together at their crossing points by chemical adhesion.
5. The tampon of claim 1 in which said overlay is adhered to a scrim of cross-laid low twist threads bonded together at their intersections.
6. The tampon of claim 2 in which said web is in the weight range of 1 to 25 grams per square yard.
7. The tampon of claim 2 in which said web is in the weight range of 5 to 16 grams per square yard.
8. The tampon of claim 1 in which the exposed polypropylene fibers disposed on the compressed tampon surface have a glazed finish.
Description:
BACKGROUND OF THE INVENTION
Tampons have been used for internal absorption of body fluids for many years, especially for catamenial purposes. The more common types of tampons in use today usually comprise a rectangular batt of absorbent material, such as cotton, cellulose wadding, synthetic sponge, cellulose fluff or combinations thereof, compressed to a cylindrical shape and a size small enough to fit into the vaginal tract. The uncompressed batt may or may not be wrapped in a fluid pervious web, depending on whether or not the batt contains short or loose fibers. In compressed condition the tampons are preferably in a self-sustaining form, which form is substantially stable under normal atmospheric conditions but which expands readily when wetted. Thus, after a compressed tampon is inserted in the vaginal tract, the moist environment coupled with absorption of body fluids causes it to reexpand toward its original uncompressed size into conforming engagement with the walls of the vaginal cavity and hopefully to seal against leakage.
Because the material used necessarily is very absorbent, conventional unmodified tampons, even in their relatively small compressed size, tend to wipe the vaginal tract dry during insertion and in so doing may cause undesirable irritation to the mucous membrane which lines the cavity. Drying of the membrane also increases frictional resistance to insertion which is also objectionable. In order to relieve the difficulties and annoyances encountered during insertion, it is therefore desirable to provide tampons having surface characteristics which reduce frictional resistance to insertion and have a less absorbent wiping action during insertion, without hampering the effectiveness of the tampon in performing its absorptive function subsequent to placement in the body cavity.
While the desirability of having reduced frictional resistance and absorbent wiping action applies to all forms of tampons, these characteristics are particularly important for those tampon styles which are not enclosed in the rigid telescoping tubes commonly employed as the insertion device. For example, in using digital tampons for direct finger insertion and also in using tampons which employ a detachable stick for insertion, the absorbent surface of the tampon is normally exposed prior to use so that it comes in direct contact with the body tissue during insertion. Tampons with stick type inserters, which are not enclosed in a protective tube, have advantages in that they are less costly to produce, yet provide a more positive means of placement. However, since the absorbent surface area of stick tampons, and the still more economical digital style tampons, directly contacts the body tissues during insertion, such tampons have a tendency to absorb prematurely the moisture normally present on the surface of mucoid or epithelial tissue. As stated previously, this early absorptive action tends to dry the surface, and contributes to the difficulties involved in tampon insertion. When tampons are used for menstrual purposes, this drying effect is particularly evidenced during times of light flow, especially at the beginning and at the waning days of the menstrual period.
Many efforts have been made to overcome these latter difficulties. Such efforts include coating the tip or leading end of the tampon itself with lubricants such as petroleum jelly, emulsified mineral oil, soaps, surgical gel, and the like, or enclosing the tip of the tampon in a water-soluble film comprised of materials such as methyl cellulose, gelatin, dextrin, glucose, polyvinyl alcohol, sodium alginate, etc. While these prior modifications result in reduced frictional resistance and a concomitant improvement in insertion ease, each of them tends to interfere with the absorption capabilities of the tampon after insertion. Furthermore, such insertion-aiding materials require an additional manufacturing step and therefore add considerably to the production cost. The tampon of this invention utilizes fibers which have a slick, slippery surface as the outer component of the tampon and which comprise an integral part of the tampon construction before compression, thus eliminating additional steps in its manufacture.
Accordingly, the main object of the present invention is to provide an absorbent tampon with an outer surface having frictional characteristics which reduce resistance to insertion.
A further object is to provide an absorbent tampon which reduces the tendency to wipe the skin dry during insertion.
Another object is to provide an absorbent tampon in which reduced frictional resistance characteristics of the surface are obtained without impairing the absorptive function of the tampon.
Still another object is to provide an absorbent compressed tampon in which the friction-reducing material is fibrous and is an integral part of the tampon body before compression.
SUMMARY OF THE INVENTION
The tampon of this invention generally comprises an elongated cylindrical body of compressed absorbent material having a liquid-pervious overlay of polypropylene fibers. The overlay preferably comprises and overwrapping web of non-woven construction in which the fibers are bonded by tiny, spaced, heat embossments, or by adhesive means at the fiber crossover points. The compressed tampon of preferred construction is manufactured in the usual manner, starting with an uncompressed batt of loosely felted fibers, overwrapping it with a fibrous polypropylene jacket and then compressing it to the desired self-sustaining form of a size suitable for insertion in the vaginal tract. The surface of the polypropylene fibers in the overwrap has a much-improved lubricity over conventional overwrap materials and as a result the amount of force required for insertion is considerably reduced. The reduction in insertion force being in the range of about 40- 60 percent when compared to prior art tampons. The polypropylene overwrap is sufficiently pervious to allow menstrual fluids to penetrate to the absorbent core with substantially no reduction in speed of penetration as compared to conventional overwraps, and with substantially no reduction in the absorbent capacity of the tampon. In addition, because the fibers are hydrophobic they do not absorb fluids themselves and thus decrease the tendency to wipe the mucoidal tissue dry during insertion. The latter factor also contributes to the ease of insertion. It will thus be seen that the invention has the advantage of providing an absorbent tampon with a fibrous surface which acts to ease insertion while avoiding the disadvantages of the usual supplementary insertion aids formerly required.
These and other advantages, objects, and features attendant the improved construction will become apparent by reference to the following specification and accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWING
In the drawing:
FIG. 1 is a perspective illustration, with surface portions cut away, of a typical tampon body as employed in this invention and before compression.
FIG. 2 is a perspective illustration of the uncompressed tampon body of FIG. 1 provided with a conventional draw string. FIG. 3 is a perspective illustration of a compressed tampon made from the uncompressed tampon body of FIG. 2 and being provided with an insertion stick. FIG. 4 is a longitudinal section taken through the tampon portion only of FIG. 3.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the preferred embodiments shown in the drawing, the tampon comprises an absorbent body 10 of fibrous material and a fluid-pervious outer wrapper 12 of polypropylene fibers. The absorbent body 10 may initially be rectangular in shape, as illustrated, and is usually cut to a suitable size from a continuous supply of web of fibrous material. Other starting shapes may, of course, be used. The absorbent body may comprise any suitably formed batt of fibers; a plurality of superposed fiber layers; an assembly of long fibers assembled in transverse array and secured together by a line of longitudinal stitching; layers of cellulose wadding; absorbent sponge, or any desired combination of these.
Pervious outer wrapper 12 comprises polypropylene fibers preferably in the form of a non-woven web bonded by spaced areas of tiny heat embossments. Chemical bonding may also be used. Alternatively, the web may also consist of a non-woven scrim of low twist polypropylene threads with an overlay of polypropylene fibers. Other fibers coated overall with polypropylene are also contemplated.
In the embodiment shown, the overwrap encircles the tampon body and is overlapped at 14. The loose ends of the overwrap are tucked into the ends of the absorbent body as shown at 16.
A withdrawal string 18 is anchored to one end of the wrapped tampon in any suitable manner and extends from the rear portion thereof.
The tampon body is then compressed to an elongate cylindrical shape 19, and in the form shown in FIG. 3 has a socket 20 impressed into the rear end in which a removable insertion stick 22 is seated.
In the sectional view of FIG. 4 the relationship of wrapper 12, compressed body 10, and stick-holding socket 10 are shown.
As indicated previously, the polypropylene fiber outerwrap produces a tampon surface which has markedly less frictional resistance than conventional prior art absorbent covers. The following comparisons involving conventional tampons and various embodiments of the tampon of this invention will more clearly illustrate the differences in surface lubricity expressed in the amount of force required for insertion.
The tampons tested were made in accordance with the procedure described in U.S. Pat. No. 2,761,449. The uncompressed body measured about 4 × 1-1/4 × 3/4 inches and was compressed to a self-sustaining cylindrical form measuring about 1-3/4 inches in length and approximately one half inch in diameter.
The conventional control tampon was wrapped in a non-woven scrim of the type described in U.S. Pat. No. 2,900,980 having a 6 × 5 thread count and weighing about 6.66 grams per square yard. The various embodiments of the tampons of this invention were wrapped with a non-woven web of heat-bonded polypropylene weighing 5 grams per square yard (sample 1 ), 10 grams per square yard (Sample 2 ) and 16 grams per square yard (Sample 3 ), respectively. Compression was done at room temperature.
Samples 1A and 2A were constructed the same as Samples 1 and 2, respectively, but were compressed at approximately 200° F, which gave the exposed polypropylene fibers on the tampon surface a smoother, somewhat glazed, appearance. Another sample (Sample 4 ) was the same construction as the control but was coated with a surgical gel which acted as a lubricant to aid insertion.
Results were as follows:
Average Insertion Force Required % Reduction Sample No. (kilograms) Over Control ____________________________________________________________ ______________ 1 .50 51.9% 1A .41 61.6% 2 .64 38.5% 2A .48 53.9% 3 .54 48.1% 4 .43 58.6% Control 1.04 -- ____________________________________________________________ ______________
It will be noted that the tampons having a polypropylene wrapper displayed a reduction in insertion force ranging from 38.5 to 61.6 percent when compared to a control tampon with a conventional absorbent wrapper. It is also noted that the reduction in insertion force is well within the range of the reduction in force achieved when a conventional tampon is lubricated with a surgical jelly, the best previous insertion aid known.
The non-woven polypropylene wrapper preferably should be as thin as possible but still be of a strength which permits handling during conversion. Webs in the weight range of 1 to 25 grams per square yard may be used, with the preferred range being 5 to 16 grams per square yard. Fibers ranging in denier from 0.5 to 3 have been found useful. Other fibers may be mixed with polypropylene but as the amount of polypropylene present is decreased, the improvement in reduction of insertion force is correspondingly less. The web should permit easy penetration of fluids but should have substantially no absorption capacity itself. The web may also be treated with a wetting agent which speeds penetration of fluids during use. Non-ionic agents such as the commercially available nonyl-phenoxypoly (ethyleneoxy) ethanols were found particularly useful for this purpose, in amounts as small as 0.1 percent by weight.
It will also be seen that instead of a separate overwrap the absorbent tampon body may be formed with a thin layer of polypropylene fibers integrally deposited and joined to the surface of the absorbent body itself.
In compressing the tampon either heated or unheated dies may be used. It was found that in either case the lubricity of the tampon with the polypropylene fiber overwrap is considerably improved over conventional tampons. However, when heat in the range of 175° to 225° F, is used, the tampon takes on a smoother glazed appearance which apparently improves the effective lubricity. In addition to having slightly less frictional resistance whereby slightly less insertion force is required, when compared with tampons made with unheated dies, the glazed tampons also seemed to have a psychological effect on the user who seemed convinced that the smoother-appearing surface must necessarily insert easier than a similar polypropylene fiber surfaced tampon which has a fuzzy appearance. Accordingly, the heat-glazed embodiment is preferred.
While several specific embodiments of the inventive concept have been set forth above, it is understood that the invention is not to be construed as limited thereby, and that suitable changes, modifications, and variations may be made without departing from the spirit and scope of the invention as defined in the appended claims.
Tampons have been used for internal absorption of body fluids for many years, especially for catamenial purposes. The more common types of tampons in use today usually comprise a rectangular batt of absorbent material, such as cotton, cellulose wadding, synthetic sponge, cellulose fluff or combinations thereof, compressed to a cylindrical shape and a size small enough to fit into the vaginal tract. The uncompressed batt may or may not be wrapped in a fluid pervious web, depending on whether or not the batt contains short or loose fibers. In compressed condition the tampons are preferably in a self-sustaining form, which form is substantially stable under normal atmospheric conditions but which expands readily when wetted. Thus, after a compressed tampon is inserted in the vaginal tract, the moist environment coupled with absorption of body fluids causes it to reexpand toward its original uncompressed size into conforming engagement with the walls of the vaginal cavity and hopefully to seal against leakage.
Because the material used necessarily is very absorbent, conventional unmodified tampons, even in their relatively small compressed size, tend to wipe the vaginal tract dry during insertion and in so doing may cause undesirable irritation to the mucous membrane which lines the cavity. Drying of the membrane also increases frictional resistance to insertion which is also objectionable. In order to relieve the difficulties and annoyances encountered during insertion, it is therefore desirable to provide tampons having surface characteristics which reduce frictional resistance to insertion and have a less absorbent wiping action during insertion, without hampering the effectiveness of the tampon in performing its absorptive function subsequent to placement in the body cavity.
While the desirability of having reduced frictional resistance and absorbent wiping action applies to all forms of tampons, these characteristics are particularly important for those tampon styles which are not enclosed in the rigid telescoping tubes commonly employed as the insertion device. For example, in using digital tampons for direct finger insertion and also in using tampons which employ a detachable stick for insertion, the absorbent surface of the tampon is normally exposed prior to use so that it comes in direct contact with the body tissue during insertion. Tampons with stick type inserters, which are not enclosed in a protective tube, have advantages in that they are less costly to produce, yet provide a more positive means of placement. However, since the absorbent surface area of stick tampons, and the still more economical digital style tampons, directly contacts the body tissues during insertion, such tampons have a tendency to absorb prematurely the moisture normally present on the surface of mucoid or epithelial tissue. As stated previously, this early absorptive action tends to dry the surface, and contributes to the difficulties involved in tampon insertion. When tampons are used for menstrual purposes, this drying effect is particularly evidenced during times of light flow, especially at the beginning and at the waning days of the menstrual period.
Many efforts have been made to overcome these latter difficulties. Such efforts include coating the tip or leading end of the tampon itself with lubricants such as petroleum jelly, emulsified mineral oil, soaps, surgical gel, and the like, or enclosing the tip of the tampon in a water-soluble film comprised of materials such as methyl cellulose, gelatin, dextrin, glucose, polyvinyl alcohol, sodium alginate, etc. While these prior modifications result in reduced frictional resistance and a concomitant improvement in insertion ease, each of them tends to interfere with the absorption capabilities of the tampon after insertion. Furthermore, such insertion-aiding materials require an additional manufacturing step and therefore add considerably to the production cost. The tampon of this invention utilizes fibers which have a slick, slippery surface as the outer component of the tampon and which comprise an integral part of the tampon construction before compression, thus eliminating additional steps in its manufacture.
Accordingly, the main object of the present invention is to provide an absorbent tampon with an outer surface having frictional characteristics which reduce resistance to insertion.
A further object is to provide an absorbent tampon which reduces the tendency to wipe the skin dry during insertion.
Another object is to provide an absorbent tampon in which reduced frictional resistance characteristics of the surface are obtained without impairing the absorptive function of the tampon.
Still another object is to provide an absorbent compressed tampon in which the friction-reducing material is fibrous and is an integral part of the tampon body before compression.
SUMMARY OF THE INVENTION
The tampon of this invention generally comprises an elongated cylindrical body of compressed absorbent material having a liquid-pervious overlay of polypropylene fibers. The overlay preferably comprises and overwrapping web of non-woven construction in which the fibers are bonded by tiny, spaced, heat embossments, or by adhesive means at the fiber crossover points. The compressed tampon of preferred construction is manufactured in the usual manner, starting with an uncompressed batt of loosely felted fibers, overwrapping it with a fibrous polypropylene jacket and then compressing it to the desired self-sustaining form of a size suitable for insertion in the vaginal tract. The surface of the polypropylene fibers in the overwrap has a much-improved lubricity over conventional overwrap materials and as a result the amount of force required for insertion is considerably reduced. The reduction in insertion force being in the range of about 40- 60 percent when compared to prior art tampons. The polypropylene overwrap is sufficiently pervious to allow menstrual fluids to penetrate to the absorbent core with substantially no reduction in speed of penetration as compared to conventional overwraps, and with substantially no reduction in the absorbent capacity of the tampon. In addition, because the fibers are hydrophobic they do not absorb fluids themselves and thus decrease the tendency to wipe the mucoidal tissue dry during insertion. The latter factor also contributes to the ease of insertion. It will thus be seen that the invention has the advantage of providing an absorbent tampon with a fibrous surface which acts to ease insertion while avoiding the disadvantages of the usual supplementary insertion aids formerly required.
These and other advantages, objects, and features attendant the improved construction will become apparent by reference to the following specification and accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWING
In the drawing:
FIG. 1 is a perspective illustration, with surface portions cut away, of a typical tampon body as employed in this invention and before compression.
FIG. 2 is a perspective illustration of the uncompressed tampon body of FIG. 1 provided with a conventional draw string. FIG. 3 is a perspective illustration of a compressed tampon made from the uncompressed tampon body of FIG. 2 and being provided with an insertion stick. FIG. 4 is a longitudinal section taken through the tampon portion only of FIG. 3.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the preferred embodiments shown in the drawing, the tampon comprises an absorbent body 10 of fibrous material and a fluid-pervious outer wrapper 12 of polypropylene fibers. The absorbent body 10 may initially be rectangular in shape, as illustrated, and is usually cut to a suitable size from a continuous supply of web of fibrous material. Other starting shapes may, of course, be used. The absorbent body may comprise any suitably formed batt of fibers; a plurality of superposed fiber layers; an assembly of long fibers assembled in transverse array and secured together by a line of longitudinal stitching; layers of cellulose wadding; absorbent sponge, or any desired combination of these.
Pervious outer wrapper 12 comprises polypropylene fibers preferably in the form of a non-woven web bonded by spaced areas of tiny heat embossments. Chemical bonding may also be used. Alternatively, the web may also consist of a non-woven scrim of low twist polypropylene threads with an overlay of polypropylene fibers. Other fibers coated overall with polypropylene are also contemplated.
In the embodiment shown, the overwrap encircles the tampon body and is overlapped at 14. The loose ends of the overwrap are tucked into the ends of the absorbent body as shown at 16.
A withdrawal string 18 is anchored to one end of the wrapped tampon in any suitable manner and extends from the rear portion thereof.
The tampon body is then compressed to an elongate cylindrical shape 19, and in the form shown in FIG. 3 has a socket 20 impressed into the rear end in which a removable insertion stick 22 is seated.
In the sectional view of FIG. 4 the relationship of wrapper 12, compressed body 10, and stick-holding socket 10 are shown.
As indicated previously, the polypropylene fiber outerwrap produces a tampon surface which has markedly less frictional resistance than conventional prior art absorbent covers. The following comparisons involving conventional tampons and various embodiments of the tampon of this invention will more clearly illustrate the differences in surface lubricity expressed in the amount of force required for insertion.
The tampons tested were made in accordance with the procedure described in U.S. Pat. No. 2,761,449. The uncompressed body measured about 4 × 1-1/4 × 3/4 inches and was compressed to a self-sustaining cylindrical form measuring about 1-3/4 inches in length and approximately one half inch in diameter.
The conventional control tampon was wrapped in a non-woven scrim of the type described in U.S. Pat. No. 2,900,980 having a 6 × 5 thread count and weighing about 6.66 grams per square yard. The various embodiments of the tampons of this invention were wrapped with a non-woven web of heat-bonded polypropylene weighing 5 grams per square yard (sample 1 ), 10 grams per square yard (Sample 2 ) and 16 grams per square yard (Sample 3 ), respectively. Compression was done at room temperature.
Samples 1A and 2A were constructed the same as Samples 1 and 2, respectively, but were compressed at approximately 200° F, which gave the exposed polypropylene fibers on the tampon surface a smoother, somewhat glazed, appearance. Another sample (Sample 4 ) was the same construction as the control but was coated with a surgical gel which acted as a lubricant to aid insertion.
Results were as follows:
Average Insertion Force Required % Reduction Sample No. (kilograms) Over Control ____________________________________________________________ ______________ 1 .50 51.9% 1A .41 61.6% 2 .64 38.5% 2A .48 53.9% 3 .54 48.1% 4 .43 58.6% Control 1.04 -- ____________________________________________________________ ______________
It will be noted that the tampons having a polypropylene wrapper displayed a reduction in insertion force ranging from 38.5 to 61.6 percent when compared to a control tampon with a conventional absorbent wrapper. It is also noted that the reduction in insertion force is well within the range of the reduction in force achieved when a conventional tampon is lubricated with a surgical jelly, the best previous insertion aid known.
The non-woven polypropylene wrapper preferably should be as thin as possible but still be of a strength which permits handling during conversion. Webs in the weight range of 1 to 25 grams per square yard may be used, with the preferred range being 5 to 16 grams per square yard. Fibers ranging in denier from 0.5 to 3 have been found useful. Other fibers may be mixed with polypropylene but as the amount of polypropylene present is decreased, the improvement in reduction of insertion force is correspondingly less. The web should permit easy penetration of fluids but should have substantially no absorption capacity itself. The web may also be treated with a wetting agent which speeds penetration of fluids during use. Non-ionic agents such as the commercially available nonyl-phenoxypoly (ethyleneoxy) ethanols were found particularly useful for this purpose, in amounts as small as 0.1 percent by weight.
It will also be seen that instead of a separate overwrap the absorbent tampon body may be formed with a thin layer of polypropylene fibers integrally deposited and joined to the surface of the absorbent body itself.
In compressing the tampon either heated or unheated dies may be used. It was found that in either case the lubricity of the tampon with the polypropylene fiber overwrap is considerably improved over conventional tampons. However, when heat in the range of 175° to 225° F, is used, the tampon takes on a smoother glazed appearance which apparently improves the effective lubricity. In addition to having slightly less frictional resistance whereby slightly less insertion force is required, when compared with tampons made with unheated dies, the glazed tampons also seemed to have a psychological effect on the user who seemed convinced that the smoother-appearing surface must necessarily insert easier than a similar polypropylene fiber surfaced tampon which has a fuzzy appearance. Accordingly, the heat-glazed embodiment is preferred.
While several specific embodiments of the inventive concept have been set forth above, it is understood that the invention is not to be construed as limited thereby, and that suitable changes, modifications, and variations may be made without departing from the spirit and scope of the invention as defined in the appended claims.