Patent Abstract:
The present invention relates to an intravaginal tampon for feminine hygiene. In particular, it relates to methods for producing such a tampon having relatively deep, penetrating grooves in which adjacent penetrating jaws pass through the same tampon press space during manufacture and to an apparatus useful in making such a tampon as well as the tampons made therewith.

Full Description:
This application claims the benefit of U.S. provisional application 61/706,346 filed on Sep. 27, 2012, the complete disclosure of which is hereby incorporated herein by reference for all purposes. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to an intravaginal tampon for feminine hygiene. In particular, it relates to methods for producing such a tampon having relatively deep, penetrating grooves in which adjacent penetrating jaws pass through the same tampon press space during manufacture and to an apparatus useful in making such a tampon as well as the tampons made therewith. 
     BACKGROUND OF THE INVENTION 
     Devices for intravaginally capturing and storing bodily fluid are commercially available and known in the literature. Intravaginal tampons for feminine hygiene are the most common example of such devices. Commercially available tampons are generally compressed cylindrical masses of absorbent fibers that may be contained by an absorbent or nonabsorbent cover layer. 
     The tampon is inserted into the human vagina and retained there for a time for the purpose of capturing and storing intravaginal bodily fluids, most commonly menstrual fluid. As intravaginal bodily fluid contacts the tampon, it should be absorbed and retained by the absorbent material of the tampon. After a time, the tampon and its retained fluid is removed and disposed, and if necessary, another tampon is inserted. 
     A drawback often encountered with commercially available tampons is the tendency toward premature failure, which may be defined as bodily fluid leakage from the vagina while the tampon is in place and before the tampon is completely saturated with the bodily fluid. The patent art typically describes a problem believed to occur that an unexpanded, compressed tampon is unable to immediately absorb fluid. Therefore, it presumes that premature leakage may occur when bodily fluid contacts a portion of the compressed tampon, and the fluid is not readily absorbed. 
     One way to prevent premature leakage from occurring is to provide designed pathways for fluid moving along the outer tampon surface. While this increase to the pathways may improve the fluid absorption, adding grooves during the manufacturing process can raise process issues. The prior art is replete with examples of attempts to incorporate grooves into tampons. Often new steps are added to an already complicated manufacturing process or the process is not fully described. 
     Friese et al., EP 0422660 B2, discloses an apparatus for producing a tampon with longitudinal grooves. The apparatus for making the tampon includes two groups of dies arranged in a plane perpendicular to the press axis. The first group of dies form press segments and the second group of dies form sliding plates. Each of the dies has press cutters projecting from the faces. The blank is pressed into a preform having a core with high compression and longitudinal ribs separated by grooves. The dies do not include a surface for forming shoulders. 
     Schoelling, US 2002-0151859 A1, discloses an apparatus for producing tampons having spirally shaped, pressed longitudinal grooves. The apparatus has press jaws of substantially equal dimensions which are arranged in a star formation with respect to the press axis. The jaws can be moved synchronously between open and closed positions. Each press jaw has a stepped pressing surface including a pressing blade and a pressing shoulder. The area of the pressing shoulder is great than the area of the pressing blade. The pressing blade and pressing shoulder can extend over a circumferential angle α of between 80 to 150° in the closed or pressing position. The press jaws are slightly retracted to give clearance when the preform is ejected from the press. 
     Van Ingelgem et al., EP 1547555 B1 purports to disclose an apparatus for manufacturing tampons with at least three press jaws, each press jaw having a penetrating segment for penetrating the absorbent material and pressing shoulder. The median of the penetrating segment diverges from the radius of that penetrating segment when in the press. The median of the penetrating segment is the straight line drawn in a cross section of the penetrating segment, through its tip and the midpoint of its base. One press jaw may comprise either a penetrating segment or a pressing shoulder, or a combination of one penetrating segment and pressing shoulders arranged at either or both sides of the penetrating segment. If the penetrating segment and pressing shoulders are fixed to separate press jaws, it is preferably that they press simultaneously. The press jaws, in particular, the penetrating segments can have a straight, sinusoidal, spiral or helical shape in the longitudinal direction to form essentially straight, sinusoidal, spiral, or helical grooves in the axial direction of the tampon. The resultant tampon has at least three ribs, in transverse cross-section, has a median at least partially diverging from the radius where the median of the rib is the line drawn through the midpoint of a series of arc lines, bound by the edges of the rib, wherein the arcs have a common center which is the midpoint of the X-X cross-section of the tampon. 
     Schmidt, EP 1459720 B1, purports to disclose increasing the surface area of a tampon by utilizing grooves that are formed in a wave shape. While multiple examples are shown, including wavy grooves with angled points, this publication does not disclose specifics on how to manufacture the tampons. In particular, the publication does not include specifics about compression, the press jaws or how the preform or tampon is ejected from the press. 
     Ruhlmann, WO 2009/129910 A1, purports to disclose a tampon having at least one first surface groove and at least one second surface groove that crosses the first surface groove along their path between a proximal end and a distal end of the tampon. However, the disclosure fails to teach how the crossing grooves are formed, especially in a commercially-feasible manufacturing process and/or with a cover. 
     Fung, US 2011-0092940 A1, discloses an intravaginal tampon formed of compressed material and has an outer surface with at least two segmented grooves are formed therein, and each segmented groove is separated from and spaced at a distance from an adjacent segmented groove. Each segmented groove has at least one substantially longitudinal segment and at least one accumulator segment. The arrangement of the segments provides a pooling region to impede bodily fluid flow along the outer surface of the tampon. 
     While the above examples describe tampons with grooves or the process for making such tampon, these tampons do not have visually distinct zones with different bodily fluid handling characteristics. In addition, the processes do not show how to make such a unique intravaginal tampon. 
     Further, the above examples fail to provide a tampon having intersecting longitudinal groove segments that penetrate deeply to provide fluid access into the absorbent structure and to provide column strength. Such penetrating grooves also provide a place into which to tuck or fold excess liquid permeable cover material resulting from tampon blank compression with a generally (non-stretchy) coverstock. 
     SUMMARY OF THE INVENTION 
     It has been discovered that intersecting groove segments can form deeply penetrating grooves in substantially cylindrical tampons to provide the benefits of deep grooves to transfer fluid into the tampon core and the benefits of intersecting grooves on the surface of the tampon. 
     In one aspect of the invention, a process of forming a compressed tampon pledget having substantially longitudinal grooves and a predetermined finished diameter includes inserting a tampon blank substantially enclosed in a liquid permeable cover into a press cavity, performing an initial compression step by moving into the press cavity toward the central press axis a plurality of longitudinal penetrating dies having pressing faces, backing the penetrating dies away from the central press axis, performing a second compression step, transferring the compressed tampon pledget to a cylindrical carrier having an internal diameter less than the predetermined finished diameter, and enclosing the compressed tampon pledget in a primary package having an internal diameter substantially equal to predetermined finished diameter thereby allowing the compressed tampon pledget to expand to the predetermined finished diameter. The press cavity has a central press axis and a plurality of elongate press dies disposed about the central press axis, wherein the tampon blank has a longitudinal axis that is disposed substantially along the central press axis. The pressing faces of the penetrating dies correspond to a plurality of longitudinal groove segments in the desired compressed tampon pledget, and at least one first penetrating die has a pressing face corresponding to a desired first groove segment shape and at least one second penetrating die has a pressing face corresponding to a second groove segment shape. The initial compression step produces a preform that has a plurality of substantially longitudinal grooves interspaced with a plurality of substantially longitudinal ribs. The first and second groove segment shapes combine to provide a groove form on the outer surface of the compressed tampon pledget, wherein the groove form has an intersection proximate to one end of the compressed tampon pledget. The pressing faces of the first and second penetrating dies are positioned at a closed position having a clear distance from the central press axis that is less than the predetermined finished diameter in the initial compression step. The pressing face of the first penetrating die extends longitudinally beyond the pressing face of the second penetrating die toward the end of the compressed tampon pledget whereby the first and second penetrating die pass through the same space within the press to form the groove form. The second compression step includes applying to the substantially longitudinal ribs of the preform a radial pressure directed toward the central press axis to provide a compressed tampon pledget of reduced diameter relative to the preform. 
     In another aspect, the present invention relates to an intravaginal tampon for feminine hygiene including a generally cylindrical absorbent pledget and a withdrawal element operatively connected to the generally cylindrical pledget proximate to the withdrawal end thereof. The absorbent pledget has a length, a longitudinal axis, an insertion end, and a withdrawal end. It includes a mass of fibers compressed into a self sustaining shape and a sheet-like fluid-permeable cover substantially enclosing the mass of fibers. The absorbent pledget has at least one groove form on the outer surface of the compressed tampon pledget, wherein the groove form has a turn comprising an intersection of at least two groove segments having a depth of at least about 0.7 mm proximate to one end of the compressed tampon pledget. 
     In yet another aspect, the present invention relates to an apparatus for manufacturing an intravaginal tampon for feminine hygiene. The apparatus includes a tampon press, a cylindrical carrier, and means to enclose the compressed tampon pledget in a primary package having an internal diameter substantially equal to a predetermined finished diameter. The press has a central press axis and it includes a plurality of elongate press dies disposed about central press axis to form a press cavity. The elongate press dies include a plurality of longitudinal penetrating dies having pressing faces corresponding to a plurality of longitudinal groove segments in a desired compressed tampon pledget. At least one of the press dies is a first penetrating die having a pressing shape corresponding to a desired first groove segment shape and at least one other of the press dies is a second penetrating die having a pressing face corresponding to a second groove segment shape. The first groove segment shape and the second groove segment shape combine to form a groove form on a tampon formed in the press. In addition, the pressing face of the first penetrating die extends longitudinally beyond the pressing face of the second penetrating die toward an end of the of the press cavity. Thus, the first and second penetrating dies are capable of passing through the same space within the press to form the groove form. The press also includes a control mechanism to control movement of the elongate press dies into and out of the press cavity. 
     Other aspects and features of the present invention will become apparent in those ordinarily skilled in the art upon review of the following description of specific embodiments of the invention in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
         FIG. 1  is a side view of one embodiment of a tampon according to the present invention. 
         FIG. 2  is a side view of another embodiment of a tampon according to the present invention. 
         FIG. 3  is a side view of a third embodiment of a tampon according to the present invention. 
         FIG. 4  is a side view of a fourth embodiment of a tampon according to the present invention. 
         FIG. 5  is a side view of a fifth embodiment of a tampon according to the present invention. 
         FIG. 6  is a side view of a sixth embodiment of a tampon according to the present invention. 
         FIG. 7  is a perspective view of a press having a single cam useful in forming tampons of the present invention; the cam is partially broken away, and some of the press elements have been removed for increased clarity of the illustrated press elements. 
         FIG. 7A  is a side view of the central portion of the press of  FIG. 7  including the press dies and central cavity; outer portions of the cam and other press elements are broken away for increased clarity of the central press portion. 
         FIG. 8  is perspective view of four of the press dies of the press of  FIG. 7 . 
         FIG. 9  is cross-section of the central portion of the press of  FIG. 7A  along line (D-D) in an open position; outer portions of the press elements are broken away for increased clarity of the central press portion. 
         FIG. 10  is a cross-section of the central portion of the press of  FIG. 7  proximate the notch during an initial compression step; outer portions of the press elements are broken away for increased clarity of the central press portion. 
         FIG. 11  is an enlarged cross-section view of the press of  FIG. 10  clearly showing the penetrating die tips crossing during an initial compression step; the remaining press elements are broken away. 
         FIG. 12  is an enlarged perspective view of the press of  FIG. 11 ; the remaining press elements are broken away. 
         FIG. 13  is cross-section view of the central portion of the press of  FIG. 7A  along line (D-D) during an ejection step; outer portions of the press elements are broken away for increased clarity of the central press portion. 
         FIG. 14  is an end view of the press of  FIG. 13  in the ejection position. 
         FIG. 15  is a longitudinal cross-section of the press of  FIG. 13 , during an ejection step. 
         FIG. 16  is a side elevation of a compressed tampon pledget prior to finishing the insertion end and packaging. 
         FIG. 17  is cross-section view of the central portion of an alternative press during an initial compression step. 
         FIG. 18  is cross-section view of the press of  FIG. 17  during an ejection step showing penetrating dies capable of guiding the compressed tampon pledget from the press cavity. 
         FIG. 19  is a line view of the pressing faces of three penetrating dies useful to form the tampon of  FIG. 6 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     As used herein the specification and the claims, the term “groove” and variants thereof relate to an indention into the surface of the tampon. For clarification, grooves may be “penetrating grooves”, extending at least 0.7 mm (or 10% of the radius, whichever is greater) into the tampon or they may be “shallow grooves”, primarily surface indentations without significant penetration (of not more than 0.7 mm, not more than 10% of the radius) into the tampon body. Regions between grooves may take the form of ribs. 
     As used herein the specification and the claims, the term “groove form” and variants thereof relates to a groove or combination of groove segments that are connected in a visibly identifiable manner to provide a unique detached feature at least on the surface of the tampon pledget. 
     As used herein the specification and the claims, the term “turn” and variants thereof relates to a portion of the groove form in which the groove and/or groove elements reverse(s) upon itself/themselves in a substantially U-shaped or a substantially V-shaped configuration. A “turn” can also have a generally linear extension from the intersection, such as a substantially Y-shaped configuration. 
     As used herein the specification and the claims, the term “major axis” and variants thereof relating to the groove form is defined by the shortest line connecting the most distant points of the groove form. Generally, this major axis will pass through at least one turn proximate to one end of the pledget. 
     As used herein the specification and the claims, the term “longitudinal axis” and variants thereof relate to an axis that runs from the insertion end to the withdrawal end substantially through the center of the tampon. 
     As used in the specification and the claims, the term “self sustaining shape” and variants thereof relate to a tampon pledget that is compressed and/or shaped to assume a general shape and size that is dimensionally stable. For example, a digital tampon that has a self-sustaining shape will generally maintain its shape after a primary package or overwrap is removed and will generally maintain such shape for vaginal insertion. It will be recognized that the tampon is intended to absorb bodily fluids, and may substantially change shape during use as it absorbs such fluids. 
     As used in the specification and the claims, the term “pledget” and variants thereof relate to a pad or a compress of absorbent material such as fibers designed to absorb bodily fluids. 
     As used in the specification and the claims, the term “oriented substantially longitudinally” and variants thereof relate to a groove or a groove segment or a groove form that has a helix angle of greater than 45°. 
     As used in the specification and the claims, the term “fiber density” and variants thereof relate to the relative proportion of fibers to void space in a given volume of the fibrous structure. 
     The present invention relates to a tampon with reduced opportunity for bodily fluid to flow along the surface without being absorbed into the tampon pledget. This is accomplished by providing at least two detached groove forms each having a generally longitudinal orientation, a length (measured along the groove) that is at least 150% of the length of the pledget, and a turn proximate to at least one of an insertion end and a withdrawal end. The detached groove forms provide visually distinct zones with different bodily fluid handling characteristics. In addition, the turn proximate to at least one end of the tampon provides at least two groove paths for the fluid to follow to be distributed to different portions of the tampon pledget. Thus, not only does the present invention provide tampons with a plurality of grooves, recognized by the prior art as providing improved fluid handling characteristics, but it also provides either fully or partially closed absorption zones that visually communicate functional benefits to the user, including absorbent reservoirs to better contain bodily fluids in the tampon. 
     Referring to  FIG. 1 , an intravaginal tampon  10  for feminine hygiene includes a generally cylindrical absorbent pledget  20  and a withdrawal element  30  extending therefrom. The pledget  20  has a longitudinal axis  21 , an insertion end  22  (which may terminate in a dome  23 ), and a withdrawal end  24 . The pledget includes a mass of fibers compressed into a self sustaining shape and a sheet-like fluid-permeable cover  25  (such as an apertured film cover) substantially enclosing the mass of fibers. The withdrawal element  30 , such as a string, is operatively connected to and extends from the pledget  20  proximate to the withdrawal end  24  thereof. 
     The pledget  20  includes a plurality of detached groove forms  40  arranged about the outer surface of the pledget  20 . In embodiment of  FIG. 1 , the detached groove forms  40  each comprise a pair of wavy groove segments  41 , 42  that intersect to create a turn  43  proximate to the insertion end  22  of the pledget  20  and are separate proximate to the withdrawal end  24 . 
     In the embodiment of  FIG. 2 , additional longitudinal grooves  44  are disposed between detached groove forms  40 . 
     The embodiment of  FIG. 3  is similar to the embodiment of  FIG. 1 . However, in the embodiment of  FIG. 3 , the turn  43  is proximate to the withdrawal end  24 . 
     The embodiment of  FIG. 4  is similar to the embodiment of  FIG. 1 . However, in the embodiment of  FIG. 4 , an additional longitudinal groove segment  45  intersects with groove segment  42  to form a second turn  43  proximate to the withdrawal end  24 . This forms a substantially inverted “N-shaped” detached groove form. 
     In the embodiment of  FIG. 5 , the detached groove forms  40 ′ each comprise a pair of groove segments  41 ′, 42 ′ that intersect to create a turn  43 ′ proximate to both the insertion end  22  and the withdrawal end  24  of the pledget  20  to provide discrete surface zones  46  bounded by the encircling groove forms  40 ′. 
     In the embodiment of  FIG. 6 , additional longitudinal grooves  44  are disposed between detached groove forms  40 ′. 
     Again the groove forms may comprise a plurality of groove segments. These groove segments may have a configuration that is a straight line, a plurality of linked angled segments (such as a saw tooth waveform or a square waveform), a plurality of curved segments (such as a sinusoidal waveform), and combinations thereof. 
     The configuration of the groove segments may differ between groove forms, or they may be the same. The configuration of groove segments within each groove form may also be the same or different. Additional grooves, including longitudinal grooves  44 , may be configured similarly to or distinct from each other and the configuration of the groove segments making up the groove forms  40 . 
     The absorbent pledget includes a mass of fibers compressed into a self sustaining shape. The pledget may also include additional absorbent materials such as foam, superabsorbent, hydrogels, and the like. Preferred absorbent material for the present invention includes foam and fiber. Absorbent foams may include hydrophilic foams, foams which are readily wetted by aqueous fluids as well as foams in which the cell walls that form the foam themselves absorb fluid. 
     Preferably, the fibers employed in the formation of the absorbent body include regenerated cellulosic fiber, natural fibers and synthetic fibers. Preferably, the materials employed in the formation of a tampon according to the present invention include fiber, foam, hydrogels, wood pulp, superabsorbents, and the like. A useful, non-limiting list of useful absorbent body fibers includes natural fibers such as cotton, wood pulp, jute, and the like; and processed fibers such as regenerated cellulose, cellulose nitrate, cellulose acetate, rayon, polyester, polyvinyl alcohol, polyolefin, polyamine, polyamide, polyacrylonitrile, and the like. Other fibers in addition to the above fibers may be included to add desirable characteristics to the absorbent body. Preferably, tampon fibers are rayon, cotton, or blends thereof, and more preferably, the fibers are rayon. The fibers may have any useful cross-section. 
     Fiber cross-sections include multi-limbed and non-limbed. Multilimbed, regenerated cellulosic fibers have been commercially available for a number of years. These fibers are known to possess increased specific absorbency over non-limbed fibers. A commercial example of these fibers is the Galaxy® multilimbed viscose rayon fibers available from Kelheim Fibres GmbH, Kelheim, Germany. These fibers are described in detail in Wilkes et al., U.S. Pat. No. 5,458,835, the disclosure of which is hereby incorporated by reference. Preferably, the fibers include hydrophilic fibers, and more preferably, the fibers include absorbent fibers, i.e., the individual fibers, themselves, absorb fluid. A useful, non-limiting list of useful tampon fibers includes natural fibers such as cotton, wood pulp, jute, hemp, and the like; and processed fibers such as regenerated cellulose, cellulose nitrate, cellulose acetate, rayon, polyester, polyvinyl alcohol, polyolefin, polyamine, polyamide, polyacrylonitrile, and the like. Other fibers in addition to the above fibers may be included to add desirable characteristics to the absorbent body. For example, hydrophobic fibers may be used in outer surfaces of the tampon to reduce surface wetness and hydrophilic fibers may be used to increase the rate of fluid transport into and throughout the body. Preferably, the tampon fibers are rayon or cotton, and more preferably, the fibers are rayon. The fibers may have any useful cross-section. 
     The pledget includes a mass of fibers substantially enclosed by a sheet-like cover material fluid-permeable cover. Thus, the cover encloses a majority of the outer surface of the tampon. This may be achieved as disclosed in Friese, U.S. Pat. No. 4,816,100, the disclosure of which is herein incorporated by reference. In addition, either or both ends of the tampon may be enclosed by the cover. Of course, for processing or other reasons, some portions of the surface of the tampon may be free of the cover. For example, the insertion end of the tampon and a portion of the cylindrical surface adjacent this end may be exposed, without the cover to allow the tampon to more readily accept fluids. 
     The cover can ease the insertion of the tampon into the body cavity and can reduce the possibility of fibers being separated from the tampon. Useful covers are known to those of ordinary skill in the art, and they are generally dimensionally stable with low elongation in both the machine and cross-direction. They may be selected from an outer layer of fibers which are fused together (such as by thermobonding), a nonwoven fabric, an apertured film, or the like. Preferably, the cover has a hydrophobic finish. 
     While liquid permeable covers are beneficial additions to radially-compressed tampons, their dimensional stability can produce some processing challenges. For example, radially compressing a cylindrical tampon blank having a dimensionally stable cover disposed about the cylindrical outer surface can result in cover wrinkles or loose cover extending from the outer surface of the compressed tampon pledget. Therefore, many processes involving radial compression of a tampon blank account for this by folding or tucking the cover material into grooves or folds that penetrate relatively deeply into the absorbent structure. 
     A process useful in the formation of an intravaginal tampon for feminine hygiene of the present invention with grooved zones begins with an open fibrous structure. The open structure may be a nonwoven fibrous web, a mass of randomly or substantially uniformly oriented fibers and optional materials, such as foams, or particles, and the like. This mass is then manipulated to form a tampon blank. 
     A nonwoven web useful in the present invention can be formed in any manner desired by the person of ordinary skill in the art. For example, fibers can be opened and/or blended by continuously metering them into a saw-tooth opener. The blended fibers can be transported, e.g., by air through a conduit to a carding station to form a fibrous web. Alternatively, a mass of substantially randomly oriented fibers can be formed by opening and/or blending them, transporting them, as above, to a station to form, e.g., a teabag-type tampon blank. Further processes may employ oriented fibers in a fibrous tow. 
     The tampon blank can be further processed to form a tampon. In a tampon forming process, a web can be formed into a narrow, fibrous sliver and convolutedly wound to form a tampon blank. In addition, a liquid-permeable cover material can be wrapped around the tampon blank to substantially contain the fibrous absorbent portion of the tampon. It may be desired to process the fibrous sliver with selective needle-punching of the sliver as disclosed in U.S. Pat. No. 7,845,055 to Kimball et al., the disclosure of which is herein incorporated by reference. 
     As shown in  FIGS. 7-16 , the intravaginal tampon for feminine hygiene of  FIG. 1  having a predetermined finished diameter can be formed in a press  100  having (1) a generally cylindrical press cavity  102  having a central press axis  104  and a substantially cylindrical circumference and (2) a plurality of elongate press dies. A partially broken-away perspective view of the press  100  is shown in  FIG. 7 . This figure includes only seven of sixteen press dies and a portion of the press cam removed for clarity. The press dies may include penetrating dies  106  having pressing faces for defining a set of penetrating grooves that extend into the finished tampon pledget and shaping dies  108  for forming surface features, including shallow grooves on the outer surface of a resulting compressed tampon pledget, or smoothing the outer surface of a resulting compressed tampon pledget, or forming a continuous diameter for guiding resulting compressed tampon pledget out of the press during the ejection step. The penetrating dies  106  and shaping dies  108  alternate about the circumference of the cylindrical press cavity. 
     More detail of the press dies can be seen in  FIG. 8 , an enlarged view of the bottom right four press dies of  FIG. 7 . In this view, a first penetrating die  106   a  has a pressing face  107  and shape corresponding to groove segment  41  and a second penetrating die  106   b  has a shape corresponding to groove segment  42  (of  FIG. 1 ). As can be seen in  FIG. 8 , one end  150   a  of the first penetrating die  106   a  extends beyond the corresponding end  150   b  of the second penetrating die  106   b . Indeed, the end  150   b  of the second penetrating die  106   b  is curved toward the first penetrating die  106   a  in order to form the turn  43  in the surface of the tampon pledget  20  (as shown in  FIG. 1 ) proximate to the insertion end  22 . In this embodiment, the end  150   a  of the first penetrating die  106   a  corresponds to the insertion end  22  of the tampon pledget  20  of  FIG. 1 . 
     Turn  43  of the detached groove form  40  is formed by the intersection between groove segments  41  and  42  (see  FIG. 1 ). To form a groove form  40 , the penetrating dies  106   a , 106   b  travel on a path that crosses during the compression of the tampon blank  200  (see  FIG. 9 ) to form the pledget  20 . Therefore, the longer penetrating die  106   a  has a notch  152  formed (see  FIG. 8 ) proximate to, although spaced from, the end  150   a  to permit the end  150   b  of penetrating die  106   b  to pass across the path of travel of penetrating die  106   a.    
     The shaping dies  108  are shaped to accommodate the shape of the penetrating dies  106  disposed therebetween. Thus, shaping die  108   a  corresponds to the surface of the pledget  20  contained by the groove segments  41  and  42  and the turn  43 . This shaping die  108   a  is shorter than shaping die  108   b  corresponds to the surface of the pledget  20  that is open to the insertion end  22 . 
     In the foregoing description, the grouping of the four press pieces may be repeated four times to provide four “petals” around the circumference of the tampon pledget. Alternatively, there could be three sets of the four press dies to form three “petals” around the circumference of the tampon pledget. 
     In this process, a substantially cylindrical tampon blank  200  is inserted into the press cavity  102  in an open position shown in  FIG. 9  (a cross-section of the press of  FIG. 7A  and tampon proximate to the notch  152  in the first penetrating die  106   a , looking from the interior of the press toward the end of the press corresponding to the insertion end of the tampon in  FIG. 1 ), after which an initial compression step is performed. In this initial compression step, at least the penetrating dies  106  are moved into the press cavity  102  to a penetrating die closed position having a clear distance “r” (see  FIG. 11 ) from the press axis  104  that is less than the predetermined finished diameter as shown in  FIG. 10  and in detail in  FIGS. 11 and 12 . This causes portions of adjacent penetrating dies that form the turn to pass through the same space within the press. As shown in  FIG. 12 , this can be accomplished by forming a notch  152  in the first penetrating dies  106   a  to permit the second penetrating dies  106   b  to cross therethrough in the penetrating die closed position. This initial compression step forms the compressed fibrous core of the tampon and provides column strength for easy insertion without need for a tampon applicator, known in the art as digital insertion. 
     In one embodiment, a second compression step that applies to the substantially longitudinal ribs of the preform a radial pressure directed toward the central press axis to provide a compressed tampon pledget of reduced diameter relative to the preform is represented in  FIG. 13  (a cross-section of the press, proximate to the center of the press cavity) and  14  (an end view of the press). In this step, the penetrating dies  106  are retracted to assume a clear distance from the press axis that is sufficient to permit the shaping dies  108  to advance toward the press axis beyond the penetrating dies. Then the set of shaping dies is moved to a shaping die closed position. The compressed tampon pledget may be ejected from the press cavity  102  using the shaping dies  108  to provide a substantially smooth guide for the compressed tampon pledget to permit removal of the compressed tampon pledget from the press and pushing on one end of the compressed tampon pledget with a push rod  110  (shown in  FIG. 15 ). 
     The tampon can be further shaped and packaged. For example, the insertion end can be formed into a hemispherical or elliptical dome shape, and the tampon can be enclosed in a primary packaging material that can also support the final shape of the tampon. 
     In somewhat greater detail, the tampon press  100  of  FIGS. 7 and 8  includes a cam  120 , penetrating die assemblies  130 , and shaping die assemblies  140 . The cam  120  is generally circular and includes slots  122  to urge the die assemblies  130 ,  140  into and out of the press cavity  102  as the cam is pivoted about the press axis  104 . Each penetrating die assembly  130  includes a pair of slides (an exemplary slide  132  is shown on one side of the cam  120 ; another, not shown, would be on the opposite side of the cam  120 ) and the penetrating die  106 . Each shaping die assembly  140  includes a pair of slides (an exemplary slide  142  is shown on one side of the cam  120 ; another, not shown, would be on the opposite side of the cam  120 ) and the shaping die  108 . Alternatively, multiple cams  120   a ,  120   b  may be used to permit more variability to the control of the movement of the dies, e.g., one cam could operate penetrating dies  106  and another could operate shaping dies. 
     Upon ejection from the press  100 , compressed pledget  20  is generally cylindrical as shown in  FIG. 16 . The pressed groove segments generally extend from the insertion end  22  to the withdrawal end  24 . Those pressed groove segments  50  that extend from the turn  43  to the insertion end  22  of the pledget will essentially be restructured in the doming process mentioned above to substantially eliminate them, both aesthetically and functionally. This is enhanced by the absence of the cover  25  in the region of the dome  23 . 
     In an alternative embodiment, especially enabled by a multiple cam controlled process, the penetrating jaws  106   a ,  106   b  may be controlled to advance them separately. For example, penetrating jaw  106   b  may be advanced to the closed position, withdrawn sufficiently to permit penetrating jaw  106   a  to fully advance toward the press axis  104  in the closed position. This eliminates the need for notch  152  in penetrating jaw  106   a , as the two penetrating jaws do not need to occupy the same space at the same time. In addition, as described in the embodiment, below, this could permit penetrating jaws  106   a  to remain in contact with the compressed tampon pledget  20  during ejection from the press. 
     In an alternative process, shown in  FIGS. 17-18 , the shaping dies  108  may be eliminated. Again, a substantially cylindrical tampon blank  200  is inserted into the press cavity  102  in an open position (similar to that shown in  FIG. 9 ), after which an initial compression step is performed. In this initial compression step, at least the one set of penetrating dies  106   b  are moved into the press cavity  102  to a penetrating die closed position having a clear distance from the press axis  104  of less than a final compressed radius of the compressed tampon pledget as shown in  FIG. 17 . The first set of penetrating dies  106   b  are withdrawn sufficiently to permit penetrating jaw  106   a  to fully advance toward the press axis  104  in the closed position. The penetrating jaws  106   a  may remain in contact with the compressed tampon pledget  20  during ejection from the press. This compression forms the densified fibrous core of the tampon and provides column strength for easy insertion without need for a tampon applicator, known in the art as digital insertion. The compressed tampon pledget is ejected from the press cavity  102  into a reducing bushing to transfer the compressed pledget into a hollow mandrel by pushing on one end of the compressed tampon pledget with a push rod  110  (similar to that shown in  FIG. 15 ). 
     While the foregoing detailed embodiments describe tampons having four groove forms resulting from eight intersecting groove segments, it will be recognized that the number of groove forms and/or groove segments can be varied, as desired. There may be an even or odd number of groove forms and/or groove segments—for example, embodiments similar to that shown in  FIG. 6  could have three or four groove forms separated by an equal number of additional grooves. Thus, a three groove form structure with three additional grooves could be formed with a combination of six intersecting groove segments (forming the three groove forms) and three additional grooves; a total of nine groove segments and/or grooves. A corresponding number of penetrating dies would be required in contrast with the sixteen penetrating dies described in reference to  FIGS. 7-16 , above. A line drawing of the pressing faces  107  of a set of three adjacent penetrating dies for such an embodiment is shown in  FIG. 19 . In this drawing, penetrating dies  106   a ′, 106   b ′ create the groove form, while independent penetrating die  106   c  forms the additional groove  44  between groove forms  40 ′ of  FIG. 6 . 
     The specification and embodiments above are presented to aid in the complete and non-limiting understanding of the invention disclosed herein. Since many variations and embodiments of the invention can be made without departing from its spirit and scope, the invention resides in the claims hereinafter appended.

Technology Classification (CPC): 0