US3607520A

US3607520A - Tampon manufacture

Info

Publication number: US3607520A
Application number: US879984A
Authority: US
Inventors: John Leslie Jones
Original assignee: Kimberly Clark Corp
Current assignee: Kimberly Clark Corp
Priority date: 1969-11-26
Filing date: 1969-11-26
Publication date: 1971-09-21
Anticipated expiration: 1988-09-21
Also published as: FR2071324A5; GB1298476A

Abstract

A process and apparatus for simultaneously manufacturing a multiplicity of one-piece, regenerated cellulose sponge tampons, for permanently bonding a coaxially disposed withdrawal string within the interior of each of the tampon bodies, and for compressing the tampons into their final form.

Description

United States Patent Inventor John Leslie Jones [56] References Cited 1 N 51 3 33 UNITED STATES PATENTS P 3,347,237 10/1967 Jones 128/285 F'led 1969 3 499 44s 3/1970 Jones 128/285 Patented Sept 21,1971 Assignee Kimberly-Clark Corporation Primary Examiner Benjamin R. Padgett Neenah, Wis. Assistant Examiner--Stephen J. Lechert, Jr.

Allameys Daniel J. Hanlon, Jr, and Raymond J. Miller TAMPON MANUFACTURE 6 Claims, 12 Drawing Figs.

U.S. Cl 156/198, ABSTRACT: A process and apparatus for simultaneously 156/221, 156/250, 156/273, 156/293, 156/303.1 manufacturing a multiplicity of one-piece, regenerated cellulut.Cl B29c 17/00 lose sponge tampons, for permanently bonding a coaxially Field of Search 156/273, disposed withdrawal string within the interior of each of the 293, 306, 250, 242, 245, 198,221, 303.1, 244; tampon bodies, and for compressing the tampons into their 128/270, 285 final form,

mmmm 3.601.520

' sum 2 0F 3 J: n I a v 55 by. A256 TAMPON MANUFACTURE This application is a division of copending application Ser. No. 619,509 filed Feb. 13, 1967. This application is also a continuation-in-part of my copending application, Ser. No. 350,193, filed Mar. 9, 1964, now US. Pat. No. 3,342,237. My present invention relates to new and useful improvements in a method and machine for manufacture of menstrual tampons.

Included in the objects of my invention are:

First, to provide a simple, relatively inexpensive and rapid method of simultaneously manufacturing multiple quantities of individual, dry, radially compressed, cylindrical, regenerated cellulose sponge tampons.

Second, to provide an inexpensive and simple machine for rapidly fabricating simultaneously a plurality of individual menstrual tampons, each tampon having a coaxially centered withdrawal string centered in and bonded in the tampon.

Third, to provide a method of simultaneously making a large number of catamenial devices or menstrual tampons from a single billet or block of a dry, fine-pore regenerated cellulose sponge.

Fourth, to provide a method of permanently bonding a coaxial withdrawal string in a polygonal cross section cylinder of dry, one piece, fine-pore regenerated cellulose sponge.

Fifth, to provide compressing means for rapidly forming and individually radially compressing one piece, fine-pore regenerated cellulose menstrual tampons in a multiple-fortning operation.

Sixth, to provide a machine for simultaneously manufacturing a multiple number of menstrual tampons from a regenerated cellulose sponge billet.

Further objects and advantages of my invention will become apparent in the following description, to be read in connection with the accompanying drawings.

My earlier copending application, Ser. No. 350,193 teaches a dry, radially compressed, regenerated fine-pore cellulose sponge, having a coaxial withdrawal string disposed in the length of the cylinder, and forming a menstrual tampon.

FIG. 1a is a perspective view of a radially compressed menstrual tampon of my invention.

FIG. lb is a perspective and partial sectional view of an uncompressed, or fully expanded, menstrual tampon of my invention, showing details of my withdrawal string structure. The relative diameters of the tampons of FIG. 1b and FIG. 1a show the relative diameter of my tampons before and after radial compression of the one piece, regenerated cellulose sponge.

FIG. 1c shows enlarged details of my withdrawal string structure, in use in my tampon.

FIG. 2 is a plan view of a modification of my machine invention capable of simultaneously manufacturing multiple lots of menstrual tampons of my invention.

FIG. 3 is an elevation view of my machine of FIG. 2 at its station I.

FIG. 4 is a detailed elevation sectional view of components illustrating the performance at station I of my machine on a billet of expanded, fine-pore regenerated cellulose.

FIG. 4a illustrates details of my invention relating to the retainer rod structure.

FIG. 5 is a partial elevation view of components of my machine invention operating at station II of my machine, as illustrated in FIG. 2.

FIG. 6 is a more detailed elevational sectional view of the machine of my invention performing at station II of my machine of FIG. 2.

FIG. 7 is a perspective elevation view of my machine operating at station III, as previously illustrated in FIG. 2.

FIG. 8 is a detailed elevation sectional view of one modification of the machine components of my invention operating at station III of my machine as illustrated in FIG. 2.

FIG. 9 is another modification representing a detailed elevation sectional view of the machine components of my invention operating at station III of my machine shown in FIG. 2.

Referring to FIG. lain detail, the menstrual tampon 1 comprises a dry, radially compressed, minimum pore volume, regenerated cellulose cylinder 2, and a withdrawal string 3 coaxially located in and along the cylinder axis length and extending beyond the cylinder, forming a sting handle 6. FIG. lb shows more detail of my tampon invention, being a perspective and partial crosssection view of the dry, fine-pore, expanded, regenerated cellulose, polygonal cross section cylinder 2', prior to radial compression to form the cylinder 2. The coaxially located withdrawal string 3, shown in the cylinder 2', is also coaxially surrounded by a permanent bond means 4 extending the length of the cylinder 2'. The cylinder 2 has

area ends

5 and 5. The permanent bond means 4 is an annular cylindricaLshaped zone which is shown in enlarged cross-sectional detail in FIG. lc, taken through lc 1c of FIG. 1b.

I have found that the permanent bond means 4 can comprise a thermally fused bond formed between a fused yarn structure of the withdrawal string and the regenerated cellulose sponge structure. The fused yarn is cooled to room temperature to form a permanent bond means 4. l have also found that the permanent bond means 4 can be formed by a hot melt adhesive, cooled to room temperature to form a bond between the withdrawal string and the regenerated cellulose sponge structure. My permanent bond means 4 provides a bond between the withdrawal string and the regenerated cellulose sponge which will withstand the stresses of commercial storage conditions, immersion in menstrual fluid and the force required to remove a wet used tampon from a vagina.

I have found that a bifilament withdrawal string made of 50 wt. percent regenerated cellulose rayon yarn-50 wt. percent cellulose acetate yarn, made in a conventional two-ply with a wet strength of 6.5 pounds, is a representative bitilament yarn or string useful in my invention.

By using such an above described bifilament yarn as the withdrawal string 3 in the cylinder 2, I may then thermally fuse or melt the cellulose acetate yarn in the string 3. On cooling the fused yarn, the solidifying cellulose acetate yarn melt will bond to both the rayon yarn and the regenerated cellulose sponge, particularly if the sponge is rapidly radially compressed, before the fused yarn begins to solidify. I use a second nonmelting or nonthermally decomposing yarn as a second filament in the bifilament yarn structure, to provide a second strength member of the bifilament yarn which will not fuse. A fusible yarn used alone may stress crack on cooling, possibly breaking off the withdrawal string on application of the force required to withdraw a used tampon from a vagina, the nonfusing yarn will not break off.

Cotton yarn plied with cellulose acetate yarn is also a suitable bifilament yarn construction for my withdrawal string 3. Cotton yarn plied with polyvinyl chloride yarn; also regenerated rayon plied with nylon yarn, or like combinations of fusible yarns plied with nonfusible yarns can be used to make my withdrawal string 3. The bifilament yarns form a permanent bond means 4 on application of the required heat of fusion for the fusible yarn, followed by rapid radially compressing the cylindrical tampon, allowing the fused yarn to cool and solidify.

I have likewise found that a hot melt adhesive can coat, or impregnate and coat, a nonfusible string, forming a string composition which is not melted or sticky at body temperature, or soluble in menstrual fluid. A typical mercerized cotton string impregnated and coated with a plasticized cellulose diacetate composition can be used to form a suitable string 3. The above cotton string, with the plasticized cellulose acetate coating thereon, is preheated prior to location in the sponge billet, but not to the coating fusion temperature. After locating the preheated, coated cotton string in the sponge cylinder, both the sponge cylinder 2 and the coated string are further heated above the fusion temperature of the cellulose acetate coating and then rapidly compressed. The compressive force aids the formation of a strong permanent bond means 4 between the withdrawal string 3 and the sponge cylinder 2,

when the string 3 and sponge cylinder 2 are cooled to room temperature.

Other nonfusible yarns or strings, selected from cotton, linen, hemp, regenerated cellulose rayon or the like, can be combined with hot melt adhesive coatings. Suitable hot melt coatings are plasticized vinyl chloride resin, plasticized vinyl acetate vinyl chloride copolymer, plasticized cellulose acetate butyrate, polyethylene or the like fusible coatings. My hot melt coatings should not fuse or lose bonding strength at human body or commercial storage temperatures, yet should be readily fusible at the higher temperatures to which the regenerated cellulose sponge can be heated without decomposing the sponge. Controlled heating of all bond components can effect a good bond between the sponge, the cooled and solidified hot melt coating, and the nonfusible, yarn or string.

I have invented a method of rapidly manufacturing a multiplicity of menstrual tampons in a combination of simple steps, also enabling the manufacture in seconds of multiple lots of several hundred tampons on one machine of my invention, as described herein.

In my method, a billet of dry, expanded, fine-pore, regenerated cellulose sponge is shaped to provide a thickness equal to a typical tampon length, as for the tampon device of FIG. 1a or lb, and also to provide a pair of parallel plane billet faces. One separate billet face area is at least equal to the combined areas of the ends and the other billet face is equal to the combined areas of the separate ends 5' for the multiple number of tampons to be made in one lot. An additional small rim area of the sponge billet provides a mounting means during the manufacturing procedure.

My method is summarized as follows:

1. Place a dry, expanded, tine-pore, regenerated celluloseshaped sponge, sufficing in face area for multiple tampons, in position under a multiple strings insertion means. See FIG. 3, for example.

2. Optionally, preheat the multiple-bondable withdrawal strings and the sponge billet to a temperature slightly less than the respective fusion temperatures of the fusible yarn structure or the hot melt adhesive coating of FIG. 1c of my above described withdrawal string structures. See FIG. and FIG. 3, for example.

3. Insert the multiple-bondable withdrawal strings simultaneously into a multiplicity of parallel, regularly spaced positions, perpendicular through both parallel plane faces of the sponge billet, each string located in a position adapted to later form a coaxial string length in a single tampon. See FIG. 4, for example.

4. Heat the cellulose sponge billet and the multiple-bondable withdrawal strings to the required fusion temperature for the respective fusible yarn structures or the hot melt coatings. See FIGS. 5 and 6, for example.

5. Very rapidly after the step 4 above, simultaneously cut the sponge billet into a multiplicity of individual polygonal sponge cylinders, each one of said polygonal cylinders shaped and arranged to contain a single withdrawal string coaxial with the axis of the cylinder length. See FIGS. 7, 8 and 9, for exampie.

6. Very rapidly after step 5 above, simultaneously radially compress each one of the multiplicity of individual polygonal cylinders to a diameter range of 0.40-0.50 of the original polygonal cross section area cylinder diameter. See FIGS. 7, 8 and 9, for example. i

7. Cut the multiple withdrawal strings to the required lengths.

As further steps in my process I may proceed further with the multiple lot of tampons, as follows:

8. Drop and align the inner plunger tubes of a multiplicity of a pair of telescoping tampon insertion tubes, along the uncut multiplicity of withdrawal strings, prior to insertion of the individual tampons in the outer tampon insertion tubes.

9. Place each one of the multiplicity of individual compressed tampons into the separate individual outer tampon insertion tubes, by the application of a pneumatic or ram force to the tampon end from which the withdrawal string extends.

10. Then, cut the multiple withdrawal strings to the required lengths.

Referring to FIG. 2 through FIG. 9, I illustrate embodiments of my machine invention which can rapidly, simultaneously manufacture my menstrual tampons of FIGS. 1a and lb in large lots. My machine invention embodies the steps of my process invention; however, my process invention can be practiced by-other means than shown in my machine invention. I do not wish to be limited in my process invention to the machine invention herein disclosed and claimed.

Referring to FIG. 2 in detail, my tampon-manufacturing machine 21 has a rotary index table 23 adapted to rotate on the pivot means 40, with the three index stations I, II and III, as shown. Each station I, II and III of the index table 23 has a withdrawal string yarn hopper 24 disposed thereon, adapted to provide a multiple cone storage source of yarn for withdrawal string for each of three multiple yarn insertion means 25. The multiplicity of parallel, regularly spaced bondable withdrawal string yarn are arranged to simultaneously feed from the yarn cones located in the yarn hopper 24, individually through multiple yarn insertion means 25. The multiple-yarn insertion means 25 are shown located directly above and cover an inner plunger tube tray at each station I, II, III. A fourth inner plunger tube tray 26 is shown in an inner plunger tube-loading position in the station I area, adjacent to an automatic inner plunger tube loader and photoelectric eye tube position scanner 27 which counts the number of tubes in the tray 26.

In the station II area of FIG. 2 the high frequency dielectric power heater 28 is shown, connected by wires 29 and 30 to the electrodes (not shown) located below the multiple-yarn insertion means 25. At station III of FIG. 2, the multiple-yarn insertion means 25 shown is located directly above a multiple-diecutting, sponge-compressing and tube-loading means, not shown. At tray 31 the multiplicity of tampons are being unloaded, each tampon enclosed in a pair of standard telescoping insertion tubes and the withdrawal string 3 projecting from one end of the inner plunger tube. At tray 32 the multiplicity of outer tampon insertion tubes are loaded from an outer insertion tube loader 33, which is provided with a photoelectric eye scanner to count the number of tubes loaded in tray 32.

The three

hollow arms

34, 35, 36 are adapted to support the trays 32, 31 and the tray located underneath the insertion means 25 at station III, and also adapted to rotate on the pivot means 39. The compressed air vacuum source means 37 is connected through the hollow tube means 38 to the three rotary

hollow arms

34, 35, 36, to provide air pressure or vacuum to the trays, as required on signal. The rotary index table 23 rotates on the pivot means 40 on signal, to transfer a partially fabricated product output from station I to station ll, then to station III and final unloading of the multiplicity of individual tampons.

The inner plunger tube loader 27 operates on signal in a reciprocal motion along guide means 41, to index above the inner plunger tube tray 26 for loading purpose. The outer tampon insertion tube loader 33 also operates on signal in a reciprocal motion along guide means 42, to index above the tray 32 for loading purposes. Personnel are stationed at stations I and II for manual tending and control operations.

At station I, referring to FIG. 3 in detail, the withdrawal string yam hopper 24 is shown elevated above the rotary index table 23. A multiplicity of heat conductive heater tubes 43 contain the bondable yarns, electrically preheated to just below the fusion temperature of the permanent bond means 4. The multiplicity of tubes 43 are flexible and attach to the yarn insertion needle force plate 45. The plate 45 has a multiplicity of hollow needles 46 secured to it, the needles 46 spaced and adapted to insert the multiplicity of withdrawal string yarns, one yarn extending through each single needle 46, and through the inner plunger tube tray 47. Each individual hollow needle 46 has a yarn terminus protruding slightly from the open needle terminus. The multiplicity of needles 46 can be inserted in the sponge billet 48 by a force applied to the force plate 45. The length of the needles 46 and the guided downward motion of the force plate 45 are both adapted to control the penetration of the needles completely through the sponge billet 48. The bottom plate of the inner plunger tube tray 47 forms a combination electrically insulated electrode and force plate 49, which can secure the sponge billet 48 in position on the rotatable comer billet supports 50, above the opening 51 of the index table 23. There is a separate similar opening 51 at each corresponding position of stations II and III of the table 23. FIG. 3 illustrates my index table 23 station I prior to insertion of the hollow insertion needles 46 in the sponge billet 48.

At station I, referring to FIG. 4 in detail, multiple hollow insertion needles 46 coaxially extend through the inner plunger tubes 52, and also pass through the openings 53 in the bottom combination electrically insulated electrode and force plate 49 of the electrically nonconducting, inner plunger tube tray 47. The hollow needles 46 are shown positioned with their open terminii 54 flush with the bottom face 55 of the sponge billet 48. The withdrawal string yarn tips 56 are shown pro jecting a small distance (one-eighth-one-fourth inch) below the sponge billet face 55.

The rotary tube retainer rods 57 are shown in cross section view located in the combination electrically insulated electrode and force plate 49. The conical plunger tube tray entrances 58, and the conical plunger tube tray exits 53, facilitate the movement of the plunger tubes through the close fitting tube openings 59.

In FIG. 40 I show details of my rotary tube retainer rods 57 in projected sectional view. The view shows the pair of retainer rods 57 inserted in the pair of close fitting cylindrical openings 61, with the pair of lands 62 shown projecting as tube stops into the inner plunger tube circular openings 53 in the plate 49. Each of the rods 57 rotate within the cylindrical opening 61 on signal. When the pair of lands 62 of the pair of rods 57 are rotated 180 in the cylindrical openings 61, the pair of lands 62 are indexed into the openings 61, permitting any inner plunger tube 52 to drop down from the tray 47, as in FIG. 4.

In FIGS. 5 and 6 the elevation view of the machine through 11-11 of station II shows the yarn cone hopper 24, the yarn heater tubes 43, the needle force plate 45, and the multiplicity of hollow needles 46 which were shown in detail in FIGS. 3 and 4. In this view of station II the needles 46 have been withdrawn from the sponge billet 48, also through the openings 59 of the tray 47, to a position coaxially and vertically above the openings 59. Just prior to withdrawing the needles 46 as described above, the lower electrode clamp plate 64, which is permanently located at station II is elevated from below the index table 23, from the position of electrode clamp plate 64', compressively securing the yarn projections 56'. The electrode clamp plate 64 is then located in contact with the face 55 of the billet 48, compressing the yarn projectors 56 into close physical contact with the billet 48, as shown in detail in FIG. 6. The surface of the electrode clamp plate 64 adjacent the sponge billet 48 is coated with tetrafluoroethylene resin to prevent the sticking of fused yarn or adhesive and the like to the plate 64.

Thus, in station 11, as illustrated by FIGS. 5 and 6, the sponge billet 48 is clamped between the electrode clamp plate 64 and the force plate 49, the electrode clamp 64 compressively securing the yarn projections 56'. The high-frequency dielectric heating power source 28 is turned on or activated on signal, when the components are in the detailed position illustrated in FIG. 6. The high-frequency power is conducted to the electrode clamp 64 and force plate 49, through the wire conductors 29 and 30.

In FIGS. 7 and 8 I show further steps in the operation of my machine at station Ill. In FIG. 7 I show the yarn cone hopper 24, the heat conductive heater tubes 43, the force plate 45 and the multiplicity of insertion needles 46, all together'operated as a component subunit, and shown elevated perpendicularly above the other station III operations taking place below. The multiplicity of withdrawal. string yarns which connect the sponge billet 48 to the yarn cone hopper 24 at stations I and II are now cut.

Further, in FIG. 7 the tray 47 is now pushed down and rests on the honeycomb die plate 66, which is permanently indexed below the index table 23 at the opening 51. A shaping orifice plate 67 lies directly below the die plate 66. A vacuumtight tampon compressor die 68 lies directly below the orifice plate 67, and a vacuumtight outer applicator tube tray 69 lies directly below the die 68. The tubular

rotary arms

35 and 36 support the two shown separate sets of cooperative multiple die-cutting means, multiple individual radial compressive means, and multiple tampon insertion means for outer applicator tubes embodied in

components

66, 67, 68 and 69. The

arms

36 and 35 rotate on the pivot means 39, and are supplied through line 38 with the air pressure and vacuum means on signal. In FIG. 7, the sponge billet 48, which was shown earlier at stations I and II in FIGS. 3, 4, 5 and 6, is now die cut into a multiplicity of individual polygonal sponge cylinders which are inside the

components

66, 67, 68 and 69 located in the opening 51.

In FIG. 8 I show the details of my multiple die-cutting means 66, multiple individual radial compressive means 67 and 78, and multiple tampon insertion means 93 for outer applicator tubes. The view shows an individual regular hexagonal cross section, cylindrical tampon 74 radially compressed in the tampon compressor means 78. Prior to the compression step, the tray force plate 49 has moved vertically downward, forcing the sponge billet 48 through the sharp edges of the regular hexagonal-shaped honeycomb-cutting die 70, then through the converging venturi-type-shaped opening of the shaping orifice 72. The cutting die 70 cuts the sponge billet into a multiplicity of individual hexagonal cross section cylindrical tampons, one tampon in each shaped die opening of die 70. The shaping orifice 72 lying directly under the thin wall blades of the die 70, supports the die 70, on the top plate 71 ofthe compressor mold means 78. The orifice 72 slightly reduces the diameter of the tampon when the tampon is pushed through the cutting die 70, and then through the orifice 72. The tampon 74, prior to the radial compression step, drops into the thin wall, rubber tubular membrane hollow cylinder 73. Prior to dropping tampon 74 into cylinder 73, the thin wall, rubber cylinder 73 is in the fully stretched or expanded state, as a result of applying a vacuum to the interior of the compressor mold means 78. The compressor mold means 78 is an airtight mold or box having the top plate 71 and the bottom plate 76. The individual thin wall, rubber tubular membrane hollow cylinders 73 are secured to the top plate 71 and the bottom plate 76 by the expanding retaining rings 75 and 77 respectively. The retainer rod lands 79 can be rotated on signal in the cylindrical openings 80, providing a stop for the tampon sponge as it is pushed through the orifice opening 72 and drops into the expanded cylinder 73. The lands 79 distend the rubber cylinder 73 when rotated into position against the rubber membrane, providing the stop. When high-pressure air is applied on signal to the interior of the compressor mold means 78, the tampon sponge 74 is radially compressed.

The outer applicator tube tray 69 of FIG. 7 is shown in structural detail in the outer applicator component tray assembly 93, wherein the removable tray top plate 82 and the removable tray bottom plate 83 enclose the evacuable components. The removable top plate 82 has a multiplicity of shaped openings 94, one opening 94 coaxially located directly below each rubber tubular membrane cylinder 73. Between the removable top plate 82 and the support plate 84, the outer tampon applicator tube 86 is supported perpendicularly in the opening 92 in the tube block 85. The removable top plate 82, the tube block 85, and the support plate 84 have a set of concentric or coaxial openings located therein, providing an aligned passage for the radially compressed tampon on release of the stop provided by the bands 79, when they are engaged to distend the rubber tubular membrane 73. By providing for the evacuation of the outer applicator tray assembly 93 on signal, together with the simultaneous evacuation of the vacuumtight compressive mold means 78, and the simultaneous rotation of the lands 79, to release the tampon stop, the compressed tampon is pushed by the atmosphere above the tampon into the evacuated outer applicator tube 86. The tube 86 is held in position by the close fitting opening 92 in the tube block 85 and the rotary lands 90 of the retainer rods 89 in the openings 91. The

openings

87, 88 provide ample space for evacuation of tray assembly 93, preventing the collapse of the tube 86 due to a pressure differential across the thin tube wall.

in FIG. 9 i show a further modification of my individual radial compressive means adapted to receive the individual tampon cylinder and to radially compress the tampon. Inner plunger tubes 52 are shown located in the tube tray 47, concentric with the yarns 66, and adjacent the force plate 49. The lands 62 of the retainer rods 57 are in the exposed position supporting the tube ends. The force plate 49 is exerting a uniform pressure on the sponge billet 48', pushing the billet down on the regular hexagon-shaped honeycomb die 70', which cuts the billet into individual tampons. The shaping orifice 72' has a venturi-type contour entrance, which begins the radial compression step. The force applied by the force plate 49 is assisted by the vacuum applied through the conical openings 101 of the conical-shaping dies 100. Thus the sponge billet 48' is shown partially cut into individual tampons having i the faces 55, and the yarn projections 56'. The vacuum is obtained by evacuating on signal the tray 69' through the opening 87', the opening 88' and the empty outer applicator tubes 86'. The tubes 86' are located in the openings 92' in the tray 35', supported by the retainer rods 91'. As the force plate 49 pushes down the sponge billet 48 and completes cutting the billet into individual tampons, the vacuum sucks and elongates the individual tampons. The pressure differential between the individual sponge face 55' and the opposite end of the sponge tampon may be increased by increasing the air pressure through the inner plunger tube 52. The pressure differential forces the individual sponge tampons down through the conical mold openings 10!, into the individual outer applicator tubes 86.

In the compressed tampon-forming means of FIG. 8, when the tampon 74 drops and is sucked into the outer applicator tube 86 on signal, a similar signal actuates the retainer rods 57, permitting the inner plunger tube 52 to drop down along the uncut yarn 66 as a guide. The tube 52 passes through the expanded rubber cylinder 73, locating on top of the tampon end 95. Similar steps can take place on signal in the compressed tampon-forming means of FIG. 9, placing the inner plunger tube 52 on the compressed tampon face opposite tampon face 55.

As a final step I sever or cut the yarn 66 to form a completed tampon with a withdrawal string. The yarn'cutting step may be completed simultaneously with the arrival in final position of the tampon 74 in the applicator tube 86. In FIG. 8 i show a pair of cutting blades 96, which can move in a reciprocating horizontal motion, cutting the yarn 66 on signal, to form a tampon withdrawal string.

My invention uses dry, expanded, regenerated cellulose sponge of fine-pore structure as a basic raw material. I define expanded, fine-pore regenerated cellulose sponge as the dry sponge of fully distended pore structure, not yet subjected to a compressive force which collapses the pore dimensions.

Typically, my white sponge has pores in the dry, expanded state ranging from 0.5 to 2.0 mm. diameter and the like, and a 1 mm. pore diameter is common. A typical dry, expanded regenerated cellulose sponge density is 0.0296 g./cc. When fully saturated with water the typical regenerated cellulose sponge density is 1.00 g./cc., so a fully saturated wet sponge may absorb approximately 0.97 g./cc. of water or relatively similar density menstrual fluid.

1 may preheat the sponge billet 48, or the like, in an air heated oven, or the like, prior to placing the sponge billet on the station I four rotatable corner supports 50. The sponge billet may be preheated in the oven to 250 F. and then transferred to station I, then station ii and station lll. Thus, time and electric power input required for the yarn fusion step at station II is decreased. 1 may also conductively preheat the yarns 66 in the heater tubes 43, or the like, preheating the yarn to slightly less than the fusion temperature of the fusible yarn structure or the hot melt adhesive of the yarn 66 modification. Thus, a shortened heating cycle is possible for the station I]. FOr example, I may preheat the sponge billet to 250 F. in an air oven, and preheat a permanent bond means 4 forming modification, such as a hot melt adhesive coated yarn to a temperature just below the fusion temperature of the hot melt adhesive. Then the hot melt adhesive coated yarn 66 is inserted in the hot sponge billet and the fusion of the hot melt adhesive can be completed, as the adhesive melts at a temperature below the sponge billet temperature. Thus, the electrical heater requirement of the dielectric power heater 28 or the like is completely eliminated.

if additional heat energy is required as an input at station ll, the high-frequency dielectric power heater is a very suitable heater means for rapidly generating the heat with the sponge billet and the yarn, where it is needed, As an example, an 1 1X1 1 inch parallel face area X2 V4 inch thick dry, expanded sponge billet can be heated to about 250 F. in less than 2 seconds, but the application of 12 kilowatts of 40.68 me. at 10,000 volts. Preheated biiilament yarn of cellulose rayon yarn and cellulose acetate yarn plied together may be conductively preheated, then inserted in the sponge billet in station I, and further heated in the station ll dielectric power heater to the cellulose acetate yarn ply fusion temperature range, as l have earlier described. I may use other high-frequency power bands allotted to industrial use, ranging typically from l3.56 mc., 27.12 me., to 40.68 mc., with corresponding changes in required dielectric heating times.

An advantage of my process and of my machine is the conservation of regenerated cellulose sponge raw material and the high rate of simultaneous manufacture of radially compressed tampons. Typically, an 1 1X1 1 inch billet face of sponge can be cut into approximately 4009/ 16 inch cross section hexagons with a honeycomb opening die. Likewise, a l0 l0 inch billet face can be cut into approximately 280 tampons of it-inch hexagon cross section diameter, and approximately 203 tam pons of 35-inch hexagon cross section diameter, all diameters measured normal to two opposite parallel edges of the hexagon. i may likewise simultaneously cut Vs, or round cross section tampon contiguous cylinders in appropriate numbers from a sponge billet. Each tampon cylinder-cutting die is matched with a corresponding coaxial yarn insertion needle centered on the tampon die center, so as to provide a withdrawal string yarn coaxially located in the polygonal cross section cylinder length of sponge.

I may use also a standard straight-sewing needle having an eyelet on the free needle end, with the yarn inserted through the needle eyelet, as in standard industrial sewing practice.

My dry, radially compressed minimum pore volume, regenerated cellulose tampons, having coaxially located withdrawal strings permanently bonded the length of the sponge cylinder, have been tested in menstrual absorption application with very favorable results. The small diameter radially compressed sponge cylinder does not cause discomfort in females and is easily inserted by a correspondingly sized conventional pair of telescoping paper tubes. The sponge tampon expands on absorption of menstrual fluid and is removed by pulling on the permanently bonded withdrawal string 3, or the like. The wet sponge is soft and pliable, and does not damage or tear tissue. if the menstrual fluid is insufficient to fully wet the tampon, the dry portion of the tampon does not expand, and hence is easily removed from the vagina.

Typical absorption test data is listed below in table l. The data clearly establish the use of my tampon to absorb a daily menstrual flow at the range of normal flow rate in a normal use pattern, without discomfort. In addition, the relative small diameter of my radially compressed tampons are supported in table ll by the comparison of my sponge tampon diameters, before and after radial compression to a minimum pore TABLE I.TAMPON PERFORMANCE Test No. 1.Tampon size: inch hexagon x 2% in. long; Dry blank wt.: 0.9 gram Day of Time Tampon menstrual weight Tampon N 0. period Insertion Removal (grams) 1st2nd. :00 PM.-. 8:30A.M. 11.0 2nd 8:30 A.M. i1:00A.M- 9.0 2nd 11:00A.M 1:30 P.M 11.5 2nd-. 1:30 P.M.- 4:30 P.M 10.1 2nd 4 30 8:30 P.M 9.0

: inch round x 2% in. long; Dry blank wt.: 0.8 gram TABLE II.TAMPON DIAMETER COMPRESSION RATIOS Ratio (after Before After compression/ compression compression et'ore Tampon No. (inch) (inch) compression) 1 0.56round 0.25 0.45 2 1.00 round. 0.44 0. 44 3 0.75 round. 0.31 0. 42 4. 0.75 hexagon- 0. 31 0. 42 5.- 0.88 hexagon. 0.39 0.44 6 0.63 hexagon. 0.28 0.44

perature, then rapidly and simultaneously cutting said billet into a multiplicity of polygonally shaped sponge cylinders, each one of said polygonal sponge cylinders arranged to contain a single coaxial bondable withdrawal string; then rapidly radially compressing to a cylinder of circular cross section and minimum pore volume each of said multiplicity of polygonal sponge cylinders, each single radially compressed cylinder forming a bond with one of said multiplicity of bondable with withdrawal strings; and cutting said multiplicity of withdrawal strings at the required lengths.

2. In the process of claim 1, the step of inserting a multiplicity of parallel, regularly spaced, bondable withdrawal strings perpendicularly through a first face and a parallel, opposed second face of a billet of dry, expanded, fine-pore regenerated cellulose sponge, each one of said multiplicity of withdrawal strings being positioned to form-securing terminus exteriorly adjacent said second face of said billet.

3. in the process of claim 1, the step wherein said multiplicity of parallel, regularly spaced, bondable withdrawal strings inserted into said billet of dry, expanded, fine-pore regenerated cellulose sponge are heated to bonding tempera- Obviously, many modifications and variations in my menstrual tampon, method and machine for manufacture of menstrual tampons may be made in the light of my teachings. It is ture by high frequency, electrical energy dielectric heat generated in said withdrawal strings and said adjacent billet.

4. In the process of claim 1, the step wherein said multiplicity of parallel, regularly spaced, bondable withdrawal strings, perpendicularly inserted into said billet ofdry, expanded, finepore, regenerated cellulose sponge are conductively heated to bonding temperature.

5. in the process of claim 1, the step of rapidly radially compressing to a minimum pore volume a multiplicity of polygonal sponge cylinders to a multiplicity of single compressed sponge cylinders of circular cross section by simultaneously enclosing each single polygonal sponge cylinder in an individual, thin wall tubular rubber membrane, and uniformly applying pneumatic pressure to the exterior face of said individual rubber membrane, whereby said membrane radially compresses each single polygonal cylinder to a cylinder of circular cross section and minimum pore volume.

6. in the process of claim 1, the step of rapidly compressing radially said multiplicity of polygonal sponge cylinders to a multiplicity of single compressed sponge cylinders by simultaneously passing each single polygonal cylinder through a single hollow truncated cone means; initially inserting a first end of each polygonal sponge cylinder into the larger opening of said cone means, then applying a forcing means to said first end of each sponge cylinder, while simultaneously applying an evacuating means to the smaller opening of said cone means, thereby radially compressing said sponge cylinder and ejecting the radially compressed sponge cylinder from the smaller opening of said cone means.

Patent No.

Inventor(s) and that said Letters Patent are hereby corrected as shown below:

In In In UNITED STATES PATENT OFFICE September 21,

Dated John Leslie Jones It is certified that error appears in the above-identified patent q Column 2, line 5, "sting" should read string Column 3, line 33, "sufficing" should read sufficient Column 8, line 7, "FOr" should read For Column 8, line 21 "needed, As" should read needed. As Column 8, line 23, "but" should read by Claim 1, line 8, delete "with" second occurrence.

Siszned and sealed this 28th day of March 1972.

(SEAL) Attest:

EDWARD M.FLETCHER.JR. ROBERT GOTTSCHALK Attesting Officer Commissioner of Patents

Claims

2. In the process of claim 1, the step of inserting a multiplicity of parallel, regularly spaced, bondable withdrawal strings perpendicularly through a first face and a parallel, opposed second face of a billet of dry, expanded, fine-pore regenerated cellulose sponge, each one of said multiplicity of withdrawal strings being positioned to form-securing terminus exteriorly adjacent said second face of said billet.
3. In the process of claim 1, the step wherein said multiplicity of parallel, regularly spaced, bondable withdrawal strings inserted into said billet of dry, expanded, fine-pore regenerated cellulose sponge are heated to bonding temperature by high frequency, electrical energy dielectric heat generated in said withdrawal strings and said adjacent billet.
4. In the process of claim 1, the step wherein said multiplicity of parallel, regularly spaced, bondable withdrawal strings, perpendicularly inserted into said billet of dry, expanded, fine-pore, regenerated cellulose sponge are conductively heated to bonding temperature.
5. In the process of claim 1, the step of rapidly radially compressing to a minimum pore volume a multiplicity of polygonal sponge cylinders to a multiplicity of single compressed sponge cylinders of circular cross section by simultaneously enclosing each single polygonal sponge cylinder in an individual, thin wall tubular rubber membrane, and uniformly applying pneumatic pressure to the exterior face of said individual rubber membrane, whereby said membrane radially compresses each single polygonal cylinder to a cylinder of circular cross section and minimum pore volume.
6. In the process of claim 1, the step of rapidly compressing radially said multiplicity of polygonal sponge cylinders to a multiplicity of single compressed sponge cylinders by simultaneously passing each single polygonal cylinder through a single hollow truncated cone means; initially inserting a first end of each polygonal sponge cylinder into the larger opening of said cone means, then applying a forcing means to said first end of each sponge cylinder, while simultaneously applying an evacuating means to the smaller opening of said cone means, thereby radially compressing said sponge cylinder and ejecting the radially compressed sponge cylinder from the smaller opening of said cone means.