US3131436A - Manufacture of cellulosic product - Google Patents

Description

May 5, 1964 C. J. GREINER ETAL 3,131,436

MANUFACTURE oF cELLULosIC PRODUCT aww."

United States Patent O MANUFACTURE F CELLULQSIC PRODUCT Charles J. Greiner, Menasha, and Anthony S. Hubin and Ralph G. Miller, Neenah, Wis., assignors to Kimberly- Clark Corporation, Neenah, Wis., a corporation of Delaware Filed Oct. 4, 1961, Ser. No. 142,898 4 Claims. (Cl. 19144.5)

This invention relates to an improved method of tampon manufacture.

A primary object of the invention is to provide an improved method of manufacture with attendant improvements in products resulting from the method which aid in the retention, during an extended shelf life, of the tampon shape and dimensions.

A further object is to provide an improved arrangement of individual fabricating steps with resultant improved sequential formation of a fibrous batt or blank into a finished tampon.

Another object is to provide an improved method of fabricating tampons with attendant increase in the optimum operating speed of the involved fabricating apparatus.

Other objects and advantages will become apparent to persons skilled in the art upon examination of the drawings and description Without departure from the concepts taught herein as defined in the appended claims.

In the drawings, in which like parts are identified by the same reference numerals,

FIG. 1 diagrammatically illustrates a known sequence of operational steps employed in the conversion of a preformed blank to a finished tampon form as disclosed in US. patent application Serial No. 773,020, filed November l0, 1958, by Henry R. Cloots et al.;

FIG. 2 diagrammatically illustrates the rearrangement, in accordance with the present concept, of the fabricating steps illustrated in FIG. l; and

FIG. 3 diagrammatically illustrates one form of cam actuated compressor mechanism suitable for employment in the processing stage shown at position 3, FIG. 2.

The invention consists of an improved arrangement of the sequential steps involved in the method and apparatus taught in U.S. patent application Serial No. 773,020 as diagrammatically illustrated in FIG. l, and assigned to a common assignee. Patent application Serial No. 773,020 is referenced to teach one type of apparatus which lends itself to modification in an obvious manner for incorporation of the present method concepts.

Prior Art Method The method of tampon fabrication taught by U.S. patent application Serial No. 773,020 comprises inserting a pre-compressed tampon body into a die, then bringing the die into registry with a needle stitcher mechanism and attaching a string to the tampon body, and then performing other operations to finish the tampon. Preparatory to inserting it in the die the tampon body may be fully compressed longitudinally or it may be only partially precompressed longitudinally, but in either case it is somewhat overcompressed transversely, in order that it may readily be slid longitudinally into the die. FIG. 1, indicates the sequence of operating stages according to this prior art method for the case in which the tampon body is only partially pre-compressed longitudinally prior to its transfer to a die at position 1. The partially pre-compressed tampon body is transferred from a suitable precompressing apparatus, not shown, into one of a plurality of suitably shaped dies of a nishing turret schematically illustrated in FIG. l. The dies are preferably formed of nylon or similar material. The transfer operation is effected at position l, FIG. l, of the sequential body proc- "ice essing stages through which the turret is indexed in accordance with the teachings of the referenced patent. No work stations are located at turret indexing positions 2 and 3 in the processing method illustrated in FIG. 1, hence the die-housed tampon body as indexed into position 4 is of a configuration and density established prior to the transfer operation. At position 4, the die-housed and partially compressed body is brought into registry with a needle stitcher mechanism which effects the first stage of string attachment. The needle has a hooked point and is reciprocated at position 4 in a manner to pierce the tampon body in offset relation to the axis there#l of. During retraction the needle pulls with it a looped cord which is drawn through the tampon body with the loop positioned laterally thereof. At position 5 the lat-A erally positioned trailing ends of the threaded cord are drawn to the opposite side of the body and inserted through the protruding needle formed loop, but are not drawn tight. W'hen the tampon body (corresponding to 8 in FIG. 3) is indexed to position 7, a plug or base former (similar to 22 of FIG. 3) is inserted into an open end of the die (which is mounted and constructed the same as die 10 in FIG. 3). A body former (similar to 14 of FIG. 3), provided with a hemispherically dished nose, is then moved axially against the other end of the tampon body and places said body, backed by the base former, undersubstantial compressive forces.

While at position 7, and immediately after tampon compression between the base and body formers occurs, a spike-like tool, mounted to move axially through the base former, is forced into one end of the tampon to provide a bore. At position 8, the tampon body, now under considerable compression but not compressed to final length, is subjected to further compression between body and base formers similar to those at position 7. Immediately thereafter a roaming tool moves axially through the base former and into the preformed bore for enlargement thereof to the approximate cross-sectional contour of a stick-like inserter to be later received therein. Since bore' reaming at position 8 is effected after the base and body formers place the body under a final degree of compression, establishing the tampon bodys finished length, the rearning operation does not affect the final tampon dimensions. Upon being indexed to position 10 the base end of an inserter stick is moved into the bore formed at positions 7 and 8. The base of the stick is of a size to insure loose insertion within the body to permit easy stick detachment during use. No additional compressive forces are imparted to the finally compressed body during stick insertion. At position l2 the cord as inserted at position 4 and looped at position 5 is drawn tight into a Larkspur knot. At position 13 the completed tampon is ejected from the turret. p

Since the tampon body as inserted into the die at position 1, has previously been compressed to a diameter somewhat less than its finished diameter (regardless of whether it has been fully, or only partially pre-compressed longitudinally), it does not tightly engage the walls of die 10. The tampon body is therefore moved into position 4 of the prior art method for string stitching while capable of being rotated within its die by the chordally applied forces of the needle. Such relative rotation has been experienced during the prior art stage 4 needling operation, with resultant needle deflection, bending and occasional breakage. Applicants improved method prevents all body rotation during needling.

The Improved Method As illustrated in FIG. 2, the present invention includes tampon body transfer to turret stage 1 in the manner above described. The major advance over the prior art sequence of forming stages, many of which operate as in the above described method, resides in the provision at stage 3 of base and body formers which move axially in- Warly to compress the body longitudinally and place it under its final degree of compression prior to the indexing thereof into station 4 for string needling. Advantages attendant placing the body under its final degree of compression at position 3 are as follows. Upon arrival at station 4, the die-held tampon body which has been radially expanded and compacted against the surrounding lateral wall of the die, due to axially applied compressive forces, is frictionally held by the lateral die Wall, and is not capable of being rotated within its die by the needle imparted forces, since it is maintained within the die under substantial radial compression. While a stitching operation identical to that in the prior art method is effected at station 4, the absence of relative rotation hetween body and die eliminates the cause of deflection, bending and breakage. As the turret thereafter indexes into looper station 5, looping operations are more uniformly effected. The fully compressed body then moves into stations 7 and 8 to be successively spiked and reamed. While the body is securely maintained between the base and body formers at stations 7 and 8 to prevent axial expansion during spiking and reaming, no further axial compression results from those operations. The subsequent operations illustrated in HG. 1 are effected in the manner described above.

Each individual stage comprising the improved method may be effected by employing apparatus as fully disclosed in patent application Serial 773,020. The improved method thus involves a sequential rearrangement of body forming stages While resulting in the elimination of undesirable conditions inherent in the prior art method. Elimination of relative rotation of the body and die by early compression to the final degree results in a substantially improved end product due to an extended period of body retention in its die while fully compressed, as more fully described below.

Apparatus suitable for effecting the final degree of body compression at position 3 is illustrated in FIG. 3. As die 10 of turret 12 is indexed into position 3, a body former 14 of rod-like configuration and terminating in a convexly contoured free end 16 is cam actuated from the laterally retracted position shown into compressive engagement with one end of the tampon body 8. Each turret die is provided with a slidable body former axially positionable Within the die by an associated cam roll-er 1S positioned for registry With a cam track 20. Cam roller 18 is rotatably mounted on bracket 26, the upper portion of which is slidably associated with a guide member 28 for proper positioning of roller 1S in respect to its track Track 20 may be mounted by an annular bracket 30. Bracket 30 includes a retention track 32, in registry with a cam roller 33 which depends from bracket 26 for periodic retraction of body former 14 during the indexed rotation of turret 12. While body former 14 remains in slidable association with its die 10 during turret rotation, a base former 22, shown fully retracted from die 10 by suitable leverage mechanism generally shown at 24, intermittently engages a registered die. As turret 12 moves into position 3 mechanism 24 moves plug portion 22a of base former 22 into the adjacent end of die 10 while firmly locking the plug in that position. A portion of bracket 30 and cam track 20 (not shown) are suitably hinged to permit an associated cam actuated rod 34 to hinge track 20 inwardly toward turret 12 with resultant movement of body former 14 into compressive engagement With the adjacent end of tampon body 8. The degree of inward movement of former 14 is such as to effect a final degree of compression of body 8. Thereafter both body former 14 and base former 22 are withdrawn to their initially retracted positions, and the turret is indexed into subsequent stations.

Since the structure forms no part of the present invention, apparatus similar to that taught by patent application Serial No. 773,020 has been described, but other suitable structures may be employed to obtain like results.

An important advantage obtained by the method taught herein results from the fact, as above stated, that the tampon, after being finally compressed, remains in its die in that condition during processing at subsequent stations. The time period in which liber bonding or aging occurs is thus long as compared to that of the prior art teaching. As a result thereof, the fibers forming the tampon body are uniformly and securely interlocked, with resultant improvement n dimensional stability and shelf life. ln addition, the extended period between final compression and tampon ejection permits substantially higher optimum turrent indexing speeds While maintaining the finished tampons Within a range of satisfactory stability characteristics.

As incorporated in the apparatus of the aforementioned patent application, the improved method was found to permit an increase in optimum operating speed of fortyfive to sixty units per minute with attendant improvement in tampon quality.

What is claimed is:

1. The method of forming a tampon with a withdrawal cord therethrough which comprises longitudinally compressing a tampon body in an elongate die to a high, substantially uniform fiber density with simultaneous compacting of said body against the surrounding lateral Wall of said die to frictionally hold it against rotation therein, and then needling a withdrawal cord transversely through said body While it remains frictionally held in said die.

2. The method defined by claim 1 which comprises needling said withdrawal cord through said body at a place odset from the longitudinal `central axis thereof.

3. The method of forming a tampon With a withdrawal cord therethrough which comprises inserting a partially precompressed elongate tampon body into an elongate die, said die having a uniform cross-section equal to the cross-section of the finished tampon, longitudinally compressing said body substantially to its final length with simultaneous compacting thereof against the surrounding lateral Wall of said die to frictionally hold it against rotation therein, and then needling a withdrawal cord transversely through said body while it remains frictionally held in said die.

4. The method defined by claim 3 which comprises needling said withdrawal cord through said body at a place offset from the longitudinal central axis thereof.

References Cited in the file of this patent UNITED STATES PATENTS 2,123,750 schulz July 12, 193s 2,176,114 Wells Oct. 17, 1939 2,330,257 Bailey Sept. 28, 1943 2,462,178 Ganz Feb. 22, 1949 2,715,374 Carrier Aug. 16, 1955 2,926,394 Bletzinger et al Mar. l, 1960

Claims (1)

1. THE METHOD OF FORMING A TAMPON WITH A WITHDRAWAL CORD THERETHROUGH WHICH COMPRISES LONGITUDINALLY COMPRESSING A TAMPON BODY IN AN ELONGATE DIE TO A HIGH, SUBSTANTIALLY UNIFORM FIBER DENSITY WITH SIMULTANEOUS COMPACTING OF SAID BODY AGAINST THE SURROUNDING LATERAL WALL OF SAID DIE TO FRICTIONALLY HOLD IT AGAINST ROTATION THEREIN, AND THEN NEEDLING A WITHDRAWAL CORD TRANSVERSELY THROUGH SAID BODY WHILE IT REMAINS FRICTIONALLY HELD IN SAID DIE.

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