Domed compressed tampons

Abstract

An improved apparatus and method compresses a cylindrical blank into a tampon which is dimensionally stable and which is provided with a domed insertion end. A cylindrical blank is radially compressed and then introduced into a cylindrical axial compression chamber. The blank is then subjected to an extreme axial overcompression. The closed insertion end of the compression chamber has a bore formed therethrough. The bore is generally coaxial and is adapted to accept a reciprocating ejection ram having a ram surface facing into the chamber. When the ram is seated in the first position, the ram surface and the insertion end wall of the compression chamber together form a smooth doming surface. The bore periphery is of a smaller diameter than the chamber and hence radially spaced from the side walls of the chamber, and the ram has sufficient clearance to move through the chamber and eject the tampon without interference from the walls of the chamber.

What is claimed is:  
     
         1 . An apparatus for axially compressing a cylindrical blank into a tampon having a domed insertion end, said apparatus comprising: 
 a cylindrical axial compression chamber having cylindrical side walls, an insertion end, and an opposed withdrawal end;    said withdrawal end being open for the introduction of the cylindrical blank into said chamber and for accepting a reciprocating compression ram adapted to exert compression force against the withdrawal end of the so introduced blank;    said insertion comprising an immovable insertion end wall having a bore therethrough;    said bore being coaxial with the compression chamber and having a periphery at the insertion end wall of a smaller diameter than that of the cylindrical compression chamber;    said bore being adapted to accept a reciprocating ejection ram, said ram being capable of reciprocating through said bore and through said compression chamber for ejecting the axially compressed blank;    said rejection ram having a ram surface facing into said compression chamber;    said ram surface and said insertion end wall of said compression chamber together forming a smooth doming surface for imparting a smooth surface dome to the insertion end of the blank when said blank is compressed by the action of the compression ram.    
     
     
         2 . The apparatus of    claim 1    wherein said bore has a diameter ranging from about 40 to about 95% of the diameter of the compression chamber.  
     
     
         3 . The apparatus of    claim 1    wherein said bore has a diameter ranging from about 70 to about 90% of the diameter of the compression chamber.  
     
     
         4 . The apparatus of    claim 1    wherein said ejection ram terminates in a ram head having said ram surface thereon; said ram head tapering axially away from said chamber.  
     
     
         5 . A method for axially compressing a cylindrical blank having an insertion end, a withdrawal end, and cylindrical walls therebetween, into a dimensionally stable tampon comprising: 
 introducing said blank coaxially into a cylindrical compression chamber having a closed insertion end, a withdrawal end and cylindrical walls therebetween wherein the cylindrical walls of said blank make frictional contact with the cylindrical walls of the compression chamber;    axially over-compressing said blank, said overcompression being applied to the extent that, through the action of the frictional contact, a plurality of circular pleats are formed around the axially compressed blank, said compression being sufficient to fold said pleats, in the direction of the withdrawal end of the axially compressed blank, to overlie the next adjacent portion of the cylindrical wall of the axially compressed blank.    
     
     
         6 . The method of    claim 5    wherein said overcompression is to the extent that the blank is axially compressed to about 15 to about 30% of its length prior to compression.  
     
     
         7 . The method of    claim 6    wherein the axially compressed blank is allowed to expand after axial compression to about 50-80% of the length of the blank prior to axial compression.  
     
     
         8 . A dimensionally stable tampon comprising a cylindrical fibrous body having an insertion end, a withdrawal end and cylindrical side walls therebetween, said tampon being axially compressed from a blank, said tampon having a plurality of circular pleats formed around the axially compressed blank, said pleats being folded to overlie the next adjacent portion of the cylindrical wall of the tampon.