Field of the Invention

The present invention relates to a method of packaging a tampon.

Background of the Invention

Methods for closing one end of tubular containers are known.

US 8221371 by McNeil-PPC Inc. discloses a wrapper with a folded bottom and a process for overwrapping a tampon. The process comprises a cylindrical wrapper that projects beyond the end of a tampon. The withdrawal end is heat sealed. The insertion end may be a dome or have a flattened geometry. Jaws, preferably four jaws, contact the insertion end causing the overlap to surround the insertion end of the tampon and be sealed together. For this purpose said jaws are spring mounted and heated. A folding station folds excess of overwrap. US 5,907,941 by Fuji Photo Film. Co. purports to disclose a wrapping apparatus for a web roll, preferably a photographic film. A sheet is being wound around said web roll. The web roll has a core that is connected to a holding member. A circular rack is fixed to a folding unit, a heating member and a cooling member. Said rack may rotate around an axis and thereby around the holding member with the fixed web roll. Now the folding unit, a heating member and a cooling member are moved radially closer to the axis in order to contact the rim of the web roll. The folding unit rotates in counter direction to the rotation of the rack and folding blades are used to obtain distinguished fold lines. Said heating member seals the fold lines, which are cooled by the cooling member. GB 966121 purports to disclose a wrapping machine for a roll. Any cylindrical article may be used. The wrapping machine comprises a number of folder plates spaced at angular intervals around a main axis coaxial with the roll, means for causing the folder plates to move simultaneously inwardly towards the main axis and thereby to fold the tubular projecting end of the wrapping material, and means for rotating the assembly of folder plates through an angle around the main axis, thereby flattening the pleats of the wrapping material closely against the end of the roll. Preferably the folder blades are pivoted to support members that may move inward. US 3807132 purports to disclose a wrapping machine for a "cylindrical thing", e.g. a toilet paper roll, having an axial bore. For the wrapping process it is mounted on a pushing member. A cylindrical frame rotates around the cylindrical thing and grasping members move radially inwards for the folding process. The rotation causes the folding to flatten and folding pattern. However, none of these references teach a method and apparatus for highspeed closure of a tubular plastic wrapper for use with tampons.

Summary of the Invention

The present invention relates to high-speed methods to close tubular plastic wrappers for use with tampons. In one embodiment, the process includes providing a packaging film on a mandrel in the form of a hollow tube, forming a folded surface by rotating the hollow tube and mandrel while counter-rotating a plate having a plurality of folding blades extending outwardly therefrom, to form a plurality of folds that define the folded surface, substantially perpendicular to the longitudinal axis of the hollow tube, each folding blade engaging a portion of the protruding tube portion, applying heat and pressure to the folded surface to form a closed end, inserting the tampon into the tube, and closing the first end of the tube. The packaging film material comprises at least one thermoplastic surface, and the mandrel has a first end extending from a revolving platform and a second end, distal the first end. In addition, the mandrel is capable of rotating with respect to the revolving platform on which it is mounted. In addition, the hollow tube has an overlapping longitudinal seam area having two plies of the packaging film and has a first end corresponding to the first end of the mandrel and a second end distal thereof, the second end extending beyond the second end of the mandrel to define a protruding tube portion, and a length extending from the first end to the second end; wherein the protruding tube portion has a length approximately equal to the radius of the hollow tube.

In an alternative embodiment, the folded surface is formed by rotating a plurality of folding blades perpendicular to the longitudinal axis of the hollow tube to engage the protruding tube portion to form a plurality of folds that define the folded surface, substantially perpendicular to the longitudinal axis of the hollow tube.

Brief Description of the Drawings

Fig. 1 is a side elevation of an open wrapping tube disposed on a mandrel.

Fig. 2 is an end view of the open wrapping tube and mandrel of Fig. 1.

Fig. 3 is a plan view of a fan-like folding plate useful in the method of the present invention.

Fig. 4 is a side view of the fan-like folding plate of Fig. 3.

Fig. 5 is a perspective view of a folding blade of the folding plate of Fig. 3.

Fig. 6 is a perspective view of a revolver and ancillary equipment useful in the practice of the present invention.

Figs. 7 are close-up views of the engagement of the fan-like folding plate of Fig. 3 and the mandrel of Fig. 2 during the process of forming pleats across the second end of the wrapping tube of Fig. 2.

Figs. 9-1 1 are plan views of an alternative embodiment of the wrapper tube closure apparatus of the present invention.

Fig. 12 is a perspective view of an alternative embodiment of the wrapper tube closure apparatus of the present invention.

Detailed Description of the Invention

The following is a detailed description of the present invention, wherein like elements are labeled with like numerals in Figs. 1 -1 1. Referring to Figs. 1 -2, a plastic wrapping film, formed into a flexible packaging tube 10 is disposed on a mandrel 20. The flexible packaging tube 10 has a first open end 12, a second open end 14 and a longitudinal seam 16. The mandrel 20 has a first end 22 extending from a revolving platform 30 and a second end 24, distal the first end 22, and a length extending from the first end 22 to the second end 24, and is capable of rotating with respect to the revolving platform 30. The second end 14 of the flexible packaging tube 10 extends beyond the second end 24 of the mandrel 20 to define a protruding tube portion 18.

Figs. 3-5 show features of a fan-like folding plate 40 having four folding blades 42 that is rotatable about pivot 44 in the direction of arrow 46. When the folding plate 40 rotates in the direction of arrow 46, the leading edge 48 of each folding blade 42 is elevated with respect to the plane of the folding plate 40 to enable the folding blade 42 to engage the protruding portion 18 of the flexible packaging tube 10. The remainder of the folding blade 42 curves and/or slopes down to the plane "p-p" of the folding plate 40 (shown in Fig. 4). Thus, as each folding blade 42 moves across the protruding portion 18 flexible packaging tube 10, it forms a pleat across the open second end 24 of the flexible packaging tube 10. The four folding blades 42 of the embodiment of these figures would be capable of forming four pleats across the open end 24 of the flexible packaging tube 10. After these pleats are formed, they can be heated under pressure to soften the plastic wrapping film material to seal them in a manner to close the previously open second end 14 of the flexible packaging tube 10.

While four folding blades are shown in this embodiment, one of ordinary skill in the art will recognize that other numbers may be used, from three to eight or more. Preferably, the number of blades is between four and six.

Fig. 6 shows a revolving platform 30 having mounted thereon four mandrels 20. As shown in Position 50, a first mandrel 20a engages a conveyor 60 that delivers a supply of plastic wrapping film thereto. Each mandrel 20 can be equipped with apertures and/or slots to permit vacuum pressure to be drawn therethrough to hold the plastic wrapping film in place on the mandrel. As shown in Position 52, a second mandrel 20b is engaged with a longitudinal sealing bar 62 arranged and configured to seal overlapping plies of the plastic wrapping film to form the flexible packaging tube 10. Position 54 is the tube folding apparatus (not shown in this figure) and has a third mandrel 20c with a flexible packaging tube 10 ready for engagement with the tube folding apparatus. At Position 56, a fourth mandrel 20d has transferred the flexible packaging tube 10 for further processing.

Figs. 7 and 8 show the engagement of the folding blades 42 with the protruding portion 18 of the flexible packaging tube 10. As shown in Fig. 7, the mandrel 20 rotates in a counter-clockwise direction, while the folding blades 42 rotate in a clockwise direction. Fig. 8 shows the process partially completed with two of the folding blades 42 having made a corresponding number of folds across the second open end 14.

In an alternative embodiment, shown in Figs. 9-1 1 , the mandrel (not shown) remains stationary in aperture 70 while four independently rotatable folding blades 42' rotate, sequentially, e.g., starting at Position 72, followed by Position 74, Position 76, and Position 78. Fig. 9 shows the four independent folding blades 42' ready to fold in the direction of arrows 80. Fig. 10 shows the folding blades 42' corresponding to Positions 72 furthest across aperture 70 followed closely by Position 74, while the folding blade 42' corresponding to Position 76 approaches the aperture 70. Fig. 1 1 shows all four folding blades 42' disposed across aperture 70. After these pleats are formed, they can be heated under pressure to soften the plastic wrapping film material to seal them in a manner to close the previously open second end 14 of the flexible packaging tube 10.

While four folding blades are shown in this embodiment, one of ordinary skill in the art will recognize that other numbers may be used, from three to eight or more. Preferably, the number of blades is between four and six.

In an alternative embodiment, shown in Fig. 12, the revolving platform 30 and the mandrel 20 are rotating along a fixed wave shaped plate 90. Each wave forms an individual fold or pleat. After these pleats are formed, they can be heated under pressure to soften the plastic wrapping film material to seal them in a manner to close the previously open second end (not shown) of the flexible packaging tube (not shown).

While four folding waves are shown in this embodiment, one of ordinary skill in the art will recognize that other numbers may be used, from three to eight or more. Preferably, the number of waves is between four and six.

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.