AU648068B2

AU648068B2 - Diaper of pants type

Info

Publication number: AU648068B2
Application number: AU74376/91A
Authority: AU
Inventors: Takamitsu Igaue; Takumi Nakano; Hironori Nomura; Tatsuo Takahashi; Hironori Tanji
Original assignee: Unicharm Corp
Current assignee: Unicharm Corp
Priority date: 1990-04-19
Filing date: 1991-04-15
Publication date: 1994-04-14
Anticipated expiration: 2011-04-15
Also published as: JPH04828U; KR0111421Y1; GB9108137D0; GB2245149B; DE59106836D1; EP0452951B1; GB2245149A; JPH0722256Y2; EP0452951A1; AU7437691A; CA2040578A1; CA2040578C

Description

AUSTRALIA

Patents Act COMPLETE SPECIFICATION

(ORIGINAL)

648068 Int. Class Class Application Number: Lodged: Complete Specification Lodged: Accepted: Published: Priority Related Art: Applicant(s) Uni-Charm Corporation 182, Shimobun, Kinsei-cho, Kawanoe-shi, Ehime-ken, JAPAN Address for Service is: PHILLIPS ORMONDE FITZPATRICK Patent and Trade Mark Attorneys 367 Collins Street Melbourne 3000 AUSTRALIA *e Complete Specification for the invention entitled: DIAPER OF PANTS TYPE Our Ref 213214 POF Code: 1647/76530 The following statement is a full description of this invention, including the best method of performing it known to applicant(s): 6006 m 4 DIAPER OF PANTS TYPE BACKGROUND OF THE INVENTION The present invention relates to diaper of pants type basically comprising a topsheet, a backsheet, and an absorbent core sandwiched therebetween, and, more particularly, to such diaper of pants type adapted to be folded with laterally opposite side zones thereof being tucked-in so as to be economically packaged on a production line by a manufacturer as well as to be easily handled by an user.

The diaper comprising, as mentioned above, the topsheet, the backsheet, and the absorbent core sandwiched therebetween has held a leading position in the industry of disposable diaper. Such disposable diaper is generally *o classidied into an open type and a pants type, the latter being recently attracting user's attention for ease to use it. The diaper of this type often includes elastic members around the waist-hole and the leg-holes so as to form gathers therearound and sometimes utilizes stretchable material as the backsheet in order to obtain good fitness when the diaper is put on. Such diaper, in its restrictionfree state, tends to become an ill-shaped mass due to contraction of the respective members and materials. To overcome this problem, a packaging technique of prior art having been employed on a production line is to arrange the individual products as flatly as possible so that a plurality of products may be easily stacked one upon another and then packed in a bag or a box.

With said diaper of pants type having the abosrbent core sandwiched between the top- and backsheet, it has been difficult to obtain a neat external appearance of each package reminding purchasers of valuable commodities, *because such diaper tends to become an ill-shaped mass due to bulkiness of the absorbent core and contraction of the e g.

elastic members provided around the waist-hole and the leg-

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holes. This problem is more serious when the topsheet and/or the backsheet is made of stretchable material. To arrange such diaper as flatly as possible, a packaging 0ooo0 S" operation on a production line has inconveniently required aos 0 not only a complex equipment but also mech labor.

Flatly arranging the diaper of pants type has inevitably resulted in a complicated engagement of the front body with the rear body along the waist-hole and, theiefore, when the diaper is put on, not only it has been difficult to discover the waist-hole but also separation of the front and rear bodies of the diaper from each other with the peripheral edge of the waist-hole being held between the user's fingers has usually taken much time.

3 SUMMARY OF THE INVENTION Accordingly, it is an object of this invention to provide a diaper which overcomes or reduces one or more problems of the prior art.

According to the present invention, there is provided a diaper of the pants type that includes an absorbent core having a top side and a bottom side, a topsheet on the top side of said absorbent core, said topsheet having two spaced apart edge portions and two spaced apart longitudinal sides, each longitudinal side comprising two side edge portions that are separated by a leg-hole cut, a bottom sheet on the bottom side of said absorbent core said bottom sheet having two spaced apart end edge portions and two spaced apart longitudinal sides that are aligned with the longitudinal sides of said topsheet, each longitudinal side of said bottom sheet also comprising two side portions that are separated by a leg hole cut, said topsheet and said bottom sheet not only covering the entire top side and bottom side of said absorbent core, but in addition extending laterally beyond the absorbent core, the side edge portions of the top sheet being joined to the said aligned side edge portions of said bottom sheet and the two side edge portions on each longitudinal side being joined to each other along a seal line to thereby cause the absorbent core to assume a folded over disposition and leave two leg openings, a waist opening and two laterally opposite side zones extending from each leg opening to said waist opening, said two laterally opposite side zones being tucked inwardly toward each other for packaging, said two laterally opposite- side zones extending inwardly so that the Sldc.

seal line of eachq i- zone is positioned between said folded over portions of said absorbent core and so that the Si~c thickness of said two tucked-in4s!a"e zones serve as at least a partial spacer between opposed sections of the said folded over absorbent core.

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3a Accordingly, with the laterally opposite side zones being tuck-in folded between the front body and the rear body along at least a portion of each side edge of the bulky and rigid absorbent core, the diaper folded in this manner obtains its external shape defined and stabilized by the absorbent core which is relatively deformation-resistant.

Such arrangement also permits a plurality of diapers to be easily stacked and

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neatly packed in a bag or a box, thereby allowing a packaging operation to be quickly achieved using a relatively simple packaging equipment. Moreover, the waisthole can be easily opened when it is desired to put the diaper on, because the front body and the rear body have been separated from each other in advance.

Other features and advantages of the invention will be apparent from the following more detailed description of the preferred embodiments, taken in conjunction with the 0*« I accompanying drawings, which illustrate by way of example the principles of2 the invention.

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BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a perspective view showing, by way of example, so-called diaper of pants type; Fig. 2 is an exploded perspective view of the diaper shown by Fig. 1; Fig. 3 and 4 are perspective and end views, respectively, showing an embodiment of diaper constructed according to the invention; and Fig. 5 and 6 are 'perspective and end views, respectively, showing another embodiment of diaper constructed according to the invention.

PREFERRED EMBODIMENTS OF THE INVENTION Fig. 1 illustrated so-called diaper 1 of pants type to which the invention generally relates and this diaper 1 comprises, as shown, a topsheet 2, a backsheet 3 and an absorbent core 4 (see Fig. 2) sandwiched therebetween. The diaper 1 further comprises rubber threads 6 used as elastic members for respective leg-holes and rubber threads 7 used as elastic member for a waist-hole. Laterally opposite side zones 14 have their side edges sealed by respective hot melt seal lines 8.

0* Fig. 2 is an exploded perspective view schematically showing configurations of respective components to be assembled into the diaper 1 shown by Fig. 1 the topsheet 2, the backsheet 3 having a substantially same size as that of said topsheet 2 and the absorbent core 4 of **see: hourglass shape as usually employed for a disposable diaper.

O0 The absorbent core 4 is intermittently bonded onto the rear side of the topsheet 2 by means of hot melt adhesive (not shown) and the backsheet 3 is placed on the topsheet 2 so as to cover said absorbent core 4. The backsheet 3 is bonded to the topsheet 2 by means of hot melt adhesive (not shown) along their peripheral edges. The elastic members 6, 7 are intermittently bonded, under their stretched condition, onto the surface of the backsheet 3 that faces the topsheet 2 by means of hot melt adhesive (not shown). Upon completion of such bonding of the elastic members 6, 7, the diaper is folded in two along a substantially middle line longitudinally of the diaper with longitudinal side edge portions 9, 10 being brought together and these side edge portions 9, 10 thus brought together are heat sealed by the respective heat seal lines 8 (see Fig. 1) to obtain a complete diaper, whereupon respective cuts 11 formed in the top- and backsheets 2, 3 form respective leg-holes 12 (see Fig. 1) and the elastic members 6 form gathers around outer peripheries of the respective leg-holes 12. It should be 18* 6* understood that the formation of such gathers is covered by the scope of the invention and, therefore, any further detailed thereof is not described herein. Similarly, the elastic members 7 associated with longitudinally opposite ends of the diaper form together a waist-hole 13 (see Fig.

S* The absorbent core 4 is an hourglass-shaped profile S* having longitudinally extending side edge portions 4A, 4B, 4C, oblique side edge portions 4D and transverse edges 4E.

Concerning materials for the diaper 1, the topsheet 2 may be made of liquid-permeable non-woven fabric formed from theremoplastic fibres of polyethylene, polypropylene or the like and the absorbent core 4 may be made of fluffy pulp containing 10% by weight of super water absorptive polymer powder. The backsheet 3 may be made of stretchable waterproof plastic film 20 and stretchable non-woven fabric 21 formed from thermally crimped polyethylene/polypropylene conjugated fibres, both being intermittently bonded togher by means of hot melt adhesive (not shown). As will be apparent from the exploded perspective view.' Fig. 2, the absorbent core 4 is dimensioned so as to occupy only respective central zones of the topsheet 2 and the backsheet 3. Two-dot-chain line 40 indicates the size of the absorbent core 4 as viewed in projection onto the backsheet 3.

.In the diaper 1 constructed as has been r-scibed above, the laterally opposite side zones 14 extending from the waist-hole 13 to the respective leg-holes 12 comprise the top- and backsheets 2, 3 and no absorbent core 4. Really, the diaper 1 tends to assume the appearance of an ill-shaped mass due to not only the bulkiness of the absorbent core 4 floded in two substantially along the middle live 0 longitudinally of the diaper 1 but also contraction of the elastic members, the backsheet 3 and the other elastic components. In view of this, Fig. 1 illustrates the diaper 1 as being stretched so that the configuration of the diaper 1 may be easily understood.

Figs. 3 and 4 show an embodiment of the diaper constructed according to the invention which corresponds to the diaper 1 shown by Fig. 1, wherein the laterally opposite side zones 14 extending from the waist-hole 13 to the respective leg-holes 12 are tuck-in-folded toward a r longitudinal centerline A-A with the respective hot melt seal lines 8 ahead and interposed between the front body and the rear body 16. The diaper 1 thus folded has an outline following the frofiled absorbent core 4 and comprises the planar front body 15 on the upper side, the planar rear body 16 on the bottom side and the absorbent core 4 sandwiched therebetween. Thus, the entire external shape of the diaper is defined by the relatively rigid absorbent core and, therefore, it is easy to stock a a* plurality of individual diapers. In this manner, it is also easy to pack the diapers in a bag or a box on the production line. Additionally, the thickness of the tuck-in folded zones 14 separate the front body 15 and the rear body 16 from each other so that the location of the waist-hole 13 becomes distinct and an user can easily open the waist-hole 13 with the peripheral edge of the waist-hole 13 'eing held between the user's fingers.

If the diaper 1 is compressed directly from the condition of Fig. 1 to flatten it and both of the side zones 14 are folded on the front body 15, the front and rear

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bodies 15, 16 would be brought into complicated engagement with each other along the waist-hole 13 and the configuration of the waist-hole 13 would be indecently disturbed, so time and labor required to open the waist-hole 13 would be much more than in the case of the diaper provided by the invention.

Referring the Fig. 5, another preferred embodiment of the invention is illustrated. The diaper 1 is tuck-in folded in the manner similar to the embodiment shown by Figs. 3 and 4 but the laterally opposite side zores 14 are tucked-in along the side edge portions 4B of the absorbent core 4. The pair of laterally opposite side edge portions 4B define the most narrow zone of the absorbent core 4.

SA Accordingly, wide zones extending along the longitudinal.y aJ off opposite edges 4E, respectively, of the hour-glass-shaped absorbent core 4, zones adjacent the side edge portions 4A, 4C, respectively, are also tucked-in together with said laterally opposite side zones 14 between the front body 15 and the rear body 16.

Fig. 6 is an end view taken along a line Y-Y in Fig.

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S showing the zones extending adjacent the side edge portions 4A, 4C, respectively, of the absorbent core 4 having been tucked-in together with the laterally opposite side zones 14.

Such manner of tuck-in folding as shown by Figs. 5 and 6 allows the diaper to be arranged substantially in a rectangular shape as viewed in Fig. 5, thereby, in addition to the advantages achieved by the Embodiment 1, further facilitates the packaging thereof and improves its external appearance.

Claims

1. A diaper of the pants type that includes an absorbent core having a top side and a bottom side, a topsheet on the top side of said absorbent core, said topsheet having two spaced apart edge portions and two spaced apart longitudinal sides, each longitudinal side comprising two side edge portions that are separated by a leg-hole cut, a bottom sheet on the bottom side of said absorbent core said bottom sheet having two spaced apart end edge portions and two spaced apart longitudinal sides that are aligned with the longitudinal sides of said topsheet, each longitudinal side of said bottom sheet also cormprising two side portions that are separated by a leg hole cut, said topsheet and said bottom sheet not only covering the entire top side and bottom side of said absorbent core, but in addition extending laterally beyond the absorbent core, the side edge portions of the top sheet being joined to the said aligned side edge portions of said bottom sheet and the two side edge portions on each longitudinal side being joined to each other along a seal line to thereby cause the absorbent core to assume a folded over disposition and leave two leg openings, a waist opening and two laterally opposite side zones extending from each leg opening to said waist opening, said two laterally opposite side zones being .QQ tucked inwardly toward each other for packaging, said two laterally opposite side zones extending inwardly so that the seal line of eachs94es zone is positioned between said folded over portions of said absorbent core and so that the Side thickness of said two tucked-in 1 se zones serve as at least a partial spacer between opposed sections of the said folded over absorbent core.

2. A diaper according to Claim 1 wherein said absorbent Score has end portions and side portions and some of the side portions of said absorbent core are folded inwardly toward T 0T P j~ lOa each other.

3. A diaper, substantially as herein described with reference to any one of the embodiments shown in Figures 3 and 4 of the accompanying drawings. DATED: 12 October 1993 PHILLIPS ORMONDE FITZPATRICK Patent Attorneys For: UNI-CHARM CORPORATION 7^ n 0 S.. *e S. S i297h)