CA2040578C

CA2040578C - Diaper of pants type

Info

Publication number: CA2040578C
Application number: CA002040578A
Authority: CA
Inventors: Takamitsu Igaue; Hironori Nomura; Hiroyuki Tanji; Tatsuo Takahashi; Takumi Nakano
Original assignee: Unicharm Corp
Current assignee: Unicharm Corp
Priority date: 1990-04-19
Filing date: 1991-04-16
Publication date: 2001-07-03
Anticipated expiration: 2011-04-16
Also published as: EP0452951B1; GB9108137D0; AU7437691A; KR0111421Y1; JPH0722256Y2; GB2245149B; CA2040578A1; DE59106836D1; JPH04828U; AU648068B2; GB2245149A; EP0452951A1

Abstract

A diaper (1) is comprised of a topsheet (2), a backsheet (3) and an absorbent core (4). Both of laterally opposite side zones (14) are tuck-in folded toward a longitudinal centerline (A-A) of the diaper (1) so as to be interposed between front and rear bodies (15, 16) of the diaper (1).

Description

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.
'fhe 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 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 elaatic 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 restriction-free 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 ar 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 elastic members provided around the waist-hole and the leg-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 operation on a production line has inconveniently required 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, therefore, 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.

SUMMARY OE' TFIE INVENTION
Accordingly , it is an object of this invention to solve the above-mentioned problem by providing the diaper of pants type folded with laterally oposite side zones being tuck-in folded so as to be easily packaged in a neat external appearance.
The object set forth in the above is achieved, in accordance with the invention, by providing diaper of pants type including at least a topsheet, a backsheet, and an absorbent core sandwiched therebetween, wherein laterally opposite side zones of said diaper extending from a waist-hole to respective leg-holes are tuck-in folded toward a longitudinal centerline of said diaper so as to be interposed between front and rear bodies of said diaper.
According to another aspect of, tree invention, tuck-in folding of said side zones occur alone at least a portion of each side edge of said absorbent core.
In accordance with the present invention, with the laterally opposite side zones being tuck-in folded between the front body and the rear body aloncJ at lea st 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 ~~~~ ~"~~
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 waist-hole 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 canjunction with the accompanying drawings, which illustrate by way of example the principles of the invention:
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a perspective view showing, by way of example, so-called diaper of pants ty~>e;
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 $.
Fig..2 is an exploded perspective view schem~'ti.Cally showing configurations of respectiue components to be assembled inta the diaper 1 shown by Fig. 1 ~i.e., the topsheet 2, the backsheet 3 having a substantially same size as that of said topsheet 2 and the absorbent core 4 of hourglass shape as usually employed for a disposable diaper.
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 ~, 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 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, 1). The absorbent core 4 is an hourglass-sY~aped profile having longitudinally extending side edge portions 4A, 4S, 4C, oblique side edge portions ~D and transverse edges 4E.
Concerning materials for the diaper 1, the topsheet 2 may be made of liquid-permeable non-woven fabric foamed Pram theremoplastic fibres of polyethylene, polypropylene or the like and the absorbent core ~ may be rnade of fluffy pulp containing 10'~ by weight of super water absorptive polymer powder. The backsheet 3 may be made of stretchable water-proof plastic film 20 and stretchable non-woven fabric 21 formed from thermally crimped polyethylene/polypropylene ~~'~e~rl conjugated fibres, bath being intermittently bonded togher by means of hot melt adhesive (not shown). As will be apparent from the exploded perspective view of Fig. 2, the absorbent care 4 is dimensioned sa 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 descibed 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 longitudinally of the diaper 1 but also contraction of the elastic members, the backsheet 3 arad 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 longitudinal centerline A-A with the respective hat melt seal lines 8 ahead and interposed between the front body 15 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 an 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 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 being held between the user's fingers.
If the diaper 1 is campressed directly fram the condition of Fig. 1 to flatten it arid both of the side zones 14 are folded on the front body 15, the front and rear bodies 15, 16 ~rould 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 zones 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 tYie absorbent core 4.
Accordingly, wide zones extending along the longitudinally opposite edges 4E, respectively, of the hour-glass-shaped absorbent core 4, i.e., zones adjacent the side edge portions 4A, 4C, respectively, are also tucked-in together with said laterally apposite 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. 5, 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. S and F 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

The embodiments of the invention in which an exclu-sive property or privilege is claimed are defined as follows:

(1) A diaper of pants type including at least a topsheet, a backsheet, and an absorbent core sandwiched therebetween, wherein laterally opposite side zones of said diaper extending from a waist-hole to respective leg-holes are tuck-an folded toward a longitudinal centerline of said diaper so as to be interposed between front and rear bodies of said diapers.

(2) The diaper in accordance with Claim (1), wherein tuck-in folding of said side zones occur along at least a portion of each side of said absorbent core.