GB2267024A

GB2267024A - Disposable diapers

Info

Publication number: GB2267024A
Application number: GB9310409A
Authority: GB
Inventors: Takamitsu Igaue; Kohji Inoue; Tsutomu Kido
Original assignee: Unicharm Corp
Current assignee: Unicharm Corp
Priority date: 1992-05-22
Filing date: 1993-05-20
Publication date: 1993-11-24
Anticipated expiration: 2013-05-20
Also published as: DE59306993D1; AU3859093A; CA2096672A1; AU667899B2; CN2164272Y; ES2106227T3; KR0137121Y1; CA2096672C; GB2267024B; EP0570980B1; JPH05317356A; KR930025047U; JP3096152B2; EP0570980A1; GB9310409D0

Abstract

A diaper wherein respective laterally opposite side portions 3, 3 and (4, 4) of front and rear bodies 1, (2) and base ends 7 of respective fastening flaps 6 are all bonded together along bond lines 8, and adjacent these bond lines 8, the front body 1 is provided with cutting lines 9b along which laterally opposite side portions of the front body 1 may be torn off from the corresponding opposite side portions of the rear body 2. The diaper is thus usable selectively either as pants type diaper with front and rear bodies bonded together along their laterally opposite side portions as shown, or as the open type diaper (Fig. 6) with the front and rear bodies separated at their side portions but connectible with each other by the fastening flaps when the diaper is used. <IMAGE>

Description

2267024 DISPOSABLE DIAPERS This invention generally relates to a

disposable diaper and, more particularly, to such a diaper adapted to be selectively usable either as so-called pants type diaper having front and rear bodies which are. connected together during a step of manufacturing so as to a closed loop around the waist or as so-called open type diaper having front and rear bodies to be connected together so as to form a closed loop around the waist by means of fastening flaps only when the diaper is actually put on a wearer.

Japanese Utility Model Application Disclosure Gazette No. 1992-5826 discloses a disposable diaper comprising front and rear bodies which have been previously banded together along one of the waist zone's laterally opposite side portions but can be releasably bonded together by a tapelike fastener along the other side portion. On the other hand, Japanese Patent Application Disclosure Gazette No. 1992-89050 discloses a disposable diaper comprising front and rear bodies adapted to be releasably bonded together by adhesive tape along at least one of the waist zone 1 s laterally opposite side portions.

The diaper disclosed in the above-identified Japanese Utility Model Application Disclosure Gazette No. 1992-5826 is inconvenient to put on a wearer irrespective of whether the wearer is in a standing. posture oralying posture, because one of said laterally opposite side portions is permanently closed. The diaper disclosed in the above-identified Japanese Patent Application Disclosure Gazette No. 199289050 is disadvantageous in that, when the waist-opening is widened in order to put the diaper on a wearer as it is usually done for normal pants having the waist line closed in a loop, one or both of the waist zonels laterally opposite side portions previously closed as in the case of said normal pants can be unintentionally opened, and the expected effect of previously closing the waist line can be decreased to half, because such closure is made merely by adhesive tape (in the course of manufacturing).

Accordingly, it is a principal object of the invention to provide an improved disposable diaper having front and rear bodies which have been previously bonded together along the waist zone's laterally opposite side portions in the course of manufacturing but, if desired. can be separated from each other and bonded together again so that the opposite side portions thus re-bonded together can never be unintentionally opened even if the waist-opening is widened in order to put the diaper on a wearer.

The object set forth above is achieved, in accordance with the invention, by a disposable diapergenerally comprising longitudinally continuous front and rear bodies and a pair of fastening flaps extending outward from waist zoness laterally opposite side portions of said front or rear body, said longitudinally continuous front and rear bodies being folded so that laterally opposite side portions of said front body are accurately laid upon those of said rear body; said fastening flaps carrying on respective inner surface adjacent respective front ends thereof fastening spots and having respective base ends laid upon the waist zone's laterally opposite side portions of said front body; bond lines along which said waist zone's laterally opposite side portions of said front and rear bodies and said base ends of respective said fastening flaps are bonded together; cutting lines provided inside and adjacent respective said bond lines so that said front body may be torn off along these cutting lines from said rear body; and each of said bond lines having a resistance of 1000 g/inch or higher to separation occurring between said front and rear bodies.

Preferably, said bond lines are formed by welding and said cutting lines are formed by intermittent cuts or perforations.

The invention will be described in more detail by way of example with reference to the accompanying drawings, in which:

Fig. 1 is a f ront view of a diaper erected with one of the fastening flaps being fastened to a front body; Fig. 2 is a rear view of the diaper completely made;. 1 Fig. 3 is a fragmentary sectional view showing, in an enlarged scale, a line along which the front body, the rear body and the fastening flaps are bonded together in the proximities of their laterally opposite side edges-and base ends, respectively; Fig. 4 is an upper end view of the made diaper; Fig. 5 is a view similar to Fig. 4 but showing the made diaper with laterally opposite side portions of the front body being cut apart from those of the rear body; Fig. 6 is a plan view showing the inner side of the unfolded diaper; Fig. 7 is an enlarged sectional view taken along a line X-X in Fig. 6; and Fig. 8 is a perspective view illustrating a measuring method for separation-resistance of the bond line conducted using a test piece.

Referring to Figs. 1 to 5, front and rear bodies 1, 2 of a diaper are longitudinally continuous. The front and rear bodies 1, 2 is folded back one on the other with laterally opposite side portions 3, 3 of the front body 1 at the level of the waist zone being accurately laid upon the corresponding opposite side portions 4, 4 of the rear body 2. Then a pair of fastening flaps 6 carrying on inner surfaces adjacent front ends thereof fastening spots 5 serving as fastening means are laid at base ends 7 thereof upon said laterally opposite side portions 3, 3 and 4, 4 of the front and rear bodies 1, 2 which have already been laid one upon the other. These components 1, 2, 6 thus laid one upon another are intermittently bonded together under effect of heat or supersonic wavesalong lines 8 extending parallel to and adjacent said side portions 3, 4 as well as said base ends 7 so as to leave respective outer edges of these components not bonded. The front body 1 is provided at locations 9a adjacent the respective bond lines 8 with cutting lines 9b extending parallel to the respective bond lines 8 in the form of intermittent cuts or holes (i.e., so-called perforations) so that the front body 1 can be torn off along these cutting lines 9b from the rear body 2.

Bonding strength (or separation-resi stance) of each bond line 8 along which the front and rear bodies 1, 2 have been bonded together preferably should be 1000 g/inch or higher so that the laterally opposite side portions 3, 3, and 4, 41 of the respective bodies 1, 2 bonded together along said bond lines 8 may be reliably prevented from being separated from each other,even if each bond line 8 is subjected to a tearing force possibly tending to separate off said laterally opposite side portions 3, 3 and 4, 4 from each other, for example, when it is desired to widen the waistopening formed by bonding the laterally opposite side portions 3, 3 and 4, 4 at the level of waist zone of the front and rear bodies 1, 2 in the manner as has previously been mentioned in order to put the diaper on a wearer, or when the front body 1 is pulled, with the diaper put on a wearer, to cut the front body 1 off from the rear body 2 along each cutting line 9b. It should be understood that the separation-resistance is measured using a test piece including a partial length of the bond line 8, which was sampled from the diaper by cutting off a portion surrounded by broken lines in Fig. 8. As shown, the test piece is a rectangular strip having a width of 1 inch and longitudinally extending from the bond line 8 over a length larger than 10 mm in opposite directions, respectively. The test piece is held at longitudinally opposite ends thereof by a pair of chucks, respectively, so that initially the test piece linearly extends between said pair of chucks accurately over a distance of 20 mm with the bond line 8 lying in the middle. Then, the test piece is longitudinally tensioned at a rate of 100 mm/min and thereby a value (g) at a moment of separation occurring along the bond line 8 is determined as the separationresistance value.

Referring to Figs. 1, 2 and 6, each blank of the diaper comprising longitudinally continuous front and rear bodies 1, 2 is then formed with laterally opposite concave edges 10 extending between the respective waist zones of the front and rear bodies 1, 2 so as to define respective leg-openings. This blank is composed, as best seen in Fig. 7, of a liquidpermeable topsheet 11, a liquid-impermeable backsheet 12 and an hourglassshaped liquid-absorbent panel 13 sandwiched between said top- and backsheets 11, 12. The blank is further provided along the respective waist zones of the front and rear bodies 1, 2, as well as along the abovementioned concave edges 10 destined to form the respective leg-openings, with a plurality of parallel extending thread-like elastic members 14, 15, respectively. which are attached under their longitudinally stretched condition between the top- and backsheets 11, 12 utilizing hot melt type adhesive. The elastic members 14 associated with the waist zone of the rear body 2 are arranged to occupy substantially all of this zone parallel to one another with their spacings increasing from the outermost edge toward the inside of the waist zone so that a total elasticity of these elastic members 14 is higher than that of the elastic members 14 associated with the waist zone of the front body 1. It should be understood that, though not shown. the waist zone of the rear body 2 may be partially made from pieces of elastic fabric without providing both front and rear bodies 1, 2 with the respective elastic members 14 as in the illustrated embodiment. For example, such pieces of elastic fabric may be connected to the waist zone of the rear body 2 at laterally opposite side edges thereof by means of welding or the like. While not shown, it is also possible to form the fastening flaps 6 wholly or partially from elastic material without departure from the scope of the invention.

The waist zone of the front body 1 has a scaled narrow sheet 16 stuck on an outer surface thereof in order to protect this surface which otherwise would be directly and repeatedly engaged by the fastening spots 5 of the respective fastening flaps 6. The scaled narrow sheet 16 functions also as an indicator adapted to conveniently indicate locations at which the respective fastening spots 5 are laid upon said outer surface. The fastening spots 5 may be formed by application of the adhesive conventionally used for such purpose or may be a piece of tape having thereon a plurality of hooks such as Velcro (trademark) or Magic Tape (trademark) both of which are well known to those skilled in the art. To use such piece of tape as the fastening spot 5, the scaled narrow sheet 16 must have a piled surface with which the hooks of the fastening spat 5 are ef f ectively engageable.

The fastening flap 6 may be made from nonwoven fabric or laminate sheet consisting of such nonwoven fabric and plastic film or paper of fine quality. The topsheet 11 may be made of nonwoven fabric or porous plastic film. The backsheet 12 may be made of plastic film or laminate sheet consisting of such plastic film and nonwoven fabric. The scaled narrow sheet 16 may be made of plastic film or nonwoven fabric or felt, depending on the desired nature of the fastening spot 5.

The diaper constructed according to the teachings of this invention as has been described hereinabove can be put on a wearer as a pants type diaper, i.e., in its original configuration, for example, when it is desired to put the diaper on a wearer who is in a standing posture. While the fastening flaps 6 are principally unnecessary in this case, it is preferred that the fastening spots.5 are firmly engaged with the narrow sheet 16 at appropriate locations thereof to avoid undesirable movement of the diaper with respect to a wearer's body during use of the diaper (Fig. 4). When it is desired to put the diaper on a wearer who is ina lying posture, the laterally opposite side portions of the front body lare torn off from those of the rear body 2 along the cutting lines 9b by pulling the front body 1 or the fastening flaps 6 so as to obtain the diaper of open type (Fig. 6) and, after having put it on a wearer, the fastening flaps 6 are folded inward onto the narrow sheet 16 so that the respective fastening spots 5 may be firmly engaged with said sheet 16 at desired locations thereof (Fig. 5).

The invention allows the diaper to be put on a wearer selectively either as the pants type diaper or as the open type diaper. The diaper of this invention is advantageous particularly in that, even if the bond lines extending along the laterally opposite side portions are subjected to a tearing force usually exerted thereon when the diaper is used as the pants type diaper, no separation occurs along the laterally opposite side portions of the front and rear bodies, because each of the bond lines has a separationresistance as high as 1000 g/inch or higher.

After solid excretion has been discharged on the diaper, the front body may torn off from the rear body along the cutting lines provided along the laterally opposite side pc)rtiOns and thereby the diaper may be easily removed from a wearer without undesirably smearing the weareris skin with solid excretion.

Claims

A disposable diaper generally comprising longitudi nally continuous front and rear bodies and a pair of fastening flaps extending outward from laterally opposite side portions of a waist zone of said front or rear body, wherein:

said longitudinally continuous front and rear bodies are folded so that laterally opposite side portions of said front body are accurately laid upon those of said rear body; said fastening flaps have fastening spots on re spective inner surfaces adjacent respective front ends thereof and respective base ends laid upon the laterally opposite side portions of the waist zone of said front body; bond lines are provided along which said laterally opposite side portions of the waist zone of said front and rear bodies and said base ends of said respective fastening flaps are bonded together; cutting lines are provided inside and adjacent said respective bond lines so that said front body may be torn off along these cutting lines from said rear body; and each of said bond lines has a resistance of 1000 g/inch or higher to separation occurring between said front and rear bodies.
2. A disposable diaper according to claim 1, wherein said bond lines are formed by welding.
3. A disposable diaper according to claim 1 or 2, wherein said cutting lines are formed by intermittent cuts or perforations.
4. A disposable diaper substantially as herein de scribed with reference to Figures 1 to 7 of the accompany ing drawings.