Surgery – Means and methods for collecting body fluids or waste material – Absorbent pad for external or internal application and...
Reexamination Certificate
2000-06-23
2002-10-08
Chapman, Jeanette (Department: 3765)
Surgery
Means and methods for collecting body fluids or waste material
Absorbent pad for external or internal application and...
C604S385040, C604S385101
Reexamination Certificate
active
06461338
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a disposable diaper of an underpants type or an open type and, more particularly, to a disposable diaper which enables securely holding of an absorbent core by a top sheet.
2. Description of the Related Art
FIG. 10
is a sectional view of such a portion of the underpants or open type diaper of the related art as to be applied to a crotch.
As shown in
FIG. 10
, a disposable diaper
100
of this kind includes: a liquid-permeable top sheet
101
to be directed to the side of a wearer (or a liquid receiving side); and a liquid-impermeable outer sheet
102
to be directed outward. The top sheet
101
and the outer sheet
102
are bonded to each other at two transverse side regions
100
a
and
100
a
of the diaper. In a transverse center region
100
b
, on the other hand, there is sandwiched between the aforementioned top sheet
101
and outer sheet
102
an absorbent core
103
which is made mainly of a fibrous material such as pulp and contains a highly absorbent resin.
In a process of the related art for manufacturing the disposable diaper of this kind, the absorbent core
103
is placed on the outer sheet
102
developed in a planar shape and is then overlaid by the top sheet
101
which is also developed in a planar shape. At this time, in the related art, the adhesion of the top sheet
101
is limited such that the top sheet
101
is adhered to the outer sheet
102
in the aforementioned two side regions
100
a
and
100
a
and to an upper surface
103
a
of the absorbent core
103
in a rising upper face
100
c
on the liquid receiving side.
In the related art, more specifically, the top sheet
101
is adhered only by pressing it vertically. As a result, the top sheet
101
is adhered only at the horizontal face such as the aforementioned two side regions
100
a
or rising upper face
100
c
but not at the non-horizontal face such as two side ends
103
c
of the absorbent core
103
.
Thus, the two side ends
103
c
of the absorbent core
103
and the top sheet
101
are not adhered, but the absorbent core
103
has a thickness. As a result, spaces
104
and
104
are easily formed between the two side ends
103
c
and
103
c
of the absorbent core
103
and the top sheet
101
.
In the disposable diaper of the related art, as shown in
FIG. 10
, the two side ends
103
c
and
103
c
of the absorbent core
103
and the top sheet
101
are not adhered, but the spaces
104
and
104
are formed between the two side ends
103
c
and
103
c
and the top sheet
101
. As a result, the absorbent core
103
is insufficiently held by the top sheet
101
. The holding force of the absorbent core
103
is weakened especially in the transverse direction, i.e., leftward or rightward of FIG.
10
.
If the wearer moves while wearing the disposable diaper, a twisting force, a transverse offsetting force and a kinking force act on the absorbent core
103
. Especially for the underpants type diaper, the wearer walks or crawls while wearing the disposable diaper so that the aforementioned forces to be applied to the aforementioned absorbent core
103
increase.
If the aforementioned forces continuously act, the absorbent core
103
will be twisted or offset at the aforementioned center region
100
b
of the diaper. As a result, the spaces
104
and
104
between the two side ends
103
c
and
103
c
of the absorbent core
103
and the top sheet
101
will easily spread. If the absorbent core
103
is kinked leftward or rightward, moreover, the upper surface
103
a
of the absorbent core
103
wrinkles to separate the adhesion between the upper surface
103
a
of the absorbent core
103
and the top sheet
101
, thereby to cause a clearance between the upper surface
103
a
and the top sheet
101
.
If the spaces
104
spread or if the clearance is caused between the upper surface
103
a
and the top sheet
101
, as described above, the liquid such as urine fed to the top sheet
101
cannot be efficiently absorbed by the absorbent core
103
to cause the transverse leakage of urine in the diaper.
SUMMARY OF THE INVENTION
The invention has an object to provide a disposable diaper which is hardly experienced by a twist, offset or kink of an absorbent core in the diaper by stabilizing the holding, i.e., the transverse holding of the absorbent core by a top sheet, so that the absorbing function of the absorbent core can be prevented from any reduction.
According to a first aspect of the invention, there is provided a disposable diaper having a body including a front face portion to be applied to the abdomen of a wearer; an intermediate portion to be applied to the crotch; and a back face portion to be applied to the back, in which a longitudinal direction is taken from the front face portion to the back face portion of the body, and a transverse direction is taken in a direction perpendicular to the longitudinal direction, which comprises a top sheet to be directed toward a liquid receiving side; an outer sheet; and an absorbent core sandwiched between the top sheet and the outer sheet, the top sheet being liquid-permeable at least in a portion for covering a transverse center of the absorbent core and being jointed on two transverse sides directly or indirectly to the outer sheet, wherein, in a region containing at least a longitudinal center of the intermediate portion, joint boundaries between the top sheet and the outer sheet enter farther the transverse center side than two transverse side ends of the absorbent core.
Here, the aforementioned top sheet and outer sheet may be adhered and jointed directly to each other or through another sheet. On the other hand, the top sheet may be made liquid-permeable in its portion covering at least the absorbent core.
In the diaper according to the first aspect of the invention, the top sheet is in contact with not only the liquid receiving side surface of the absorbent core but also the two transverse side ends of the absorbent core, and enters the two end portions of the back side of the absorbent core. As a result, the absorbent core can be wrapped and restricted from the two transverse sides by the top sheet so that the absorbent core is hardly twisted, offset and kinked.
Here, the top sheet may include a liquid-permeable sheet and side sheets directly or indirectly jointed to the liquid-permeable sheet on two transverse sides thereof, and joint boundaries between the side sheets and the outer sheet may enter farther the transverse center side than the two transverse side ends of the absorbent core.
Here, it is preferable that in the region containing at least the longitudinal center of the intermediate portion, the top sheet is jointed to the two transverse side ends of the absorbent core.
On the other hand, the liquid receiving side surface of the absorbent core and the top sheet are usually adhered to each other. When the back side of the absorbent core and the outer sheet are adhered, moreover, the absorbent core can be reliably held on the diaper.
In the diaper according to the first aspect of the invention, the aforementioned top sheet and the outer sheet may be jointed at the two transverse sides after the top sheet was so pressed or shaped as to wrap the absorbent core from the upper surface to the two side ends thereof.
However, if in the region containing at least the longitudinal center of the intermediate portion, there is disposed elasticity applying means for bringing the joint boundaries closer to the transverse center, it is easy to form a structure in which the two side ends of the absorbent core are wrapped by the top sheet.
In this case, it is preferable that the top sheet is not elastically shrunken in the transverse direction, or that the transverse elastic shrinking distortion in the free state of the diaper is made larger at the elasticity applying means than at the top sheet.
By combining such top sheet with the elasticity applying means, the shrinking force of the aforementioned elasticity applying means can be utilized to easily realize a struct
Jitoe Yoshikazu
Shimoe Nariaki
Chapman Jeanette
Darby & Darby
Uni-Charm Corporation
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