Sanitary napkin

The present invention provides a sanitary napkin which includes a side barrier incorporating an elastic member disposed on each side of the sanitary napkin, and a separate wing portion disposed outwardly of each side barrier, so that the wing portions can be folded onto the outer side of the crotch portion of an undergarment.

BACKGROUND OF THE INVENTION 
The present invention generally relates to a sanitary napkin or a sanitary 
pad for absorbing and retaining menses, more particularly to a sanitary 
napkin having wing portions which encircle the crotch portion of an 
undergarment for attaching the napkin thereto. 
There exist different types of sanitary napkin constructions in the prior 
art. One type of construction has a liquid permeable topsheet, a liquid 
impermeable backsheet and an absorbent core interposed between the 
topsheet and the backsheet. The backsheet and the topsheet co-extend 
outwardly from each side edge of a longitudinal middle portion of the 
absorbent core to form wing portions. When a sanitary napkin of such 
construction is put into use, each of the wing portions is folded 
outwardly toward the back face of an undergarment crotch portion, and is 
attached thereto by means of adhesives applied onto the back face of the 
wing portions. This type of construction therefore is advantageously 
effective in attaching the sanitary napkin firmly to the undergarment 
crotch portion. 
Another type of the construction has a side barrier which extends 
longitudinally along each side of a sanitary napkin. The side barrier has 
an elastic member so that the side barrier is spaced away or stands 
upwardly from the top surface of the sanitary napkin as the elastic member 
elastically contracts. The side barrier is advantageously effective in 
preventing side leakage of body fluid. 
However, no prior art has or discloses a construction which incorporates 
both of the features as described above. Accordingly, conventional 
sanitary napkin constructions fail to effectively prevent side leakage of 
body fluid or to firmly attach the sanitary napkin to the undergarment 
crotch portion. 
Therefore, it would be desirable to provide a sanitary napkin which 
incorporates the advantageous features that each of the former and latter 
napkin constructions individually has. 
SUMMARY OF THE INVENTION 
In accordance with the present invention, there is provided a sanitary 
napkin which comprises a liquid permeable topsheet having opposite side 
edges, a liquid impermeable backsheet and an absorbent core interposed 
between the topsheet and the backsheet. The sanitary napkin further 
comprises a wing portion extending laterally outwardly from each side edge 
of the absorbent core, and a fastener disposed at least on the back face 
of the wing portion for attaching the wing portion to an undergarment. 
Each of the side edges of the topsheet extends from the top face toward the 
back face of the absorbent core for securement thereof to the backsheet so 
that the topsheet surrounds the respective side edges of the absorbent 
core. The topsheet is spaced outwardly from each side edge of the 
absorbent core at least along a proximal edge of the respective wing 
portion to define a sleeved, side barrier that extends outwardly from the 
side edge of the absorbent core. Each of the side barriers incorporates an 
elastic member which extends longitudinally along a distal edge of the 
side barrier, so that the side barrier stands up by the contracting force 
of the elastic member. 
In a particular embodiment of the present invention, the wing portion 
extends laterally outwardly from a middle section of the absorbent core. 
The topsheet is illustrated to completely surround the absorbent core. The 
fastener may comprise adhesives applied onto the back face of the wing 
portion. 
When in use, an underface of the napkin is placed on the inner face of a 
crotch portion of an undergarment. Each of the wing portions can be folded 
outwardly onto the outer face of the crotch portion for securement thereto 
by a fastener. The side barrier then stands up by contracting force of the 
elastic member to snugly fit to a user's skin, without the side barrier 
falling outwardly by the influence of the folded wing portion. 
Numerous other features and advantages of the present invention will become 
readily apparent from the following detailed description, the accompanying 
drawings, and the appended claims.

PREFERRED EMBODIMENTS OF THE INVENTION 
While the present invention is susceptible of embodiments in various forms, 
there is shown in the drawing and will hereinafter be described in detail 
a specific embodiment thereof, with the understanding that the present 
disclosure is to be considered as an exemplification of the principles of 
the invention, and is not intended to limit the invention to the specific 
embodiment illustrated. 
Referring now to FIGS. 1 and 2, there is illustrated a sanitary napkin 10 
embodying the principles of the present invention. The sanitary napkin 10 
has a liquid permeable topsheet 11, a liquid impermeable backsheet 12 and 
an absorbent core 13 interposed between the topsheet 11 and the backsheet 
12. The absorbent core 13 is configured to have smaller width and length 
dimensions than the topsheet 11 and the backsheet 12. The sanitary napkin 
10 further has a side barrier 14 which is positioned forwardly toward the 
front end of the sanitary napkin 10 and extends outwardly from each side 
thereof. A wing portion 15 is disposed outwardly of each of the side 
barriers 14, and extends outwardly from the respective side of the 
sanitary napkin 10. 
In the illustrated embodiment, the side barrier 14 comprises a sleeve 
portion constructed by a portion of the topsheet 11. Specifically, the 
topsheet 11 extends from the top face of the absorbent core 13 toward the 
back face thereof to encircle the absorbent core 13. As best seen in FIG. 
2, between the top and back faces of the absorbent core 13, the topsheet 
11 extends outwardly of each side edge of the absorbent core 13 at least 
along to proximal edge of the wing portion 15 so that the topsheet portion 
is spaced outwardly from the side edge of the absorbent core 13 to define 
the sleeved, side barrier 14. 
The side barrier 14 encloses an elastic member 16 within its sleeve. In 
this embodiment, the elastic member 16 extends longitudinally along the 
distal edge of the side barrier 14, and is at least at its opposite ends 
attached to an inner face of the side barrier 14 in its stretched 
condition. The side barrier 14 has its proximal edge integrally connected 
to the absorbent core 13 and the backsheet 12 by respective adhesives 22. 
Accordingly, the side barrier 14 is configured to maintain its width 
dimension extending outwardly from the proximal edge thereof, and its 
inner volume enclosed by the sleeve thereof. 
Although the side barrier 14 comprises a part of the liquid permeable 
topsheet 11 in this embodiment, the side barrier 14 may be rendered 
hydrophobic or liquid-impermeable, when desired, by suitable treatment. 
A lateral spacing of the respective distal edges of the opposite side 
barriers 14 of the sanitary napkin 10 is suitably dimensioned to be 
greater than the width of a crotch portion of an undergarment (or a 
sanitary undergarment), so that the distal edge of each side barrier 14 
extends a proper distance outwardly from the respective outer edge of the 
undergarment crotch portion. This dimensioning desirably abates side 
leakage of menses. However, the foresaid lateral spacing may be suitably 
dimensioned for the distal edge of each side barrier 14 so as not to 
extend outwardly from the respective outer edge of the a foresaid crotch 
portion. 
In FIG. 2, the backsheet 12 is illustrated to comprise a liquid impermeable 
sheet 12a laminated onto a liquid permeable sheet 12b. The backsheet 12 
may comprise the liquid impermeable sheet 12a only. Alternatively, the 
liquid permeable sheet 12b may be replaced by another liquid impermeable 
sheet. 
A pair of laterally spaced, parallel lines or bands of adhesives 17 is 
disposed to extend longitudinally on the central lower surface of 
backsheet 12. A rectangularly shaped adhesive 18 is placed on the central 
lower surface of each of the wing portions 15. These adhesives 17, 18 are 
respectively covered by release sheets 19, 20 for protection thereof. 
As illustrated in FIG. 3, a reinforcing piece 21 is integrally interposed 
between the two sheets 12a, 12b of the wing portion 15. The reinforcing 
piece 21 is sized to be slightly larger than a wing portion area where the 
adhesives 18 is placed, and is positioned over the wing portion area. The 
reinforcing piece 21 has rigidity greater than that of either one of the 
sheets 12a, 12b or that of the laminated combination thereof. Accordingly, 
such construction helps prevent occurrence of the undesirable situation 
that the wing portion 15 adheres onto itself through the adhesives 18 when 
it is wrinkled or twisted during application procedures by a user. The 
reinforcing piece 21 may be integrally attached onto the lower surface of 
the sheet 12a, although not shown in the drawings. Then, the adhesives 18 
may be conveniently disposed on an exposed surface of the reinforcing 
piece 21. 
A user can apply the sanitary napkin 10 to an undergarment by first 
removing the release sheets 19 to expose the adhesives 17. Then the 
central section of the sanitary napkin 10 is pressed onto an inner surface 
of the undergarment crotch portion so that the central section is adhered 
to the inner surface through the adhesives 17. The user now removes the 
release sheets 20 to expose the adhesives 18, and folds each wing portion 
15 outwardly onto an outer surface of the crotch portion to adhere each 
wing portion 15 to the outer surface through the adhesives 18. When the 
sanitary napkin 10 is completely attached to the undergarment, each of the 
side barriers 14 stands up by the contracting force of the respective 
elastic member 16. Since the side barrier 14 is configured to be separated 
from the respective wing portion 15, when the wing portion 15 is folded 
onto the outer side of the undergarment crotch portion for securement 
thereto, the folding does not act to drag the side barrier 15 outwardly. 
Various materials as known in the art may be utilized to construct elements 
of the sanitary napkin 10 of the present invention. For example, the 
topsheet 11 may comprise a nonwoven fabric or an apertured plastic film. 
The sheets 12a, 12b may comprise a plastic film and a hydrophobic 
non-woven fabric, respectively. 
From the foregoing, it will be observed that numerous modifications and 
variations can be effected without departing from the true spirit and 
scope of the novel concept of the present invention. It will be 
appreciated that the present disclosure is intended as an exemplification 
of the invention, and is not intended to limit the invention to the 
specific embodiment illustrated. The disclosure is intended to cover by 
the appended claims all such modifications as fall within the scope of 
claims.