Absorbent product

The present invention refers to an absorbent product, especially a sanitary napkin (1), including an absorbent body (2) characterised by having a first portion (5) of perforated plastic film (6) and, on the surface (13) adapted to come into contact with the user's body, a longitudinal layer which includes a second central portion (7) of woven or non-woven material on the body contact surface (13), the first portion (5) being at least near the side edges (11) of the absorbent body (2) at the contact surface and having the thickness of the absorbent body (2)

FIELD OF THE INVENTION 
The present invention refers to an absorbent product, preferably a 
disposable sanitary napkin for women, with a top layer that comes in 
contact with the user's body--with a longitudinal central band made of 
non-fabric material and. a perforated plastic film covering the rest of 
the top layer, the sides of the above mentioned. napkin and. possibly the 
bottom layer. 
BACKGROUND OF THE INVENTION 
As is known in the art, feminine sanitary napkins are generally disposable 
and. used. to collect and contain vaginal exudates, especially menstrual 
bleeding, intermenstrual secretions and even urine in cases of 
incontinence. 
Typically, these sanitary napkins are made up of an elongated. body made of 
absorbent material, covered. by an external at least partially liquid 
permeable layer, at least on the top side which comes into contact with 
the users body. 
As the above mentioned sanitary napkin becomes saturated. with liquid, the 
possibility of leaking increases, because of two main reasons: 
new discharges of liquid will have less chance of being absorbed, as there 
is less absorbent material available; and 
part of the liquid inside the absorbent material may eventually be exuded, 
especially when the user moves, compressing and. deforming the sanitary 
napkin. 
Some prior art patent documents refer to sanitarty napkins or diapers which 
have a perforated. plastic film in the central longitudinal area on the 
part that comes into contact with the user's body, and non-woven on that 
same side in the areas near the edges and throughout the thickness of the 
product. WO 9312745 and. WO 9510254 of Moelnlycke and EP 523683 and EP 
523719 of Kimberly-Clark can be cited. 
These documents have as a common denominator the concern with leaking and 
comfort. They propose perforated plastic films on the user's body contact 
surface, as being presumably more efficient for retaining liquids, and 
non-wovens at the sides of the absorbent product, as being presumably more 
pleasant to touch the user's skin. Nonetheless, it is known that the 
plastic film surface is a reason for discomfort, for those users who 
complain about the feeling of swelter (thus prejudicing comfort) while the 
non-woven at the sides of the product is a subtrate which may potentially 
lead liquids through its structure which is provided with interstices 
(whereby protection against leaking may be improved). 
This technology is different from that of the present invention, and there 
is no hint in those documents that show the invention results from the 
former. 
Still referring to the prior art, GB patent application 2.262.235 of Nov. 
27, 1992 discloses that the intermediate body of absorbent material is 
wrapped with a bottom liquid permeable film, a top perforated plastic film 
and side bands of imperforate embossed plastic. 
SUMMARY OF THE INVENTION 
The object of this invention is to prevent sideways leaking of the liquid 
that has already been absorbed into the absorbent core, but the level of 
comfort is still subject to improvement, bearing in mind the feeling of 
swelter mentioned by some users of sanitary napkins with the perforated 
plastic films in contact with the body. This technology also differs from 
the one now presented and there are no indications that suggest that it is 
a result of the former.

DETAILED DESCRIPTION OF THE INVENTION 
It is desirable, therefore, to provide a sanitary napkin which will meet 
the needs stated above, which are to decrease or prevent that feeling of 
swelter due to the plastic film coming into contact with the user's body 
and to improve the barrier against sideways leaking. 
According to the present invention, these goals are met by means of an 
absorbent product which includes an absorbent body and is characterized 
for having a first part of perforated plastic film and, on the surface 
which comes into contact with the user's body, a longitudinal layer which 
includes a second central portion of woven or non-woven material on the 
surface which comes into contact with the body, the first part being at 
least near the side edges of the absorbent body at the contact surface and 
having the thickness of the absorbent body. 
Some observations must be made on the terms used in the former paragraph: 
"absorbent product" includes any materials that are absorbent per se or 
that cause absorbency, the most common of which are paper, wood pulp and 
hydrocoloids.--"elongated" includes both flat products and products that 
are curved. before use. 
longitudinal layer" means that the layer has its length aligned with the 
length of the absorbent product, but not necessarily of the same width or 
length. 
"central portion" refers to a generically spectral shape referring to the 
imaginary central longitudinal axis along the length of the absorbent 
product. 
"Non-woven" includes, needled, hydrophobic or hydrophilic non-wovens that 
are chemically or thermally bonded, with or without openings, of natural, 
artificial or synthetic fibers or mono or multilayered mixtures thereof. 
It is preferable to use a thermobonded web of polypropylene carded fibers. 
"perforated plastic film" refers to any thin films of polymeric material, 
for example, polyethylene, polyurethane and. mixtures thereof and/or of 
other polymers, or laminates of more than one material, having any 
thickness or color. The openings may have any size or geometry. The film 
can have macro or micro protrusions embossed. in the non-perforated areas. 
"first part at least near the side edges of the absorbent body" means a 
straight or otherwise strip, adjacent or partially superimposed or 
overlaid on a first part of woven/non-woven fabric. It is evident that 
this absorbent body has two side edges whereby there are two strips, of 
equal widths or otherwise, the lengths of which, when summed, preferably 
occupy approximately 1/5 to 3/5 of the width of the surface that comes 
into contact with the body, reaching up to 7/8 of this width. 
"and having the thickness of the absorbent body" means that the perforated 
plastic film, that already covers part of the surface in contact with the 
body, also covers the side of the absorbent body. 
The perforated plastic film that constitutes the first portion of that 
longitudinal layer is a substrate which begins near the side edges and on 
the surface of the absorbent body, and preferably continues throughout the 
entire thickness of the body, covering the sides as well. Optionally, the 
plastic film covers the back part: of the absorbent body, that is, the 
surface opposite that which comes into contact with the user's body and 
which touches the underwear. 
It is important to highlight one of the advantages of the present invention 
over the prior art in which a central longitudinal strip of the surface of 
the sanitary napkin in contact with the user's body comprises a perforated 
plastic film, sandwiched between non-woven fabric adjacent the edges of 
the absorbent body. Two factors seem to favor leaking: 
1. Liquid falling on the non-woven/plastic film interfaces will tend to 
flow towards the non-wovens (at the edges) which are less liquid repellent 
than the plastic film (in the center). 
2. The absorbent body, when wet and squeezed between the user's legs, can 
force the liquid towards the longitudinal edges covered by non-woven 
fabric, that is to say, it is little resistant to leakage. 
The product of the present invention eliminates or greatly minimizes these 
factors which are favorable to leakage, that is to say: 
1. Liquid which reaches the non-woven/plastic film interfaces will go 
towards the less repellent material, or non-woven. As this is found in the 
center of the surface of the absorbent body, the liquid to be absorbed 
will tend to move away from the edges, eliminating leaks. It is obvious 
that the liquid that only contacts the perforated plastic film will tend 
to go through the orificies towards the absorbent material. 
2. The absorbent body, when wet and pressed between the user's legs, may 
force the liquid towards perforated plastic film at the edges, which is 
less likely to absorb the liquid than the non-woven. This aspect is 
enhanced if the holes are conical, that is to say, if their diameter 
decreases closer to the absorbent body--and this is the form of the 
plastic film that is preferred in this invention. 
The invention will now be described in detail based on a preferred 
embodiment illustrated in the accompanying drawings, in which: 
FIG. 1 is a perspective view of a preferred embodiment of a sanitary napkin 
in accordance with this invention; 
FIG. 2 is a cross sectional view of the sanitary napkin illustrated in FIG. 
1. 
It can be observed from FIGS. 1 and 2 that the sanitary napkin 1 of this 
invention is made of a substantially flat and elongated, approximately 
parallelepiped shaped absorbent body 2, covered. by an. external layer 3. 
According to this invention, this external layer 3 has a first portion 5 
made of a plastic film containing orifices 6, and. a second portion 7 
which comes into direct contact with the user's pubic region (not 
illustrated). This second. portion 7 is made up of a layer of non-woven 
material with orifices S. 
The first portion 5 of layer 3 extends throughout the lower face of napkin 
1, which faces the user's underwear, and also along the side walls 11 and. 
a longitudinal stretch 12 of the superior face 13 of napkin 1. The second 
portion 7 extends along the entire upper central longitudinal region 13, 
which in use contacts the skin. The first and second portions 5 and 7 
overlap where they are joined together by means of an an adhesive strip 
along region 12. 
To prevent leaking at its bottom, absorbent body 2 is protected with a 
liquid-impermeable barrier (not shown) at its lower face 10, between body 
2 and the first portion 5 of layer 3. 
According to an alternative embodiment, the first portion 5 could be a 
non-woven covering that is more hydrophobic than the material of second 
portion 7. 
As the plastic film that covers the first portion 5 is opaque, the 
presently proposed construction is advantageous since it provides good 
masking, that is to say, it also partially hides any blood at the edges of 
the absorbent body 2, minimizing the impression of imminent leaking caused 
in such circumstances. 
The absorbent body 2 can be made from any material that is absorbent and/or 
retains body exudates, such as wood pulp, bamboo fibers, cane bagasse or 
corn stalk or corn cob , turf moss, absorbent foams or sponges, synthetic 
or polymeric fibers, superabsorbent materiais (that form hydrogels when in 
contact with liquids) or combinations of such materials. 
As is known in the art, bottom face 10 can be at least partially coated 
with an adhesive (not illustrated) to ensue attachment of the sanitary 
napkin to the user's underwear. A removable sheet (also not illustrated) 
protects the adhesive until the product is used. This adhesive can be in 
the form of one or more be longitudinal or transverse strips or bands, 
continuous or non-continuous lines, etc. 
The present invention also does not exclude alternative embodiments in 
which the sanitary napkin has side flaps, used better to accomodate the 
napkin on the user's underwear. 
It should be borne in mind that the sanitary napkin described above is 
merely a preferred embodiment of the present invention, the true scope of 
which is defined in the following claims.