Non woven material and hygienic absorbent article comprising such material

Multilayer nonwoven material which has a high rate of drying out, improved rate of entry of, or break-through time by, body fluids and good diffusion of the body fluids in the plane of the layers. The multilayer nonwoven material comprises at least two superposed layers (1, 2) of natural or synthetic textile fibers, joined together, the fibers of the successive layers having a denier decreasing progressively, in a given direction, from one successive layer to the other. Application as surface webs for absorbent articles of hygiene.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The invention relates generally to a composite nonwoven material made up of 
a number of layers or sheets of textile fibers. 
More particularly, the invention relates to a composite nonwoven material 
made up of a number of layers in which the fibers have a denier (measure 
of the diameter or of the thickness of the fibers) which decreases in a 
given direction, from one successive layer to the other. 
The invention also relates to an absorbent article of hygiene such as a 
diaper or dressing for an incontinent person comprising surface web or 
sheet (also referred to as covering web or sheet) a web consisting of 
multilayer nonwoven material in which the layer made with the fibers of 
lower denier is situated directly on the absorbent pad of the article. 
The invention also relates to an absorbent article of hygiene such as a 
diaper or dressing comprising, in addition to the surface web, a crotch 
region strip consisting of the multilayer nonwoven material, arranged on 
the surface web or between the surface web and the absorbent pad of the 
article, in which the layer of fibers made of the fibers of lower denier 
is situated directly in contact with the surface web or the absorbent pad 
respectively. 
2. Discussion of Related Art 
Absorbent articles of hygiene such as diapers and dressings for an 
incontinent person generally comprise a pad or mat of absorbent material 
on which a surface web or sheet is arranged. When the articles are in use, 
this surface web or sheet is in direct contact with the skin and its 
purpose is to isolate the skin from the moist absorbent pad. This web must 
therefore have certain properties, namely a pleasant contact with the 
skin, allow a rapid passage of the body fluid through as far as the 
absorbent pad, ensure good diffusion of the liquids over the whole surface 
of the absorbent pad, and avoid a rise of the body fluids absorbed by the 
pad towards the upper surface of the web. 
Absorbent pads or mats have recently been developed which contain particles 
of superabsorbent material, generally arranged between two layers of 
fibers, themselves included between a base layer generally made of 
nonwoven material and an upper layer in contact with the skin, generally 
made of cotton wadding or of a nonwoven material. Such a type of pad is 
described in EP-A-0,232,729. In order to obtain a maximum efficiency of 
the superabsorbent materials contained in these pads it is desirable that 
the liquid should diffuse or be distributed over the whole upper surface 
of the absorbent mat. The surface webs or sheets arranged on the upper 
surface of such pads generally consist of one or more layers of a nonwoven 
material. 
Document FR-A-2,588,285 describes a multilayer nonwoven textile which has 
at least two layers of nonwoven web, one of the layers being made up of 
fibers of bilobed cross-section and the other layer being made up of 
fibers of trilobed cross-section. Each web layer is preferably obtained by 
the spinning bonding technique (spun nonwoven) and the two web layers are 
joined to form the multilayer nonwoven by heat bonding in noncontinuous 
compacted regions. 
Document WO 87/07,117 describes an absorbent article of hygiene comprising 
an absorbent body surrounded by a cover. This cover or surface web 
consists of two layers of nonwoven material. The first layer of nonwoven 
material, in contact with the user's skin, consists of a thin layer of 
fibrous spin-bonded tissue (spun nonwoven) made of a hydrophobic material, 
and the second layer in contact with the absorbent body is a hydrophobic 
fibrous layer of tissue of melt-bonded fibers, similar in construction to 
the first layer. These two layers of surface web are not bonded together 
in the region intended to come into contact with the user's body. 
Document WO 88/05,269 relates to a surface web for a disposable absorbent 
article made up of at least two layers of nonwoven which may be identical 
or different and which are joined by lines of adhesive forming an open 
pattern. 
OBJECTS AND SUMMARY 
Although such surface webs or sheets have an appropriate rate of entry, or 
break-through by, body fluids and ensure a certain diffusion of the liquid 
on the surface of the absorbent mat or pad, it is always desirable to 
improve these characteristics. Moreover, it is also desirable to obtain a 
maximum reduction of any return of the body fluids, in order to obtain a 
surface web which dries out rapidly and which does not rewet. 
An aim of the present invention is therefore to provide a nonwoven material 
which has an improved rate of entry of, or time for break-through by, the 
body fluids, which dries out rapidly, which ensures good diffusion of the 
body fluids over the whole surface of the absorbent mat, and which reduces 
as much as possible any rise of the body fluids absorbed by the mat. 
Another aim of the invention is to provide an absorbent article of hygiene 
such as a diaper or dressing for an incontinent person, comprising an 
absorbent pad or mat provided at its surface with a surface web or sheet 
made of the multilayer nonwoven material of the present invention. 
Another aim of the present invention is to provide an absorbent article of 
hygiene such as a diaper or dressing for an incontinent person, comprising 
an absorbent pad or mat, a surface web made of traditional nonwoven 
material, and, to complement the traditional surface web, a strip of 
similar width to that of the crotch region of the absorbent pad and of 
length similar to that of the pad, consisting of a multilayer nonwoven 
material according to the invention. 
According to the present invention, a multilayer nonwoven material is 
produced which comprises at least two superposed layers of natural or 
synthetic textile fibers, joined together, in which the fibers of the 
successive layers have a denier decreasing progressively, in a given 
direction, from one successive layer to the other. 
The invention also provides an absorbent article of hygiene which comprises 
an outer layer made of material which is impervious to body fluids, an 
absorbent pad which is permeable to body fluids and bonded to the outer 
layer, and a surface web permeable to the body fluids and bonded to the 
outer layer, in which the surface web consists of a multilayer nonwoven 
material comprising at least two superposed layers of natural or synthetic 
textile fibers joined together, the fibers of the successive layers having 
a denier decreasing progressively from one successive layer to the other, 
the layer having the fibers of lower denier being situated directly on the 
internal surface of the absorbent pad. 
According to another embodiment of the invention, an absorbent article of 
hygiene is provided which comprises an outer layer made of material which 
is impervious to body fluids, an absorbent pad which is permeable to body 
fluids and bonded to the outer layer, a surface web made of material 
permeable to body fluids and bonded to the outer layer, and in addition to 
this surface web an additional crotch region strip with a width similar to 
that of the crotch region of the absorbent pad and a length similar to 
that of the pad and consisting of at least two superposed layers of 
natural or synthetic textile fibers joined together, the fibers of the 
successive layers having a denier decreasing progressively from one 
successive layer to the other, the layer of fibers of lower denier 
forming, in the article of hygiene, the outermost layer of the strip, that 
is to say the layer closest to the absorbent pad, and the layer of fibers 
of higher denier forming the innermost layer of the strip, that is the 
layer furthest away from the absorbent pad. 
An important characteristic of this nonwoven material lies in the fact that 
the various superposed layers consist of fibers whose denier (unit 
measuring the thickness or the diameter of the fibers) varies from one 
layer to the next with a progressive decrease from an inner or surface 
layer to an outer or base layer. A fibrous structure is thus obtained in 
which the diameter of the pores decreases from the inner to the outer 
layer. Any suitable natural or synthetic fibers, for example cellulose, 
viscose, polyester, polyethylene, polypropylene or ethylene-propylene 
copolymer fibers may be employed for the manufacture of the nonwoven 
layers. The various layers may be made up of fibers of the same kind or of 
different kinds. These layers or sheets of textile fibers may be formed by 
any process employed for the manufacture of nonwoven material, such as by 
spin-bonding, spin-lacing, chemical bonding, heat bonding, needling, 
air-laying or tangling by jets of water. As indicated, the multilayer 
nonwoven material comprises at least two layers of fibers of different 
denier, but may comprise a larger number of layers, for example three or 
more. In one embodiment, which is recommended, the nonwoven material 
according to the invention is made up of two layers of fibers with denier 
decreasing from the inner to the outer layer. In this embodiment the layer 
of fibers of higher denier generally has a denier of between 3.3 and 6.6, 
while the layer of lower denier generally has a denier of between 1.5 and 
3.3. In another embodiment of the invention the nonwoven material is made 
up of five layers of fibers such that all of the fibers in each layer have 
a denier decreasing from the inner layer to the outer layer. In this 
embodiment comprising five layers, the denier of the fibers is preferably 
chosen, in the case of each of the successive layers, from the layer of 
fibers of higher denier to the layer of fibers of lower denier, in the 
following ranges: 
layer 1 (the innermost layer): 6.6 to 9 
layer 2: 4.4 to 6.5 
layer 3: 3.3 to 4.3 
layer 4: 1.7 to 3.2 
layer 5 (the outermost layer): 0.8 to 1.6. 
In general, the layers of the multilayer nonwoven according to the 
invention have a weight per unit area of between 5 and 50 g/m.sup.2, 
preferably between 5 and 30 g/m.sup.2. In addition, in a recommended 
embodiment some of the layers may be treated with appropriate surface or 
oiling agents which are well known in the art for imparting hydrophilicity 
characteristics thereto. These treated layers have the advantage of 
increasing the rate break-through by body fluids, while the untreated 
layers have properties of diffusion of the fluids in their plane, and this 
ensures better distribution or diffusion of the body fluids over the whole 
surface of the absorbent mat. The layers of hydrophilic and hydrophobic 
nature may be advantageously alternated. The hydrophilic or hydrophobic 
nature of the various layers can be obtained by employing different 
conventional processes of manufacture for each of the layers. 
The various layers of the multilayer nonwoven material are joined together 
by any appropriate technique, for example heat-bonding or mechanical 
bonding, in particular by needling or by tangling by jets of water. A 
recommended method of joining the layers according to the invention is 
needling. 
Such a material is particularly useful for the manufacture of surface webs 
or sheets or of crotch region strips employed as a replacement for or 
addition to the conventional surface web in absorbent articles of hygiene 
such as diapers and dressings for an incontinent person. 
When it is employed as a surface web of an absorbent article of hygiene, 
replacing the conventional surface web, the multilayer nonwoven material 
of the present invention is arranged directly on the absorbent mat of the 
article with the layer consisting of fibers of lower denier in contact 
with the inner surface of the pad. Consequently, the layer of fibers of 
higher denier is found to be the upper or inner layer of the web which 
would be in contact with the user's skin. As a result, the layers which 
have a larger pore diameter are situated in the upper or inner part of the 
web and the layers which have a smaller pore diameter in the lower or 
outer part of the web. In this way a fast break-through of the upper 
layers of the web is obtained, and this ensures rapid drying out of these 
upper layers and an enhanced comfort of the user, while the presence of 
pores of smaller diameters in the lower layers of the web, and in 
particular directly above the pad reduces as much as possible any rise of 
the body fluids which have been absorbed by the absorbent pad. 
When employed in addition to the conventional surface web of an absorbent 
article of hygiene, the multilayer nonwoven material according to the 
invention preferably forms a strip with a width similar to that of the 
absorbent pad in the crotch region. The length of the strip may correspond 
to that of the article of hygiene, but will be preferably equal to that of 
the absorbent pad. The strip made of multilayer nonwoven material 
according to the invention may be arranged, in the crotch region, either 
on the web made of conventional nonwoven material or between the web made 
of conventional nonwoven material and the absorbent pad. In both cases the 
innermost layer of the strip, that is to say the layer furthest away from 
the absorbent pad, is the layer of fibers of higher denier and 
consequently the outermost layer of the strip, that is to say the layer 
closest to the absorbent pad is the layer of fibers of lower denier. When 
this additional strip is situated above the conventional surface web it 
can be joined to the inner surface of the surface web by any conventional 
process such as, for example, adhesive bonding, heat-sealing, ultrasonic 
welding or needling. When this additional strip made of multilayer 
nonwoven material according to the invention is situated between the 
surface web and the absorbent pad, it can be bonded either to the outer 
surface of the surface web or to the inner surface of the absorbent pad by 
any conventional process, for example, adhesive bonding, heat-sealing, 
ultrasonic welding or needling

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
With reference to FIG. 1, a first embodiment of a multilayer composite 
material according to the invention is shown, which comprises two 
superposed layers of polyester fibers (1, 2) whose characteristics are the 
following, starting with the upper or inner layer 1 to the lower or outer 
layer 2. The inner layer consists of polyester fibers with a denier of 
between 3.3 and 6.6, preferably 6.6, and a weight per unit area of between 
5 and 50 g/m.sup.2, for example 41 g/m.sup.2. The outer layer 2 consists 
of polyester fibers with a denier of between 1.5 and 3.3, preferably 3.3 
or 1.5 deniers, and has a weight per unit area of between 5 and 50 
g/m.sup.2, for example 22 g/m.sup.2. The layers are joined by needling or 
tangling by jets of water. The layers are preferably joined by a needling 
6. 
With reference to FIGS. 2 and 3, an absorbent article of hygiene 10, such 
as a diaper, is shown, comprising a surface web 13 made of multilayer 
composite nonwoven material according to the invention. The article of 
hygiene 10 comprises an outer layer 11 made of flexible material which is 
impervious to body fluids, on which there is arranged an absorbent mat or 
pad 12 which is permeable to body fluids, smaller in size than the outer 
layer 11 and bonded to the outer layer 11 by any appropriate means, for 
example by adhesive bonding. On this absorbent pad 12 there is a surface 
web 13 which is permeable to body fluids and of a size larger than that of 
the absorbent mat 12 and which is bonded to the outer layer 11 by any 
appropriate means such as adhesive bondings 14. As is well known, the 
outer layer 11, the absorbent pad 12 and the surface web 13 are generally 
in the form of an hourglass comprising two wide opposite end parts 
connected via a central crotch region part of general rectangular shape 
and of smaller width. As can be seen better in FIG. 3, in this embodiment 
the surface web 13 consists of the composite nonwoven material with two 
layers of FIG. 1. The lower or outer layer 2, consisting of fibers of 
lower denier is arranged directly on the pad 12, whereas the upper or 
inner layer made of fibers of higher denier forms the layer which will be 
in contact with the user's skin. This surface web 13 may be joined to the 
absorbent pad 12 by any conventional means such as adhesive bonding, 
heat-sealing, ultrasonic welding or needling. 
In this way a diaper is obtained which has improved characteristics of rate 
of break-through and resistance to rewetting by the body fluids. 
With reference to FIG. 4, this shows an embodiment of a multilayer nonwoven 
material according to the present invention which is particularly 
appropriate for the replacement of the conventional surface web and which 
comprises five superposed layers of polyester fibers (1 to 5) whose 
characteristics are the following, starting from the upper or inner layer 
to the bottom or outer layer: 
layer 1 6.6 deniers 30 g/m.sup.2 
layer 2 4.4 deniers 20 g/m.sup.2 
layer 3 3.3 deniers 20 g/m.sup.2 
layer 4 1.7 denier 15 g/m.sup.2 
layer 5 0.8 denier 15 g/m.sup.2 
The layers are joined by a needling 6 to obtain a final nonwoven web with a 
weight per unit area of 100 g/m.sup.2. The needling density was 20 
strokes/cm.sup.2 and per face. Obviously, as already indicated, one or 
more of the layers may consist of fibers of another type such as, for 
example, viscose fibers or any other natural or synthetic textile fibers. 
In particular, the use of viscose fibers in some of the layers contributes 
retention to the sheet. In addition, the thickness of each individual 
layer and also that of the final product can be adjusted by adjusting the 
needling density, when a needling process is employed for forming each of 
the layers and/or for joining the layers together. Such a multilayer 
nonwoven material employed as surface web or as crotch region strip in 
addition to the surface web in an absorbent article of hygiene is 
characterized by fast drying-out of the material and improved rate of 
entry or break-through time by the body fluids, and a good diffusion of 
these fluids over the whole surface of the absorbent mat. 
With reference to FIGS. 5 and 6, an absorbent article of hygiene 10, such 
as a diaper, has been shown, comprising a surface web 13 made of 
multilayer nonwoven material according to the invention. The article of 
hygiene 10 comprises an outer layer 11 made of a flexible material which 
is impermeable to body fluids, on which there is arranged an absorbent mat 
or pad 12 permeable to body fluids and smaller in size than the outer 
layer 11 and bonded to the outer layer 11 by any suitable means. On this 
absorbent pad 12 there is surface web 13 permeable to body fluids and of a 
size larger than that of the absorbent mat 12. As is well known, the outer 
layer 11, the absorbent pad 12 and the surface web 13 generally have the 
shape of an hourglass comprising two wide opposite end parts connected by 
a central crotch region part of general rectangular shape and smaller 
width. As can be seen better in FIG. 6, in a recommended embodiment, the 
surface web consists of five layers 1 to 5 of nonwoven material, such as, 
for example, the material of FIG. 4. The denier of the fibers of which 
each of the layers of nonwoven consists decreases progressively from the 
upper or internal layer 1 to the base or outer layer 5 which is directly 
in contact with the upper or internal surface of the absorbent pad. All 
the layers 1 to 5 are joined by needling 6. The surface web 13 made of 
multilayer nonwoven is bonded over its periphery to the impervious outer 
layer 11 by any suitable means, for example by adhesive bonding 14. 
The layer 5 of the surface web 13 consisting of fibers of lower denier is 
thus situated directly on the absorbent pad 12, while the layer 1 
consisting of fibers of higher denier is found to be the upper or internal 
layer of the web which will be in contact with the user's skin. The 
surface web 13 therefore has a pore diameter which decreases progressively 
from the upper or inner layer 1 to the base or outer layer 5, and this 
results in a rapid drying out of the surface of the web 13 and an 
increased barrier effect in respect of the rewetting by the fluids 
absorbed by the pad 12. 
With reference to FIGS. 7 and 8, an absorbent article of hygiene 10, such 
as a diaper similar to that of FIGS. 5 and 6 has been shown, which 
comprises an outer layer 11 made of a flexible material which is 
impermeable to body fluids, on which there is arranged an absorbent mat or 
pad 12 which is permeable to body fluids and smaller in size than the 
outer layer 11. On this absorbent pad 11 there is a surface web 13 made up 
of a conventional nonwoven material, for example made of polypropylene 
fibers of 2.2 denier, similar in size to that of the outer layer 11 and 
bonded to the outer layer by any appropriate means, for example adhesive 
bonding 14. On this surface web 13 is arranged a crotch region strip 15 
which is permeable to body fluids, made of nonwoven material according to 
the invention, such as, for example, the material of FIG. 4. This crotch 
region strip 15 is generally of rectangular shape which has a width 
similar to that of the pad 12 in the crotch region and a length similar to 
that of this pad 12. According to the invention this crotch region strip 
15 comprises at least two layers of nonwoven, five layers 1-5 in the 
embodiment shown, the denier of which decreases from the innermost layer 1 
to the outermost layer 5 which is in contact with the surface web 13. This 
crotch region strip 15 can be bonded to the inner surface of the surface 
web made of conventional nonwoven 13 by any conventional means such as 
adhesive bonding, heat-sealing, ultrasonic welding or needling. 
As previously, the layer 5 made of fibers of lower denier is the layer of 
the crotch region strip which is the nearest to the absorbent pad, whereas 
the layer 1 made of fibers of higher denier is found to be the layer 
furthest away from the pad 12 and, in this embodiment, the layer intended 
to come into contact with the user's body. As previously, a rapid 
drying-out of the upper layer(s) of the crotch region strip is obtained, 
and an increased barrier effect in respect of rewetting. 
With reference to FIGS. 9 and 10, an absorbent article of hygiene 10 
similar to that of FIGS. 7 and 8 has been shown, but in which the crotch 
region strip 15 is arranged between the surface web made of conventional 
nonwoven material 13 and the absorbent pad 12. In this embodiment, with 
the exception of the location of the crotch region strip 15, all the other 
components are identical to those of FIGS. 7 and 8. In this embodiment the 
crotch region strip 15 is arranged between the surface web 13 and the pad 
12 so that the layer 1 made of fibers of higher denier is the innermost 
layer, that is to say the layer closest to the surface web 13, and the 
layer 5 made of fibers of lower denier is the outermost layer of the 
strip, that is to say the layer in direct contact with the inner surface 
of the absorbent pad 12. The crotch region strip 15 made of multilayer 
nonwoven material according to the invention may be joined either to the 
outer surface of the surface web 13 or to the inner surface of the 
absorbent pad by any appropriate means such as, for example, adhesive 
bonding, heat-sealing, ultrasonic welding or needling. 
The diaper thus produced exhibits a rapid drying out of the inner surfaces 
in the crotch region and an increased barrier effect in respect of 
rewetting. 
The following examples are given by way of illustration of the present 
invention. 
Comparative Example A 
A determination was made of the rate of break-through and the rewetting 
resistance of a commercial diaper (Peaudouce Action girl.RTM. 
corresponding to the 8-18 kg size, in which the total weight is 59.2 g, 
the weight of the absorbent pad 48.6 g including 4.8 g of superabsorbent 
material) and which comprises a conventional surface web made of nonwoven 
of polypropylene fibers of the spin-bonded type (spun nonwoven) which has 
a weight per unit area of 20 g/m.sup.2. The results are given in Table 1 
below. 
Comparative Example B 
A determination was made of the rate of break-through and the rewetting 
resistance of another commercial diaper of identical size to that of 
Comparative example A and which has an identical surface web (Peaudouce 
Action boy.RTM., in which the total weight is 59.4 g, the weight of the 
absorbent pad is 49 g, including 4.94 g of superabsorbent material). The 
results are given in Table 1 below. 
Comparative Example C 
The surface web of the diaper of Comparative example B was replaced with 
three superposed layers of polyester fibers of 6.6 deniers and a weight 
per unit area of 41 g/m.sup.2, that is a total weight per unit area of 123 
g/m.sup.2. The rate of break-through and the rewetting resistance were 
determined. The results are given in Table 1. 
Comparative Example D 
The surface web of the diaper of Comparative example B was replaced with 
six superposed layers of polyester fibers of 3.3 deniers and a weight per 
unit area of 22 g/m.sup.2, that is a total weight per unit area of 132 
g/m.sup.2. The rate of break-through and the rewetting resistance were 
determined. The results are given in Table 1. 
Comparative Example E 
The surface web of the diaper of Comparative example B was replaced with 
six layers of polyester fibers of 1.5 deniers and a weight per unit area 
of 22 g/m.sup.2, that is a total weight per unit area of 132 g/m.sup.2. 
The rate of break-through and the rewetting resistance were measured. The 
results are given in Table 1. 
EXAMPLE 1 
A surface web made of a composite material according to the invention, 
comprising two layers of polyester fibers bonded together by needling, was 
added to the surface web of the diaper of Comparative example A. The 
polyester fibers of the inner layer were of 6.6 deniers and this layer had 
a weight per unit area of 41 g/m.sup.2. The polyester fibers of the outer 
layer were of 3.3 deniers and this layer had a weight per unit area of 22 
g/m.sup.2. This outer layer is arranged in contact with the conventional 
surface web of the diaper. 
The rate of break-through and the rewetting resistance were determined. The 
results are given in Table 1. 
Comparative Example 1a 
The same structure as in Example 1 was produced, but reversing the position 
of the layers of the composite material according to the invention in 
relation to the conventional surface web of the diaper, that is to say by 
placing the layer of fibers of 6.6 deniers directly on the conventional 
surface web of the diaper. The rate of break-through and the rewetting 
resistance were determined. The results are given in Table 1. 
EXAMPLE 2 
The same structure as in Example 1 was produced, but using polyester fibers 
of 1.5 deniers for the outer layer made of fibers of lower denier. This 
outer layer had a weight per unit area of 22 g/m.sup.2. This outer layer 
of fibers of 1.5 deniers was arranged directly on the conventional surface 
web of the diaper. The rate of break-through and the rewetting resistance 
were determined. The results are given in Table 1. 
Comparative Example 2a 
The same structure as in Example 2 was produced, but reversing the position 
of the layers of the composite material according to the invention in 
relation to the conventional surface web of the diaper, that is to say by 
placing the layers of fibers of 6.6 deniers directly on the conventional 
surface web of the diaper. The rate of break-through and the rewetting 
resistance were determined. The results are given in Table 1. 
TABLE 1 
__________________________________________________________________________ 
Comparative 
Comparative 
Comparative 
Comparative 
Comparative 
Comparative 
Ex- Comparative 
example A 
example B 
example C 
example D 
example E 
Example 1 
example 1a 
ample 
example 
__________________________________________________________________________ 
2a 
1st break-through time (s) 
53 85 38 39 38 55 48 36 45 
2nd break-through time (s) 
178 313 40 62 69 83 77 58 55 
3rd break-through time (s) 
211 320 52 65 78 91 87 67 69 
Rewetting resistance (g) 
after 20 minutes 
4.10 0.60 0.20 0.30 0.30 0.30 0.25 0.20 
0.30 
after 40 minutes 
36.50 7.20 0.80 21.70 30.50 1.30 6.70 0.70 
5.10 
after 60 minutes 
57.10 40.30 15.80 45.00 53.00 27.80 
30.90 17.20 
26.50 
__________________________________________________________________________ 
The break-through times and the rewetting resistance were determined as 
follows: 
The finished products are conditioned at 23.degree. C. and 50% relative 
humidity for 24 hours before the tests. 
A 7.times.7 cm sheet of Plexiglas.RTM. perforated in its center is placed 
in the center of the surface web of the tested article. 100 cm.sup.3 of a 
saline solution containing 9 g/l of sodium chloride in distilled water 
were poured into the orifice in the sheet by means of a separating funnel, 
the flow of the funnel being adjusted to have a constant high level in the 
orifice in the sheet. The time elapsed between the beginning of the entry 
of the saline solution and the instant at which the saline solution has 
disappeared into the article is measured. The measured time constitutes 
the first break-through time. 
Six Dimar ED 939.RTM. filter papers cut into squares of 10.2.times.10.2 cm 
are then weighed. A 10.2.times.10.2 cm weight of 3.5 kg is then placed for 
10 minutes on the surface web of the tested article, after the perforated 
sheet has been taken off. Once 10 minutes have elapsed, the six filter 
papers are placed under the weight and left for another 10 minutes. At the 
end of this period the weight and the filter papers are removed. The 
filter papers are weighed. The difference in weight, in grams, between the 
first and second weighing gives a measure of the rewetting resistance 
after 20 minutes. 
The above procedure is repeated twice with the same article, 24 filters 
being employed after the second addition of saline solution and 30 filters 
after the third addition, respectively. The second and third break-through 
times are thus obtained, together with the rewetting resistance after 40 
and 60 minutes. 
A comparison of the results obtained between Examples 1 and 2, on the one 
hand, and the Comparative example A, on the other hand, shows that the use 
of a composite nonwoven according to the invention in addition to a 
conventional surface web improves the rate of break-through of the liquid 
very markedly (more than 50% at the third test) although the total weight 
per unit area of the surface web is increased by 63 g/m.sup.2. 
In addition, comparison of the results obtained between Examples 1 and 2 
and Comparative examples 1a and 2a shows the greater the increase in the 
difference in the decrease between the values of the deniers of the inner 
layer and of the outer layer which are superposed, the better are 
simultaneously the rate of break-through and the rewetting resistance. It 
is noted, moreover, in Comparative examples 1a and 2a that, when the 
respective position of the two layers is reversed, the rewetting 
resistances are reduced thereby. Finally, comparison of the results 
obtained in Comparative examples C, D and E with those of Comparative 
example B shows that the use, as replacement for a conventional surface 
web, of a composite web which has a substantially constant weight per unit 
area, made up of a number of layers of nonwoven material of the same 
denier, makes it possible to improve the rate of break-through, the 
rewetting resistance is particularly strengthened only when the denier of 
the composite web is high, and therefore when the gradient between the 
average porosity of the absorbent pad and of the surface web is greatest, 
and for a high total weight per unit area.