A soft, perf-embossed, absorbent composite structure is provided which comprises an absorbing layer of a fibrous web containing at least about 200 percent by weight of superabsorbent and a wicking layer. The composite structure has a Taber stiffness value less than about 30.

BACKGROUND OF THE INVENTION 
The present invention relates to a new and improved thin absorbent 
structure, and more particularly, to a new and improved compressed 
absorbent composite containing superabsorbent material, and which 
composite absorbs large quantities of liquids. 
Disposable absorbent products have been known for some time including such 
products as disposable diapers, sanitary napkins, wound dressings, 
bandages, incontinent pads, and the like. These products incorporate an 
absorbent batt which is used to absorb and hold, or contain, body fluids. 
Initially, in many of these products, especially diapers and sanitary 
napkins, the absorbent batt consisted of what is termed "wadding" or plies 
of tissue. The wadding was disposed between an impermeable backing and a 
permeable facing and the plies of tissue were used to absorb and hopefully 
contain the liquid within the product. A diaper which utilizes such an 
absorbent batt is disclosed in U.S. Pat. No. Re. 26,151. 
The wadding type of batt was replaced for the most part by an improved 
absorbent batt which comprises what is termed "fluffed wood pulp fibers". 
This absorbent batt comprises a layer of individualized wood pulp fibers 
with the layer having substantial thickness. A diaper which incorporates 
such a fluffed wood pulp absorbent batt is described in U.S. Pat. No. 
2,788,003. This diaper had improved absorbent capacity and somewhat better 
containment than a diaper using a wadding layer. Also, the fluffed wood 
pulp layer is quite soft, flexible, and conformable, and hence produces an 
improved diaper over diapers using wadding as the absorbent layer. 
Though the fluffed wood pulp absorbent batts have improved capacity, the 
efficiency with which the capacity is used in a diaper or sanitary napkin 
is poor. The reason for this is that the fluid to be absorbed is generally 
deposited in a localized area within the absorbent batt and the ability 
for the fluid to move along the plane of the batt is poor. The fluid 
follows the path of least resistance, and consequently moves to the 
closest edge of the batt where it generally is no longer contained and the 
product leaks. Furthermore, the wood pulp batts lack stability, e.g., when 
a diaper is being worn, the batt tends to break up creating bunching. 
U.S. Pat. No. 3,017,304 discloses an absorbent product which incorporates a 
fluffed wood pulp absorbent batt having a densified paper-like layer. This 
paper-like layer acts as a wick, i.e., liquid which is placed on the layer 
tends to move rapidly along the plane of the layer. When incorporated in 
combination with fluffed wood pulp fibers, the resultant product uses the 
absorbent capacity of the fluffed wood pulp much more efficiently. Diapers 
which incorporate this paper-like layer combined with fluffed wood pulp 
are disclosed and described in U.S. Pat. Nos. 3,612,055 and 3,938,522. 
This concept of combining a wicking layer or capillary skin with fluffed 
wood pulp fibers has gained wide acceptance in many absorbent products 
including disposable diapers and sanitary napkins. Even though these 
products make much greater use of the capacity of the absorbent batt, they 
still do not totally contain the absorbed liquid. It is probable that 
these products will leak before the full capacity of the batt is used for 
absorption. This is especially true if pressure is placed on the batt 
while wet. For example, a baby sitting down on a previously wetted diaper 
will very often cause the batt to leak. Although the batt is somewhat 
stabilized by the paper-like densified skin, it may crack and separate. 
A number of years ago "superabsorbent materials", i.e., materials which 
will absorb many times their weight of liquid, were developed. Since the 
development of such materials, people have been trying to incorporate them 
in absorbent products such as diapers and sanitary napkins to enhance the 
absorptive performance of these products. Theoretically, a minimum amount 
of superabsorbent incorporated in a product would make that product 
perform as well or better than the prior art products. Perhaps one of the 
first products to incorporate such a superabsorbent material in a 
disposable diaper is disclosed in U.S. Pat. No. 3,670,731. This patent 
discloses an absorbent dressing comprising an absorbent layer sandwiched 
between a permeable facing and an impermeable backing sheet. The absorbent 
layer contains water insoluble, crosslinked, hydrocolloid polymer as the 
absorbent material. 
Even though absorbent materials have been available for some time, they 
have not gained wide acceptance in absorbent products such as disposable 
diapers and sanitary napkins. A primary reason for this lack of acceptance 
of the superabsorbents is failure to develop a product capable of 
economically utilizing the highly increased absorptive capacity of the 
superabsorbent material. In order to economically utilize the 
superabsorbent, the liquid being absorbed must be transported to the 
superabsorbent material. In other words, the superabsorbent material must 
be placed in contact with the liquid. 
Furthemore, as the superabsorbent material absorbs the liquid, it must be 
allowed to swell. If the superabsorbent is prevented from swelling, it 
will cease absorbing liquid. Hence, if the superabsorbent material is to 
function in diapers and sanitary napkins wherein the liquid to be absorbed 
is placed in a small void area, the structure of the absorbing layer 
containing superabsorbent material appears to be critical. Over the years, 
a number of techniques have been disclosed in an attempt to provide 
structures which make efficient use of the superabsorbent material, such 
products are disclosed in U.S. Pat. Nos. 4,103,062; 4,102,340; and 
4,235,237. In addition, methods for incorporating superabsorbents into 
suitable layers or suitable configurations which can be placed in an 
absorbent product are disclosed in U.S. Pat. Nos. 4,186,165; 4,340,057; 
and 4,364,992. To date, none of these products has met with any 
substantial commercial success. 
In an attempt to overcome these problems, in copending application Ser. No. 
439,963 filed Nov. 8, 1982, a particularly useful compressed composite 
structure is formed. Application Ser. No. 439,963 is hereby incorporated 
by reference. The compressed composite is a layered structure which 
contains an absorbing layer, a wicking layer and a transition zone. The 
product is compressed. The absorbing layer is generally a high loft, 
nonwoven, fabric such as polyester, which layer contains at least 200 
percent superabsorbent. Although this layer potentially has high liquid 
absorption capability, it is necessary to provide a transporting mechanism 
so that liquid which is deposited locally on the superabsorbentcontaining 
web can be transported. In order to provide this, a wicking layer is 
placed on the absorbing layer and the two layers are compressed, thus 
providing a transition zone at the contact point of the two layers. The 
wicking layer generally is a wood pulp fiber layer. Although the resulting 
compressed composite readily accepts, transports, and absorbs liquid, the 
product is somewhat stiff, and hence requires softening to provide 
flexibility for utilization in products such as diapers and the like. The 
flexibility provided needs to be permanent, i.e., the surrounding 
environment, handling of the product, and its subsequent use will not 
affect the softness and flexibility. 
The present invention provides a new and improved absorbent composite 
structure which utilizes a substantial portion of the absorptive capacity 
of superabsorbent materials and yet is reasonably soft and flexible. This 
composite remains in its substantially, completely, stable state, though 
rendered soft and flexible. Whether wet or dry the composite does not 
break, bunch, or separate. Furthermore, the composite retains absorbed 
liquid without yielding any of the liquid when the composite is under 
pressure. 
SUMMARY OF THE INVENTION 
The present invention provides an absorbent composite structure which is 
comprised of an absorbing layer and a wicking layer, the absorbing layer 
containing at least about 200 percent by weight superabsorbent. The 
absorbent composite is perf-embossed to reduce its Taber stiffness value 
by at least 75 percent to a Taber stiffness value of about 30 or less. 
The perf-embossing is carried out by known techniques such as that 
exemplified in U.S. Pat. No. 3,817,827. In order for the absorbent 
composite to be softened and reduced substantially in Taber stiffness, it 
is necessary to attain the glass transition temperature of the 
superabsorbent material so that the superabsorbent polymer is brittle and 
can be reduced in size effectively by the mechanical working and crushing 
provided by the perf embossing. The glass transition temperature is 
reached by reducing the moisture content sufficiently to permit 
satisfactory operation at the temperature of the room in which the 
operation is being carried out. For most superabsorbent materials, the 
satisfactory moisture content is less than about 10 percent by weight of 
moisture of the composite structure. 
The perf-embossing should provide sufficient impact points on the product 
to reduce the superabsorbent polymer particle size. Generally, if the 
impact points are no more than 1/4 inch apart and are somewhat continuous, 
a satisfactory change in Taber stiffness value will be achieved. In the 
process of perf-embossing, the composite is passed through a pair of rolls 
which have knuckles and which intermesh to shear the composite in the 
desired fashion. When looking at the composite after it has been 
perf-embossed, there are raised areas produced by lower knuckles and 
adjacent depressions produced by upper knuckles. If the composite is 
viewed from the other side, the raised areas become depressions and the 
depressions become raised areas. The depressions are densified regions 
which hold and wick liquid. Interconnecting the raised areas and the 
depressions are intermediate portions which have received most of the 
mechanical working which reduces the superabsorbent polymer size and fuses 
the layers of the composite together in the shear areas. At locations 
where the upper knuckles pass very close to the lower knuckles of the 
embossing rolls, the work applied to the composite exceeds the strength of 
the composite and produces apertures in it. The length of the apertures 
can be varied by controlling the overlap of the upper knuckles and lower 
knuckles or the size of the knuckles of the rolls. Though the flexibility 
of the composite is increased by the apertures, the overall strength of 
the product may be decreased, therefore the preferred product of the 
present invention employs controlled portions of both apertures and 
partially fractured or sheared regions.

DETAILED DESCRIPTION OF THE PRESENT INVENTION 
Referring now to the drawings, FIG. 1 represents a perspective view of 
starting material utilized to make the composite product of the present 
invention. The starting material 10 is a fibrous web 12 containing at 
least 200 percent superabsorbent 16 by weight of the web. The 
superabsorbent particles 16 are distributed substantially throughout the 
web 12. A wicking layer 14 is provided and the potential transition zone 
18 is at the junction of the fibrous web 12 and the wicking layer 14. 
FIG. 2 denotes a section of the product of FIG. 1 which has a fibrous web 
as an absorbing layer 22. Interspersed among the absorbing layer fibers 23 
is superabsorbent material 24. Immediately associated with the absorbing 
layer is the wicking layer 28. Some portions of the wicking layer fibers 
26 extend into and become integral with the absorbing layer 22, thus 
forming a transition zone 25. By "integral with" is meant in intimate 
contact with but not requiring physical or chemical bonding. The structure 
depicted in FIG. 2A is a compressed version of FIG. 2. Upon compression, 
some of the portions in the wicking layer 28 will extend into and become 
integral with the fibers of the absorbing layer 22. These wicking layer 
portions will also be in contact with the superabsorbent material 24. 
Generally, at least 10 percent moisture is present when the structure is 
compressed under a pressure sufficient to compact the structure and cause 
the softened surface of the superabsorbent material to provide the 
necessary adhesion to the fibers of the absorbing layer so that the 
composite remains in a compacted state even when dry. 
FIG. 3 is a perspective view of an absorbent composite which has been 
perf-embossed in accordance with the present invention. The composite 30 
contains a wicking layer 34 and an absorbing layer 32. Following the 
perf-embossing, apertures 36 are placed in the composite providing a 
pattern as shown. The Taber stiffness of the product is at least 75 
percent less than that of the product prior to perf-embossing. 
FIG. 4 depicts a disposable diaper 40 utilizing an absorbent composite of 
the present invention. A portion of the drawing is broken away for 
clarification. The disposable diaper 40 has a liquid-permeable facing 42 
and a liquid-impermeable backing 41. In between the facing 42 and the 
backing 41 is an absorbent composite 43. The composite has wicking layers 
44 and 46 and an absorbing layer 45. As is readily seen, the absorbent 
composite has been perf-embossed. The absorbent composite 43 is held in 
place between the facing 42 and the backing 41 by glue lines 47. Tape tabs 
48 are provided to secure the diaper product 40 about the waist of the 
wearer. 
FIG. 5 is a perspective view of a sanitary napkin 50. The napkin is 
comprised of a liquid-impermeable shell 52 which contains an absorbent 
structure 56 and is covered over the upper surface with a liquid-permeable 
facing 54. The absorbent structure 56 is made in accordance with the 
present invention and is similar to that of FIG. 3. 
These and other products such as incontinent pads, wound dressings, and the 
like, may be made from the absorbent structures depicted in the drawings. 
The fibrous web which contains the superabsorbent and forms the basic 
absorbing layer for the absorbent composite of the present invention is of 
substantially high loft and upon dry compression followed by a release has 
a tendency to return substantially to its original thickness. For 
instance, fibrous webs formed from synthetic staple fibers, such as 
polyethylene, polypropylene, polyester, nylon, bicomponent fibers, and the 
like, are particularly desirable. Melt blown fibrous webs also are 
suitable. Furthermore, cellulosic fibers such as rayon may be used. 
Generally, the fibers are air-laid or melt blown to form a web which if 
needed is then stabilized. Stabilization may be achieved by heat-through 
bonding, adhesive bonding, point embossing with heat or adhesive, and the 
like. The stabilizing process is selected according to the fibers used and 
the process used to form the web. Suitable procedures for forming a web 
include carding, wet-laying, air-laying, or combinations of these, melt 
blowing and other suitable known techniques. The fibrous web preferably 
has a dry bulk recovery of at least about 30 percent, an initial dry bulk 
of at least 20 cc/gm and a wet bulk of at least 30 cc/gm. The fibrous web 
generally has a weight less than 4 oz/sq. yd., preferably less than 3 
oz/sq. yd. 
A wicking layer, generally of wood pulp fibers, is placed on at least one 
side of the superabsorbent containing fibrous web and in the presence of 
about 10 percent moisture or more, the product is compressed. The 
resulting compressed composite generally possesses a Taber stiffness in 
the machine direction of at least about 130 and sometimes as high as 350. 
The superabsorbent material present in an intermittently dispersed form in 
the absorbing layer is generally a water-insoluble but water-swellable 
polymeric substance capable of absorbing water in an amount which is at 
least 10 times the weight of the substance in its dry form. The 
superabsorbent material is in the form of particles which may be in the 
shape of fibers, spheres, bits of film, globules, or the like, or may be 
applied in the form of a liquid monomer solution which is subsequently 
polymerized. Generally, the polymerized monomer solution provides globules 
and bits of film-like particles in the structure. 
In one type of superabsorbent material, the particles or fibers may be 
described chemically as having a backbone of natural or synthetic polymers 
with hydrophilic groups or polymers containing hydrophilic groups being 
chemically bonded to the backbone or an intimate admixture therewith. 
Included in this class of materials are such modified natural and 
regenerated polymers as polysaccharides including, for example, cellulose 
and starch and regenerated cellulose which are modified by being 
carboxyalkylated, phosphonoalkylated, sulphoalkylated or phosphorylated to 
render them highly hydrophilic. Such modified polymers may also be 
cross-linked to improve their water-insolubility. 
These same polysaccharides may also serve, for example, as the backbone 
onto which other polymer moieties may be bonded by graft copolymerization 
techniques. Such grafted polysaccharides and their method of manufacture 
are described in U.S. Pat. No. 4,105,033 to Chatterjee et al. and may be 
described as polysaccharide chains having grafted thereon a hydrophilic 
chain of the general formula 
##STR1## 
wherein A and B are selected from the group consisting of --OR.sup.3,--O 
(alkali metal), --OHNH.sub.3, --NH.sub.2, wherein R.sup.1, R.sup.2 and 
R.sub.3 are selected from the group consisting of hydrogen and alkyl 
having 1 to 4 or more carbon atoms, wherein r is an integer having a value 
of 0 to about 5000 or more, s is an integer having a value of 0 to about 
5000 or more, r plus s is at least 500, p is an integer having a value of 
zero or 1 and q is an integer having a value of 1 to 4. The preferred 
hydrophilic chains are hydrolyzed polyacrylonitrile chains and copolymers 
of polyacrylamide and polysodium acrylate. 
In addition to modified natural and regenerated polymers, the hydrocolloid 
particle component may comprise wholly synthetic hydrophilic particles. 
Examples of those now known in the art are polyacrylonitrile fibers which 
may be modified by grafting moieties thereon such as polyvinyl alcohol 
chains, polyvinyl alcohol itself, hydrophilic polyurethane, poly(alkyl 
phosphonates), partially hydrolyzed polyacrylamides (e.g., 
poly(N-N-dimethyl acrylamide), sulfonated polystyrene, or a class of 
poly(alkylene oxide). These highly hydrophilic synthetic polymers may be 
modified by other chemical treatments such as cross-linking or hydrolysis. 
Further examples known in the art are the non-ionic hydrophilic polymers 
such as polyoxyethylene, polyoxypropylene and mixtures thereof which have 
been suitably cross-linked, either chemically or by irradiation. Still 
another more recent type is a derivative of isobutylene-maleic anhydride 
copolymer. 
Hydrophilic polymers formed from water-soluble acrylate monomers, such as 
sodium, potassium, ammonium (or combination of cations), acrylate, may be 
placed on the absorbing layer by spraying or otherwise placing a solution 
thereon followed by polymerization and cross-linking, for example, by 
irradiation. 
In addition, naturally occurring materials such as gums, may be used. For 
instance, guar gum is suitable. 
The superabsorbent material is combined with the fibrous web by any means 
suitable to distribute the superabsorbent material therein trying to 
minimize interference by one superabsorbent entity with another upon the 
swelling of the first. If the superabsorbent material is a powder it may 
be sprinkled onto the fibrous web either in dry form or the web may be 
moistened. If the superabsorbent is in granular form it may be desirable 
to slightly moisten the superabsorbent before placing it in contact with 
the web. The superabsorbent material will contain particles which range in 
size from about 0.005 mm in diameter to globules that are continuous along 
fibers for a distance up to several inches. 
Another method of placing the superabsorbent in the web is spraying a 
monomer solution on the web or saturating the web with a monomer solution 
followed by polymerization of the monomer. One typical way to polymerize 
the monomer is by use of irradiation. It is desirable to place the 
superabsorbent somewhat evenly throughout the fibrous web. However, even 
if the superabsorbent is powderlike and in the form of a layer, it tends 
to function better than such a layer has in previously known products. It 
may be desirable to place more superabsorbent in one area than in another 
and/or to place the superabsorbent in the structure in predetermined 
patterns. 
Any superabsorbent which absorbs large amounts of liquids is suitable for 
use in the absorbing layer of the present invention. 
As mentioned heretofore, the compressed composite containing the 
superabsorbent tends to be stiff and substantially non-flexible. Since the 
end uses of the fibrous web require that the web be soft, flexible and 
pliable, it has been discovered that perf embossing of the composite 
provides the necessary reduction in stiffness without damaging the 
properties of the composite, which are desirable for its end use. 
Frequently, the Taber stiffness of the composite, wherein the absorbent 
layer contains at least 200 percent superabsorbent, exceeds 300 Taber 
stiffness in the machine direction. In the cross-direction the Taber 
stiffness generally exceeds 70. In order to have a product satisfactory 
for use in disposable products such as diapers and sanitary napkins, it is 
necessary to reduce the Taber stiffness value to about 30 or less. The 
Taber stiffness value is obtained in accordance with the procedure found 
at ASTM D 2969 and is expressed in gm/lineal cm. 
The wicking layer is comprised of hydrophilic fibers, such as rayon fibers, 
cellulosic fibers, peat moss, acrylic fibers, or mixtures thereof. The 
cellulosic fibers include wood pulp fibers, cotton linters, and the like. 
The wood pulp fibers generally are those that are used to form the fluff 
or fibrous batt layer in conventional absorbent products such as 
disposable diapers, sanitary napkins, etc. Other cellulosic fibers that 
might be used are rayon fibers, flax, hemp, jute, ramie, cotton and the 
like. The fibers or peat moss or mixtures thereof are placed in such a way 
as to form a layer in which the particles are close to one another so as 
to provide a higher capillary pressure to promote wicking of liquid in the 
plane of the layer. 
What appears to be only a small difference in capillary pressure is all 
that is required for one layer to attract and drain liquid from an 
adjacent layer. The force causing a liquid to enter a cylindrical 
capillary is expressed by the equation: 
EQU P=(2.nu. cos .theta.)/r 
wherein the force is represented by the capillary pressure and 
P is the capillary pressure, 
.nu. is the surface tension of the liquid, 
.theta. is the liquid-fiber contact angle, and 
r is the capillary radius. 
With a given liquid, the pressure (capillary force) increases with the 
cosine of the liquid-fiber contact angle (reaching a maximum where the 
angle is zero) and also increases with narrower capillary radii so that 
narrower capillaries will draw liquid from wider ones. 
The relative wickability between a first fibrous layer and a second layer 
is affected by both the relative densities of the layers and the relative 
wettability of the individual fibers in each layer. The individual fibers 
of the second layer preferably have substantially smaller liquid fiber 
contact angles than those of the first fibrous layer overcoming the 
density difference and providing a significant overall increase in 
capillary pressure to absorb liquid into the second layer. 
The fibers of the second layer of fibers (or particles) and/or the density 
of the layer are selected to create a significant difference in capillary 
pressure from the first fibrous layer. 
The second fibrous (or particle) layer is generally comprised of fibers 
having a lower liquid-contact angle or wherein the layer is provided with 
a narrower capillary radii. Examples of such fibers include hydrophilic 
fibers such as rayon fibers, cellulosic fibers, or peat moss, or mixtures 
thereof, or acrylic fibers, or the like. Cellulosic fibers include wood 
pulp fibers, cotton linters and the like. 
The wood pulp fibers generally are those that are used to form the fluff or 
fibrous batt layer in conventional absorbent products such as disposable 
diapers, sanitary napkins, etc. Other cellulosic fibers that might be used 
are rayon fibers, flax, hemp, jute, ramie, cotton, and the like. The 
fiber, or peat moss, or mixtures thereof are placed in such a way as to 
form a layer in which the particles are close to one another so as to 
promote wicking of liquid in the plane of the layer. 
The wicking layer can be preformed and placed next to the absorbing layer 
before compression or the wicking layer particles can be air-laid, 
mechanically entangled therewith, or wet-laid on to the absorbing layer 
before compression. 
The transition zone is a region formed at the junction of the absorbing 
layer and the wicking layer. Some of the particles, e.g., fibers, of the 
wicking layer extend into and become integral with the absorbing layer. 
The region in which the majority of the extending particles lie is 
identified as the transition zone. In the transition zone, there is a 
composite of absorbing layer fibers, superabsorbent material, and wicking 
layer particles. The wicking layer particles which have extended into the 
absorbing layer are in intimate contact with some of the superabsorbent 
material of the absorbing layer. This permits the liquid to commence its 
migration in the z direction to reach the superabsorbent material. As the 
liquid progresses in the z direction, the superabsorbent material becomes 
soft and releases the absorbing layer fibers which permit the absorbing 
layer or return substantially to its uncompressed thickness or more. As 
the absorbing layer returns to its uncompressed thickness, larger void 
areas are provided for storage of the liquid and for increased swelling of 
the superabsorbent material as it absorbs the liquid residing in the void 
areas. The absorbing layer tends to return to its uncompressed thickness 
or more, probably because of both the resiliency of the fibers and the 
swelling of the superabsorbent material. 
In order for the absorbing layer fibrous web to provide the necessary 
medium for absorbing liquid, it is preferred that the fibrous web has an 
initial dry bulk of at least about 20 cc/gm, a dry bulk recovery of at 
least 30 percent, (preferably 50 percent), a wet bulk of at least about 30 
cc/gm, and a weight of less than about 4 oz/yd.sup.2. The initial dry bulk 
is the area times thickness of the layer under a load of 0.01 pounds per 
square inch calculated in cubic centimeters. This value is divided by the 
weight in grams in order to provide the measurement in cubic centimeters 
per gram. The dry bulk recovery is obtained by subjecting the web to a 
load of 1.75 psi for five minutes, removing the load and allowing the web 
to rest for one minute, subjecting the web to a load of 0.01 psi for one 
minute and then measuring the final dry bulk while under the 0.01 psi 
load. The dry bulk recovery is the final bulk divided by the initial bulk 
expressed in percent. The wet bulk is measured in the same manner as the 
initial dry bulk except that the web has been saturated with water. It has 
been found that if the fibrous web is provided with a dry bulk recovery of 
at least 20 percent (preferably 50%), an initial dry bulk of at least 40 
cc/gm, a wet bulk of at least 30 cc/gm, with a web weight of less than 4 
oz/yd.sup.2, the fibrous web can retain superabsorbent material up to at 
least 1,500 percent of the dry basis weight of the web. It is preferable 
that the web contain 200 percent to 1,500 percent by weight, dry basis, 
superabsorbent to the dry basis weight of the web and most preferred is a 
range from about 400 percent to about 1,200 percent. 
It has been discovered that perf-embossing the absorbent composite defined 
in the present invention results in a flexible, pliable, soft product, 
which retains substantially its original machine direction strength while 
having been mechanically worked in such a way as to improve the absorption 
and reduce the Taber stiffness by at least 75 percent. If the compressed 
composite used in the present invention is simply put through rolls so as 
to crush the structure, the product actually becomes stiffer and has a 
higher Taber stiffness value. It is indeed surprising that the 
perf-embossing which involves crushing and shearing to some degree, 
provides the desired product with a substantial reduction in Taber 
stiffness. 
The compressed composite in its substantially stiff form is reduced in 
moisture content to about 10 percent or less and is then perf-embossed. 
In addition to the tenderizing, softening, and improved flexibility of the 
product, it has been noted that the product absorbs liquid in larger 
quantities than prior to the perf-embossing treatment. Furthermore, the 
quick absorption of liquid by the product is not substantially decreased. 
These qualities are particularly beneficial for a compressed composite 
product used in a disposable diaper. 
An example of a method of preparing the compressed composite of the present 
invention is as follows. This example is not intended to be limiting in 
any way and extensions and modifications thereof without departure from 
the spirit and scope of the invention will become apparent from this 
example. 
EXAMPLE 
An absorbing layer for a compressed composite is formed of 67 percent 
polyester fibers and 33 percent bicomponent fibers. The bicomponent fibers 
have a polyethylene sheath and a polyester core. The web is heat bonded by 
passing air at a temperature of 350.degree. F. through the web for about 
one second or less. The resulting web has a weight of 1.2 oz/sq. yd. The 
web is coated by flooding it with an aqueous solution of sodium acrylate 
and acrylic acid. The solution contains 38 percent solids. Excess solution 
is removed from the web and the web is then subjected to electron beam 
radiation. This electron beam radiation polymerizes the sodium acrylate to 
polysodium acrylate. The web is repeatedly flooded with liquid, the excess 
liquid removed, and each time subjected to irradiation until the amount of 
dry solids add-on of the polysodium acrylate is 10 times the weight of the 
web. 
The polysodium acrylate coated web is passed beneath a Hammermil that 
deposits wood pulp fibers onto the polyester web. Vacuum is applied under 
the polyester web so as to lightly compact the wood pulp fibers onto the 
web. The wood pulp fibers are present in an amount of about 4 oz/sq. yd. 
and a layer of the wood pulp fibers is deposited on each side of the 
polyester web. The surface of the pulp layer is sprayed with water so that 
the total moisture content of the pulp is about 10 percent by weight. The 
total structure is then compressed at a level of 640 psi for 30 seconds. 
Upon release of the pressure, the pulp has formed into a high density 
layer with a capillary size suitable for liquid wicking and the resilient 
fiber layer remains compressed. The product containing about 20 percent 
moisture has a Taber stiffness in the machine direction of about 343, and 
in the cross-direction 75. If the compressed composite is subjected to 
perf-embossing at 20 percent moisture, the Taber stiffness in the machine 
direction increases to about 376 while there is a slight reduction in 
cross-direction Taber stiffness to a value of about 65. In all instances, 
the Taber stiffness values are presented in grams per lineal centimeter of 
the sample. 
The compressed composite containing about 20 percent moisture is dried to a 
moisture content of about 3 percent and subjected to perf-embossing. The 
perf-embossing rolls are set at 0.05 inch engagement with 40 psi. When the 
material is processed at the reduced moisture content in this manner, the 
Taber stiffness in the machine direction is reduced to 30.5 and in the 
cross-direction to 8.0. It can be clearly seen that the stiffness in the 
product is reduced by at least 75 percent in each direction. 
The perf-embossed product exhibits an improved absorbency in that it shows 
a 7 percent increase in absorbency after being perf-embossed. 
In FIG. 6, it is noted that the perf-embossed (PE) sample absorbs liquid 
more quickly than the control sample which had not been perf-embossed. In 
this test of absorbency a GAT device (described in U.S. Pat. No. 4,357,827 
is used at 0.5 psi to determine the absorbency of the samples in given 
time periods. A simulated urine solution (1% NaCl) is used to determine 
the efficiency of the absorbent structure. In products, such as disposable 
diapers, the quick acceptance and absorbency of the liquid is needed. 
From the foregoing, it will be observed that numerous variations and 
modifications may be effected without departing from the true spirit and 
scope of the novel concept of this invention.