U.S. patent application number 10/151579 was filed with the patent office on 2002-12-12 for bonded fluff structures and process for producing same.
Invention is credited to Abuto, Frank Paul, Chang, Kuo-Shu Edward, Gryskiewicz, Stanley Michael, Hadley, Jason Douglas, Jackson, David Martin, Paul, Susan Carol, Schmidt, Richard John, Schwalen, Jerome Joseph.
Application Number | 20020187700 10/151579 |
Document ID | / |
Family ID | 25474692 |
Filed Date | 2002-12-12 |
United States Patent
Application |
20020187700 |
Kind Code |
A1 |
Gryskiewicz, Stanley Michael ;
et al. |
December 12, 2002 |
Bonded fluff structures and process for producing same
Abstract
Bonded fluff structures and a method for producing such bonded
fluff structures in which a pulp sheet having a material suitable
for producing fluff and a heat activatable fiber material is
fiberized to produce a mixture of fluff and heat activatable
fibers. The mixture is contacted with a hot air stream, heating the
heat activatable fibers to an activation temperature. The resulting
heated mixture is then deposited onto a forming structure, forming
a bonded fluff/fiber composite matrix structure.
Inventors: |
Gryskiewicz, Stanley Michael;
(Woodstock, GA) ; Jackson, David Martin; (Roswell,
GA) ; Hadley, Jason Douglas; (Atlanta, GA) ;
Schwalen, Jerome Joseph; (Marietta, GA) ; Abuto,
Frank Paul; (Duluth, GA) ; Chang, Kuo-Shu Edward;
(Roswell, GA) ; Paul, Susan Carol; (Alpharetta,
GA) ; Schmidt, Richard John; (Roswell, GA) |
Correspondence
Address: |
Pauley Petersen Kinne & Erickson
Suite 365
2800 W. Higgins Road
Hoffman Estates
IL
60195
US
|
Family ID: |
25474692 |
Appl. No.: |
10/151579 |
Filed: |
May 17, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10151579 |
May 17, 2002 |
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08940360 |
Sep 30, 1997 |
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6419865 |
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Current U.S.
Class: |
442/361 ;
442/327 |
Current CPC
Class: |
D04H 1/60 20130101; Y10T
442/60 20150401; D04H 1/5416 20200501; A61F 13/531 20130101; Y10T
442/20 20150401; Y10T 442/681 20150401; D04H 1/4291 20130101; D04H
1/5412 20200501; D04H 1/558 20130101; Y10T 442/626 20150401; D04H
1/43832 20200501; D04H 1/43835 20200501; D04H 1/4383 20200501; D04H
1/5414 20200501; D04H 1/5418 20200501; D04H 1/425 20130101; A61F
2013/53035 20130101; Y10T 442/625 20150401; D04H 1/43828 20200501;
D04H 1/544 20130101; Y10T 442/637 20150401 |
Class at
Publication: |
442/361 ;
442/327 |
International
Class: |
D04H 001/00; D04H
003/00; D04H 005/00; D04H 013/00 |
Claims
We claim:
1. A personal care absorbent article, comprising: a liquid pervious
inner layer; a bonded fluff structure adjacent the inner layer, the
bonded fluff structure comprising a fluff material and a heat
activated fiber; and a liquid impervious outer layer adjacent the
bonded fluff structure; wherein the bonded fluff structure has a
basis weight of about 200 grams/meter.sup.2 or less and a tensile
strength of at least about 100 grams.
2. The absorbent article of claim 1, wherein the bonded fluff
structure has a tensile strength of at least about 125 grams.
3. The absorbent article of claim 2, wherein the bonded fluff
structure has a tensile strength of at least about 150 grams.
4. The absorbent article of claim 1, wherein the heat activated
fiber comprises a bicomponent binder fiber.
5. The absorbent article of claim 4, wherein the bicomponent binder
fiber comprises polypropylene and polyethylene polymers.
6. The absorbent article of claim 1, wherein the bonded fluff
structure further comprises a density gradient.
7. The absorbent article of claim 1, wherein the bonded fluff
structure has a three-dimensional shape.
8. The absorbent article of claim 1, wherein the bonded fluff
structure further comprises at least one superabsorbent
material.
9. The absorbent article of claim 1, wherein the bonded fluff
structure is produced by hot air fiberizing a fluff/heat
activatable fiber pulp sheet resulting in formation of a
fluff/fiber mixture and depositing said fluff/fiber mixture onto a
forming structure resulting in formation of a fluff/fiber composite
matrix.
10. The absorbent article of claim 1 comprising a diaper.
11. The absorbent article of claim 1 comprising a feminine care
article.
12. A bonded fluff structure produced by hot air fiberizing a
fluff/heat activatable fiber pulp sheet resulting in formation of a
fluff/fiber mixture and depositing said flufffiber mixture onto a
forming structure resulting in formation of a fluff/fiber composite
matrix, wherein the bonded fluff structure has a basis weight of
about 200 grams/meter.sup.2 or less and a tensile strength of at
least about 100 grams.
13. A bonded fluff structure in accordance with claim 12, wherein
the bonded fluff structure has a tensile strength of at least about
125 grams.
14. A bonded fluff structure in accordance with claim 13, wherein
the bonded fluff structure has a tensile strength of at least about
150 grams.
15. A bonded fluff structure in accordance with claim 12, wherein
the heat activatable fiber comprises a bicomponent binder
fiber.
16. A bonded fluff structure in accordance with claim 17, wherein
the bicomponent binder fiber comprises polypropylene and
polyethylene polymers.
17. A bonded fluff structure in accordance with claim 12, further
comprising a density gradient.
18. A bonded fluff structure in accordance with claim 12, further
comprising a three-dimensional shape.
19. A bonded fluff structure in accordance with claim 12, further
comprising at least one superabsorbent material.
20. A bonded fluff structure in accordance with claim 12, further
comprising at least one odor control material.
21. A disposable diaper comprising: a bonded fluff structure
produced by hot air fiberizing a fluff/heat activatable fiber pulp
sheet resulting in formation of a fluff/fiber mixture and
depositing said fluff/fiber mixture onto a forming structure
resulting in formation of a fluff/fiber composite matrix, wherein
the bonded fluff structure has a basis weight of about 200
grams/meter.sup.2 or less and a tensile strength of at least about
100 grams.
22. A feminine care article comprising: a bonded fluff structure
produced by hot air fiberizing a fluff/heat activatable fiber pulp
sheet resulting in formation of a fluff/fiber mixture and
depositing said fluff/fiber mixture onto a forming structure
resulting in formation of a fluff/fiber composite matrix, wherein
the bonded fluff structure has a basis weight of about 200
grams/meter.sup.2 or less and a tensile strength of at least about
100 grams.
23. A bonded fluff structure produced by hot air fiberizing a
fluff/heat activatable fiber pulp sheet resulting in formation of a
fluff/fiber mixture and depositing said fluff/fiber mixture onto a
forming structure resulting in formation of a fluff/fiber composite
matrix comprising bonded heat activated fibers.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates to bonded fluff structures suitable
for use as an absorbent material in personal care absorbent
articles including diapers, feminine pads, incontinence garments,
and training pants which is required to handle relatively large
amounts of discharged body fluids, especially repeated discharges
of relatively large amounts of fluid in relatively short periods of
time, and a method for producing the same. More particularly, this
invention relates to a fiberization process for producing such
bonded fluff structures. In addition, this invention relates to a
method for producing three-dimensional and density gradient bonded
fluff structures for use in personal care absorbent articles.
[0003] 2. Description of Prior Art
[0004] Personal care absorbent products such as diapers, feminine
pads, adult incontinence products, and training pants often include
a layer of absorbent material and a backing layer or moisture
barrier which is impervious to fluid. The absorbent material
includes a surface for contacting the body of the user so that body
fluids are absorbed into the product and are contained by a
moisture barrier.
[0005] Such absorbent materials are frequently formed as nonwoven
fibrous webs, for example, fluff/binder/superabsorbent composite
matrix structures. In order to maintain proper integrity when
adhered to distribution materials to allow undisrupted capillarity
across the boundary between such absorbent material structures and
the distribution materials, and through the absorbent structure, it
is necessary to bond the absorbent structure.
[0006] Conventionally, the body contacting surface of the absorbent
materials in personal care absorbent articles is substantially flat
and uniform. There are, however, several advantages to using a
textured body contacting surface, such as a greater absorbent
surface area and improved anatomical fit. The method of this
invention is suitable for forming contoured fibrous webs or pads
which have an increased weight of material in selected regions.
When forming pads of absorbent material, the regions having the
greater weight of material generally have a corresponding greater
degree of absorbency. Such contoured absorbent pads are
particularly useful in articles that are subjected to a greater
fluid loading in certain "target" areas than in other areas. For
example, in a baby diaper comprised of an absorbent bat or pad
located between a liquid pervious inner layer and a liquid
impervious outer layer, the crotch and front areas of the diaper
are more heavily wetted by the infant than the areas closer to the
infant's waist or back. A similar situation may also arise in the
case of wound dressings, incontinence garments, and feminine
sanitary napkins.
[0007] Developments in nonwoven technology have made tremendous
strides over the past several years. Today, there exists a wide
variety of technologies for forming nonwoven materials including
meltblowing, spunbonding, melt spinning, solution spinning,
carding, melt spraying, and wet/dry air laying. Many of these
technologies are used individually to form single component
materials. As an example, spunbonding is used to form nonwoven
materials which can be used in such articles as workwear and
personal care products including diapers. Meltblowing can be used
to generate fine pore structures adaptable for use as filter media
or absorbents for oil and other liquids. Air laying can be used to
form such products as fibrous wood pulp bats for use as absorbents
in diapers and sanitary napkins. In contrast to such processes
which produce single component materials, the method of this
invention is suitable for producing multicomponent materials.
[0008] Diaper dermatitis is a skin condition resulting from the
prolonged contact of wet occlusive diapers with the skin of the
wearer. This prolonged contact can lead to excessive hydration of
the outermost skin layer, thereby reducing the skin's ability to
function as a barrier. As a result, there is an increase in the
permeation of irritants, susceptibility of the skin to physical
damage, and invasion of the skin by microorganisms. Maintaining a
normal skin hydration level helps the skin maintain its optimum
barrier properties. Thus, it is important that personal care
absorbent articles, to the extent possible, prevent excessive skin
hydration while containing body exudates and providing a soft, dry
and comfortable feel to the wearer.
[0009] Current occlusive absorbent garments with flap liners hold
body exudates against the skin of the wearer. Heat and moisture are
prevented from escaping from the product due to the close fitting
nature of the product designed to prevent leakage. This problem is
most severe in the insult region of personal care absorbent
products. The flat liner provides a high contact area with the skin
which can act as a pathway to conduct back to the skin free liquid
that is not locked up by the absorbent core, especially when the
product is under pressure at the insult point, because the flat
liner cannot provide a sufficient degree of separation of the
wearer from the free liquid. In addition, flat liners do not allow
the insult region of the personal care absorbent product to
communicate with the ambient air to allow humidity to be reduced in
the insult region as well as away from the insult region.
[0010] There are a number of methods known to those skilled in the
art for addressing these problems including the use of breathable
back sheets, waist vents, and leg vents. However, these methods
suffer from a variety of deficiencies which render them less
effective than desired. For example, waist and leg vents through
the back sheet tend to either be occluded against the skin or
provide leakage pathways. Other known methods include the use of
folded absorbent cores or layers under the liner to dry the liner.
However, these methods require undesirable process options and
economics. Three-dimensional absorbent fabrics, such as those
produced in accordance with the method of this invention, can be
used to address these issues.
SUMMARY OF THE INVENTION
[0011] Accordingly, it is one object of this invention to provide a
method for bonding of fiber structures which maintain proper
integrity when adhered to distribution materials so as to allow
undisrupted capillarity across the distribution/fibrous structure
boundary.
[0012] It is another object of this invention to provide a method
of in-situ matrix bonding of fibrous structures using conventional
product conversion machines without the addition of lengthy through
air bonding ovens.
[0013] It is another object of this invention to provide an
absorbent material for use in personal care absorbent articles,
such as diapers and sanitary pads, having a density gradient.
[0014] It is yet another object of this invention to provide a
bonded three-dimensional fluff structure for use in personal care
absorbent articles.
[0015] These and other objects of this invention are achieved by a
method for producing bonded fluff structures by which a pulp sheet
comprising a material suitable for producing fluff and a heat
activatable fiber material is fiberized, producing a mixture of
fluff and heat activatable fibers. The mixture of fluff and heat
activatable fibers is then contacted with a hot air stream at a
flow rate and temperature sufficient to activate the heat
activatable fibers without agglomeration of the mixture. The heated
mixture is then deposited onto a forming structure, such as a
forming wire, resulting in formation of a bonded fluff/fiber
composite matrix structure.
[0016] In accordance with one embodiment of the method of this
invention, the bonded fluff/fiber composite matrix structure is
further processed in a manner which imparts a density gradient into
the structure, for example, by passing the bonded fluff/fiber
composite matrix structure through an embosser.
[0017] In accordance with another embodiment of the method of this
invention, the bonded fluff/fiber composite matrix structure is
shaped to form a bonded three-dimensional fluff structure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] These and other objects and features of this invention will
be better understood from the following detailed description taken
in conjunction with the drawings wherein:
[0019] FIG. 1 is a schematic diagram of the hot air fiberization
process used to produce the bonded fluff/fiber composite matrix
structures in accordance with one embodiment of this invention;
and
[0020] FIG. 2 is a schematic diagram showing a bonded fluff/fiber
composite matrix structure comprising a density gradient in
accordance with one embodiment of this invention.
DEFINITIONS
[0021] As used herein, the term "nonwoven web" means a web that has
a structure of individual fibers or threads which are interlaid,
but not in an identifiable, repeating manner. Nonwoven webs have
been, in the past, formed by a variety of processes such as, for
example, melt-blowing processes, spunbonding processes, and bonded
carded web processes.
[0022] As used herein, the term "polymer" generally includes, but
is not limited to, homopolymers, copolymers, such as for example,
block, graft, random and alternating copolymers, terpolymers, etc.,
and blends and modifications thereof. Furthermore, unless otherwise
specifically limited, the term "polymer" includes all possible
geometrical configurations of the material. These configurations
include, but are not limited to, isotactic, syndiotactic, and
random symmetries.
[0023] As used herein, the term "bicomponent fibers" refers to
multicomponent fibers of various configurations including, but not
limited to, side-by-side, core and sheath, pie segments, and
islands in the sea configurations.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0024] The method for producing bonded fluff structures in
accordance with one embodiment of this invention comprises
fiberizing a pulp sheet comprising a material suitable for
producing fluff and a heat activatable fiber material resulting in
formation of a mixture of fluff and heat activatable fibers. By the
term "heat activatable" we mean a fiber which tackifies upon
heating. Suitable materials for producing fluff include, but are
not limited to, cellulosic materials. Any heat activatable
polymeric fiber may be used to produce the bonded flufffiber
composite matrix structure of this invention. A particularly
preferred heat activatable fiber is a polypropylene/polyethylene
polymer bicomponent binder fiber. Such bicomponent binder fibers
tackify at a temperature of less than about 550.degree. F.
(288.degree. C.), more particularly less than about 350.degree. F.
(177.degree. C.).
[0025] After formation of the mixture of fluff and heat activatable
fibers, the mixture is contacted with a hot air stream having a
flow rate and a temperature sufficient to activate the heat
activatable fibers. The heated mixture is then deposited onto a
forming structure, such as a forming wire, resulting in formation
of the bonded fluff/fiber composite matrix structure. The bonded
fluff/fiber composite matrix structure is then densified, for
example, in a nip. In accordance with one preferred embodiment of
the method of this invention, prior to densifying, the bonded
fluff/fiber composite matrix structure is further treated with a
hot air knife to maintain the temperature of the structure at a
desired level until it reaches the nip. A hot air knife, used for
pre- or primary bonding a just produced microfiber to give it
sufficient integrity, is a device which focuses a stream of heated
air at a very high flow rate, generally from about 1000 to about
10000 feet per minute (fpm) (305 to 3050 meters per minute), or
more particularly from about 3000 to 5000 feet per minute (915 to
1525 m/min.) directed at the nonwoven web immediately after its
formation. The air temperature is usually in the range of the
melting point of at least one of the polymers used in the web,
generally between about 200 and 550.degree. F. (93 and 290.degree.
C.) for the thermoplastic polymers commonly used in spunbonding.
The control of air temperature, velocity, pressure, volume and
other factors helps avoid damage to the web while increasing its
integrity. The hot air knife's focused stream of air is arranged
and directed by at least one slot of about 1/8 to 1 inches (3 to 25
mm) in width, particularly about 3/8 inch (9.4 mm), serving as the
exit for the heated air towards the web, with the slot running in a
substantially cross-machine direction over substantially the entire
width of the web. In other embodiments, there may be a plurality of
slots arranged next to each other or separated by a slight gap. The
at least one slot is usually, though not essentially, continuous,
and may be comprised of, for example, closely spaced holes. The hot
air knife has a plenum to distribute and contain the heated air
prior to its exiting the slot. The plenum pressure of the hot air
knife is usually between about 1.0 and 12.0 inches of water (2 to
22 mmHg), and the hot air knife is positioned between about 0.25
and 10 inches and more preferably 0.75 to 3.0 inches (19 to 76 mm)
above the forming wire.
[0026] The use of hot air during fiberization of fluff/bicomponent
binder fiber pulp sheets activates the bicomponent fibers, thereby
increasing the strength of the resulting composite matrix
structure.
EXAMPLE
[0027] CR-54 pulp from U.S. Alliance Forest Products of Coosa
Pines, Ala. and Danaklon ES-C polypropylene/polyethylene 2.0 dpf
(denier per fiber), 6 mm bicomponent binder fibers from Danaklon
a/s of Varde, Denmark were wet formed into pulp sheets. One of the
sheets from this matrix of materials, 90% by weight CR-54/10% by
weight Danaklon binder fiber, was fiberized on a six-inch
continuous energy transfer (CET) fiberizer to produce a bonded
fluff/fiber composite matrix structure. Although the process of
this invention is described in terms of a CET fiberizer, there is
no intention to limit the type of fiberizer used to produce the
fluff/fiber mixture. Thus, for example, a hammermill fiberizer may
be employed as opposed to a CET fiberizer. FIG. 1 is a schematic
diagram of the hot air fiberization method of this invention
utilizing a continuous energy transfer fiberizer. In this method,
500 cubic feet per minute of hot air was fed into a Chromalox 125
kilowatt air heater which was subsequently divided into two air
sources that feed the fiberizer, tangential and stripper air. The
temperatures and pressures at which this process was carried out
are shown in Table 1:
1TABLE 1 Temperature Ranges Used During the Trial All Temperatures
are in deg. F. Air Heater Temperature 609-633 deg. F. CET Outlet
Temperature 330-350 deg. F. Down Stream Air Temperature 500-522
deg. F. Air pressure 3.2 psig. Forming Chamber Temperature 388-393
deg. F. Air Knife Temperatures 310-355 deg. F.
[0028] FIG. 1 is a schematic diagram of the continuous energy
transfer fiberizer, in very general terms, used to form the bonded
fluff/fiber composite matrix structure of this invention. CET
fiberizer 10 comprises forming chamber 11 which contains the
mixture of fluff and heat activatable fibers used in the formation
of the composite matrix structure. Compressed air from a compressor
(not shown) is heated in air heater 12 to a temperature in the
range of about 350-700.degree. F. 177-371 .degree. C.). The heated
air is introduced through CET outlet 15 at a temperature of about
330-350.degree. F. (165-177.degree. C.) into forming chamber 11.
The heated mixture of fluff and heat activatable fibers in forming
chamber 11 is deposited onto collection or forming surface 14. As
shown in FIG. 1, forming surface 14 is in the form of a continuous
loop foraminous wire which travels in the direction of arrow 18. It
will, however, be apparent to those skilled in the art that the
collection/forming surface 14 may take other forms, such as the
form of a rotating drum. Forming surface 14, as shown in FIG. 1,
travels in the direction of arrow 18 about a pair of rollers 16,
17, either one or both of which may be driven. If desired, the
speed of forming surface 14 can be variably driven so that the line
speed can be controlled in relation to the deposition rates of the
heated mixture of fluff and heat activatable fiber.
[0029] As previously stated, Table 1 shows the temperatures and
pressures used during sample collection. The temperature of air
heater 12 was about 609-633.degree. F.; the temperature at the CET
outlet 15 was about 330-350.degree. F.; the temperature in forming
chamber 11 was in the range of about 388-393.degree. F. (198-201
.degree. C.); and the temperature of hot air knife 13 was in the
range of 310-355.degree. F. (154-179.degree. C.). Samples were
collected from the forming surface and pressure was placed on the
materials by hand from a roller. Tensile strengths of the resulting
material were measured, the results of which are shown in Table
2.
2 TABLE 2 Heated-Air Sample Control Tensile Strengths Tensile
Strength 200 g/m.sup.2 web 200 g/m.sup.2 web (Grams) (Grams) 59.2
157.92 59.2 177.66 78.96 157.92 98.7 177.66 74.01 ave. 167.79
ave.
[0030] As can be seen, tensile strengths for the bonded fluff/fiber
composite matrix structure produced in accordance with the method
of this invention using hot air fiberization were significantly
higher than the control material, thereby clearly establishing that
the heat activatable fibers were fused during fiberization. Indeed,
tensile strengths for the hot-air formed samples were more than two
times higher than tensile strengths of the samples formed without
heated air. It is, thus, apparent that the method of this invention
enables in-situ matrix bonding of fiber structures on conventional
product converting machines without the addition of lengthy through
air bonding ovens.
[0031] The bonded fluff/fiber composite matrix structure of this
invention contains interfiber bonds throughout the structure. The
temperature in the forming chamber 11 should be high enough to
activate, that is tackify, the heat activatable fibers. The melted
or heat activated fibers form substantially uniform interfiber
bonds throughout the matrix structure, particularly at the fiber
crossover contact points, providing a nonwoven web that is soft and
strong. Illustrative articles that can be produced using the
composite matrix structure of this invention include personal care
absorbent products and components thereof, such as body-conforming
sanitary napkin shells over an absorbent core, shape-retaining
diaper components, incontinent care products, and the like.
[0032] Suitable polymers for use in the composite matrix structure
of this invention are selected from the group consisting of
polyolefins, polyamides, polyesters, polycarbonates, polystyrenes,
thermoplastic elastomers, fluoropolymers, vinyl polymers, and
blends and copolymers thereof. Suitable polyolefins include, but
are not limited to, polyethylene, polypropylene, polybutylene, and
the like.
[0033] Absorbent personal care articles such as sanitary napkins,
disposable diapers, incontinent-care pads and the like are widely
used, and much effort has been made to improve the effectiveness
and functionalities of these articles. Thick, flat, personal care
articles of the past that do not fit the shape of the human body
and do not conform to the movements of the user have been largely
replaced by resiliently conforming three-dimensional, body-shaped
articles.
[0034] In accordance with one embodiment of the method of this
invention, the bonded fluff/fiber composite matrix structure is
shaped to form a bonded three-dimensional fluff structure. In
particular, after the bonded fluff/fiber composite matrix structure
exits forming chamber 11, it can be deposited onto a
three-dimensional surface as is taught, for example, by U.S. Pat.
No. 4,761,258. Through vacuum control and a male or female assist
device, the bonded fluff/fiber composite matrix structure can be
contoured to readily accept exudates. The resulting structure is
resilient and holds its shape. In accordance with a further
embodiment, a film layer can be applied during this process to
allow formation of a product with a cavity. The structures produced
in accordance with this embodiment are suitable for feminine care
devices and BM inserts.
[0035] In accordance with another embodiment of the method of this
invention, the bonded fluff/fiber composite matrix structure is
further processed in a manner which imparts a density gradient into
the bonded fluff/fiber composite matrix structure. For example,
after the fluff is deposited onto forming surface or forming wire
14, it can then be passed through an embosser which imparts a
density gradient into the structure. In particular, an insert can
be a fluff/superabsorbent material (SAM)/fiber composite and be
configured less dense in the target zone and more dense as one
moves away from this zone, thereby enabling fluid to be rapidly
received and spread through the increasing dense regions. Because
the structure is resilient, the intake area is ready for subsequent
insult due to the fluid draining from this structure, through
in-plane wicking and transfer and/or deposition into an underlying
structure. Such a density gradient structure is shown is FIG.
2.
[0036] In accordance with one embodiment of the method of this
invention, additional materials may be introduced into forming
chamber 11 so as to provide the resulting composite matrix
structure with additional desired features. For example, in
accordance with one embodiment, a superabsorbent material is added
to the fluff/fiber mixture in forming chamber 11. In accordance
with another embodiment of this invention, an odor control material
is added to the fluff/fiber mixture. It will be apparent to those
skilled in the art that other additions which impart a variety of
characteristics to the end product may also be incorporated into
the fluff/fiber mixture.
[0037] While in the foregoing specification this invention has been
described in relation to certain preferred embodiments thereof, and
many details have been set forth for purpose of illustration, it
will be apparent to those skilled in the art that the invention is
susceptible to additional embodiments and that certain of the
details described herein can be varied considerably without
departing from the basic principles of the invention.
* * * * *