FIELD OF INVENTION
[0001] The invention is directed to a method for making a nonwoven material including forming
at least one layer of continuous filaments and subjecting the layer(s) to hydroentanglement
in the absence of any prebonding of the continuous filaments in the layer(s) prior
to being subjected to hydroentanglement, as well as the nonwoven material made thereby.
The nonwoven material has improved physical properties such as increased tensile and
elongation properties, hand and drape, very low surface linting, etc. The nonwoven
material provided is preferably spunlaid or meltblown or is a composite and can be
present as a single layer or as one or more layers in a multi-layer nonwoven material.
The material of the invention is in particular useful in personal care absorbent products,
such as feminine hygiene products, diapers, adult incontinence products, etc., as
well as for dry or wet wipes, medical products which come in contact with skin, and
the like.
BACKGROUND OF THE INVENTION
[0002] Hydroentangled nonwoven webs and processes for making such webs are known in the
art. In conventional processes, the process is usually limited by one or more critical
parameters in order to provide a nonwoven product having a desired characteristic
or quality dictated by the use to which the material is to be applied. In particular,
prior art hydroentanglement processes require some type of prebonding of the filaments
or fibers prior to being subjected to hydroentanglement. This adds to the time and
cost of the process, but also affects the properties of the resulting nonwoven material,
in particular as to the softness and durability of the material. Examples of known
hydroentanglement processes are as follows:
- U.S. Patent No. 5,023,130 describes a process for water jet entangling continuous
filament fibers to form a web wherein the combination of the water jet pressure and
total impact energy provided by the water jets is controlling for producing a nonwoven
web suitable for producing durable comfortable apparel. At column 4, lines 4-9, the
patent teaches that "lightly consolidated webs" are suitable for use in the described
process.
- EP 0 333 211 B1 describe nonwoven fibrous hydraulically entangled web materials formed
from a laminate of at least one layer of meltblown fibers and at least one layer of
nonwoven fibrous material such as pulp fibers, staple fibers, meltblown fibers, continuous
filaments, nets, foams, etc. Conventional hydraulic entangling techniques are disclosed
as being suitable for use.
- EP 0 333 228 B1 describes hydraulically entangled nonwoven fibrous material formed
by entangling a coform of an admixture of non-elastic meltblown fibers and fibrous
material.
- U.S. Patent No. 3,508,308 describes a jet treatment apparatus for producing entangled
nonwoven fabrics involving supporting a layer of fibrous material on a smooth supporting
member and subjecting the layer to multiple high pressure water jets. The layer of
fibrous material is staple fibers or continuous filaments in the form of mats, batts,
webs and the like, including layered composites or blends.
- International Published Application WO 01/51693 A1 discloses an apparatus and method
for continuously producing a multi-layer nonwoven fabric. The process involves sandwiching
a first web of cellulosic fibers between two webs of spunlaid filaments. Consolidation
of the resulting complex is then by hydroentanglement.
- U.S. Patent No. 5,801,107 describes a nonwoven fibrous material of pulp fibers which
are loosened and rearranged by low energy jets of liquid so that the nonwoven material
can absorb, transport and release liquid. The material is provided with a defined
porosity.
- U.S. Patent No. 6,163,943 describes nonwoven material based on a foam-formed fibrous
web, staple fibers and a layer of continuous filaments which are hydroentangled together
to form a composite material.
- International Published Application WO 01/53588 describes a nonwoven composite material
made from at least one spunbonded woven fiber and wood pulp layer. The nonwoven fiber
is compressed or calendered as a prebonding treatment prior to being subjected to
hydrodynamic water needling.
- U.S. Patent No. 6,321,425 B1 describes a hydroentangled nonwoven fabric. The precursor
web used to form the nonwoven fabric is subjected to compression and light bonding
prior to hydroentanglement in order to facilitate handling of the web.
- U.S. Patent No. 5,151,320 describes a hydroentangled spunbonded composite fabric formed
from a base web which is a prebonded web made from continuous filaments.
[0003] The conventional processes as known in the art produce nonwoven materials having
strength in the tensile direction but not in the cross-direction. When the material
is pulled in a cross-direction, the material will stretch and ultimately tear. Thus,
a nonwoven material having both good tensile and cross-directional strengths is desirable,
as well as a consolidated continuous process for producing such material. The ability
to provide such improved material from a single raw material, in a continuous process
in particularly being capable of pre-formation treatment or post-formation treatment
to affect physical properties of the material, is desirable.
OBJECTS OF THE INVENTION
[0004] Accordingly, a primary object of the present invention is to provide a method for
making a nonwoven material utilizing hydroentanglement as a means of bonding thereby
eliminating the need for thermal bonding or chemical bonding agents, and a nonwoven
material having improved strength.
[0005] More particularly, it is an object of the invention to provide a single layer or
multi-layer nonwoven material having improved cross-directional strength made in a
continuous in-line process wherein at least one layer of spunlaid or meltblown continuous
filaments are bonded together by hydroentanglement in the absence of any prebonding
such as by chemical, thermal compression, needling, calendering or the like.
[0006] It is a further object to provide a process for forming a nonwoven product from at
least one layer of spunlaid or meltblown continuous filaments which require no prebonding
treatment prior to being subjected to hydroentanglement by a plurality of high pressure
water jets which can control the properties obtained in the resulting product.
[0007] It is a further object that the continuous filaments of each layer present are made
from a thermoplastic polymer, preferably a polyolefin or polyester, and most preferably
polypropylene.
[0008] A further object is to provide a nonwoven material with improved tensile and elongation
properties, in particular increased strength in the cross-direction, so that the material
is suitable for processing and use as a barrier for solids, such as superabsorbent
polymers (SAPs) as used in diapers, adult incontinence products, feminine hygiene
products and the like.
[0009] A further object is to alter one or more physical characteristics of the nonwoven
material, such as the fluid handling property (e.g. hydrophobicity and hydrophilicity)
of at least a portion of the nonwoven material, flame retardancy, absorbency, antistatic
nature and the like, by incorporating one or more components into the nonwoven material,
such as an additive added to an extruder polymeric melt or topical application to
the resulting hydroentangled nonwoven material.
BRIEF DESCRIPTION OF THE INVENTION
[0010] A durable improved strength hydroentangled single layer or multi-layer nonwoven material
is described. The nonwoven material is formed from at least one layer of continuous
filaments, which are preferably spunlaid or meltblown, and the filaments are bonded
by hydroentanglement in the absence of any prebonding of the filaments prior to being
subjected to hydroentanglement. The filaments are preferably of a thermoplastic polymer,
more preferably a polyolefin or polyester, and most preferably polypropylene. Certain
properties of the nonwoven material, such as phobicity, philicity, flame retardancy,
absorbency, antistatic nature, etc. can be imparted to or changed in the nonwoven
material by including a suitable additive in the polymer to be extruded during production
of the one or more layers of filaments, or by topically treating the resulting nonwoven
material following hydroentanglement. For example, an additive or topical treating
to affect hydrophilicity involves the use of a surfactant.
[0011] The process of the invention provides a nonwoven material having improved tensile
and elongation properties as well as an improved hand. Notably the nonwoven material
is provided with a cottony velveteen feel. The improved properties are obtained by
provision of the spunlaid or meltblown layer(s) from continuous filaments in a continuous
in-line process which includes hydroentangling the continuous filaments as part of
the in-line process without any prebonding of the filaments. The process of the invention
allows for the use of a single raw material, such as polypropylene, and avoids the
necessity of using staple fibers. Staple fibers require a separate process of manufacture,
interim storage and subsequent incorporation into another process to make a final
product. Staple fibers were believed necessary for use in conventional processes to
obtain hydroentangled fibers since it was believed necessary to have defined end structures
to obtain the desired knotting during hydroentanglement to achieve bonding of the
fibers. The process of the invention allows for the use of continuous filaments, thereby
allowing for a continuous in-line process of production and treatment by hydroentanglement
to join or bond the filaments together.
[0012] More in particular, a desired spunlaid or meltblown layer (or layers) is (are) produced
by a conventional method for producing continuous filaments. The continuous filaments
are laid onto a moving support, e.g. a moving mesh screen or a series of moving supports.
e.g. perforated godet rollers. When a multi-layer material is being produced, second
and subsequent layer(s) are laid sequentially upon the prior formed layer(s) on the
moving support. The layer or layers then are subjected to hydroentanglement. No prebonding,
e.g. by heat, compression, calendering, chemical or the like, is utilized. The moving
support is structured to extend or transfer the layer or layers to the hydroentanglement
equipment such that the layer(s) is essentially continually supported to the hydroentanglement
apparatus. This serves to maintain the structure of the layer(s) and allow direct
impact of water on the layer(s) from the plurality of high pressure water jets providing
the hydroentanglement while avoiding flying apart of the layer(s) when the water hits
the layer(s).
[0013] In the hydroentanglement process, a plurality of water jets are positioned above
the moving support(s). The moving support(s) is preferably structured to allow for
drainage of the water. The screen mesh or perforations in the godet rollers preferably
have openings with a diagonal in the range of from about 0.1 to 2.0 mm. The number
of water jets present and the pressure at which the water is ejected are critical
in determining the properties obtained in the treated nonwoven material. The water
jets are positioned so as to be spaced apart and provide about 50 water jets per linear
inch. The water jets are arranged to cover the width of the layer(s) being treated.
A single line or a plurality of lines of water jets may be used. The support(s) for
the layer(s) moves at a speed generally in a range of about 20 to 250 meters per minute.
Thus, adequate exposure to the water jets is provided. Water is fed under pressure
through nozzles, preferably at a pressure of from about 20 to 250 bar. Nozzle orifice
diameters can be from about 0.1 to 0.2 mm to provide the desired sized water streams.
A preferred combination of number of water jets, pressure and orifice size is as follows:
number of jets 25 to 50 per linear inch, pressure about 20 to 200 bar, and orifice
size about 0.1 to 0.2 mm. If a material with looser filament structure is desired,
the parameters are as follows: number of jets 25 to 50, pressure about 20 to 150 bar
and orifice size about 0.1 to 0.2 mm. If a material with a tight filament structure
is desired, the parameters are as follows: number of jets 30 to 50, pressure about
50 to 250 bar and orifice size about 0.1 to 0.2 mm.
[0014] The filament content of the nonwoven material is preferably of high density in order
to prevent movement or migration of solids from one side to another of the material
while at the same time allowing fluids to move through quickly based on additive or
topical treatment with a surfactant. More particularly, the basis weight of the overall
nonwoven material is preferably about 17 to 150 gsm (grams per square meter). In a
multi-layer nonwoven material, each layer is preferably from about 8 to 80 gsm as
to basis weight.
[0015] The hydroentangled nonwoven material will be hydrophobic when made from a thermoplastic
polymer, such as polypropylene. To render the hydroentangled nonwoven material hydrophilic,
which is a desired property in many conventional uses of nonwoven materials, a surfactant
can be incorporated into the material. A suitable surfactant for use as an additive
in a polymer melt is STANDAPOL™ 1353A or 1480, as sold by Cognis Deutschland GmbH,
Dusseldorf, Germany, which are each a fatty ester. A preferred surfactant for topically
treating the formed hydroentangled nonwoven material is STANTEX® S 6327, as sold by
Cognis Deutschland GmbH, which is a blend of fatty acid esters. An example of a suitable
topical treatment for imparting hydrophilicity to the nonwoven material is as described
in U.S. Patent Nos. 5,709,747 and 5,885,656, the disclosure of each patent being incorporated
herein by reference. The surfactant is preferably present in the nonwoven material
in an amount of from about 0.2 to 3.0 wt.%.
[0016] The nonwoven materials of the invention are useful in a wide variety of applications.
For example, the nonwoven material is useful as a component of absorbent products
such as disposable diapers, feminine hygiene products, adult incontinence products;
medical products which contact the human skin such as surgical gowns and masks; disposable
dry or wet wipes (both plain and impregnated dry wipes); industrial garments; filtration
media; etc. The nonwoven material of the invention is in particularly well suited
for those applications requiring both high strength and soft hand feel. The nonwoven
material is also suitable for use as a barrier layer for retaining solids within a
desired location, e.g., SAPs in diapers, adult incontinence products and feminine
hygiene products. Continuous filament spunmelt webs subjected to water jet bonding
have improved wet strength properties making the material in particularly useful in
wet wipe applications, such as baby wipes, hard surface cleaning wipes, general purpose
solution-containing wipes, specialty wipes having graphics applied thereto, and the
like. Dry wipes include static dusting wipes or mops and wipes impregnated with a
substance which is activated on addition to water.
[0017] The nonwoven material of the invention, following hydroentangling, further can be
provided with a pattern, such as by conventional embossing or the like, to provide
aesthtic appeal and/or enhancing fluid absorption, fluid retention, and fluid channeling
characteristics in the nonwoven material.
BRIEF DESCRIPTION OF DRAWING
[0018]
FIGURE 1 is a schematic of a process for producing nonwoven material according to
the invention.
FIGURE 2 is a schematic of a preferred support for use during transfer and hydroentanglement
and a positioning of water jets in relation thereto.
DETAILED DESCRIPTION OF PRESENTLY PREFERRED EMBODIMENTS
[0019] The hydroentangled nonwoven material provided by the process of the invention includes
at least one layer of continuous filaments or fibers bonded by hydroentanglement in
the absence of any prebonding of the filaments. The nonwoven material can be a single
layer or multi-layer and include a combination of spunlaid and/or meltblown filament
layer(s). The filaments forming the at least one layer are polymeric and continuous.
The filaments can be made using conventional extrusion apparatus and techniques. The
invention avoids the use of staple fibers. Preferably when a single layer, the nonwoven
material is spunlaid. The hydroentangled nonwoven material of the invention has a
superior tensile and elongation properties as compared to hydroentangled nonwoven
materials made from staple fibers.
[0020] To provide a nonwoven material with high strength in the machine direction and cross-direction
as well as having improved processability, both during manufacture and after manufacture,
the hydroentangled nonwoven material preferably has a basis weight of about 17 to
150 gsm. More preferably the nonwoven layer has a basis weight of from about 25 to
100 gsm, most preferably from about 30 to 70 gsm.
[0021] The filaments of the layer(s) is (are) made of a thermoplastic polymer. Suitable
polymers include polyolefins such as polypropylene and polyethylene; polyesters such
as polyethylene terephthalate; polyamides; polyacrylates; polystyrene; thermoplastic
elastomers; and blends of these and other known fiber forming thermoplastic materials.
The preferred useful polymer is polypropylene. If the nonwoven material is multi-layer,
each layer is preferably of the same polymeric material. The process of the invention
is advantageous for providing improved physical properties while using one raw material
and an in-line continuous process to obtain the desired product.
[0022] The denier size of the filaments is effective to alter physical properties of the
resulting material. Preferably the denier size is about 0.8-5 dpf to provide a nonwoven
material of desired strength.
[0023] Various physical properties, such as hydrophilicity, can be imparted to at least
one portion of or completely to the hydroentangled nonwoven material depending on
the use to which the nonwoven material is to be applied. At least one portion of the
nonwoven material includes where one or more layers in their entirety are modified
as to a given property, or any preselected portion or one or more of the layers have
a preselected area thereof modified as to a preselected property. The manner of imparting
a particular property to the nonwoven material can be based on the inclusion of an
additive in the polymer melt or by topical treatment. This will be further evident
from the description below of the method of making the nonwoven material. Properties
which can be affected include fluid phobicity, fluid philicity, fire retardancy, absorbency,
softness, antistatic nature, etc.
[0024] The method of the invention for making a nonwoven material will be described in relation
to the figures. An advantage of the method of the invention is the provision of a
single layer or multi-layer nonwoven material in a process which combines the manufacture
of continuous thermoplastic polymer filaments, the formation of a layer therefrom
and, if desired, the combining of multiple layers, and thereafter treating along the
same processing line, without any prebonding of the filaments, of the layer or layers
with a plurality of water jets to provide a bonded nonwoven material with improved
strength and feel. This improves on conventional multi-stage processes wherein staple
fibers are made by a first process, stored and subsequently used to form a product
in a separate process, or a first layer is made and then processed for storage or
use in another process. The conventional processes require multiple lines and stages
which necessarily include lost or down time between processing stages. The invention
provides for a consolidated continuous process in terms of space, time, material storage,
etc. Additionally, savings are achieved by not requiring prebonding equipment or processing
prior to hydroentanglement.
[0025] With reference to FIGURE 1, a moving support 1 (which can be a belt, mesh screen,
or the like) moving continuously along rollers 3 is provided beneath the exit orifices
for one or more extruders, illustrated for example as extruders 5, 7 and 9. Extruder
5 receives a polymeric melt which is extruded through a substantially linear diehead
11 to form a plurality of continuous filaments 13 which randomly fall to the moving
support 1 to form a layer 15, preferably, of spunlaid fibers thereon. The extrusion
process parameters used are conventional and as known to one skilled in the art. The
diehead includes a spaced array of die orifices having diameters of preferably about
0.1 to about 1.0 millimeters (mm). The continuous filaments following extrusion are
quenched, such as by cooling air.
[0026] Positioned downstream in relation to the moving support 1 in the processing direction
can be additional extruders, 7 and/or 9 for example, for providing continuous filaments
17 and/or 21, which can be, for example, spunlaid or meltblown. Extruders 7 and 9
can make additional continuous filaments as described in relation to continuous filaments
13. Filaments 17 and 21 randomly fall to moving support 1 and are laid atop a preceding
deposited layer to form superposed layers 19 and 23, respectively. Thus, if desired,
along one continuous line a multi-layer nonwoven material can be provided using continuous
filaments.
[0027] The single layer or stacked layers are then joined or bonded together to form a coherent
material by hydroentanglement utilizing a plurality of water jets 25 such as illustrated
in FIGURES 1 and 2. Prebonding, such as conventional compression, thermal bonding,
calendering or the like, of the layer(s) together to provide interlocking of the filaments
is not required. Hydroentanglement therefore is conducted in the absence of conventional
processes such as thermal bonding, chemical bonding, adhesive bonding, mechanical
punch needling and the like, to provide a nonwoven material having acceptable physical
properties, and in fact superior tensile and elongation properties as compared to
nonwoven materials based on hydroentangled staple fibers.
[0028] The process of the invention provides hydroentanglement of continuous filaments.
In conventional processes of hydroentanglement, staple fibers are used in order to
provide free end structures capable of providing knotting upon being subjected to
water jets. Conventional processes provide nonwoven material which have adequate strength
in the tensile direction but not in the cross-direction. Thus, upon being subjected
to stretching, conventional nonwoven materials will tear. The present invention provides
for hydroentanglement of continuous filaments resulting in a finished product with
improved cross-directional strength and improved feel. The finished product has a
cottony velveteen feel. Further, the raw material used can be the same for each layer
present in the product. This additionally results in a very economic process and thus
economically advantageous product. If desired, other filaments or pulp can be added
to further enhance the improved properties. However, such are not required. The continuous
filaments utilized can have a variety of deniers, e.g., preferably about 0.8-5 dpf,
and/or bicomponent filaments to further alter the physical properties of the nonwoven
material. Deniers of about 0.8 to 5 dpf are preferred to enhance the properties of
softness and uniformity.
[0029] The hydroentanglement process of the invention involves moving the formed layer or
layers along moving support 1 to the hydroentanglement station 27. A transfer belt
29 and godet rollers 33, or other equivalent structures, serve to essentially maintain
the layer(s) on a support surface so that when the layer(s) are hit with water from
the water jets, the filaments do not fly apart. FIGURE 2 illustrates a preferred embodiment
of hydroentanglement according to the present invention. The single layers or stack
of layers is indicated at 28 which moves to a transfer belt 29 moving around rollers
31. From transfer belt 29, the layer(s) move along godet rollers 33. Godet rollers
33 will have a screen which allows for the passage of water therethrough for drainage.
Water jets are depicted at 25. Initial water jet treatment can begin in relation to
transfer belt 29. Other water jets 25 are spaced in relation to godet rollers 33 in
order to meet the parameters as more specifically described below. The resulting hydroentangled
nonwoven material 35 is then transported by means of tension roller 36 for subsequent
treatments as desired, e.g. topical treatment, drying, winding, embossing, etc. The
support which passes beneath the water jets is preferably a series of moving supports.
Perforated godet rollers, as illustrated in FIGURE 2, preferably have openings with
a diagonal of from about 0.1 to about 2.0 mm. This allows for good support and drainage
of the water. Drainage can be simply obtained by gravity feed or else by utilization
of a vacuum box or by other conventional structures.
[0030] The ability to determine and control the properties obtained in the nonwoven material
is based on the number of water jets present, and the pressure of the water ejected
from the water jets and applied to the nonwoven material. Water jets are present in
number so as to provide from 25 to 50 water jet streams per linear inch of nonwoven
material with the water being ejected at a pressure of from about 20 to about 250
bar. The orifice of the water jet nozzles are preferably from about 0.1 to about 0.2
mm in diagonal. The layer(s) preferably move at a speed of from about 20 to about
250 meters per minute while being subjected to the water jets. The water jets preferably
are positioned over the nonwoven material being treated and in one or more lines extending
across the width of the layer(s) being processed at essentially a right angle to the
direction of advance of the layer(s).
[0032] Physical properties (e.g., fluid phobicity, fluid philicity, fire retardancy, absorbency,
antistatic nature, etc.) can be imparted to or changed in the nonwoven material in
different ways. For example, subsequent to hydroentanglement and dehydration of the
layer(s), the nonwoven material can be subjected to topical treatment 37, such as
described in U.S. Patent Nos. 5,709,747 and 5,885,656 which are incorporated herein
by reference. As described therein, topical treatment can be to preselected areas
depending on the use to which the nonwoven material will be applied. For example,
if used in the manufacture of a diaper, a central areal portion may be treated with
a surfactant to impart a hydrophilic character thereto. For example, to affect hydrophilicity,
a surfactant can be used, such as STANTEX® S 6327, as sold by Cognis Deutschland,
GmbH, Dusseldorf Germany, which is a blend of fatty acid esters. The surfactant is
a liquid suitable for topical application to the nonwoven material. Other examples
of surfactants suitable for use include PPH 53 as sold by Dr. Bohme GmbH, Germany;
and PP 842 as sold by Uniquema, United Kingdom.
[0033] Alternatively, physical properties can be imparted to or changed in the nonwoven
material by providing a suitable additive to the extrusion polymeric melt fed to one
or more of extruders 5, 7 and/or 9. A suitable surfactant additive to affect hydrophilicity
is STANDAPOL™ 1353A or 1480, sold by Cognis Deutschland, GmbH, which each are a fatty
ester(s). These additives maybe present in either liquid or granular form. Other examples
of surfactants suitable for use include PPH 53 as sold by Dr. Bohme GmbH, Germany;
and PP 842 as sold by Uniquema, United Kingdom. Whether a surfactant additive is fed
to one or more of extruders 5, 7 and/or 9 depends on the characteristics of the nonwoven
material desired. For example, whether a complete strike through of liquid is desired
or only a partial strike through is desired.
[0034] A surfactant is preferably present in an amount of about 0.2-3.0% by weight of the
nonwoven material when the nonwoven is hydrophobic and is to be rendered hydrophilic.
[0035] Other properties of the nonwoven material can be affected, such as fire retardency,
absorbency, antistatic nature and the like, by additive or topical application of
an appropriate modifying component as described above with regard to affecting the
hydrophobic property of the nonwoven material.
[0036] Following hydroentanglement, and topical treatment if carried out, the nonwoven material
is subjected to conventional drying and winding so as to provide a finished product
ready for use.
[0037] Also following hydroentanglement, the resulting nonwoven material can be subjected
to embossing or other conventional process to provide a pattern to the nonwoven material.
The pattern can provide aesthetic appeal and/or enhance certain physical properties,
for example fluid absorption, fluid retention and fluid channeling or direction control
of fluid upon contact with the material to control the site of absorption.
[0038] As will be apparent to one skilled in the art, various modifications can be made
within the scope of the aforesaid description. Such modifications being within the
ability of one skilled in the art form a part of the present invention and are embraced
by the appended claims.
1. A process of forming a non-woven material comprising
- providing continuous thermoplastic polymer filaments
- laying the continuous filaments upon a moving support to provide at least one layer
on the support, and
- joining the continuous filaments of the at least one layer together by hydroentangling
the filaments forming the at least one layer, characterised in that the joining step is carried out without any pre-bonding of the filaments,
- and the hydroentangling is provided by subjecting the at least one layer to water
emitted at a pressure of from about 20 to about 250 kg-f/cm2 from a plurality of water jets with at least 10 water jets per linear centimetre
of planar surface of the at least one layer.
2. A process according to Claim 1 wherein the polymer is a polyolefin, such as polypropylene
or is a polyester.
3. A process according to Claim 1 or 2 further comprising, following the hydroentangling,
topically treating the at least one layer with an additive to impart to or change
a physical property in the at least one layer.
4. A process according to any one of Claims 1 to 3 further comprising incorporating an
additive in the continuous thermoplastic polymer filaments to impart to or change
a physical property of the filaments.
5. A process according to Claim 3 or 4 wherein the additive renders the non-woven material
at least in part lyophobic, lyophilic, fire retardant, antistatic, and/or absorbent.
6. A process according to any one of Claims 1 to 5 wherein the at least one layer is
spunlaid or meltblown.
7. A process according to any one of Claims 1 to 6 wherein the water jets have nozzle
orifices ranging from about 0.1 to about 0.2 mm in diameter.
8. A process according to any one of Claims 1 to 7 wherein the at least one layer is
supported on a series of perforated godet rollers during the hydroentangling.
9. A process according to any one of Claims 1 to 8 wherein the continuous filaments are
provided at a denier of from about 0.8-5 dpf.
10. A process according to any one of Claims 1 to 9 further comprising, following the
hydroentangling, providing a pattern on the non-woven material.