Composite nonwoven fabric and articles produced therefrom

The invention is directed to a composite nonwoven fabric comprising first and second nonwoven webs of spunbonded substantially continuous thermoplastic filaments, and a nonwoven hydrophobic microporous web of thermoplastic meltblown microfibers sandwiched between the first and second nonwoven webs. The filaments of the nonwoven spunbond webs are formed of continuous multiconstituent filaments which include a lower melting gamma radiation stable polyethylene polymer component and one or more higher melting gamma radiation stable polymer constituents, wherein a substantial portion of the surfaces of the multiconstituent filaments consists of the lower melting gamma radiation stable polyethylene constituent. The nonwoven hydrophobic microporous web is formed from a gamma radiation stable polyethylene polymer. The webs are bonded together to form the composite nonwoven fabric by discrete point bonds in which the polyethylene constituent of said multiconstituent filaments and the polyethylene of said third nonwoven web are fused together.

FIELD OF THE INVENTION 
The invention relates to nonwoven fabrics and more specifically, to 
composite nonwoven barrier fabrics particularly suited for medical 
applications. 
BACKGROUND OF THE INVENTION 
Nonwoven barrier fabrics have been developed which impede the passage of 
bacteria and other contaminants and which are used for disposable medical 
articles, such as surgical drapes, disposable gowns and the like. For 
example, such barrier fabrics can be formed by sandwiching an inner 
fibrous web of thermoplastic meltblown microfibers between two outer 
nonwoven webs of substantially continuous thermoplastic spunbonded 
filaments. The fibrous meltblown web provides a barrier to bacteria or 
other contaminants, while the outer spunbonded layers provide good 
strength and abrasion resistance to the composite nonwoven fabric. 
Examples of such fabrics are described in U.S. Pat. No. 4,041,203 and U.S. 
Pat. No. 4,863,785. 
In the manufacture of this type of fabric, the respective nonwoven layers 
are thermally bonded together to form a unitary composite fabric. 
Typically, the thermal bonding involves passing the nonwoven layers 
through a heated patterned calender and partially melting the inner 
meltblown layer in discrete areas to form fusion bonds which hold the 
nonwoven layers of the composite together. Without sufficient melting and 
fusion of the meltblown layer, the composite fabric will have poor 
inter-ply adhesion. However, unless the thermal bonding conditions are 
accurately controlled, the possibility exists that the thermal bond areas 
may be heating excessively, causing "pinholes" which can compromise or 
destroy the barrier properties of the inner meltblown layer. Thus in 
practice, the thermal bonding conditions which are used represent a 
compromise between the required inter-ply adhesion strength on the one 
hand, and the required barrier properties which must be provided by the 
meltblown layer on the other. 
The conventional spunbond-meltblown-spunbond type barrier fabrics also have 
limitations in the types of sterilization procedures which can be used. 
For some applications, it is desired that the fabric or garment be 
sterilized in the final stages of manufacture by exposure to gamma 
radiation. For example, the fabric or garment may first be sealed in a 
protective package, and then exposed to gamma radiation to sterilize the 
package and its contents. However, sterilization by gamma irradiation has 
been found to be unsuitable for many of the known medical barrier fabrics. 
Some of the polymers conventionally used in such medical barrier fabrics, 
such as conventional grades of polypropylene for example, are especially 
sensitive to degradation by gamma irradiation. Fabrics produced from such 
polymers tend to lose strength over time, becoming brittle as a result of 
the gamma irradiation. Also, the instability of the polymers to the 
irradiation results in the generation of distasteful odors in the product 
which are unacceptable to the consumer. 
Conventional spunbond-meltblown-spunbond type barrier fabrics have 
limitations in the way they can be fabricated into a product, such as 
surgical gowns, surgical drapes, and the like. Typically these type of 
fabrics do not lend themselves to forming seams in a fabric construction 
by thermal bonding or welding. Further, such seams can be weak, and lack 
the integrity needed to provide a complete barrier to the passage of 
contaminants. Fabrics formed of conventional spunbond-meltblown-spunbond 
fabrics can be constructed by sewing, but this can be disadvantageous, 
since punching the fabric with a needle results in holes in the fabric, 
which impairs the integrity of the fabric and the continuity of the 
barrier properties thereof. 
Various attempts have been made to overcome these limitations. For example, 
efforts have been made to render the polypropylene polymers more stable to 
gamma irradiation, such as by incorporating certain additives in the 
polymer to reduce the amount of degradation. For example, U.S. Pat. No. 
4,822,666 describes a radiation stabilized polypropylene fabric in which a 
long-chain aliphatic ester is added to the polymer. U.S. Pat. No. 
5,041,483 discloses incorporating a rosin ester into the polypropylene to 
stabilize the polymer and reduce the tendency toward odor generation after 
gamma irradiation. However, the use of such additives adds expense to the 
manufacturing process. Further, polypropylene is difficult to render 
gamma-stable at standard commercial dosage levels, even with the use of 
additives or stabilizers. 
The component layers of spunbond-meltblown-spunbond type barrier fabrics 
can also be formed of polymers which are stable to gamma irradiation. Such 
polymers include polyamides, polyesters, some polyolefins, such as 
polyethylene, and the like. However, fabrics formed using high melt 
temperature polymers, such as polyamide and polyester, are not easily 
thermally bonded. The high temperatures which are required to sufficiently 
bond the fabric can destroy the meltblown barrier properties and the 
structure of the outer spunbonded webs. Adhesives can be used to bond the 
high melt temperature layers together, but this can result in stiffness of 
the resultant fabric and adds cost. 
It would therefore be advantageous to provide a fabric that provides a 
barrier to the transmission of contaminants and which retains its strength 
and does not create an unpleasant odor when sterilized in the presence of 
gamma radiation. It would also be advantageous to provide such a fabric 
which exhibits good aesthetic properties, such as desirable softness, 
drape and breathability, as well as good strength and abrasion resistance, 
and which can be easily constructed into a product, such as a surgical 
gown. 
SUMMARY OF THE INVENTION 
The present invention provides composite nonwoven fabrics having desirable 
barrier properties and which are stable to gamma irradiation. The 
composite nonwoven fabrics of the invention include first and second 
spunbonded nonwoven web of substantially continuous thermoplastic 
filaments, and a third nonwoven web sandwiched between the first and 
second webs and containing one or more hydrophobic microporous layers 
which form a barrier which is highly impervious to bacteria but permeable 
to air. The nonwoven webs are formed of polymers which are stable to gamma 
irradiation. The spunbonded webs are engineered so that the webs are 
bonded together to form a composite fabric without compromising the 
barrier properties of the microporous layer. More particularly, the 
spunbonded nonwoven webs are formed of continuous multiconstituent 
filaments which include a lower melting gamma radiation stable 
polyethylene polymer component and one or more higher melting gamma 
radiation stable polymer constituents, wherein the lower melting gamma 
radiation stable polyethylene constituent is present over a substantial 
portion of the surface of the filament and the higher melting polymer 
constituent is in a substantially continuous form along the length of the 
filaments. The nonwoven microporous layer or layers may comprise a web of 
meltblown microfibers formed from a gamma radiation stable polyethylene 
polymer. The webs are bonded together to form the composite nonwoven 
fabric by discrete point bonds in which the polyethylene constituent of 
said multiconstituent filaments and the polyethylene microfibers of said 
third nonwoven web are fused together. 
The composite nonwoven fabric of this invention is characterized by having 
an excellent balance of strength, breathability, and barrier properties, 
as well as stability to gamma radiation, which properties make the fabric 
particularly useful in medical and industrial applications for use as 
protective garments. Composite nonwoven fabrics of this invention have a 
grab tensile strength of at least 15 pounds in the cross direction (CD) 
and 25 pounds in the machine direction (MD) and a Gurley air permeability 
of at least 35 cfm for fabrics having a basis weight in the range of 40 to 
120 gsm. The excellent barrier properties of the fabrics of this invention 
are illustrated by high hydrostatic head ratings, typically 35 cm or 
greater, and by bacterial filtration efficiency (BFE) ratings of 85 
percent and higher. 
In one embodiment of the invention, the continuous filaments of the 
spunbonded nonwoven webs have a bicomponent polymeric structure. Such 
bicomponent polymeric structures include sheath/core structures, 
side-by-side structures, and the like. Preferably, the bicomponent 
structure is a sheath/core bicomponent structure wherein the sheath is 
formed from polyethylene and the core is formed from polyester. 
In another embodiment of the invention, the continuous filaments of the 
spunbonded nonwoven web are formed of a blend of at least two different 
thermoplastic polymers. The polymer blend comprises a dominant phase and 
at least one phase dispersed therein. Illustrative of blends in accordance 
with the invention are blends wherein the dominant phase is a polymer 
selected from the group consisting of polyamides and polyesters, and the 
dispersed phase is polyethylene. 
The composite fabrics of the present invention can be sealed or seamed by 
fusing the lower melting polyethylene constituent by means of a thermal 
heat sealer, heated die, ultrasonic sealer, RF sealer or the like. This 
property is particularly advantageous in fabricating products such as 
protective garments from the composite fabric. Two or more pieces of the 
composite fabric can be joined together by forming a continuous seam by 
fusion. The continuous fusion bonded seam maintains the protective barrier 
properties of the fabric along the seam, whereas other conventional 
methods, such as sewing, require penetration of the nonwoven barrier 
layer, and may thus risk disrupting the barrier properties.

DETAILED DESCRIPTION OF THE INVENTION 
FIG. 1 is a diagrammatical cross-sectional view of a composite nonwoven 
fabric in accordance with one embodiment of the invention. The fabric, 
generally indicated at 10, is a three ply composite comprising an inner 
ply 12 sandwiched between outer plies 11 and 13. The composite fabric 10 
has good strength, flexibility and drape. The barrier properties of the 
fabric 10 make it particularly suitable for medical applications, such as 
surgical gowns, sterile wraps, surgical drapes, caps, shoe covers, and the 
like, but the fabric is also useful for any other application where 
barrier properties would be desirable, such as overalls or other 
protective garments for industrial applications for example. 
Outer ply 11 may suitably have a basis weight of at least about 3 g/m.sup.2 
and preferably from about 10 g/m.sup.2 to about 30 g/m.sup.2. In the 
embodiment illustrated, ply 11 is comprised of continuous multiconstituent 
filaments which have been formed into a nonwoven web by a conventional 
spunbonding techniques. Preferably, the filaments of the spunbonded fabric 
are prebonded at the filament crossover points to form a unitary cohesive 
spunbonded web prior to being combined with the other webs of the 
composite fabric. Outer ply 13 is also a spunbonded nonwoven web of 
substantially continuous thermoplastic filaments. In the embodiment 
illustrated, ply 13 is a nonwoven web of similar composition and basis 
weight as outer ply 11. 
The multiconstituent filaments of ply 11 have a lower melting thermoplastic 
polymer constituent and one or more higher melting thermoplastic 
constituents. For purposes of this invention, it is important that a 
significant portion of the filament surface be formed by the lower melting 
polymer constituent, so that the lower melting constituent will be 
available for bonding, as explained more fully below. At least one of the 
higher melting constituents should be present in the multiconstituent 
filament in a substantially continuous form along the length of the 
filament for good tensile strength. Preferably the lower melting polymer 
constituent should have a melting temperature at least 5.degree. C. below 
that of the higher melting constituent, so that at the temperatures 
employed for thermal bonding of the plies of the composite fabric the 
higher melting constituent retains its substantially continuous fibrous 
form to provide a strengthening and reinforcing function in the composite 
fabric. 
The particular polymer compositions used in the higher and lower melting 
constituents of the multiconstituent filaments may be selected from those 
gamma radiation stable polymers conventionally used in forming melt-spun 
fibers. Particularly preferred for the lower melting polymer constituent 
is polyethylene, including polyethylene homopolymers, copolymers and 
terpolymers. Examples of suitable polymers for the higher melting 
constituent include polyesters such as polyethylene terephthalate, 
polyamides such as poly(hexamethylene adipamide) and poly(caproamide), and 
copolymers and blends thereof. The filaments may also contain minor 
amounts of other polymer or non-polymer additives, such as antistatic 
compositions, soil release additives, water or alcohol repellents, etc. 
In a preferred embodiment of the invention, the filaments are formed from a 
bicomponent polymeric structure. The polymeric bicomponent structure may 
be a sheath/core structure, a side-by-side structure, or other structures 
which provide that the lower melting gamma radiation stable polyethylene 
constituent is present over a substantial portion of the surface of the 
filament and the higher melting polymer constituent is in a substantially 
continuous form along the length of the filaments. The bicomponent 
filaments can provide improved aesthetics such as hand and softness based 
on the surface component of the bicomponent filaments, while providing 
improved strength, tear resistance and the like due to the stronger core 
component of the filament. Preferred bicomponent filaments include 
polyethylene/polyester sheath/core filaments such as 
polyethylene/polyethylene terephthalate bicomponent sheath/core filaments. 
In another embodiment of the present invention, the filaments are formed 
from a polymer blend. In this embodiment of the invention, the dominant 
phase is a polymer selected form the group consisting of polyesters and 
polyamides, and the dispersed phase is a polyethylene. The dispersed phase 
polymer is present in the blend in an amount of about 1 to 20% by weight, 
and preferably about 5 to 15% by weight, of the polymer blend so that the 
lower melting gamma radiation stable polyethylene constituent is present 
over a substantial portion of the surface of the filament and the higher 
melting polymer constituent is in a substantially continuous form along 
the length of the filaments. 
The inner ply 12 comprises at least one hydrophobic microporous layer. The 
microporous layer may comprise a microporous film, a microporous sheet or 
web formed of thermally consolidated microfibers, or a microporous 
nonwoven web of microfibers. The microfibers are preferably manufactured 
in accordance with the process described in Buntin et al. U.S. Pat. No. 
3,978,185. The inner ply 12 may suitably have a basis weight in the range 
of about 10 to 80 gsm, and preferably in the range of about 10 to 30 gsm. 
The microfibers preferably have a diameter of up to 50 microns, and most 
desirably the fiber diameter is less than 10 microns. 
The polymer used for forming the microporous layer or layers of ply 12 is 
also preferably selected for its stability to gamma irradiation. In 
addition, it should be selected so that it is thermally miscible with the 
lower melting polyethylene constituent of the multiconstituent filaments 
By "thermally miscible", we mean that the polymers, when heated to thermal 
bonding temperatures, will be cohesive and will join together to form a 
single, unitary bond domain. Typically, to be "thermally miscible", the 
polymers will be of the same chemical composition or of such a similar 
chemical composition that the polymers are miscible with one another. If 
of different chemical compositions, the surface energies of the polymers 
are sufficiently similar such that they readily form a cohesive bond when 
heated to thermal activation temperature. In contrast, polymers which are 
not thermally miscible with one another do not have such an affinity to 
one another to form cohesive bonds. Under thermal bonding conditions, the 
polymers may bond together, but the bond mechanism is predominately, if 
not exclusively, a mechanical bond resulting from mechanical interlocking 
or encapsulation. The polymers do not form a unitary polymer domain but 
remain as separate identifiable polymer phases. For purposes of the 
present invention, the microporous layer 12 is suitably formed from a 
polyethylene. In a preferred embodiment, the thermoplastic meltblown 
microfibers comprise linear low density polyethylene (LLDPE), prepared by 
copolymerizing ethylene and an alpha olefin having 3 to 12 carbon atoms. 
More preferably, the polymer is LLDPE having a melting point of about 
125.degree. C. 
After the respective plies of the composite nonwoven fabric have been 
assembled, the plies are bonded. Bonding may be achieved by heating the 
composite fabric to a temperature sufficient to soften the polyethylene 
constituent so that it fuses the composite nonwoven fabric together to 
form a unitary structure. For example, when a bicomponent filament is 
used, the composite laminate is thermally treated to a temperature 
sufficient to soften the lower melting polyethylene constituent thereof so 
that it fuses the nonwoven webs together to form a unitary nonwoven 
composite fabric. 
The plies may be bonded in any of the ways known in the art for achieving 
thermal fusion bonding. Bonding may be achieved, for example, by the use 
of a heated calender, ultrasonic welding and similar means. The heated 
calender may include smooth rolls or patterned or textured rolls. Thus, 
the fabric may also be embossed, if desired, through the use of textured 
or patterned rolls, to impart a desired surface texture and to improve or 
alter the tactile qualities of the composite fabric. The pattern of the 
embossing rolls may be any of those known in the art, including spot 
patterns, helical patterns, and the like. The embossing may be in 
continuous or discontinuous patterns, uniform or random points or a 
combination thereof, all as are well known in the art. 
While a three-ply composite fabric has been shown in the drawings, it is to 
be understood that the number and arrangement of plies may vary depending 
upon the particular properties sought for the laminate. For example, 
several microporous layers can be employed in the invention and/or greater 
numbers of other fibrous webs can be used. Additionally, at least one of 
the outer webs may be treated with a treatment agent to render any one of 
a number of desired properties to the fabric, such as flame retardancy, 
hydrophilic properties, and the like. 
The presence of the lower melting polyethylene constituent at the surface 
of the spunbonded outer layers 11 and 13 of the composite fabric 10 
enables the fabric to be sealed or seamed by fusing the lower melting 
polyethylene constituent by means of a thermal heat sealer, heated die, 
ultrasonic sealer, RF sealer or the like. Thus, for example the edges of a 
fabric can be finished by forming a substantially continuous fusion bond 
extending the peripheral edge, the fusion bond being formed between the 
polyethylene constituent of the multiconstituent filaments of the outer 
spunbond layers 11 and 13 and the polyethylene component of the inner web 
12. This property is also advantageous in fabricating products such as 
protective garments from the composite fabric. Two or more pieces of the 
composite fabric can be joined together by forming a continuous seam by 
fusion. The continuous fusion bonded seam maintains the protective barrier 
properties of the fabric along the seam. 
FIG. 2 schematically illustrates one method for forming a composite 
nonwoven fabric of the invention. A conventional spunbonding apparatus 20 
forms a first spunbonded layer 22 of substantially continuous 
thermoplastic polymer filaments. Web 22 is deposited onto forming screen 
24 which is driven in a longitudinal direction by rolls 26. 
The spunbonding process involves extruding a polymer through a generally 
linear die head or spinneret 30 for melt spinning substantially continuous 
filaments 32. The spinneret preferably produces the filaments in 
substantially equally spaced arrays and the die orifices are preferably 
from about 0.002 to about 0.040 inches in diameter. 
As shown in FIG. 2, the substantially continuous filaments 32 are extruded 
from the spinneret 30 and quenched by a supply of cooling air 34. The 
filaments are directed to an attenuator 36 after they are quenched, and a 
supply of attenuation air is admitted therein. Although separate quench 
and attenuation zones are shown in the drawing, it will be apparent to the 
skilled artisan that the filaments can exit the spinneret 30 directly into 
the attenuator 36 where the filaments can be quenched, either by the 
supply of attenuation air or by a separate supply of quench air. 
The attenuation air may be directed into the attenuator 36 by an air supply 
above the entrance end, by a vacuum located below a forming wire or by the 
use of eductors integrally formed in the attenuator. The air proceeds down 
the attenuator 36, which narrows in width in the direction away from the 
spinneret 30, creating a nozzle effect accelerating the air and causing 
filament attenuation. The air and filaments exit the attenuator 36, and 
the filaments are collected on the collection screen 24. The attenuator 36 
used in the spunbonding process may be of any suitable type known in the 
art, such as a slot draw apparatus or a tube-type (Lurgi) apparatus. 
After the spunbonded layer 22 is deposited onto screen 24, the web passes 
longitudinally beneath a conventional meltblowing apparatus 40. 
Meltblowing apparatus 40 forms a meltblown fibrous stream 42 which is 
deposited on the surface of the spunbonded web 22 to form a meltblown 
fibrous layer. Meltblowing processes and apparatus are known to the 
skilled artisan and are disclosed, for example, in U.S. Pat. 3,849,241 to 
Buntin, et al. and U.S. 4,048,364 to Harding, et al. The meltblowing 
process involves extruding a molten polymeric material through fine 
capillaries into fine filamentary streams. The filamentary streams exit 
the meltblowing spinneret face where they encounter converging streams of 
high velocity heated gas, typically air, supplied from nozzles 46 and 48. 
The converging streams of high velocity heated gas attenuate the polymer 
streams and break the attenuated streams into meltblown microfibers. 
A spunbonded web/meltblown web structure 50 is thus formed. The structure 
50 is next conveyed by forming screen 24 in the longitudinal direction 
beneath to a point where a nonwoven web of thermoplastic filaments is 
formed on the surface thereof. FIG. 2 illustrates a spunbonded layer 
formed by a second conventional spunbonding apparatus 60. The spunbonding 
apparatus 60 deposits a spunbonded nonwoven layer onto the composite 
structure 50 to thereby form a composite structure 64 consisting of a 
spunbonded web/meltblown web/spunbonded web. 
The composite structure is then passed to a conventional thermal fusion 
bonding station 70 to provide a composite bonded nonwoven fabric 80. Here 
the lower melting polyethylene constituent is softened so as to securely 
fuse the inner meltblown ply to the outer spunbonded plies while 
maintaining the integrity of the inner meltblown ply. The resultant 
composite web 80 exits the thermal fusion station 70 and is wound up by 
conventional means on roll 90. 
The thermal fusion station 70 is constructed in a conventional manner as 
known to the skilled artisan, and advantageously is a calender having 
bonding rolls 72 and 74 as illustrated in FIG. 2. The bonding rolls 72 and 
74 may be smooth rolls, point rolls, helical rolls, or the like. 
Although the thermal fusion station is illustrated in FIG. 2 in the form of 
a calender having bonding rolls, other thermal treating stations, such as 
through-air bonding, radiant heaters or ultrasonic, microwave and other RF 
treatments which are capable of bonding the fabric in accordance with the 
invention can be substituted for the calender of FIG. 2. Such conventional 
heating stations are known to those skilled in the art. 
The method illustrated in FIG. 2 is susceptible to numerous variations. For 
example, although the schematic illustration of FIG. 2 has been described 
as forming a spunbonded web directly during an in-line continuous process, 
it will be apparent that the spunbonded webs can be preformed and supplied 
as rolls of preformed webs. Similarly, although the meltblown web 42 is 
shown as being formed directly on the spunbonded web 22, the meltblown web 
can be preformed and such preformed webs can be combined to form the 
composite fabric, or can be passed through heating rolls for further 
consolidation and thereafter passed on to a spunbonded web or can be 
stored in roll form and fed from a preformed roll onto the spunbonded 
layer 22. Similarly, the three-layer web 64 can be formed and stored prior 
to bonding at station 70. 
In FIG. 3, the reference character 95 indicates a surgical gown fabricated 
from the composite nonwoven fabric of the present invention. For use as a 
surgical gown, the basis weight of the fabric is preferably within the 
range of 40 to 60 gsm and most desirably within the range of 50 to 60 gsm. 
The fabric has a hydrostatic head rating of 35 cm or greater and a 
bacterial filtration efficiency (BFE) rating of 85 percent or greater. The 
gown 95 is fabricated by seaming precut panels or pieces of the nonwoven 
fabric together with a seam formed by fusion bonding. More particularly, 
as seen in FIG. 4, one of the panels 96 has a portion positioned in 
face-to-face contacting relation with a portion of another of the panels 
97, and a seam 98 joins the panels to one another along said contacting 
portions. The seam 98 is a fusion bond formed between the polyethylene 
constituent of the multiconstituent filaments of panel 96 and the 
polyethylene constituent of the multiconstituent filaments of the other 
panel 97. 
The following examples serve to illustrate the invention but are not 
intended to be limitations thereon. 
EXAMPLE 1 
Samples of a trilaminate composite fabric were prepared by combining two 
outer layers of a spunbonded nonwoven fabric formed from 3 denier per 
filament polyethylene/polyester (PET) sheath/core bicomponent filaments 
with a central inner layer of a meltblown web formed from linear low 
density polyethylene. Samples were prepared using two different basis 
weights of spunbond bicomponent filament fabric. Bonding was performed 
using a heated patterned calender. The fabric physical properties are 
shown in Table 1 below: 
TABLE 1 
______________________________________ 
Spunbond 20 gsm 15 gsm 
Meltblown 16.5 gsm 16.5 gsm 
Spunbond 20 gsm 15 gsm 
Total basis wt. 
1.70 osy 1.47 osy 
______________________________________ 
Grab tensile (lbs) 
AVG STD AVG STD 
______________________________________ 
MD 47.4 3.3 37.9 3.1 
CD 23.5 3.1 18.9 1.9 
Hydrostatic pressure 
39.9 1.4 35.7 2.9 
(cm) 
Gurley Air 76.3 4.4 98.9 4.1 
Permeability (cfm) 
______________________________________ 
EXAMPLE 2 
Additional samples were prepared as in Example 1 using a 24 gsm linear low 
density polyethylene meltblown layer and 3 denier per filament 
polyethylene/polyester (PET) sheath/core bicomponent spunbonded layers of 
20 gsm and 15 gsm basis weights respectively. The physical properties are 
shown in Table 2. 
TABLE 2 
______________________________________ 
PROPERTIES 
______________________________________ 
Spunbond layers 15 gsm bico 
20 gsm bico 
Meltblown layer 24 gsm PE 24 gsm PE 
BASIS WEIGHT 
osy 1.6 1.9 
gsm 54.3 63.5 
GRAB TENSILE, lb 
CD 18.7 25.0 
MD 33.0 42.9 
GRAB TEA, in-lb 
CD 26 37 
MD 38 49 
TRAPEZOID TEAR, lb 9.4 11.8 
CD 
ELMENDORF TEAR, g 
CD 1150 1421 
MD 686 1029 
MULLEN BURST, psi 42.9 51.4 
HYDROSTATIC HEAD, cm 
37.8 38.9 
ALCOHOL REPELLENCY 7 7 
IMT PENETRATION, g 
4.2 7.1 
AIR PERMEABILITY, cfm 
77.7 82.9 
HANDLE-0-METER 89 143 
______________________________________ 
The invention has been described in considerable detail with reference to 
its preferred embodiments. However, it will be apparent that numerous 
variations and modifications can be made without departure from the spirit 
and scope of the invention as described in the foregoing detailed 
specification and defined in the appended claims.