Creped nonwoven liner with gradient capillary structure

A unitary creped nonwoven web has a hydrophobic uncreped side and a creped side. The hydrophobic side includes looped regions. The creped side includes relatively narrow hydrophilic regions. The looped regions and creped regions act in conjunction with each other to form gradient capillaries, which urge the transfer of liquid toward the hydrophilic regions and away from the hydrophobic looped regions. The creped nonwoven web can be used as a top liner for an absorbent structure, such as a diaper, with the hydrophilic ends facing the absorbent core. When used in this fashion, the creped nonwoven web helps keep the wearer's skin dry.

FIELD OF THE INVENTION 
This invention relates to permanently creped nonwoven materials having low 
density, high permeability, improved loft and softness, looping, and 
out-of-plane fiber orientation and both hydrophobic and hydrophilic 
surfaces. 
BACKGROUND OF THE INVENTION 
Creped thermoplastic nonwoven materials are known from U.S. Pat. No. 
4,810,556, issued to Kobayashi et al. In the disclosed process, a raw 
nonwoven fabric is coated with a lubricant and then pressed between a 
drive roll and a plate having a rough sandpaper-like surface. The plate is 
positioned near the drum and is substantially parallel or tangential to 
the outer surface of the drum. The raw nonwoven fabric is crinkled in a 
wavelike fashion in the direction of movement of the fabric by the 
frictional force caused by the pressing. The resulting creped fabric has 
wavelike crepes which contribute to softness. However, the creping 
accomplished by this process is not believed to be permanent. It is 
believed that the creping accomplished by this process can be removed or 
reduced significantly by subjecting the nonwoven web to mechanical 
stretching sufficient to flatten out the wavelike crepes. Also, the 
creping is naturally reduced over time during use of the fabric. 
The creping of paper is also known in the art. However, paper has 
traditionally been creped using processes different from those used to 
crepe thermoplastic nonwoven webs. U.S. Pat. No. 3,879,257, issued to 
Gentile et al., discloses a process used for producing creped paper. A 
bonding material, preferably elastomeric, is applied to first and second 
surfaces of the paper so that it covers from about 15-60% of both paper 
surfaces and penetrates into about 10-40% of the paper thickness from both 
surfaces. Then, one side of the paper is adhered to a creping surface, 
such as a creping drum, using the bonding material to cause the adhesion. 
Then, the paper is creped from the creping surface using a doctor blade 
positioned at an angle to the surface. This creping method greatly 
disrupts the fibers in the unbonded regions of the paper increasing the 
overall softness, absorbency and bulk of the paper, and finely crepes the 
bonded areas of the paper to soften them. 
There is a need or desire for a creped thermoplastic nonwoven web in which 
some or portions of the fibers are greatly disrupted to cause permanent 
creping. There is also a need or desire for a permanently creped nonwoven 
web containing individual filament loops, suitable for use as the female 
component in a hook-and-loop fastener. Furthermore, there is a need or 
desire for a permanently creped nonwoven web suitable for use as a liner, 
which has a hydrophobic side and a hydrophilic side. 
SUMMARY OF THE INVENTION 
The present invention is a permanently creped thermoplastic nonwoven web 
having interfilament bonded areas which are bent or oriented permanently 
out of plane, unbonded areas between the bonded areas, and substantial 
filament looping in the unbonded areas. The permanently creped web has low 
density, high permeability and excellent softness, and is useful as a loop 
material for a hook and loop fastener. The web also has a crinkled, 
puckered texture, and is useful for liners, transfer and surge layers, 
outercovers, wipes, and other fluid handling products. The web has a 
hydrophobic side and a hydrophilic side, thereby favoring the movement of 
liquid water and moisture away from the skin surface in end use 
applications. 
The starting material used to make the invention includes an uncreped 
hydrophobic thermoplastic nonwoven web which can, for instance, be a 
hydrophobic thermoplastic spunbonded web or a hydrophobic thermoplastic 
meltblown web. The nonwoven web is at least partially coated on one side 
with a hydrophilic adhesive, so that about 5-100% (preferably 10-70%) of 
the total surface area on one side is coated, and about 0-95% (preferably 
30-90%) of the area is uncoated. The adhesive renders one side of the web 
hydrophilic. The nonwoven web also possesses interfilament bonding, in the 
form of a pattern called the "nonwoven web bond pattern," which is 
imparted during manufacture of the nonwoven web. The adhesive penetrates 
the nonwoven web to some extent in the coated areas, causing increased 
interfilament bonding in those areas. The at least partially coated side 
of the thermoplastic nonwoven web is then placed against a creping 
surface, such as a creping drum, and is peelably bonded to the creping 
surface. The creping surface is preferably heated, and is moved (e.g. 
rotated) in a machine direction. As the creping surface moves, the leading 
edge of the nonwoven web bonded to the surface is creped off using a 
doctor blade. 
The doctor blade penetrates the adhesive coating underneath the web and 
lifts the nonwoven web off the drum, resulting in permanent filament 
bending in the bonded areas corresponding to the nonwoven web bond 
pattern, and permanent looping of the filaments in the unbonded areas. 
Only one side of the web need be creped in this fashion to form a loop 
material suitable for use as the female component in a hook and loop 
fastener, and for forming a liner suitable for use in diapers and other 
surge applications. 
The resulting creped sheet has a soft, contoured hydrophobic side with 
relatively large pores, that is intimately connected to a hydrophilic side 
having smaller pores. The size of the pores decreases from the hydrophobic 
side to the hydrophilic side of the creped nonwoven sheet. The structure 
provides low liner saturation, leading to low skin hydration. Because of 
the unique surface topography caused by the creped pattern, only the 
hydrophobic areas will be in contact with the wearer's skin, contributing 
to a dry feel. 
With the foregoing in mind, it is a feature and advantage of the invention 
to provide a permanently creped nonwoven web having low density, high 
permeability and excellent softness and texture. 
It is also a feature and advantage of the invention to provide a 
permanently creped nonwoven web having a looped structure suitable for use 
as the female component of a hook and loop fastener. 
It is also a feature and advantage of the invention to provide a 
permanently creped nonwoven web having textured hydrophilic and 
hydrophobic surfaces suitable for use in liners, transfer and surge 
layers, outercovers, wipers, and other fluid handling materials. 
The foregoing and other features and advantages of the invention will 
become further apparent from the following detailed description of the 
presently preferred embodiments, read in conjunction with the accompanying 
drawings. The detailed description and drawings are intended to be merely 
illustrative rather than limiting, the scope of the invention being 
defined by the appended claims and equivalents thereof.

DEFINITIONS 
"Permanently creped" refers to a creped nonwoven web having bonded and 
unbonded areas, in which the bonded areas are permanently bent 
out-of-plane and the unbonded portions are permanently looped, such that 
the nonwoven web cannot be returned to its original uncreped state by 
applying a mechanical stress. 
"Crepe level" is a measure of creping and is calculated according to the 
following equation: 
##EQU1## 
"Bent out-of-plane" refers to a bonding or orientation of portions of the 
nonwoven web in a direction away from the plane in which the nonwoven web 
substantially lies before being subjected to the creping process. As used 
herein, the phrase "bent out-of-plane" generally refers to nonwoven webs 
having creped portions bent at least about 15 degrees away from the plane 
of the uncreped nonwoven web, preferably at least about 30 degrees. 
"Looped" refers to unbonded filaments or portions of filaments in a creped 
nonwoven web which define an arch, semi-circle or similar configuration 
extending above the plane of the uncreped nonwoven web, and terminating at 
both ends in the nonwoven web (e.g. in the bonded areas of the creped 
nonwoven web). 
"Nonwoven web" means a web having 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. 
"Nonwoven web bond pattern" is a pattern of interfilament bonding in the 
nonwoven web which is imparted during manufacture of the nonwoven web. 
"Meltblown fibers" means fibers formed by extruding a molten thermoplastic 
material through a plurality of fine, usually circular, die capillaries as 
molten threads or filaments into a high velocity gas (e.g. air) stream 
which attenuates the filaments of molten thermoplastic material to reduce 
their diameter, possibly to microfiber diameter. Thereafter, the meltblown 
fibers are carried by the high velocity gas stream and are deposited on a 
collecting surface to form a web of randomly disbursed meltblown fibers. 
Such a process is disclosed, for example, in U.S. Pat. No. 3,849,241 to 
Butin, the disclosure of which is hereby incorporated by reference. 
"Microfibers" means small diameter fibers having an average diameter not 
greater than about 100 microns, for example, having an average diameter of 
from about 0.5 microns to about 50 microns, or more particularly, an 
average diameter of from about 4 microns to about 40 microns. 
"Spunbonded fibers" refers to small diameter fibers which are formed by 
extruding a molten thermoplastic material as filaments from a plurality of 
fine, usually circular, capillaries of a spinnerette with the diameter of 
the extruded filaments then being rapidly reduced as by, for example, 
eductive drawing or other well-known spunbonding mechanisms. The 
production of spunbonded nonwoven webs is illustrated in patents such as, 
for example, in U.S. Pat. No. 3,802,817 to Matsuki et al. and U.S. Pat. 
No. 5,382,400 to Pike et al. The disclosures of these patents are hereby 
incorporated by reference. 
"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, the term "polymer" shall include all possible geometrical 
configurations of the material. These configurations include, but are not 
limited to, isotactic, syndiotactic and random symmetries. 
"Bicomponent fibers" refers to fibers which have been formed from at least 
two polymers extruded from separate extruders but spun together to form 
one fiber. The polymers are arranged in substantially constantly 
positioned distinct zones across the cross-section of the bicomponent 
fibers and extend continuously along the length of the bicomponent fibers. 
The configuration of such a bicomponent fiber may be, for example, a 
sheath/core arrangement wherein one polymer is surrounded by another or 
may be a side-by-side arrangement or an "islands-in-the-sea" arrangement. 
Bicomponent fibers are taught in U.S. Pat. No. 5,108,820 to Kaneko et al., 
U.S. Pat. No. 5,336,552 to Straek et al., and European Patent 0586924. For 
two component fibers, the polymers may be present in ratios of 75/25, 
50/50, 25/75 or any other desired ratios. 
"Biconstituent fibers" refers to fibers which have been formed from at 
least two polymers extruded from the same extruder as a blend. The term 
"blend" is defined below. Biconstituent fibers do not have the various 
polymer components arranged in relatively constantly positioned distinct 
zones across the cross-sectional area of the fiber and the various 
polymers are usually not continuous along the entire length of the fiber, 
instead usually forming fibrils which start and end at random. 
Biconstituent fibers are sometimes also referred to as multiconstituent 
fibers. Fibers of this general type are discussed in, for example, U.S. 
Pat. No. 5,108,827 to Gessner. Bicomponent and biconstituent fibers are 
also discussed in the textbook Polymer Blends and Composites by John A. 
Manson and Leslie H. Sperling, copyright 1976 by Plenum Press, a division 
of Plenum Publishing Corporation of New York, IBSN 0-306-30831-2, at pages 
273 through 277. 
"Blend" means a mixture of two or more polymers while the term "alloy" 
means a sub-class of blends wherein the components are immiscible but have 
been compatibilized. "Miscibility" and "immiscibility" are defined as 
blends having negative and positive values, respectively, for the free 
energy of mixing. Further, "compatibilization" is defined as the process 
of modifying the interfacial properties of an immiscible polymer blend in 
order to make an alloy. 
"Hydrophilic" refers to a surface or material that has an affinity for 
water, and is wettable by water. Some hydrophilic materials are capable of 
absorbing water, dissolving in water, and/or swelling. 
"Hydrophobic" refers to a surface or material that is poorly wetted by 
water, has little or no affinity for water, and tends to repel water. 
"Gradient capillary" refers to a unitary structure having a hydrophobic end 
and a hydrophilic end, with a transformation from hydrophobic to 
hydrophilic occurring between the two ends. 
"Consisting essentially of" does not exclude the presence of additional 
materials which do not significantly affect the desired characteristics of 
a given composition or product. Examples of such materials include, 
without limitation, pigments, antioxidants, stabilizers, surfactants, 
waxes, flow promoters, particulates and materials added to enhance 
processability of the composition. 
DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS 
FIG. 1 illustrates a process for preparing a creped nonwoven web of the 
invention, which can be a creped spunbonded web. The nonwoven web is 
preferably creped on only one side, using a hydrophilic adhesive. The 
nonwoven web can be creped on its other side, using a hydrophobic 
adhesive. A nonwoven web 12, which can be a spunbonded web, is unwound 
from a supply roll 10. The nonwoven web 12 may be passed through a first 
creping station 20, a second creping station 30, or both. If it is desired 
to crepe the nonwoven web 12 on only one side, it may be passed through 
either the first creping station 20 or the second creping station 30, with 
one creping station or the other being bypassed. If it is desired to crepe 
the nonwoven web 12 on both sides, it may be passed through both creping 
stations. 
A first side 14 of the web 12 may be creped using the first creping station 
20. The creping station 20 includes first a printing station including a 
lower patterned or smooth printing roller 22, an upper smooth anvil roller 
24, and a printing bath 25, and also includes a dryer roller 26 and 
associated creping blade 28. 
The rollers 22 and 24 nip the web 12 and guide it forward. As the rollers 
22 and 24 turn, the patterned or smooth printing roller 22 dips into bath 
25 containing a hydrophilic adhesive material, and applies the adhesive 
material to the first side 14 of the web 12 in a partial coverage at a 
plurality of spaced apart locations, or in a total coverage. The 
hydrophilic adhesive-coated web 12 is then passed around drying drum 26 
whereupon the adhesive-coated surface 14 becomes adhered to the roller 26. 
The first side 14 of the web 12 is then creped (i.e. lifted off the drum 
and bent) using doctor blade 28. 
It is generally preferred that the nonwoven web 12 be creped on only one 
side. However, a second side 16 of the web 12 may be creped using the 
second creping station 30, with the aid of a hydrophobic adhesive. The 
second creping station 30 includes a second printing station including a 
lower patterned or smooth printing roller 32, an upper smooth anvil roller 
34, and a printing bath 35, and also includes a dryer drum 36 and 
associated creping blade 38. The rollers 32 and 34 nip the web 12 and 
guide it forward. As the rollers 32 and 34 turn, the printing roller 32 
dips into bath 35 containing a hydrophobic adhesive material, and applies 
the hydrophobic adhesive to the second side 16 of the web 12 in a partial 
or total coverage. The adhesive-coated web 12 is then passed around drying 
roller 36 whereupon the hydrophobic adhesive-coated surface 16 becomes 
adhered to the roller 36. The second side 16 of the web 12 is then creped 
(i.e. lifted off the drum surface and bent) using doctor blade 38. 
After creping, the nonwoven web 12 may be passed through a chilling station 
40 and wound onto a storage roll 42. The level of creping is affected by 
the surface speed of the windup roll 42 relative to the surface speed of 
the creping drum 36, according to the equation presented above. The 
surface speed of the windup roll 42 is slower than the surface speed of 
the creping drum 36, and the difference between the two speeds affects the 
level of creping. The level of creping should generally be about 5-75%, 
preferably about 15-60%, most preferably about 25-50%. 
The nonwoven web 12 may be any type of thermoplastic nonwoven web. For 
instance, web 12 may be a spunbonded web, a meltblown web, a bonded carded 
web, or a combination including any of the following. Preferably, the web 
12 is a spunbonded web. A wide variety of thermoplastic polymer materials 
can be used to make the nonwoven web 12. Exemplary polymer materials 
include without limitation, polypropylene, polyethylene (high and low 
density), ethylene copolymers with C.sub.3 -C.sub.20 .alpha.-olefins, 
propylene copolymers with ethylene or C.sub.4 -C.sub.20 .alpha.-olefins, 
butene copolymers with ethylene, propylene, or C.sub.5 -C.sub.20 
.alpha.-olefins, polyvinyl chloride, polyesters, polyamides, 
polyfluorocarbons, polyurethane, polystyrene, polyvinyl alcohol, 
caprolactams, and cellulosic and acrylic resins. Bicomponent and 
biconstituent thermoplastic webs may also be utilized, as well as webs 
containing blends of one or more of the above-listed thermoplastic 
polymers. The web 12 may have a basis weight of about 0.2-2.0 ounces per 
square yard (osy) before creping, desirably about 0.3-1.5 osy. 
A wide variety of hydrophilic adhesive bonding materials may be applied to 
the first side 14 of the web 12 to reinforce the fibers of the web 12 at 
the locations of adhesive application, to render the first side 14 
hydrophilic, and to temporarily adhere the first side 14 of the web 12 to 
the surface of the drum 26. Example of suitable hydrophilic adhesives 
includes without limitation a material sold under the trade name 
HYCAR.RTM. by the B.F. Goodrich Company. HYCAR.RTM. is an acrylic polymer 
emulsion containing a 20:1 weight ratio of a latex acrylic polymer and an 
additional surfactant. The additional surfactant is sold under the trade 
name AHCOVEL.RTM. by Imperial Chemical Industries, Ltd. and is composed of 
a 55:45 mixture of hydrogenated ethoxylated castor oil and sorbitan 
monooleate. The effective wetting agent is the castor oil derivative. 
Other hydrophilic latex-based adhesives may also be used including, for 
example, other acrylic based latices. One such acrylic-based latex is sold 
by Air Products Co. under the trade name AIRFLEX.RTM. A-105. Hydrophilic 
styrene butadiene rubber-based adhesives may also be employed. Other 
surfactants may also be employed in combination with the adhesives, which 
surfactants are useful as wetting or rewetting agents. Another example of 
a suitable surfactant is TRITON.RTM. X-100, sold by the Union Carbide 
Corp. 
The above-described adhesives can be described generally as latex-based 
adhesives which are rendered hydrophilic by the inclusion of hydrophilic 
surfactants. As an alternative to employing a surfactant, the adhesive 
itself may be composed of one or more hydrophilic polymer materials. An 
example of a hydrophilic polymer-based adhesive is AIRVOL.RTM. 523, sold 
by Air Products Co. This adhesive is based on polyvinyl alcohol having a 
medium molecular weight and about 88% hydrolysis. In other embodiments of 
the adhesive, polyvinyl alcohol may be combined with sorbitol at weight 
ranges of about 70-100% polyvinyl alcohol and 0-30% sorbitol. 
Other hydrophilic polymer-based adhesives include without limitation 
adhesives based on natural gums (e.g., guar gum and pectin), starch and 
starch derivatives, and cellulose derivatives (e.g., methylcellulose, 
carboxymethyl cellulose, and hydroxyalkyl celluloses), and combinations 
thereof. Hydrophilic adhesives may be applied using the printing technique 
described above or, alternatively, by melt blowing, melt spraying, 
dripping, splattering, or any technique capable of producing a partial or 
total adhesive coverage on the first side 14 of the web 12. 
When the second side 16 of the web 12 is creped a wide variety of 
hydrophobic adhesive bonding materials may be utilized to reinforce the 
fibers of the web 12 at the locations of adhesive application, and to 
temporarily adhere the web 12 to the surface of the second creping drum 
36. Elastomeric adhesives (i.e. materials capable of at least 75% 
elongation without rupture) are especially suitable. Suitable materials 
include without limitation aqueous-based styrene butadiene adhesives (not 
treated with hydrophilic surfactants), neoprene, polyvinyl chloride, vinyl 
copolymers, polyamides, and ethylene vinyl terpolymers. A suitable 
hydrophobic adhesive material is an acrylic polymer emulsion (not treated 
with hydrophilic surfactants) sold by the B.F. Goodrich Company under the 
trade name HYCAR.RTM.. The hydrophobic adhesive may be applied using the 
printing technique described above or may, alternatively, be applied by 
meltblowing, melt spraying, dripping, splattering, or any technique 
capable of forming a partial or total adhesive coverage on the second side 
16 of the web 12. 
The percent adhesive coverage of the web 12 generally affects the level of 
creping obtained. Generally the adhesive should cover about 5-100% of the 
web surface, preferably about 10-70% of the web surface, more preferably 
about 25-50% of the web surface. In the presently preferred embodiment, 
the web 12 is coated with hydrophilic adhesive and creped on only one 
side. The web 12 may be coated with hydrophobic adhesive and creped on the 
other side, however. The adhesive should also penetrate the nonwoven web 
12 in the locations where the adhesive is applied. Generally, the adhesive 
should penetrate through about 10-50% of the nonwoven web thickness, 
although there may be greater or less adhesive penetration at some 
locations. 
The resulting creped nonwoven web product has a controlled pattern creping 
which corresponds generally to the nonwoven web interfilament bond pattern 
and, to a lesser degree, the applied adhesive material. A presently 
preferred nonwoven web bonding pattern is a regular point bond pattern 
referred to as the "HP" pattern, shown in FIG. 5. The HP pattern has a 
bond area of 19-32%, a bond density of 204 points/in.sup.2, and a point 
height or depth of 0.030 in. This bond pattern results in the formation of 
regular fiber loops and excellent bulk. 
Another suitable nonwoven web bond pattern is the "rib knit" pattern shown 
in FIG. 6. The rib knit pattern is designed for a knitted fabric 
appearance. The pattern has a bond area of 10-20%, a bond density of 212 
bond points/in.sup.2, and a bond point height or depth of 0.044 in. This 
pattern provides creped nonwoven fabrics with excellent softness. 
Another suitable nonwoven web bond pattern, characterized by 
elliptical-shaped point bonds, is the "wire weave" pattern shown in FIG. 
7. The wire weave pattern has a bond area of 15-21%, a bond density of 302 
point/in.sup.2, and a bond point height or depth of 0.038 in. This pattern 
is designed to provide a nonwoven fabric with a woven look, and results in 
creped nonwoven fabrics having good softness, bulk, and fiber looping. 
The creping of the nonwoven web is primarily manifested in the bonded areas 
of the base ("raw") nonwoven web, corresponding to the nonwoven web bond 
pattern. As a result of the creping, the bonded regions are bent out of 
plane so as to cause permanent creping of the web, and the formation of 
filament looped regions in the unbonded regions alternating with (in 
between) the creped bonded regions. 
FIG. 2 illustrates an uncreped nonwoven web, which is a spunbonded web. 
FIGS. 3 and 4 illustrate the same spunbonded web creped according to the 
invention at creping percentages of 25% and 50%, respectively. As shown in 
FIGS. 3 and 4, each of the creped webs has creped nonwoven web bond 
regions 50 which are bent permanently out of plane due to the creping. 
Looped regions 52 corresponding to the unbonded, non-creped regions exist 
between the creped regions. The creped regions 50 include tightly bonded 
filament regions, while the looped regions 52 include loose filament 
regions. The individual filament loops terminate at both ends in the 
adhesive-reinforced regions, and are anchored in the adhesive-reinforced 
regions. As seen in FIGS. 3 and 4, the degree of looping increases 
substantially when the level of creping is increased from 25% to 50%. The 
completeness of the loops suggest that there is very little fiber 
breakage. 
As is further apparent from FIGS. 3 and 4, the creping provides an 
effective gradient pore or capillary structure whose contour corresponds 
to the contour of creped regions 50 and looped regions 52, and whose 
individual capillaries are in the form of cup-shaped protuberances. Each 
capillary is narrower at an end corresponding to a creped region 50, and 
is wider at an end defined by surrounding looped regions 52. The narrower 
ends defined by creped regions 50, which have been covered with 
hydrophilic adhesive resulting in the creping, provide the hydrophilic 
mechanism away from the wearer's skin that helps remove water and keep it 
away from the skin. The wider ends defined by looped regions 52, which 
have not been covered with adhesive and are not bent out of plane, help 
propel the water away from the skin toward the hydrophilic tops of looped 
regions 52. The hydrophilic creped regions 50 of the nonwoven web are 
positioned away from the wearer's skin, and the hydrophobic looped regions 
52 are against the wearer's skin. 
Put another way, the creped nonwoven web structure includes a large pore, 
generally hydrophobic top side and a smaller pore, more hydrophilic bottom 
side. This creates a capillarity gradient, with more capillarity at the 
bottom compared to the top. In use, the liquid is drawn away from the top 
and is prevented from coming back to rewet the skin, hence insuring a much 
drier top surface and correspondingly drier skin. 
The resulting unitary creped nonwoven web has low density, high 
permeability, excellent surface and bulk softness, excellent fluid 
transfer properties, recoverable stretch properties, surface topology, and 
permanent out-of-plane fiber orientation. The creped nonwoven web can be 
used in a variety of end products including inkers, transfer and surge 
layers, outercovers, wipers, and other fluid handling materials. One 
excellent use of the creped nonwoven web is as a top cover component for a 
diaper. The creped nonwoven web is positioned on the top side of a diaper 
with the hydrophilic creped protuberances facing the absorbent core of the 
diaper, and with the uncreped hydrophobic looped side facing away from the 
absorbent core and adapted to contact the wearer's skin. The creped 
nonwoven web is also useful as a top cover for other personal care 
absorbent products including training pants, incontinence garments, and 
tampons. In each case, the creped nonwoven web is positioned so that 
liquid migrates away from the wearer's skin and toward the hydrophilic 
creped regions 50 of the nonwoven web. 
FIG. 8 illustrates an absorbent article 60, which can be a diaper. The 
article 60 includes a top liner 62, an absorbent core 64, and a back sheet 
66. The liner 62 includes the nonwoven web of the invention having the 
hydrophilic creped protuberances facing the absorbent core 64. The outer 
surface 68 of the liner 62 is hydrophobic and looped, and touches the 
wearer's skin. The inner creped surface 70, having the hydrophilic 
regions, faces the absorbent core. The gradient effect of the liner 62, 
which progresses from hydrophobic to hydrophilic, urges any liquid matter 
away from the wearer's skin and toward the absorbent core 64. 
Because of the looping caused in the uncreped, unbonded regions, the creped 
nonwoven web 12 is also highly suitable for use as the female ("loop") 
component in a hook-and-loop type fastener. The loops in the web 12 engage 
the male fastener components in a peelable fashion, such that the hook and 
loop fastener can be opened and closed a number of times. 
In another embodiment, the nonwoven web can be mechanically stretched in 
the machine direction (causing the web to contract or neck in the cross 
direction) before applying the adhesive and creping the web. The resulting 
necked web product is stretchable in the cross direction. Mechanical 
stretching of the web is accomplished using processes well known in the 
art. For instance, the web may be pre-stretched by about 0-100% of its 
initial length in the machine direction to obtain a necked web that can be 
stretched (e.g. by about 0-100%) in the cross direction. Preferably, the 
web is stretched by about 10-100% of its initial length, more commonly by 
about 25-75% of its initial length. The stretched web is then 
dimensionally stabilized to some extent, first by the adhesive which is 
applied to the web, and second by the heat which is imparted from the 
creping drum. This stabilization sets the cross-directional stretch 
properties of the web. The machine direction stretch is further stabilized 
by the out-of-plane deformation of the nonwoven web bonded areas that 
occurs during creping. 
The pre-stretching of the web can be used to optimize and enhance physical 
properties in the creped nonwoven product including softness, bulk, 
stretchability and recovery, permeability, basis weight, density, and 
liquid holding capacity. The elastic behavior of the creped nonwoven web 
can be further enhanced by laminating it to a layer of elastic material, 
for example, an isotropic elastic web or a layer of elastic strands. 
EXAMPLES 
The following measurement procedures were used to test the fabrics of the 
Examples. The basis weight is determined by measuring the mass of a creped 
nonwoven web sample and dividing it by the area covered by the nonwoven 
web sample. Generally, the basis weight increases at higher levels of 
creping due to crinkling and bulking of the web. 
The liner saturation test measures the level of saturation in the liner 
after it has been saturated and allowed to desorb. Low liner saturation is 
important in reducing skin hydration. The test apparatus is illustrated in 
FIG. 9. The apparatus 10 includes a porous plate 12 charged with a 0.9% 
saline solution. The porous plate 12 is raised to a height h of 10 cm 
above a fluid reservoir 14, hence providing 10 cm capillary suction, 
simulating an absorbent system. The liner 16 to be tested is weighed and 
placed on top of a surge material 18, and both webs are placed on the 
porous plate. Both liner and surge material are 3 inches in diameter. 50 
ml of saline is then poured over the liner and surge and allowed to 
saturate both webs. The porous plate then drains excess liquid and any 
liquid that can be removed from both surge and liner due to the capillary 
suction of the porous plate. A 0.3 psi load is placed over the webs for 5 
minutes to allow equilibrium to occur. At the end of the 5 minute period, 
the liner is carefully removed and immediately weighed. The percentage 
gain in the weight of the liner is reported as percentage liner 
saturation. 
The surge material used was a 2.5 osy bonded carded web composed of 60% by 
weight 3 denier bicomponent polyethylene/polypropylene fibers from Chisso 
Corporation, and a 40% by weight 6 denier polyethylene terephthalate 
fibers. The web density was 0.034 grams/cc. 
The skin dryness test is described as follows: 
Method: Armband Trans Epidermal Water Loss (TEWL) Protocol; 
Reference: F. J. Akin, J. T. Lemmen, D. L. Bozarth, M. J. Garofalo, G. L. 
Grove: A refined method to evaluate diapers for effectiveness in reducing 
skin hydration using the adult forearm, Skin Research and Technology 1997; 
3: 173-176, Denmark. 
This method is a full product test and actually measures the level of 
hydration on human skin after a prescribed method of loading the diaper. 
The product is worn (on the forearm) for one hour after which the level of 
hydration on the skin is measured by an evaporimeter. The measurement unit 
is g/m.sup.2 hour. Lower numbers indicate lower skin hydration. The 
following results are from full product test wherein only the liner was 
changed. 
Example 1 
Control 
For use as a control, a polypropylene spunbond web having a basis weight of 
0.5 ounces per square yard (osy) and 2.2 denier fibers was topically 
treated with 0.3% by weight Ahcovel Base N-62, available from Hodgson 
Chemical Co. Ahcovel Base N-62 is a surfactant used to promote topical 
wettability, and is a blend of ethoxylated hydrogenated castor oil and 
sorbitan monooleate. The spunbond web was not creped. The resulting liner 
was tested for liner saturation and skin dryness. 
Example 2 
A polypropylene spunbond web having a basis weight of 0.4 osy and 3.5 
denier fibers was printed on one side with a fluid containing 35% by 
weight HYCAR.RTM. 26684 latex adhesive solids sold by B.F. Goodrich Co. 
and 65% by weight water. The print pattern uses a 60.times.90 diamond 
pattern. The wet pickup was 1% by weight of the web. The web was creped on 
the coated side to a 25% crepe level. The resulting liner was tested for 
liner saturation and skin dryness. 
Example 3 
A polypropylene spunbond web having a basis weight of 0.3 osy and 2.2 
denier fibers was printed on one side with a fluid containing 35% by 
weight HYCAR.RTM. 26884 latex adhesive solids, 1% by weight Ahcovel Base 
N-62, and 64% by weight water. The print pattern was an overall dot 
pattern. The wet pickup was 3% by weight of the web. The web was creped on 
the coated side to a 25% crepe level. The resulting liner was tested for 
skin dryness. 
Example 4 
A polypropylene spunbond web having a basis weight of 0.3 osy and 2.2 
denier fibers was printed on one side with a fluid containing 35% by 
weight HYCAR.RTM. 26884 latex adhesive solids and 65% by weight water. The 
print pattern was an overall dot pattern. The wet pickup was 3% by weight 
of the web. The web was creped to a 25% level. The resulting liner was 
tested for skin dryness. 
Example 5 
A polypropylene spunbond web having a basis weight of 0.4 osy and 3.2 
denier fibers was topically treated with 0.37% by weight of a surfactant 
containing 0.28 parts by weight Ahcovel Base N-62 and 0.09 parts by weight 
Masil SF-19 (an ethoxylated trisiloxane available from PPG). The web was 
then printed on one side with a fluid containing 35% by weight HYCAR.RTM. 
26884 latex adhesive solids and 65% by weight water. The print pattern was 
an overall dot pattern. The wet pickup was 3% by weight of the web. The 
web was creped to a 25% level. The resulting liner was tested for skin 
dryness. 
The test results are reported below. 
______________________________________ 
Liner Saturation, 
Skin Dryness, TEWL change 
percent from control, grams/m.sup.2 -hour 
______________________________________ 
Example 1 120 0 
Example 2 83 -2.4 
Example 3 Not measured 
-5.5 
Example 4 Not measured 
-6.3 
Example 5 Not measured 
-7.1 
______________________________________ 
The foregoing examples reflect a significant decrease in liner saturation, 
and improvement in skin dryness, when the creped nonwoven material of the 
invention is used as the liner. 
While the embodiments of the invention disclosed herein are presently 
considered preferred, various improvements and modifications can be made 
without departing from the spirit and scope of the invention. The scope of 
the invention is indicated in the appended claims, and all changes that 
fall within the meaning and range of equivalents are intended to be 
embraced therein.