Creped nonwoven laminate loop fastening material for mechanical fastening systems

The creped nonwoven laminate loop material of the present invention includes a creped nonwoven layer attached to a support layer. The creped nonwoven layer may be, for example, a spunbond nonwoven web or a staple fiber bonded carded web. The support layer may be formed of any material that can be suitably attached or bonded to the creped nonwoven layer, including a foam, a plastic film or another nonwoven web. The exposed, top surface of the creped nonwoven layer includes raised "loop" areas having low fiber density and high z-directional fiber orientation that are designed to receive and engage the hook elements projecting from a hook material. The raised areas of the creped nonwoven layer are separated by non-raised areas having relatively higher fiber density and relatively lower z-directional fiber orientation when compared to the fiber density and z-directional fiber orientation of the raised areas. The primary areas of bonding or attachment of the bottom surface of the nonwoven layer to the top surface of the underlying support layer are the non-raised areas; in addition, some secondary bonding of the nonwoven layer to the support layer outside of the non-raised areas may exist. The support layer provides structural integrity for the creped nonwoven laminate material and dimensionally stabilizes the creped nonwoven layer. The creped structure of the nonwoven layer further provides resistance against compression of the fibers forming the hook receiving loop material during use, thereby facilitating entry and engagement of hook elements projecting from the hook material. The creped nonwoven loop laminate of this invention can be employed as the loop material of a hook and loop fastening system, such as used on disposable personal care absorbent articles.

FIELD OF INVENTION 
The present invention is directed to a loop fastening material for 
mechanical fastening systems, commonly referred to as hook and loop 
fastener systems. More specifically, this invention relates to a loop 
fastening material in the form of a nonwoven laminate having a creped 
nonwoven layer attached to a support layer for engaging the hooks of a 
complementary hook material. 
BACKGROUND OF THE INVENTION 
Mechanical fastening systems, of the type otherwise referred to as hook and 
loop fastener systems, have become increasingly widely used in various 
consumer and industrial applications. A few examples of such applications 
include disposable personal care absorbent articles, clothing, sporting 
goods equipment, and a wide variety of other miscellaneous articles. 
Typically, such hook and loop fastening systems are employed in situations 
where a refastenable connection between two or more materials or articles 
is desired. These mechanical fastening systems have in many cases replaced 
other conventional devices used for making such refastenable connections, 
such as buttons, buckles, zippers, and the like. 
Mechanical fastening systems typically employ two components--a male (hook) 
component and a female (loop) component. The hook component usually 
includes a plurality of semi-rigid, hook-shaped elements anchored or 
connected to a base material. The loop component generally includes a 
resilient backing material from which a plurality of upstanding loops 
project. The hook-shaped elements of the hook component are designed to 
engage the loops of the loop material, thereby forming mechanical bonds 
between the hook and loop elements of the two components. These mechanical 
bonds function to prevent separation of the respective components during 
normal use. Such mechanical fastening systems are designed to avoid 
separation of the hook and loop components by application of a shear force 
or stress, which is applied in a plane parallel to or defined by the 
connected surfaces of the hook and loop components, as well as certain 
peel forces or stresses. However, application of a peeling force in a 
direction generally perpendicular or normal to the plane defined by the 
connected surfaces of the hook and loop components can cause separation of 
the hook elements from the loop elements, for example, by breaking the 
loop elements and thereby releasing the engaged hook elements, or by 
bending the resilient hook elements until the hook elements disengage the 
loop elements. 
Mechanical fastening systems can be advantageously employed in disposable 
personal care absorbent articles, such as disposable diapers, disposable 
garments, disposable incontinence products, and the like. Such disposable 
products generally are single-use items which are discarded after a 
relatively short period of use--usually a period of hours--and are not 
intended to be washed and reused. As a result, it is desirable to avoid 
expensive components in the design of such products. Thus, to the extent 
that the hook and loop components are employed in such products, the hook 
and loop components need to be relatively inexpensive in terms of both the 
materials used and the manufacturing processes for making these 
components. On the other hand, the hook and loop components must have 
sufficient structural integrity and resiliency to withstand the forces 
applied thereto during normal wear of the absorbent article, in order to 
avoid potentially embarrassing situations for the wearer that can result 
from premature separation or disengagement of the hook and loop 
components. 
U.S. Pat. No. 4,761,318 to Ott et al. discloses a loop fastening material 
useful in a mechanical fastening system for disposable articles. The loop 
fastening material disclosed by this patent includes a fibrous layer 
having a plurality of loops on a first surface adapted to be releasably 
engaged by a mating hook fastener portion and a layer of thermoplastic 
resin adhered to a second surface of the fibrous structure opposite the 
first surface. The thermoplastic resin anchors the loops in the fibrous 
structure. 
U.S. Pat. No. 5,032,122 to Noel et al. discloses a loop fastening material 
useful in a mechanical fastening system for a disposable article. The loop 
fastening material disclosed by this patent includes a backing of 
orientable material and a multiplicity of fibrous elements extending from 
the backing. The fibrous elements are formed by continuous filaments 
positioned on and intermittently secured to the backing when the 
orientable material of the backing is in its dimensionally unstable state. 
The fibrous elements are formed by the shirring of the filaments between 
spaced, fixed regions of securement to the backing when the orientable 
material is caused to be transformed to its dimensionally stable state 
such that it is caused to contract or gather along its path of response. 
Thus, the loop material of this patent requires a backing of orientable 
material, such as an elastic or elastomeric or heat shrinkable material, 
that is caused to be transformed from a dimensionally stable state to a 
dimensionally unstable state and returned it to its dimensionally stable 
state. 
U.S. Pat. No. 5,326,612 to Goulait discloses another a loop fastening 
material useful in a mechanical fastening system for a disposable article. 
The loop fastening material disclosed by this patent includes a nonwoven 
web secured to a backing. The nonwoven web serves to admit and entangle 
the hooks of a complementary hook component. The nonwoven web has a 
specified basis weight range of between about 5 to about 42 g/m.sup.2, an 
inter-fiber bond area of less than about 10 percent, and a total plan view 
bonded area of less than about 35 percent. 
Notwithstanding the teachings of the aforementioned references, the need 
nonetheless exists for an improved loop fastening material for a 
mechanical fastening system, particularly as such are used in disposable 
personal care absorbent articles. The creped nonwoven laminate loop 
fastening material of the present invention is soft and cloth-like, and 
therefore, aesthetically appealing in terms of appearance and feel. The 
loop material of the present invention is relatively inexpensive to 
produce, especially in comparison to conventional loop materials formed by 
knitting, warp knitting, weaving, and the like, yet exhibits comparable 
and/or improved peel and shear strengths as compared to conventional loop 
fastening materials when used with commercially available hook fastener 
materials. 
SUMMARY OF THE INVENTION 
The present invention is directed to an improved loop fastening material 
for hook and loop fastening systems. The loop material of this invention 
has a three-dimensional surface topography particularly suitable for 
receiving and engaging hook elements of a complementary hook material. The 
hook material can be any of a wide variety of commercially available hook 
components which, as is known in the art, typically include a base 
material from which a plurality of hook elements project. 
The creped nonwoven laminate loop material of the present invention 
includes a creped nonwoven layer attached to a support layer. The creped 
nonwoven layer may be, for example, a spunbond nonwoven web or a staple 
fiber bonded carded web. The support layer may be formed of any material 
that can be suitably attached or bonded to the creped nonwoven layer, 
including a plastic film or another nonwoven web. The exposed, top surface 
of the creped nonwoven layer includes raised "loop" areas having low fiber 
density and high z-directional fiber orientation that are designed to 
receive and engage the hook elements projecting from a hook material. The 
raised areas of the creped nonwoven layer are separated by non-raised 
areas having relatively higher fiber density and relatively lower 
z-directional fiber orientation when compared to the fiber density and 
z-directional fiber orientation of the raised areas. The primary areas of 
bonding or attachment of the fibers or filaments forming the nonwoven 
layer to the top surface of the underlying support layer are the 
non-raised areas; in addition, some secondary bonding of the fibers or 
filaments of the nonwoven layer to the support layer outside of the 
non-raised areas may exist. The support layer provides structural 
integrity for the creped nonwoven laminate material and dimensionally 
stabilizes the creped nonwoven layer. The creped structure of the nonwoven 
layer further provides resistance against compression of the fibers 
forming the hook receiving loop material during use, thereby facilitating 
entry and engagement of hook elements projecting from the hook material. 
The creped nonwoven loop laminate of this invention can be employed as the 
loop material of a hook and loop fastening system, such as used on 
disposable personal care absorbent articles. 
A suitable process for forming the creped nonwoven laminate loop material 
of this invention includes: providing a nonwoven layer, providing a 
support layer, providing opposedly positioned first and second heated 
calender rolls defining a nip therebetween, said first roll having a 
patterned outermost surface and said second roll having a flat outermost 
surface, rotating said first and second rolls in opposite directions, said 
first roll having a first rotational speed and said second roll having a 
second rotational speed, said second rotational speed being 2 to 8 times 
greater than said first rotational speed, and passing the nonwoven layer 
and support layer within the nip formed by said first and second 
counter-rotating rolls to form a creped nonwoven laminate. As a result of 
this forming process, the basis weight of the nonwoven layer is increased 
from a first basis weight prior to being creped and laminated to a second, 
higher basis weight after it exits the nip formed by the counter-rotating 
pattern and anvil rolls. 
When used as the loop component of a hook and loop fastening system for a 
disposable personal care absorbent article, the creped nonwoven laminate 
loop material of this invention can be bonded or attached to the outer 
layer or backsheet of the article as a discrete patch of loop material. 
Alternatively, the creped nonwoven laminate loop material can form the 
entire outer cover or backsheet of such a disposable personal care 
absorbent article.

DETAILED DESCRIPTION OF THE INVENTION 
The present invention relates to an improved loop fastening material for a 
mechanical or hook and loop fastening system. For purposes of illustration 
only, the present invention will be described separately and in 
conjunction with its use with disposable personal care absorbent articles, 
which include diapers, training pants, incontinence garments, sanitary 
napkins, bandages and the like. As such, the invention should not be 
limited to these specific uses, as it is instead intended that the present 
invention be used in all applications in which hook and loop fasteners can 
be employed. 
The loop material of the present invention is intended to be utilized with 
a wide variety of hook materials. Exemplary of hook materials suitable for 
use with the loop material of the present invention are those obtained 
from: Velcro Group Company, of Manchester, N.H., under the trade 
designations CFM-22-1097; CFM-22-1121; CFM-22-1162; CFM-25-1003; 
CFM-29-1003; and CFM-29-1005; or Minnesota Mining & Manufacturing Co., of 
St. Paul, Minn., under the designation CS 200. Suitable hook materials 
generally comprise from about 16 to about 620 hooks per square centimeter, 
or from about 124 to about 388 hooks per square centimeter, or from about 
155 to about 310 hooks per square centimeter. The hooks suitably have a 
height of from about 0.00254 centimeter (cm) to about 0.19 centimeter, or 
from about 0.0381 centimeter to about 0.0762 centimeter. 
As can be seen in FIGS. 3 and 4, the hook material 22 includes a base layer 
24 with a plurality of bi-directional hook elements 26 extending generally 
perpendicularly therefrom. As used herein, the term "bi-directional" 
refers to a hook material having individual adjacent hook elements 
oriented in opposite directions in the machine direction of the hook 
material. The term "uni-directional," on the other hand, refers to a hook 
material having individual adjacent hook elements oriented in the same 
direction in the machine direction of the hook material. 
In order to achieve constant data regarding the present invention, a single 
type of hook material was used in evaluating the loop material of the 
present invention. The hook elements 26 have an average overall height H 
measured from the top surface 25 of the base material 24 to the highest 
point on the hook elements 26. The average height of the hook elements 26 
used in conjunction with the present invention is about 0.5 millimeter 
(mm). Hook material 22 has a hook density of about 265 hooks per square 
centimeter. The thickness of base material 24 is about 3.5 mils. The hook 
material 22 used in conjunction with the present invention is available 
from Velcro USA as CFM-29-1003. Other dimensions and properties of the 
hook material 22 are as outlined in the examples described hereinbelow. 
Although the term "hook material" is used herein to designate the portion 
of a mechanical fastening system having engaging (hook) elements, it is 
not intended to limit the form of the engaging elements to only include 
"hooks" but shall encompass any form or shape of engaging element, whether 
uni-directional or bi-directional, as is known in the art to be designed 
or adapted to engage a complementary loop fastening material, such as the 
creped nonwoven laminate loop material of the present invention. 
Referring to FIGS. 1 and 2, an embodiment of the creped nonwoven laminate 
loop material 10 of the present invention is illustrated. By way of 
definition, the term "creped nonwoven laminate loop material" as used 
herein is intended to refer to a loop or female component for a hook and 
loop fastening system that comprises, in its simplest form, a creped 
nonwoven layer or web secured to a support layer or web. This term is not 
intended to limit the loop material of the present invention to only 
nonwoven materials; rather, the loop material of the present invention 
also includes alternative embodiments in which, for example, the support 
layer or web is not a nonwoven layer or web, as will described 
hereinbelow. Nor is use of the term "loop" intended to limit the loop 
material of the present invention to only materials in which discrete, 
separately formed loops of material are employed to receive and engage the 
hook elements of a complementary hook material; rather, the loop material 
of the present invention includes fibrous nonwoven layers in which the 
individual fibers function to engage the hook elements without such fibers 
being formed into discrete loops. 
As used herein, the terms "layer" or "web" when used in the singular can 
have the dual meaning of a single element or a plurality of elements. As 
used herein, the term "laminate" means a composite material made from two 
or more layers or webs of material which have been attached or bonded to 
one another. 
Referring again to FIGS. 1 and 2, loop material 10 is shown comprising a 
creped nonwoven layer 12 bonded to a support layer 14. Nonwoven layer 12 
can be generally described as any nonwoven web that, when formed in 
accordance with the present invention, is suitable for receiving and 
engaging the hooks of a complementary hook material. As used herein, the 
terms "nonwoven layer" or "nonwoven web" mean a web having a structure of 
individual fibers or threads which are interlaid, but not in an 
identifiable manner as in a knitted fabric. Commercially available 
thermoplastic polymeric materials can be advantageously employed in making 
the fibers or filaments from which nonwoven layer 12 is formed. As used 
herein, the term "polymer" shall include, but is not limited to, 
homopolymers, copolymers, such as, for example, block, graft, random and 
alternating copolymers, terpolymers, etc., and blends and modifications 
thereof. Moreover, unless otherwise specifically limited, the term 
"polymer" shall include all possible geometrical configurations of the 
material, including, without limitation, isotactic, syndiotactic and 
random symmetries. As used herein, the terms "thermoplastic polymer" or 
"thermoplastic polymeric material" refer to a long-chain polymer that 
softens when exposed to heat and returns to its original state when cooled 
to ambient temperature. Exemplary thermoplastic materials include, without 
limitation, polyvinyl chlorides, polyesters, polyamides, 
polyfluorocarbons, polyolefins, polyurethanes, polystyrenes, polyvinyl 
alcohols, caprolactams, and copolymers of the foregoing. The fibers used 
in making nonwoven layer 12 may have any suitable morphology and may 
include hollow or solid fibers, straight or crimped fibers, bicomponent, 
multicomponent, biconstituent or multiconstituent fibers, and blends or 
mixes of such fibers, as are well known in the art. 
Nonwoven webs that can be employed as nonwoven layer 12 of the present 
invention can be formed by a variety of known forming processes, including 
spunbonding, airlaying, or bonded carded web formation processes. Spunbond 
nonwoven webs are made from melt-spun filaments. As used herein, the term 
"melt-spun filaments" refers to small diameter fibers and/or filaments 
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, 
for example, by non-eductive or eductive fluid-drawing or other well known 
spunbonding mechanisms. The production of spunbond nonwoven webs is 
described in U.S. Pat. No. 4,340,563 to Appel et al., U.S. Pat. No. 
3,692,618 to Dorschner et al., U.S. Pat. No. 3,802,817 to Matsuki et al., 
U.S. Pat. Nos. 3,338,992 and 3,341,394 to Kinney, U.S. Pat. No. 3,502,763 
to Hartmann, U.S. Pat. No. 3,276,944 to Levy, U.S. Pat. No. 3,502,538 to 
Peterson, and U.S. Pat. No. 3,542,615 to Dobo et al., all of which are 
incorporated herein by reference. The melt-spun filaments formed by the 
spunbond process are generally continuous and have diameters larger than 7 
microns, more particularly, between about 10 and 20 microns. 
In making the specific embodiment of the present invention shown in FIGS. 1 
and 2, a conventional spunbond process may be used to form a nonwoven web 
of melt-spun filaments formed from an extrudable thermoplastic resin which 
is a random copolymer of propylene and ethylene. A random copolymer 
containing from about 0.5 to about 10 percent, by weight, ethylene and 
from about 99.5 to about 90 percent, by weight, propylene has been found 
to work well in the present invention. 
A suitable spunbond process and apparatus for producing a nonwoven web of 
melt-spun copolymer filaments are schematically illustrated in FIG. 9. In 
forming such a spunbond web of melt-spun copolymer filaments (e.g., 
spunbonded filaments), pellets, chips or the like of a copolymer material 
are introduced into a pellet hopper 80 of an extruder 82. The extruder 82 
has an extrusion screw (not shown) that is driven by a conventional drive 
motor (not shown). As the copolymer advances through the extruder 82, due 
to rotation of the extrusion screw by the drive motor, the copolymer is 
progressively heated to a molten state. Heating of the copolymer to the 
molten state may be accomplished in a plurality of discrete steps with its 
temperature being gradually elevated as it advances through discrete 
heating zones of the extruder 82 toward an extrusion die 84. The die 84 
may be yet another heating zone where the temperature of the copolymer is 
maintained at an elevated level for extrusion. The temperature which will 
be required to heat the copolymer to a molten state will vary somewhat 
depending upon the type of copolymer used. For example, a random block 
copolymer containing about 3.2 percent, by weight, ethylene and about 96.8 
percent, by weight, propylene, may be extruded at a temperature of from 
about 227.degree. C. to about 260.degree. C. Heating of the various zones 
of the extruder 82 and the extrusion die 84 may be achieved by any of a 
variety of conventional heating arrangements (not shown). 
The filaments of the molten copolymer are initially formed and discharged 
in a stream 86 from spaced-apart filament forming means 88. The forming 
means 88 may be any suitable filament forming means, such as spinnerettes, 
die orifices, or similar equipment associated with melt-spinning processes 
such as, for example, the spunbonding process. The melt-spun filaments 
discharged from the forming means 88 are drawn through passage 85 in fiber 
draw unit 87, to which high speed fluid sources 89, such as jet streams of 
air, are operatively connected. The action of the high speed fluid on the 
melt-spun filaments 86 passing downwardly through passage 85 stretches the 
melt-spun filaments 86, and increases the speed of delivery of the 
melt-spun filaments to a forming surface. The melt-spun filaments upon 
exiting passage 85 are deposited in a random manner on a foraminous 
forming surface 90, generally assisted by a vacuum device (not shown) 
placed underneath the forming surface 90. The melt-spun filaments are 
between 1.5 and 5.0 denier per filament (dpf), and more particularly 
between 2.0 and 2.5 dpf. The purpose of the vacuum is to eliminate the 
undesirable scattering of the filaments and to guide the filaments onto 
the forming surface 90 to form a nonwoven web 92 of melt-spun copolymer 
filaments. The forming surface 90 is supported in turn on roller 94 driven 
by conventional drive means (not shown). 
The nonwoven web 92 separates from the forming surface 90, and is directed 
into and through nip 96 of a patterned roller arrangement 100. The pattern 
roll 98 is used for thermal bonding of the web 92. The smooth anvil roll 
99, together with the pattern roll 98, defines a thermal pattern bonding 
nip 96. Alternatively, anvil roll 99 also may bear a bonding pattern on 
its outer surface. The pattern roll 98 is heated to a suitable bonding 
temperature by heating means (not shown) and is rotated by conventional 
drive means (not shown), so that when the web 92 passes through nip 96, a 
series of thermal pattern bonds is formed. Nip pressure within nip 96 
should be sufficient to achieve the desired degree of bonding of web 92, 
given the line speed, bonding temperature and materials forming web 92. 
For example, nip pressures within the range of about 60 to 85 pounds per 
lineal inch (pli) (about 1.07 to 1.51 kilograms per lineal millimeter) are 
suitable. As a result of the thermal pattern bonding, the web 92 of 
filaments becomes a pattern bonded web 102 of enhanced stability. 
The percent bond area of the pattern bonded web 102 is important to the 
functionality of the creped nonwoven laminate loop material of this 
invention. Generally speaking, the percent bond area of the nonwoven web 
should be sufficiently high so that a majority of the generally continuous 
melt-spun filaments have portions that extend through at least two pattern 
bonds. In this way, individual filaments within the nonwoven web can more 
securely engage the hook elements of a hook material, resulting in 
suitable peel and shear strength properties for the loop material. In 
addition, a sufficiently high percent bond area serves to reduce fiber 
pull-out, which can result from repeated disengagement of hook elements 
from the loop material. A high incidence of fiber pull-out can reduce the 
peel and/or shear strength of the loop material, and deleteriously affect 
the appearance (i.e., increased fuzziness) of the loop material. Thus, 
increasing the percent bond area tends to improve the surface integrity 
and durability of the loop material. On the other hand, the percent bond 
area should not be so high that the number and size of inter-filament 
areas in which the hook elements of the hook material are received when 
engaging the loop material are insufficiently large to allow a sufficient 
number of hook elements to be received into the loop material. For 
example, in the spunbond apparatus illustrated in FIG. 9, the pattern roll 
98 has a point bond pattern with a surface bond area between about 10 
percent and about 25 percent or more, using a bond point density of 
between about 15.5 and 46.5 bond points per square centimeter. 
Alternatively, a pattern roll 98 having a surface bond area within the 
range of about 13 percent to about 22 percent, or within the range of 
about 15 percent to about 20 percent, has been found suitable for use in 
the present invention. Bond densities above and below the above-stated 
range also can be used, with the specific bond density being dependent 
upon the size of the individual bond points. The pattern bonded web 102 
then is passed to other process and/or treatment steps. 
Nonwoven layer 12 also may be made from bonded carded webs. Bonded carded 
webs are made from staple fibers, which are usually purchased in bales. 
The bales are placed in a picker, which separates the fibers. Then, the 
fibers are sent through a combing or carding unit, which further breaks 
apart and aligns the staple fibers in the machine direction to form a 
generally machine direction-oriented fibrous nonwoven web. Once the web is 
formed, it then is bonded by one or more of several known bonding methods. 
One such bonding method is powder bonding, wherein a powdered adhesive is 
distributed through the web and then activated, usually by heating the web 
and adhesive with hot air. Another suitable bonding method is pattern 
bonding, wherein heated calender rolls or ultrasonic bonding equipment are 
used to bond the fibers together, usually in a localized bond pattern, 
though the web can be bonded across its entire surface if so desired. 
Another suitable bonding method, particularly when using bicomponent 
staple fibers, is through-air bonding. 
Through-air bonders are well known in the art and need not be described in 
detail herein. Generally, a common type of through-air bonder includes a 
perforated roller, which receives the web, and a hood surrounding the 
perforated roller. A flow of heated air is directed from the hood and 
applied through the web and into the perforated roller. The heated air 
heats the web to a temperature above the melting point of the lower 
melting point component of the bicomponent filaments, but below the 
melting point of the higher melting point component. Upon heating, the 
lower melting polymer portions of the web filaments melt and adhere to 
adjacent filaments at their cross-over points, while the higher melting 
polymer portions of the filaments tend to maintain the physical and 
dimensional integrity of the web. For example, when polypropylene and 
polyethylene are used as the polymer components, the air flowing through 
the through-air bonder can have a temperature ranging from about 
110.degree. C. to about 140.degree. C. and a velocity from about 30 to 
about 150 meters per minute. The dwell time of the web in the through-air 
bonder typically should not exceed about 6 seconds. It should be 
understood, however, that the parameters of the through-air bonder depend 
on factors such as the type of polymers used, the thickness of the web, 
etc. 
Airlaying is another well known process by which fibrous nonwoven layer 12 
can be formed. In the airlaying process, bundles of small fibers having 
typical lengths ranging from about 6 to about 19 millimeters (mm) are 
separated and entrained in an air supply and then deposited onto a forming 
screen, usually with the assistance of a vacuum supply. The randomly 
deposited fibers then are bonded to one another using, for example, hot 
air or a spray adhesive. 
In order to obtain the specified range of physical properties in the 
resultant creped nonwoven layer 12 in accordance with the present 
invention, the bonding process used to bond the fibers or filaments of the 
nonwoven layer should be a process that can control the level of 
compression or collapse of the fibrous structure during the formation 
process. Whatever forming process is utilized, the degree of bonding will 
be dependent upon the fibers/polymers used, but in any event, it is 
desirable that the amount of web compression be controlled during the 
heating stage. 
As a result of the creping process employed in making the creped nonwoven 
laminate loop material of this invention, nonwoven layer 12 (see FIGS. 1 
and 2) is creped or "bunched," thereby forming raised areas 16 separated 
by non-raised areas 18 in nonwoven layer 12 and thus imparting rugosities 
or wrinkles in nonwoven layer 12. Within raised areas 16, hydroentangled 
nonwoven layer 12 may be physically separated from and/or unbonded to 
support layer 14. The raised areas 16 have a first, low fiber density and 
the fibers within the raised areas 16 exhibit a first, high z-directional 
orientation. As such, the raised areas 16 are intended to receive and 
engage the hook elements of a complementary hook material, as shown in 
FIGS. 3 and 4. The non-raised areas 18 have a second, relatively higher 
fiber density as compared to the raised areas 16 due to compression or 
compaction of the fibers of nonwoven layer 12 in the non-raised areas and 
exhibit a second, relatively lower z-directional fiber orientation. The 
creping imparted to nonwoven layer 12 by the forming process further 
serves to increase the basis weight of the nonwoven material, as a larger 
amount of nonwoven material is compacted within a given unit area. The 
basis weight of the nonwoven material has been observed to increase by as 
much as a factor of 2, or more, depending, for example, on the degree of 
creping imparted by the creping apparatus described hereinafter. The 
creped structure of nonwoven layer 12 provides resistance to compression 
of the fibrous structure of nonwoven layer 12, thereby facilitating entry 
and engagement of the hook elements of hook material 22 during use of the 
hook and loop fastening system. FIG. 5 illustrates in detail the features 
and contours of nonwoven layer 12. 
Support layer 14 can be generally described as any material, including 
woven or nonwoven materials or thermoplastic films, that can be suitably 
bonded to an outer surface of the nonwoven layer 12 in order to provide a 
foundation for the nonwoven layer 12. Support layer 14 can, for example, 
be formed by the material of an underlying substrate, such as the outer 
cover or backsheet of an absorbent article. Thus, support layer 14 
provides structural integrity to the creped nonwoven laminate material, 
and serves to dimensionally stabilize the fibers within nonwoven layer 12. 
Suitable film formulations used in forming support layer 14 include 
homopolymers and copolymers of ethylene or propylene, such as low density 
polyethylene (LDPE), linear low density polyethylene (LLDPE), 
ethylene/vinyl acetate copolymers (EVA), high density polyethylene (HDPE), 
or a mixture of two or more of these polymers. Such films may be monolayer 
or multi-layer and can be formed by any suitable film manufacturing 
process as is well known in the art, including, for example, blow-molding, 
cast-extrusion and bioriented-extrusion. For example, in the specific 
embodiment shown in FIGS. 1 and 2, support layer 14 is a 0.6 mil thick, 
blow-molded mono-layer film sold under the product designation XBPP-133 by 
Consolidated Thermoplastics Co., having offices in Dallas, Tex. Based upon 
nuclear magnetic resonance (NMR) analysis, this film includes 84 percent 
polypropylene and 16 percent polyethylene, by weight, based upon the total 
film weight. Other suitable films used in forming support layer 14 can be 
made of or include a heterophasic polymer composition as described in U.S. 
Pat. No. 5,368,927 to Lesca et al., or U.S. Pat. No. 5,453,318 to 
Giacobbe, the disclosures of which are incorporated herein by reference. 
Typical commercially available thermoplastic film materials have initial 
thicknesses ranging from about 0.4 mil to about 5 mils. 
If support layer 14 is formed of a nonwoven material, such nonwoven layer 
can be formed by any suitable known process, such as those described 
hereinabove. 
Although in the embodiments shown, support layer 14 is illustrated as 
coextensive with nonwoven layer 12, the present invention is not limited 
to such embodiments. For example, nonwoven layer 12 can be creped singly 
and then secured or attached directly to an underlying substrate, such as 
an outer cover of an absorbent article. In this alternative embodiment, 
the substrate functions as a support layer 14. If the outer cover of an 
absorbent article forms the support layer 14 of the present invention, the 
outer cover may be formed of any suitable material that provides the 
required functionality as described herein for support layer 14. By way of 
example only, a typical material used in forming absorbent article outer 
covers is polyethylene film. 
Referring now to FIG. 7, a process and apparatus for forming the creped 
nonwoven laminate loop material of this invention now will be described. A 
suitable process and apparatus for forming such creped nonwoven laminate 
materials is described in detail in the commonly assigned U.S. patent 
application Ser. No. 463,592, filed on Jun. 5, 1995, which is incorporated 
herein by reference. It should be understood, however, that any process 
and apparatus suitable for forming a creped nonwoven laminate loop 
material having the functionality and attributes described herein with 
respect to Applicants' invention may be employed. 
In FIG. 7, apparatus for forming the creped nonwoven laminate loop material 
of this invention is represented generally as element 30. The apparatus 30 
includes a first web unwind 36 for a first web 38 and an optional second 
web unwind 32 for a second web 34. For purposes of illustration only, the 
first web unwind 36 shall be described as having a roll of plastic film 38 
and the second web unwind 32 shall be described as having a roll of 
nonwoven web material 34 such as a spunbond, air laid, wet laid or bonded 
carded web. It should be understood, however, that unwinds 32 and 36 may 
be used to feed any type of web material into the apparatus shown that is 
compatible therewith and forms the creped nonwoven laminate loop material 
of the present invention. It further should be understood that although 
the apparatus of FIG. 7 shows web unwinds 36 and 32, the creping assembly 
30 may be placed in a continuous (in-line) process with the conventional 
nonwoven forming and/or film forming apparatus described herein. 
In order to further manipulate the properties of the creped nonwoven 
laminate loop material formed by the apparatus depicted in FIG. 7, it has 
been found advantageous to control the respective rotational speeds of the 
unwinds 32 and 36. As a result, it is desirable to provide both unwinds 
with driving and/or braking means (not shown) to control the rotational 
speeds of the unwinds, as will be explained in further detail below. Such 
driving and/or braking means are widely known to those of ordinary skill 
in the art and are commonly used in conjunction with such unwinds to 
control tension in the web materials being unwound. 
First web 38 (or simply "web" if only one unwind is used) is taken off the 
unwind 36 and second web 34 is taken off second unwind 32. Both webs 34 
and 38 are passed into a creping assembly 40 that includes a first or 
pattern roll 42 and a second or an anvil roll 44, both of which are driven 
and/or braked with respect to one another so as to create a rotational 
speed differential between the two rolls 42 and 44. Suitable means for 
driving the first and second rolls 42 and 44 include, for example, 
electric motors (not shown). 
Pattern roll 42 is a right circular cylinder that may be formed of any 
suitable, durable material, such as, for example, steel, to reduce the 
wear on the rolls during use. Pattern roll 42 has a pattern of raised 
areas 46 separated by a pattern of non-raised or depressed areas 48. The 
raised areas 46 are designed to form a nip with the smooth or flat outer 
surface of opposedly positioned anvil roll 44, which also is a right 
circular cylinder that can be formed of any suitable, durable material. 
The size, shape and number of raised areas 46 on pattern roll 42 can be 
varied to meet the particular end-use needs of the creped nonwoven 
laminate loop material being formed thereby. Likewise, the pattern of 
raised areas 46 on pattern roll 42 can be continuous or discontinuous, as 
necessitated by the end use application. Typically the relative percentage 
of raised areas per unit area of the pattern roll 42 will range between 
about 5 and about 50 percent and the average contact area of each of the 
raised areas 46 will range between about 0.20 and about 1.6 square 
millimeters (mm.sup.2). Generally, the height of the raised areas 46 will 
range from about 0.25 to about 1.1 millimeters (mm), although heights 
outside of this range can be used for specific applications if so desired. 
The number of contact areas per unit area of the pattern roll 42 generally 
will range between about 3 and about 100 raised areas per square 
centimeter (cm.sup.2) of the pattern roll 42. The shape, geometry or 
footprint of the raised areas 46 on pattern roll 42 also can be varied. 
Ovals, squares, circles and diamonds are examples of shapes that can be 
advantageously employed. 
The temperature of the outer surface of pattern roll 42 can be varied by 
heating or cooling relative to anvil roll 44. Heating and/or cooling can 
affect the features of the web(s) being processed and the degree of 
bonding of multiple webs being passed through the nip formed between the 
counterrotating pattern roll 42 and anvil roll 44. The specific ranges of 
temperatures to be employed in bonding nonwoven layer 12 to support layer 
14 is dependent upon a number of factors, including the types of materials 
employed in forming nonwoven layer 12 and support layer 14, the inlet or 
line speed(s) of the layers 12 and 14 passing through the nip formed 
between pattern roll 42 and anvil roll 44, and the nip pressure between 
pattern roll 42 and anvil roll 44. Common heating techniques include hot 
oil and electrical resistance heating, as are well known to those of 
ordinary skill in the art. 
Anvil roll 44 has an outer surface that is much smoother than pattern roll 
42, and preferably is smooth or flat. It is possible, however, for anvil 
roll 44 to have a slight pattern on its outer surface and still be 
considered smooth or flat for purposes of the present invention. For 
example, if anvil roll 44 is made from or has a softer surface, such as 
resin impregnated cotton or rubber, it will develop surface 
irregularities, yet it will still be considered smooth or flat for 
purposes of the present invention. Such surfaces are collectively referred 
to herein as "flat." Anvil roll 44 provides the base for pattern roll 42 
and webs of material 12 and 14 to contact and shear against. Typically, 
anvil roll 44 will be made from steel, or materials such as hardened 
rubber, resin-treated cotton or polyurethane. 
Anvil roll 44 also may have flat areas separated by depressed areas (not 
shown) so that only select areas of anvil roll 44 will contact raised 
areas 46 of pattern roll 42. The same technique may be used on pattern 
roll 42. As a result, creping can be selectively imparted to specific 
regions of the web being processed. As with pattern roll 42, anvil roll 44 
may be heated and/or cooled to further affect the properties of the webs 
being processed. 
Pattern roll 42 and anvil roll 44 are rotated in opposite directions to one 
another so as to draw the webs of materials 12 and 14 through the nip area 
defined therebetween. Pattern roll 42 has a first rotational speed 
measured at its outer surface and anvil roll 44 has a second rotational 
speed measured at its outer surface, with the second rotational speed of 
the anvil roll 44 exceeding the first rotational speed of the pattern roll 
42. The inlet speeds of the webs 12 and 14 may be adjusted to be less 
than, equal to or greater than the first rotational speed of pattern roll 
42. 
The locations of the opposedly positioned two rolls 42 and 44 may be varied 
to create a nip area 50 between pattern roll 42 and anvil roll 44. The nip 
pressure within nip area 50 can be varied depending upon the properties of 
the web itself or webs themselves and the degree of bonding and/or creping 
desired. Other factors which will allow variances in the nip pressure will 
include the speed differential between pattern roll 42 and anvil roll 44, 
the temperature of the rolls 42 and 44 and size and spacing of the raised 
areas 46. For such materials as films and nonwovens, the nip pressure 
typically will range between about 2.0 and about 6.0 kilograms per lineal 
millimeter (kg/lmm). Other nip pressures are possible depending upon the 
particular end use application desired. 
By manipulating the respective rotational speeds of the pattern roll 42 and 
anvil roll 44 such that the speed of the anvil roll 44 exceeds that of the 
pattern roll 42, the creped nonwoven laminate loop material of the present 
invention can be formed. Rotating the anvil roll 44 faster than the 
pattern roll 42 causes the web of material contacting the pattern roll 42, 
which is nonwoven layer 12 in FIG. 7, to be creped, compacted or bunched 
in and around the raised areas 46 of pattern roll 42 as it passes through 
the nip area 50 formed between the rolls. The web of material contacting 
the faster rotating anvil roll 44, however, need not be compacted or 
bunched. Increasing the speed differential between the pattern roll 42 and 
anvil roll 44 has been observed to increase the amount of crepe in the 
material being processed. As nonwoven layer 12 and support layer 14 are 
bonded together or laminated within the nip area 50, raised areas 16 are 
formed wherein the nonwoven material is bunched to form rugosities in 
nonwoven layer 12. In the embodiment shown, raised areas 16 encircle 
bonding points 20 within the non-raised areas 18 of nonwoven layer 12. The 
degree of creping or bunching will depend not only upon the speed 
differential of the two rolls, but also upon other processing conditions, 
including the windup speeds, the respective roll temperatures and the area 
(spacing and depth) between the raised areas 46. Once the webs 12 and 14 
pass through the creping assembly 40, the creped nonwoven laminate loop 
material 52 formed thereby has features and contours as shown in the 
photomicrograph of FIG. 5 hereof. 
Nonwoven layer 12 and support layer 14 are bonded to one another at a 
plurality of bond points 20 within the non-raised areas 18 of nonwoven 
layer 12, thereby forming a plurality of raised areas 16 in nonwoven layer 
12 separating the non-raised areas 18. The degree of bonding or attachment 
between nonwoven layer 12 and support layer 14 should be sufficient to 
prevent delamination of layers 12 and 14 when subjected to the forces and 
pressures typically exerted during normal use (i.e., during repeated 
fastening and removal of the hook elements of a complementary hook 
material). As noted above, the non-raised areas 18 adjacent the bond 
points 20 will have an increased fiber density, as compared to the fiber 
density of the raised areas 16 intermediate non-raised areas 18, resulting 
from the compression or compaction of the fibers of nonwoven layer 12 
imparted by the bonding process described above. In the embodiment shown, 
bond points 20 are discrete or discontinuous bonded areas encircled by 
raised areas 16 in which nonwoven layer 12 and support layer 14 are less 
bonded or unbonded. The term "unbonded" as used herein is meant to refer 
to the absence of bonds of sufficient strength to withstand the forces 
typically encountered during ordinary use of the creped nonwoven laminate 
loop material of the present invention. 
Alternatively, nonwoven layer 12 and support layer 14 may be bonded 
together along a plurality of bond lines within the non-raised areas 18 of 
nonwoven layer 12, thereby forming a plurality of substantially continuous 
pleats or corrugations in raised areas 16 in nonwoven layer 12. These 
pleats or corrugations are oriented in a direction generally perpendicular 
to the machine direction of travel of nonwoven layer 12. By "generally 
perpendicular" it is meant that the angle between the longitudinal axis of 
the corrugations or pleats formed in nonwoven layer 12, or extensions 
thereof, and the machine direction is between 60.degree. and 120.degree.. 
As used herein, the term "machine direction" or MD means the length of a 
material or fabric in the direction in which it is produced (from left to 
right in FIG. 7). The term "cross machine direction" or CD means the width 
of a material or fabric, i.e. a direction generally perpendicular to the 
MD. Such bond lines can be continuous or discontinuous and will be 
generally parallel to one another. By "generally parallel" it is meant 
that the bond lines themselves or extensions of the bonds lines will 
either not intersect, or if they do intersect, the interior angle formed 
by the intersection will be less than or equal to 30.degree.. 
Although bonding or lamination of nonwoven layer 12 and support layer 14 is 
specifically described herein with reference to heated calender rolls 42 
and 44 shown in FIG. 7, any suitable pattern bonding method and apparatus 
may be employed that achieves sufficient lamination of the two layers 12 
and 14. For example, an adhesive bonding process and apparatus as is well 
known to those of ordinary skill in the art could be utilized to bond 
layers 12 and 14 together. Alternatively, an ultrasonic bonding process 
and apparatus as is likewise well known to those of ordinary skill in the 
art could be used. 
As the creped nonwoven laminate loop material 52 exits the creping assembly 
40, the loop material 52 is collected on a web take-up winder 54. As with 
the first unwind 36 and second unwind 32, take-up winder 54 is driven by 
an electric motor or other drive source which can be varied so as to 
adjust the speed at which the loop material 52 is wound up into a roll 56. 
The speed at which the laminate material 52 is wound on the winder 54 will 
also affect the properties and appearance of the material. Alternatively, 
take-up winder 54 may be eliminated and laminate material 52 may continue 
in-line for further processing in web converting apparatus (not shown), 
such as, for example, application onto an outer cover or backsheet of a 
personal care absorbent article. 
Both the inlet speed of the webs 12 and 14 and the withdrawal speed of the 
laminate material 52 can be varied to change of the conditions of the 
process. For example, the inlet speed of webs 12 and 14 can be equal to or 
greater than the rotational speed of first or pattern roll 42, and equal 
to or slower than the rotational speed of the second or anvil roll 44. 
Exiting the nip area 50 formed by pattern roll 42 and anvil roll 44, 
laminate material 52 can have a withdrawal speed which is equal to or 
greater than the rotational speed of pattern roll 42, and slower or equal 
to the rotational speed of anvil roll 44. It is considered advisable, 
however, to adjust the withdrawal speed of the laminate material 52 such 
that stretching of the material 52 is limited, or avoided entirely, in 
order to maintain the 3-dimensional surface topography of the material 52, 
and particularly the z-directional orientation of fibers within the raised 
areas 16. 
Once the creped nonwoven laminate loop material of the present invention is 
formed, it can be attached to the outer cover or backsheet of a personal 
care absorbent article, such as disposable diaper 60 shown in FIG. 6. More 
specifically, the exposed surface of support layer 14 opposite the surface 
attached to creped nonwoven layer 12 can be secured to outer cover 62 of 
diaper 60 by known attachment means, including adhesives, thermal bonding, 
ultrasonic bonding or a combination of such means. A wide variety of 
adhesives can be employed, including, but not limited to, solvent-based, 
water-based, hot-melt and pressure sensitive adhesives. Powdered adhesive 
can also be applied to the materials and then heated to activate the 
powder adhesive and perfect bonding. 
Diaper 60, as is typical for most personal care absorbent articles, 
includes a liquid permeable body side liner 64 and a liquid impermeable 
outer cover 62. Various woven or nonwoven fabrics can be used for body 
side liner 64. For example, the body side liner may be composed of a 
meltblown or spunbond nonwoven web of polyolefin fibers, or a bonded 
carded web of natural and/or synthetic fibers. Outer cover 62 is typically 
formed of a thin thermoplastic film, such as polyethylene film. The 
polymer film outer cover may be embossed and/or matte finished to provide 
a more aesthetically pleasing appearance. Other alternative constructions 
for outer cover 62 include woven or nonwoven fibrous webs that have been 
constructed or treated to impart the desired level of liquid 
impermeability, or laminates formed of a woven or nonwoven fabric and 
thermoplastic film. Outer cover 62 may optionally be composed of a vapor 
or gas permeable, "breathable" material, that is permeable to vapors or 
gas yet substantially impermeable to liquid. Breathability can be imparted 
in polymer films by, for example, using fillers in the film polymer 
formulation, extruding the filler/polymer formulation into a film and then 
stretching the film sufficiently to create voids around the filler 
particles, thereby making the film breathable. Generally, the more filler 
used and the higher the degree of stretching, the greater the degree of 
breathability. 
Disposed between liner 64 and outer cover 62 is an absorbent core 66 
formed, for example, of a blend of hydrophilic cellulosic woodpulp fluff 
fibers and highly absorbent gelling particles (e.g., superabsorbent). 
Absorbent core 66 is generally compressible, conformable, non-irritating 
to the wearer's skin, and capable of absorbing and retaining liquid body 
exudates. For purposes of this invention, absorbent core 66 can comprise a 
single, integral piece of material, or a plurality of individual separate 
pieces of material. The size and absorbent capacity of absorbent core 66 
should be compatible with the size of the intended user and the liquid 
loading imparted by the intended use of the diaper 60. 
Elastic members may optionally be disposed adjacent each longitudinal edge 
68 of diaper 60. Such elastic members are arranged to draw and hold the 
lateral, side margins 68 of diaper 60 against the legs of the wearer. 
Additionally, elastic members also may be disposed adjacent either or both 
of the end edges 70 of diaper 60 to provide an elasticized waistband. 
Diaper 60 may further include optional containment flaps 72 made from or 
attached to body side liner 64. Suitable constructions and arrangements 
for such containment flaps are described, for example, in U.S. Pat. No. 
4,704,116, to K. Enloe, the disclosure of which is incorporated herein by 
reference in its entirety. 
To secure the diaper 60 about the wearer, the diaper will have some type of 
fastening means attached thereto. As shown in FIG. 6, the fastening means 
is a hook and loop fastening system including hook elements 74 attached to 
the inner and/or outer surface of outer cover 62 in the back waistband 
region of diaper 60 and one or more loop elements or patches 76 made from 
the loop material of the present invention attached to the outer surface 
of outer cover 62 in the front waistband region of diaper 60. 
Having described the above embodiments of the present invention, a series 
of sample creped nonwoven laminate loop materials were formed to further 
illustrate the present invention. These samples were tested to determine 
peel strength, shear strength, and the degree of attachment (lamination) 
between the creped nonwoven layer and support layer. 
The peel strength of a loop material is a gauge of its functionality. More 
specifically, peel strength is a term used to describe the amount of force 
needed to pull apart the male and female components of a hook and loop 
fastening system. One way to measure the peel strength is to pull one 
component from the other at a 180 degree angle. 
Shear strength is another measure of the strength of a hook and loop 
fastening system. Shear strength is measured by engaging the male and 
female components and exerting a force along the plane defined by the 
connected surfaces in an effort to separate the two components. 
The degree of attachment or lamination between the creped nonwoven layer 
and support layer of the creped nonwoven laminate loop material of the 
present invention is another gauge of its functionality. Delamination 
refers to the separation of the layers of a laminate material when the 
bonding mechanism fails. Bond strength is a measure of the average peel 
force required to separate the component layers of a laminate material. 
The test methods used to evaluate individual samples of the creped nonwoven 
laminate loop material of the present invention are set forth below. 
TEST METHODS 
Basis Weight 
The basis weights of various materials described herein were determined in 
accordance with Federal Test Method No. 191A/5041. Sample size for the 
sample materials was 15.24.times.15.24 centimeters and three values were 
obtained for each material and then averaged. The values reported below 
are for the average. 
180.degree. Peel Strength Test 
The 180.degree. peel strength test involves attaching a hook material to a 
loop material of a hook and loop fastening system and then peeling the 
hook material from the loop material at a 180.degree. angle. The maximum 
load needed to disengage the two materials is recorded in grams. 
To perform the test, a continuous rate of extension tensile tester with a 
5000 gram full scale load is required, such as a Sintech System 2 Computer 
Integrated Testing System available from Sintech, Inc., having offices in 
Research Triangle Park, N.C. A 75 mm by 102 mm sample of the loop material 
is placed on a flat, adhesive support surface. A 45 mm by 12.5 mm sample 
of hook material, which is adhesively and ultrasonically secured to a 
substantially inelastic, nonwoven material, is positioned over and applied 
to the upper surface of the loop material sample. To ensure adequate and 
uniform engagement of the hook material to the loop material, a 4 1/2 
pound hand roller is rolled over the combined hook and loop materials for 
one cycle, with one cycle equaling a forward and a backward stroke of the 
hand roller. One end of the fingertab material supporting the hook 
material is secured within the upper jaw of the tensile tester, while the 
end of the loop material directed toward the upper jaw is folded downward 
and secured within the lower jaw of the tensile tester. The placement of 
the respective materials within the jaws of the tensile tester should be 
adjusted such that minimal slack exists in the respective materials prior 
to activation of the tensile tester. The hook elements of the hook 
material are oriented in a direction generally perpendicular to the 
intended directions of movement of the tensile tester jaws. The tensile 
tester is activated at a crosshead speed of 500 mm per minute and the peak 
load in grams to disengage the hook material from the loop material at a 
180.degree. angle is then recorded. 
Dynamic Shear Strength Test 
The dynamic shear strength test involves engaging a hook material to a loop 
material of a hook and loop fastening system and then pulling the hook 
material across the loop material's surface. The maximum load required to 
disengage the hook from the loop is measured in grams. 
To conduct this test, a continuous rate of extension tensile tester with a 
5000 gram full scale load is required, such as a Sintech System 2 Computer 
Integrated Testing System. A 75 mm by 102 mm sample of the loop material 
is placed on a flat, adhesive support surface. A 45 mm by 12.5 mm sample 
of hook material, which is adhesively and ultrasonically secured to a 
substantially inelastic, nonwoven material, is positioned over and applied 
to the upper surface of the loop material sample. To ensure adequate and 
uniform engagement of the hook material to the loop material, a 4 1/2 
pound hand roller is rolled over the combined hook and loop materials for 
five cycles, with one cycle equaling a forward and a backward stroke of 
the hand roller. One end of the nonwoven material supporting the hook 
material is secured within the upper jaw of the tensile tester, and the 
end of the loop material directed toward the lower jaw is secured within 
the lower jaw of the tensile tester. The placement of the respective 
materials within the jaws of the tensile tester should be adjusted such 
that minimal slack exists in the respective materials prior to activation 
of the tensile tester. The hook elements of the hook material are oriented 
in a direction generally perpendicular to the intended directions of 
movement of the tensile tester jaws. The tensile tester is activated at a 
crosshead speed of 250 mm per minute and the peak load in grams to 
disengage the hook material from the loop material is then recorded. 
Bond Strength Test 
To test the bond strength between the creped nonwoven layer and support 
layer, a delamination or bond strength test is performed. Samples of the 
creped nonwoven laminate loop material measuring 102 mm by 152 mm are cut 
and manually separated at one end for a distance of about 55 mm to produce 
edges that can be placed within the jaws of a Sintech System 2 Computer 
Integrated Testing System. The free end of the nonwoven layer is secured 
in the moving, upper jaw, while the free end of the support layer is 
secured in the stationery, lower jaw. The jaw gap is set at a span of 100 
millimeters and enough of the loop material is left in the laminated state 
so that the jaws can travel 65 millimeters. The sample is positioned in 
the jaws so that the sample will start delaminating before the jaws expand 
10 millimeters. The crosshead speed is set at 300 millimeters per minute 
and the average peel strength in grams to delaminate the nonwoven layer 
from the support layer is then recorded as the bond strength. 
EXAMPLES 
A total of 18 examples are set forth below. In all of the examples, the 
support layer was a blown thermoplastic film. The film composition 
included, on a weight percent basis based upon the total weight of the 
film, about 84 percent polypropylene and about 16 percent polyethylene, 
according to NMR analysis. The film had a thickness or bulk of 0.6 mil. 
This film is sold under the product designation XBPP-133 by Consolidated 
Thermoplastics Co. 
The samples of the creped nonwoven laminate loop material all were formed 
using a creping process and apparatus, as described herein. The nonwoven 
layer and film support layer were passed through the nip formed between 
two counter-rotating thermal bonding rolls including a pattern roll and an 
anvil roll. The nonwoven layer was positioned adjacent to and in contact 
with the pattern roll, while the film support layer was positioned 
adjacent to and in contact with the anvil roll. The pattern roll was 
heated to a temperature of about 127.degree. C. and the anvil roll was 
heated to a temperature of about 116.degree. C. Both rolls were heated 
using an internal hot oil system. The nip pressure along the interface 
between the pattern roll and the anvil roll was about 65.7 pounds per 
lineal inch (pli) (about 1.17 kilograms per lineal millimeter (kg/lmm)). 
As a result of the nonwoven layer and film support layer passing through 
the creping assembly, a creped nonwoven laminate loop material was formed 
in accordance with the teachings herein. 
EXAMPLES 1-7 
In these examples, the nonwoven web was formed of melt-spun filaments made 
using a pilot-scale apparatus, essentially as described in U.S. Pat. No. 
3,802,817 to Matsuki et al. The melt-spun filaments were formed from an 
extrudable thermoplastic resin of a random copolymer of propylene and 
ethylene containing, on a weight percent basis based upon the total weight 
of the resin, about 5.5 percent ethylene and about 94.5 percent propylene, 
obtained from Shell Oil Company, having offices in Houston, Tex., under 
the product designation WRD6277. The melt-spun filaments were essentially 
continuous in nature and had an average fiber size of 2-3 dpf. The 
spunbond nonwoven web had a percent bond area of about 10% and a basis 
weight of about 23.6 grams per square meter (gsm). The spunbond nonwoven 
web and film support layer were formed into a creped nonwoven laminate 
loop material using the creping assembly described herein. The inlet speed 
of the nonwoven web into the nip formed between the pattern roll and anvil 
roll was about 11.0 meters per minute (m/min.). The pattern roll had a 
rotational speed of about 6.1 m/min. and the anvil roll had a rotational 
speed of about 18.3 m/min., resulting in a pattern roll/anvil roll speed 
differential of about 3:1. 
EXAMPLE 8 
The creped nonwoven laminate loop material of this example was formed under 
the same process conditions and using the same melt-spun filaments 
described above for Examples 1-7 except as follows: 
In this example, the inlet speed of the nonwoven web into the nip formed 
between the pattern roll and anvil roll was about 16.5 meters per minute 
(m/min.). The pattern roll had a rotational speed of about 9.1 m/min. and 
the anvil roll had a rotational speed of about 18.3 m/min., resulting in a 
pattern roll/anvil roll speed differential of about 2:1. 
EXAMPLE 9 
The creped nonwoven laminate loop material of this example was formed under 
the same process conditions and using the same melt-spun filaments 
described above for Examples 1-7 except as follows: 
In this example, the nonwoven web had a basis weight of about 16.9 gsm. 
EXAMPLES 10 
The creped nonwoven laminate loop material of this example was formed under 
the same process conditions and using the same melt-spun filaments 
described above for Example 8 except as follows: 
In this example, the nonwoven web had a basis weight of about 16.9 gsm. 
EXAMPLE 11 
In this example, the nonwoven web was formed of melt-spun filaments formed 
from an extrudable thermoplastic resin of a random copolymer of propylene 
and ethylene containing, on a weight percent basis based upon the total 
weight of the resin, about 3.0 percent ethylene and about 97.0 percent 
propylene, obtained from Exxon Corp., having offices in Houston, Tex., 
under the product designation 9355. The melt-spun filaments were 
essentially continuous in nature and had an average fiber size of 2-3 dpf. 
The spunbond nonwoven web had a percent bond area of about 10% and a basis 
weight of about 23.6 grams per square meter. The inlet speed of the 
nonwoven web into the nip formed between the pattern roll and anvil roll 
was about 16.5 meters per minute (m/min.). The pattern roll had a 
rotational speed of about 9.1 m/min. and the anvil roll had a rotational 
speed of about 18.3 m/min., resulting in a pattern roll/anvil roll speed 
differential of about 2:1. 
EXAMPLE 12 
The creped nonwoven laminate loop material of this example was formed under 
the same process conditions and using the same melt-spun filaments 
described above for Example 11 except as follows: 
In this example, the basis weight of the nonwoven web was about 16.9 gsm. 
EXAMPLE 13 
The creped nonwoven laminate loop material of this example was formed under 
the same process conditions and using the same melt-spun filaments 
described above for Example 11 except as follows: 
In this example, the inlet speed of the nonwoven web into the nip formed 
between the pattern roll and anvil roll was about 11.0 meters per minute 
(m/min.). The pattern roll had a rotational speed of about 6.1 m/min. and 
the anvil roll had a rotational speed of about 18.3 m/min., resulting in a 
pattern roll/anvil roll speed differential of about 3:1. 
EXAMPLE 14 
The creped nonwoven laminate loop material of this example was formed under 
the same process conditions and using the same melt-spun filaments 
described above for Example 13 except as follows: 
In this example, the basis weight of the nonwoven web was about 16.9 gsm. 
EXAMPLE 15 
The creped nonwoven laminate loop material of this example was formed under 
the same process conditions and using the same melt-spun filaments 
described above for Example 12 except as follows: 
In this example, the nonwoven web had a percent bond area of about 15%. 
EXAMPLE 16 
The creped nonwoven laminate loop material of this example was formed under 
the same process conditions and using the same melt-spun filaments 
described above for Example 14 except as follows: 
In this example, the nonwoven web had a percent bond area of about 15%. 
EXAMPLE 17 
The creped nonwoven laminate loop material of this example was formed under 
the same process conditions and using the same melt-spun filaments 
described above for Example 13 except as follows: 
In this example, the nonwoven web had a percent bond area of about 15%. 
EXAMPLE 18 
The creped nonwoven laminate loop material of this example was formed under 
the same process conditions and using the same melt-spun filaments 
described above for Example 11 except as follows: 
In this example, the nonwoven web had a percent bond area of about 15%. 
The above-described sample materials had the following properties: 
TABLE I 
______________________________________ 
Attachment 
Strength Peel Strength 
Shear Strength 
EXAMPLE (grams) (grams) (grams) 
NO. n = 3** n = 4 n = 4 
______________________________________ 
1 1425 517 3529 
2 1483 711 3805 
3 1110 590 3188 
4 894 518 3300 
5 2477 483 3454 
6 2039 405 3511 
7 2410 419 2635 
8 888 546 2695 
9 N/A* 504 3421 
10 N/A 365 3128 
11 940 504 3540 
12 1226 421 2646 
13 1754 627 3356 
14 N/A 518 3487 
15 1164 246 2720 
16 1190 313 2526 
17 1130 234 2638 
18 1153 239 2884 
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*N/A Indicates spunbond nonwoven layer could not be manually separated 
from film support layer. 
**The values indicated in Table I above are average values, based upon n 
measurements performed on each sample material described in Examples 1-18 
 
For certain of the above-described Examples, the basis weight of the sample 
laminate material, and the nonwoven and film support layers after 
lamination, were measured. 
TABLE II 
______________________________________ 
LAMINATE NONWOVEN FILM 
BASIS BASIS BASIS 
EXAMPLE WEIGHT WEIGHT WEIGHT 
NO. (gsm) n = 5 (gsm) n = 5 (gsm) n = 5 
______________________________________ 
7 78.2 47.6 17.0 
8 54.4 37.4 17.0 
9 61.2 N/A N/A 
10 47.6 N/A N/A 
11 57.8 37.4 20.4 
12 51.0 27.2 23.8 
13 78.2 44.2 34.0 
14 64.6 32.3 30.6 
______________________________________ 
Although specific values for attachment, peel and shear strength were 
provided for the above-described examples, the creped nonwoven laminate 
loop material of the present invention should not be limited to such 
values. Generally, the creped nonwoven laminate loop material should have 
a combination of attachment, peel and shear strength that is suitable for 
its intended end use application. More specifically, in order to avoid 
delamination of the nonwoven and support layers during use, the attachment 
strength should exceed about 500 grams, or suitably exceed about 800 
grams. Peel strengths in the range of from about 200 grams to about 800 
grams, or higher, are considered suitable for use in the present 
invention. Likewise, shear strengths ranging from about 2300 grams to 
about 4200 grams, or higher, are considered suitable for use in the 
present invention. Likewise, the total basis weight of the creped nonwoven 
laminate loop material may be adapted to suit its intended end use 
application. Total basis weights in the range of from about 34 grams per 
square meter to about 85 grams per square meter, and more particularly in 
the range of from about 44 grams per square meter to about 75 grams per 
square meter, are considered suitable for use in the present invention. 
It is contemplated that the creped nonwoven laminate loop material 
constructed in accordance with the present invention will be tailored and 
adjusted by those of ordinary skill in the art to accommodate various 
levels of performance demand imparted during actual use. Accordingly, 
while this invention has been described by reference to the above 
embodiments and examples, it will be understood that this invention is 
capable of further modifications. This application is, therefore, intended 
to cover any variations, uses or adaptations of the invention following 
the general principles thereof, and including such departures from the 
present disclosure as come within known or customary practice in the art 
to which this invention pertains and fall within the limits of the 
appended claims.