U.S. patent application number 15/806402 was filed with the patent office on 2018-05-10 for prestretched apertured elastic film with resistance to web breaks.
The applicant listed for this patent is Berry Plastics Corporation. Invention is credited to Michael A. KINNAN, Brooke D. KITZMILLER, Jeffrey A. MIDDLESWORTH.
Application Number | 20180126618 15/806402 |
Document ID | / |
Family ID | 62065946 |
Filed Date | 2018-05-10 |
United States Patent
Application |
20180126618 |
Kind Code |
A1 |
MIDDLESWORTH; Jeffrey A. ;
et al. |
May 10, 2018 |
PRESTRETCHED APERTURED ELASTIC FILM WITH RESISTANCE TO WEB
BREAKS
Abstract
Apertured elastic films include a polyolefin, a styrene block
copolymer, a non-styrene block copolymer, or a combination thereof.
Methods for forming polymeric films and articles of manufacture
prepared therefrom are described.
Inventors: |
MIDDLESWORTH; Jeffrey A.;
(Wauconda, IL) ; KITZMILLER; Brooke D.; (North
Canton, OH) ; KINNAN; Michael A.; (North Canton,
OH) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Berry Plastics Corporation |
Evansville |
IN |
US |
|
|
Family ID: |
62065946 |
Appl. No.: |
15/806402 |
Filed: |
November 8, 2017 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62419805 |
Nov 9, 2016 |
|
|
|
62455827 |
Feb 7, 2017 |
|
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B29L 2009/00 20130101;
B29C 48/0018 20190201; A61F 13/49012 20130101; B29C 39/123
20130101; B29C 41/26 20130101; B29L 2007/008 20130101; B29K 2023/12
20130101; B29K 2105/04 20130101; B29L 2031/4878 20130101; B29C
41/42 20130101; B29K 2995/0046 20130101; B29C 48/022 20190201; B29C
48/916 20190201; B29C 55/065 20130101; B29C 48/917 20190201; B29C
55/02 20130101; B29C 55/06 20130101; A61F 13/15707 20130101; B29K
2023/0633 20130101; B29C 39/42 20130101; A61F 2013/15715 20130101;
B29K 2023/0625 20130101; B29C 48/21 20190201; B29C 48/18 20190201;
B29C 48/914 20190201; B29K 2995/0065 20130101 |
International
Class: |
B29C 47/00 20060101
B29C047/00; B29C 47/88 20060101 B29C047/88; B29C 47/06 20060101
B29C047/06 |
Claims
1. A process for making an apertured elastic film comprising the
steps of extruding a composition comprising a polyolefin, a styrene
block copolymer, a non-styrene block copolymer, or a combination
thereof to form a molten web, casting the molten web against a
surface of a chill roll using an air knife, an air blanket, a
vacuum box, or a combination thereof to form a quenched film,
stretching the quenched film in a machine direction in at least a
2:1 draw to form a stretched film, relaxing the stretched film to
form a relaxed film, and perforating the relaxed film to introduce
at least one aperture therein.
2. The process of claim 1, wherein the polyolefin comprises low
density polyethylene, high density polyethylene, linear low density
polyethylene, ultra-low density polyethylene, or a combination
thereof.
3. The process of claim 1, wherein the polyolefin comprises linear
low density polyethylene.
4. The process of claim 1, wherein the polyolefin comprises linear
low density polyethylene and the linear low density polyethylene
comprises a metallocene polyethylene.
5. The process of claim 1, wherein the polyolefin comprises
polypropylene.
6. The process of claim 1, wherein the polyolefin comprises
polypropylene impact copolymer.
7. The process of claim 1, wherein the styrene block copolymer
comprises styrene-isoprene block copolymer,
styrene-(ethylene-butylene) block copolymer,
styrene-(ethylene-propylene) block copolymer, styrene-butadiene
block copolymer, or a combination thereof
8. The process of claim 1, wherein the molten web is cast against
the surface of the chill roll under negative pressure by the vacuum
box.
9. The process of claim 1, wherein the molten web is cast against
the surface of the chill roll under positive pressure by the air
knife.
10. The process of claim 1, wherein the extruding and the casting
are achieved via in-line processing, and wherein one or more of the
stretching, the relaxing, and the perforating is achieved via
post-processing of the quenched film.
11. The process of claim 1, wherein each of the extruding, the
casting, the stretching, the relaxing, and the perforating is
achieved via in-line processing.
12. The process of claim 1, wherein the stretching in the machine
direction is in at least a 3:1 draw.
13. The process of claim 1, wherein the stretching in the machine
direction is in at least a 4:1 draw.
14. The process of claim 1, wherein at least a portion of the
stretching is performed at room temperature.
15. The process of claim 1, wherein the perforating is performed in
a machine direction.
16. The process of claim 1, further comprising co-extruding one or
a plurality of additional compositions substantially
contemporaneously with the extruding of the composition.
17. The process of claim 1, wherein the extruding of the
composition forms a first film layer, wherein the process further
comprises co-extruding at least a second composition to form at
least one second film layer and at least a third composition to
form at least one third film layer, the second composition and the
third composition being identical or different, wherein the first
film layer is disposed between the at least one second film layer
and the at least one third film layer.
18. The process of claim 17, wherein each of the second composition
and the third composition comprises a polyolefin, wherein the first
film layer is a core layer, and wherein each of the at least one
second film layer and the at least one third film layer is an outer
skin layer.
19. The process of claim 17, wherein each of the second composition
and the third composition comprises a polyolefin, and wherein the
polyolefin is polyethylene, polypropylene, or a combination
thereof.
20. The process of claim 1, wherein the apertured elastic film has
a basis weight of less than or equal to about 50 gsm.
21. The process of claim 1, wherein the apertured elastic film has
a basis weight of less than or equal to about 30 gsm.
22. The process of claim 1, wherein the apertured elastic film has
a basis weight of less than or equal to about 20 gsm.
Description
PRIORITY CLAIM
[0001] This application claims priority under 35 U.S.C. .sctn.
119(e) to U.S. Provisional Application Ser. No. 62/419,805, filed
Nov. 9, 2016, and U.S. Provisional Application Ser. No. 62/455,827,
filed Feb. 7, 2017, each of which is expressly incorporated by
reference herein.
BACKGROUND
[0002] The present disclosure relates to polymeric materials, and
particularly to polymeric films. More particularly, the present
disclosure relates to elastic films formed from polymeric
material.
SUMMARY
[0003] According to the present disclosure, an elastic film is made
using a manufacturing process. The manufacturing process comprises
the steps of extruding a composition to form a molten web and
casting the molten web to form a quenched film.
[0004] In illustrative embodiments, the manufacturing process used
to form the elastic film further includes stretching the quenched
film to form a stretched film, relaxing the stretched film to form
a relaxed film, and perforating the relaxed film to form at least
one aperture therein. Optionally, the manufacturing process may
further include the step of ageing the quenched film to form an
aged film.
[0005] In illustrative embodiments, the composition extruded to
form the molten web comprises an elastomer. The quenched film is
formed by casting the molten web against a surface of a chill roll
using a vacuum box and/or blowing air (e.g., an air knife and/or an
air blanket). The quenched film is stretched in a machine direction
in at least a 2:1 draw to form the stretched film.
[0006] In illustrative embodiments, an apertured elastic film
comprises a polyolefin, a styrene block copolymer, a non-styrene
block copolymer, or a combination thereof. The apertured elastic
film has a basis weight of less than or equal to about 30 gsm. A
notched elongation to break of the apertured elastic film is equal
to or greater than a notched elongation to break of a comparative
apertured elastic film prepared without the stretching.
[0007] In illustrative embodiments, an apertured elastic film
comprises an elastomer, at least one slit that extends from a top
surface of the film through to a bottom surface of the film. At
least one edge of the apertured elastic film is folded, thereby
providing at least one tear-resistant edge to the apertured elastic
film. The apertured elastic film has a basis weight of less than or
equal to about 30 gsm.
[0008] In illustrative embodiments, an elastic film comprises an
elastomer. At least one edge of the elastic film is folded, thereby
providing at least one tear-resistant edge to the elastic film. The
elastic film has a basis weight of less than or equal to about 30
gsm.
[0009] In illustrative embodiments, a personal hygiene product
comprises at least one apertured elastic film and at least one
outer non-woven layer. The at least one apertured elastic film is
configured to contact skin and/or clothing of a user of the
personal hygiene product.
[0010] Additional features of the present disclosure will become
apparent to those skilled in the art upon consideration of
illustrative embodiments exemplifying the best mode of carrying out
the disclosure as presently perceived.
BRIEF DESCRIPTIONS OF THE DRAWINGS
[0011] The detailed description particularly refers to the
accompanying figures in which:
[0012] FIG. 1 is a diagrammatic view of a representative embodiment
of an apertured elastic film that includes a core layer and two
skin layers;
[0013] FIG. 2 is a diagrammatic view of an exemplary process for
casting a molten web against a chill roll using a vacuum box;
[0014] FIG. 3 is a diagrammatic view of an exemplary process for
casting a molten web against a chill roll using an air knife;
[0015] FIG. 4 is a diagrammatic view of an exemplary process for
machine direction (MD) stretching of a polymeric film;
[0016] FIG. 5 is a diagrammatic view of an exemplary in-line
process for extruding, quenching, stretching, relaxing, and
perforating a polymeric film;
[0017] FIG. 6 is a diagrammatic view of a representative embodiment
of an elastic film that includes a folded edge;
[0018] FIG. 7 is a diagrammatic view of a representative process
for forming an elastic film having a folded edge;
[0019] FIG. 8 is a diagrammatic view of a representative process
for post-stretching an apertured elastic film and ultrasonically
bonding the post-stretched apertured elastic film to a non-woven
material; and
[0020] FIG. 9 is a diagrammatic view of a representative embodiment
of a multi-layer apertured elastic film bonded to a non-woven
material.
DETAILED DESCRIPTION
[0021] In some embodiments, the present disclosure provides a
multi-layer apertured elastic film that includes a core layer
interposed between one or more outer skin layers adjacent to the
core layer. A first embodiment of a multi-layered apertured elastic
film 2 in accordance with the present disclosure is shown, for
example, in FIG. 1. The multilayer apertured elastic film 2
includes a core layer 4 interposed between a first skin layer 6 and
a second skin layer 8. The apertured elastic film 2 further
includes one or more slits 10 that extend from a top surface 11
through to a bottom surface 12. Although the apertured elastic film
2 is shown in FIG. 1 as including the first skin layer 6 and the
second skin layer 8, one or both of these two outer skin layers is
optional and, in some embodiments, may not be present. Thus, in
some embodiments, the present disclosure alternatively provides a
monolayer apertured elastic film. A monolayer apertured elastic
film in accordance with the present disclosure is analogous to the
core layer 4 shown in FIG. 1 without the first skin layer 6 and the
second skin layer 8.
[0022] The core layer 4 may include a thermoplastic polymer (or
combination of thermoplastic polymers), whereas the outer skin
layers 6 and 8 may have either the same composition as the core
layer 4 or a different composition than the core layer 4. By way of
example, one or both of the first skin layer 6 and the second skin
layer 8 may contain a thermoplastic polymer or combination of
thermoplastic polymers. The choice of the thermoplastic polymer or
combination of thermoplastic polymers in each of the core layer 4,
the first skin layer 6, and the second skin layer 8 shown is FIG. 1
is independent of the other layers.
[0023] In one example, an apertured elastic film 2 in accordance
with the present disclosure is formed via a blown film process. In
another example, an apertured elastic film 2 in accordance with the
present disclosure is formed via a cast film process. The cast film
process involves the extrusion of molten polymers through an
extrusion die to form a thin film. The film is pinned to the
surface of a chill roll with an air knife, an air blanket, and/or a
vacuum box.
[0024] In illustrative embodiments, a process for making an
apertured elastic film 2 in accordance with the present disclosure
includes (a) extruding a composition containing a thermoplastic
polymer to form a molten web, (b) casting the molten web against a
surface of a chill roll using an air knife, an air blanket, a
vacuum box, or a combination thereof to form a quenched film, (c)
stretching the quenched film in a machine direction in at least a
2:1 draw to form a stretched film, (d) relaxing the stretched film
to form a relaxed film, and (e) perforating the relaxed film to
introduce at least one aperture therein. Optionally, the process
for making an apertured elastic film 2 in accordance with the
present disclosure further includes ageing the quenched film to
form an aged film, which has an increased elasticity relative to
the quenched film, prior to performing the stretching.
[0025] It has been discovered that by pre-stretching the quenched
film (e.g., in a machine direction in at least a 2:1 draw), a
notched elongation to break of the resultant apertured elastic film
will be equal to or greater than a notched elongation to break of a
comparative apertured elastic film prepared without the stretching.
In other words, with pre-stretching, a notch put into a sample film
does not reduce the break elongation of the film nearly as much as
the same notch put into a similar un-stretched sample. Moreover, it
has further been discovered that by using a vacuum box, blowing air
(e.g., an air knife and/or an air blanket), or a vacuum box in
combination with blowing air to cast the molten web against a chill
roll in accordance with the present disclosure, apertured elastic
films 2 exhibiting surprisingly and unexpectedly improved
properties as compared to other elastic films may be prepared. As
further described below, these properties may include reduced basis
weight.
[0026] In some embodiments, the thermoplastic polymer-containing
compositions may be extruded in a cast-embossed process with an
engraved pattern (matte or less than about 2-mil depth). In other
embodiments, the compositions may be extruded via a blown
co-extrusion process. In illustrative embodiments, as further
explained below, the film extrusion is performed using a vacuum box
casting process, which circumvents the limitations of draw
resonance that may affect embossed films, as well as bubble
instability that may affect blown films.
[0027] In illustrative embodiments, the molten web is cast against
the surface of the chill roll under negative pressure using a
vacuum box as shown in simplified schematic form in FIG. 2. A
vacuum box works by evacuating air between the film and the surface
of the chill roll. For example, as shown in FIG. 2, a film 46 is
extruded from an extrusion die 40 in the direction of arrow 47 and
quenched from the molten state with a vacuum box 42. The vacuum box
42 draws a vacuum behind the molten web 46 in the direction of
arrow 44 to draw the film 46 down onto the chill roll 38. The
vacuum drawn in the direction of arrow 44 removes the entrained air
between the surface of the chill roll 38 and the film 46. The
vacuum box process is not subject to draw resonance for high
molecular weight polymers that would tend to extrude unstable
thickness in a nipped quench process due to the draw resonance
phenomenon.
[0028] When a vacuum box 42 is used, the molten polymer may exit
the die 40 and hit the chill roll 38 within a smaller distance than
in an embossed process. For example, in some embodiments, the melt
curtain is configured to hit the chill roll 38 within a distance of
less than about 12 inches, 11 inches, 10 inches, 9 inches, 8
inches, 7 inches, 6 inches, 5 inches, 4 inches, 3, inches, 2
inches, or 1 inch. In illustrative embodiments, the melt curtain is
configured to exit the die and hit the roll within a distance of
less than about 3 inches and, in some examples, within a distance
of about or less than 1 inch. One advantage of reducing the
distance between the die 40 and the roll surface 38 as compared to
in a nipped quench process is that smaller distances are less
susceptible to the phenomenon of neck-in. Neck-in refers to a
reduction in width of the molten web that occurs as the web leaves
the die. By drawing the film 46 onto a surface of the chill roll 38
over a short distance as shown in FIG. 2, the vacuum box 42 may
enhance web cooling, facilitate higher line speeds, reduce film
neck-in, and/or reduce drag at the lip exit.
[0029] In another example, the molten web is cast against the
surface of the chill roll under positive pressure using an air
knife or air blanket, as shown in simplified schematic form in FIG.
3. An air knife works to promote web quenching by gently blowing a
high-velocity, low-volume air curtain over the molten film, thereby
pinning the molten film to the chill roll for solidification. For
example, as shown in FIG. 3, a film 54 is extruded from an
extrusion die 50 in the direction of arrow 55 and quenched from the
molten state with an air knife 52 blowing an air curtain over the
molten film 54, thereby pinning the molten web 54 against a surface
of the chill roll 48. An air blanket (a.k.a. "soft box") works
similarly to an air knife and promotes web quenching by gently
blowing an air curtain over the molten film. However, in the case
of an air blanket, the air curtain is low velocity and high
volume.
[0030] In a further example, the molten web is cast against the
surface of the chill roll under a combination of negative pressure
from a vacuum box, as shown in FIG. 2, and positive pressure from
an air knife, as shown in FIG. 3. In illustrative embodiments, in
the casting of the molten web against a surface of the chill roll,
an exit temperature of cooling fluid passing through the chill roll
is between about 50 degrees Fahrenheit and about 130 degrees
Fahrenheit and, in some examples, between about 75 degrees
Fahrenheit and about 130 degrees Fahrenheit.
[0031] Thermoplastic materials that have elastomeric properties are
typically called elastomeric materials. Thermoplastic elastomeric
materials are generally defined as materials that exhibit high
resilience and low creep as though they were covalently crosslinked
at ambient temperatures, yet process like thermoplastic
non-elastomers and flow when heated above their softening point.
The thermoplastic polymer 4 (or combination of thermoplastic
polymers 4) used to make an apertured elastic film 2 in accordance
with the present disclosure is not restricted, and may include all
manner of thermoplastic polymers capable of being stretched.
[0032] In illustrative embodiments, the thermoplastic polymer is a
polyolefin, (including but not limited to homopolymers, copolymers,
terpolymers, and/or blends thereof), a non-styrene block copolymer,
a styrene block copolymer, or a combination thereof.
[0033] Representative polyolefins that may be used in accordance
with the present disclosure include but are not limited to low
density polyethylene (LDPE), high density polyethylene (HDPE),
linear low density polyethylene (LLDPE), ultra-low density
polyethylene (ULDPE), medium density polyethylene, polypropylene,
isotactic polypropylene, polybutylene, ethylene-propylene
copolymers, polymers made using a single-site catalyst, ethylene
maleic anhydride copolymers (EMAs), ethylene vinyl acetate
copolymers (EVAs) such as those available under the trade
designation ELVAX from E. I. DuPont de Nemours, Inc. (Wilmington,
Del.), polymers made using Zeigler-Natta catalysts,
styrene-containing block copolymers, ethylene acrylic acid
copolymers, ethylene methacrylic acid copolymers such as those
available under the trade designation SURLYN 1702 from E.I. DuPont
de Nemours, Inc., polymethylmethacrylate, polystyrene, ethylene
vinyl alcohol, and/or the like, and combinations thereof.
[0034] Methods for manufacturing LDPE are described in The Wiley
Encyclopedia of Packaging Technology, pp. 753-754 (Aaron L. Brody
et al. eds., 2nd Ed. 1997) and in U.S. Pat. No. 5,399,426, both of
which are incorporated by reference herein, except that in the
event of any inconsistent disclosure or definition from the present
specification, the disclosure or definition herein shall be deemed
to prevail.
[0035] ULDPE may be produced by a variety of processes, including
but not limited to gas phase, solution and slurry polymerization as
described in The Wiley Encyclopedia of Packaging Technology, pp.
748-50 (Aaron L. Brody et al. eds., 2nd Ed. 1997), incorporated by
reference above, except that in the event of any inconsistent
disclosure or definition from the present specification, the
disclosure or definition herein shall be deemed to prevail.
[0036] ULDPE may be manufactured using a Ziegler-Natta catalyst,
although a number of other catalysts may also be used. For example,
ULDPE may be manufactured with a metallocene catalyst.
Alternatively, ULDPE may be manufactured with a catalyst that is a
hybrid of a metallocene catalyst and a Ziegler-Natta catalyst.
Methods for manufacturing ULDPE are also described in U.S. Pat. No.
5,399,426, U.S. Pat. No. 4,668,752, U.S. Pat. No. 3,058,963, U.S.
Pat. No. 2,905,645, U.S. Pat. No. 2,862,917, and U.S. Pat. No.
2,699,457, each of which is incorporated by reference herein in its
entirety, except that in the event of any inconsistent disclosure
or definition from the present specification, the disclosure or
definition herein shall be deemed to prevail. The density of ULDPE
is achieved by copolymerizing ethylene with a sufficient amount of
one or more monomers. In illustrative embodiments, the monomers are
selected from 1-butene, 1-hexene, 4-methyl-1-pentene, 1-octene, and
combinations thereof. Methods for manufacturing polypropylene are
described in Kirk-Othmer Concise Encyclopedia of Chemical
Technology, pp. 1420-1421 (Jacqueline I. Kroschwitz et al. eds.,
4th Ed. 1999), which is incorporated herein by reference, except
that in the event of any inconsistent disclosure or definition from
the present specification, the disclosure or definition herein
shall be deemed to prevail.
[0037] In illustrative embodiments, a polyolefin for use in
accordance with the present disclosure includes polyethylene,
polypropylene, or a combination thereof. In one example, the
polyethylene includes linear low density polyethylene which, in
some embodiments, includes a metallocene polyethylene. In another
example, the polyethylene includes a combination of linear low
density polyethylene and low density polyethylene. In a further
example, the polyolefin consists essentially of only linear low
density polyethylene.
[0038] Representative non-styrene block copolymers (elastomers or
plastomers) suitable for use in accordance with the present
disclosure include but are not limited to ethylene copolymers.
Representative ethylene copolymers include but are not limited to
ethylene vinyl acetates; ethylene octane; ethylene butane;
ethylene/propylene copolymer or propylene copolymer elastomers,
such as those available under the trade designation VISTAMAXX.RTM.
available from ExxonMobil (Irving, Tex.); ethylene/propylene/diene
terpolymer elastomers; metallocene polyolefins, such as
polyethylene, poly (1-hexane), copolymers of ethylene and 1-hexene,
and poly(1-octene); thermoplastic elastomeric polyurethanes, such
as that available under the trade designation MORTHANE PE44-203
polyurethane from Morton International, Inc. (Chicago, Ill.) and
the trade designation ESTANE 58237 polyurethane from Noveon
Corporation, Inc. (Cleveland, Ohio); polyvinyl ethers;
poly-.alpha.-olefin-based thermoplastic elastomeric materials, such
as those represented by the formula --(CH.sub.2CHR).sub.x where R
is an alkyl group containing from about 2 to about 10 carbon atoms;
poly-.alpha.-olefins based on metallocene catalysis, such as ENGAGE
8200, ethylene/poly-.alpha.-olefin copolymer available from Dow
Plastics Co. (Midland, Mich.); polybutadienes; polybutylenes;
polyisobutylenes such as VISTANEX NM L-80, available from Exxon
Chemical Co.; polyether block amides such as PEBAX available from
Elf Atochem North America, Inc. (Philadelphia, Pa.); and/or the
like; and combinations thereof.
[0039] Thermoplastic elastomeric materials, in particular block
copolymers, useful in accordance with the present disclosure
include but are not limited to linear, radial, star, and tapered
block copolymers, such as styrene block copolymers. Representative
styrene block copolymers for use in accordance with the present
disclosure include but are not limited to KRATON.RTM. or
KRATON.RTM.-based styrene block copolymers available from Kraton
Polymers, Inc. (Houston, Tex.), styrene-isoprene block copolymers,
styrene-(ethylene-butylene) block copolymers,
styrene-(ethylene-propylene) block copolymers, styrene-butadiene
block copolymers, and/or the like, and combinations thereof. In
some embodiments, thermoplastic elastomeric materials in accordance
with the present disclosure include polyether esters such as those
available under the trade designation HYTREL G3548 from E.I. DuPont
de Nemours, and/or polyether block amides such as those available
under the trade designation PEBAX from Elf Atochem.
[0040] Additional thermoplastic materials which may be used in
accordance with the present disclosure include but are not limited
to polyesters including amorphous polyester, polyamides,
fluorinated thermoplastics such as polyvinylidene fluoride;
halogenated thermoplastics such as chlorinated polyethylene,
polyether-block-amides such as those available under the trade
designation PEBAX 5533 from Elf-Atochem, and/or the like, and
combinations thereof.
[0041] A precursor film containing a thermoplastic polymer that is
stretched, relaxed, and apertured to form an apertured elastic film
2 in accordance with the present disclosure may be prepared by
mixing together the thermoplastic polymer (or a combination of
thermoplastic polymers) and any optional components until blended,
heating the mixture, and then extruding the mixture to form a
molten web. A suitable film-forming process may be used to form a
precursor film en route to forming an apertured elastic film. For
example, the precursor film may be manufactured by casting or
extrusion using blown-film, co-extrusion, or single-layer extrusion
techniques and/or the like. In one example, the precursor film may
be wound onto a winder roll for subsequent stretching in accordance
with the present disclosure (e.g., following optional ageing of the
quenched film to allow for elasticity of the film to increase over
time). In another example, the precursor film may be manufactured
in-line with a film stretching apparatus such as shown in FIG.
4.
[0042] In addition to containing one or more thermoplastic
polymers, the precursor film may also contain other optional
components to improve the film properties or processing of the
film. Representative optional components include but are not
limited to anti-oxidants (e.g., added to prevent polymer
degradation and/or to reduce the tendency of the film to discolor
over time) and processing aids (e.g., added to facilitate extrusion
of the precursor film). In one example, the amount of one or more
anti-oxidants in the precursor film is less than about 1% by weight
of the film and the amount of one or more processing aids is less
than about 5% by weight of the film. Additional optional additives
include but are not limited to whitening agents (e.g., titanium
dioxide), which may be added to increase the opacity of the film.
In one example, the amount of one or more whitening agents is less
than about 10% by weight of the film. Further optional components
include but are not limited to antiblocking agents (e.g.,
diatomaceous earth) and slip agents (e.g. erucamide a.k.a.
erucylamide), which may be added to allow film rolls to unwind
properly and to facilitate secondary processing (e.g., diaper
making). In one example, the amount of one or more antiblocking
agents and/or one or more slip agents is less than about 5% by
weight of the film. Further additional optional additives include
but are not limited to scents, deodorizers, pigments other than
white, noise reducing agents, and/or the like, and combinations
thereof. In one example, the amount of one or more scents,
deodorizers, pigments other than white, and/or noise reducing
agents is less than about 10% by weight of the film.
[0043] The type of stretching used to transform a quenched film
into an apertured elastic film 2 in accordance with the present
disclosure is not restricted. All manner of stretching
processes--and combinations of stretching processes are
contemplated for use. In illustrative embodiments, the stretching
includes MD stretching. In other examples, the stretching may
include one or more of CD IMG stretching, MD IMG stretching, cold
draw, and/or the like.
[0044] In illustrative embodiments, the type of stretching used to
transform a quenched film into an apertured elastic film 2 in
accordance with the present disclosure includes MD stretching. In
addition, in illustrative embodiments, at least a portion of the MD
stretching is performed at ambient temperature (i.e., room
temperature). In some embodiments, the stretching in the machine
direction is in at least a 3:1 draw and, in other embodiments, in
at least a 4:1 draw.
[0045] In one example, stretching may be achieved via machine
direction (MD) orientation by a process analogous to that shown in
simplified schematic form in FIG. 4. For example, the film 14 shown
in FIG. 4 may be passed between at least two pairs of rollers in
the direction of an arrow 15. In this example, first roller 16 and
a first nip 20 run at a slower speed (V.sub.1) than the speed
(V.sub.2) of a second roller 18 and a second nip 22. The ratio of
V.sub.2/V.sub.1 determines the degree to which the film 14 is
stretched. Since there may be enough drag on the roll surface to
prevent slippage, the process may alternatively be run with the
nips open. Thus, in the process shown in FIG. 4, the first nip 20
and the second nip 22 are optional.
[0046] In illustrative embodiments, a process for making an
apertured elastic film 2 in accordance with the present disclosure
may be executed as shown in simplified schematic form in FIG. 5.
The process includes extruding a composition containing a
thermoplastic polymer 4 from a die 60 to form a molten web. The
molten web is cast against a surface of a chill roll 64 under
negative pressure from a vacuum box 62 to form a quenched film 66.
The quenched film 66 is stretched by MD stretching from a series of
rollers moving at different speeds (e.g., machine direction
stretching) at an MD stretching station 68, and subsequently
relaxed at an MD relaxation station 70. The MD-relaxed film exiting
MD relaxing station 70 receives subsequent perforating at a
slitting station 74 to form an apertured elastic film 2 in
accordance with the present disclosure. The apertured elastic film
2 exiting the slitting station 72 in the direction 74 may be sent
for winding.
[0047] In the MD stretching station 68, the elastic co-extrusion is
stretched in a series of three closely spaced rolls with nips. In
illustrative embodiments, the film is stretched 100% (2:1) between
the first and second roll and an additional 100% (2:1) between the
second and third roll. Thus, the total stretch is 4:1
(2.times.2).
[0048] In the relaxing station 70, the speed of downstream rolls is
reduced to allow the web to nearly relax and be wound up. Somewhere
within the area of relaxation, the perforation may be implemented
via the slitting station 74.
[0049] As shown in FIG. 5, the extruding, the casting, the
stretching, the relaxing, and the perforating are all achieved via
in-line processing. However, this is not required. In some
embodiments, it may be beneficial to perform the stretching in an
out-of-line operation. The reason is that some elastic materials
may need extra time after extrusion to achieve their full elastic
potential. As a result, any break issues or downtime may be less
costly in an out-of-line operation. Therefore, in some embodiments,
it may be advantageous to age the quenched film to form an aged
film prior to performing the stretching. For example, some
elastomeric materials (e.g., polypropylene-based elastomers such as
those sold under the trade designation VISTAMAXX) may require
additional time to crystallize in order to achieve optimum
elasticity. For such materials, the aged film has increased
elasticity relative to the quenched film, and better results may be
obtained when stretching is performed on the aged film.
[0050] In some embodiments, the extruding and the casting are
achieved via in-line processing, and one or more of the stretching,
the relaxing, and the perforating is achieved via post-processing
of the quenched film. In other embodiments, at least the extruding,
the casting, and the stretching are achieved via in-line
processing. In further embodiments, at least the extruding, the
casting, the stretching, and the relaxing are achieved via in-line
processing. In additional embodiments, each of the extruding, the
casting, the stretching, the relaxing, and the perforating is
achieved via in-line processing.
[0051] In illustrative embodiments, perforating is performed in a
machine direction. Perforation of a relaxed film in accordance with
the present disclosure may be achieved by a wide array of physical
processes, including but not limited to those described in U.S.
Patent Application Publication Nos. 2005/0158513 A1 and
2007/0237924 A1. The entire contents of both of these documents are
hereby incorporated herein by reference, except that in the event
of any inconsistent disclosure or definition from the present
specification, the disclosure or definition herein shall be deemed
to prevail.
[0052] For elastic films that are to be perforated in a relaxed
state and subsequently subjected (e.g., by an end user) to
post-stretching ranging from about 2:1 to about 2.5:1, a wide array
of perforation techniques may be implemented in accordance with the
present disclosure. By way of example, a score cutting assembly
with gaps between the cutting teeth may be used, and blades or
other perforating surfaces may be mounted side by side for cutting
against a hardened steel cutting roll. Alternatively, die cutting
may be used to form slits aligned nearly with the machine direction
In other embodiments, perforation techniques including but not
limited to hot needles, water jets, laser perforation, and/or the
like, and combinations thereof may be used.
[0053] Prior to stretching, the precursor film may have an initial
basis weight of less than about 100 grams per square meter (gsm).
In one example, the precursor film has an initial basis weight of
less than about 75 gsm. The precursor film may be a monolayer film,
in which case the entire precursor film comprises the thermoplastic
polymer (or combination of thermoplastic polymers). In another
example, the precursor film may be a multilayer film as suggested
in FIG. 1.
[0054] In illustrative embodiments, as noted above, an apertured
elastic film 2 prepared in accordance with the present disclosure
(e.g., by using a vacuum box and/or air knife to cast a molten web
containing a thermoplastic polymer (e.g., an elastomer) against a
chill roll) may have reduced basis weight as compared to
conventional apertured elastic films.
[0055] The basis weight of an apertured elastic film 2 in
accordance with the present disclosure may be varied based on a
desired end use (e.g., the desired properties and/or applications
of the apertured elastic film). In one example, the basis weight
ranges from about 5 gsm to about 30 gsm. In another example, the
basis weight ranges from about 6 gsm to about 25 gsm. In some
examples, the basis weight is less than about 50 gsm and, in
illustrative embodiments, less than about 45 gsm, 40 gsm, 35 gsm,
30 gsm, 25 gsm, or 20 gsm. In illustrative embodiments, the basis
weight is between about 20 gsm and about 30 gsm. Although basis
weights outside this range may also be employed (e.g., basis
weights above about 30 gsm), lower basis weights minimize material
cost as well as maximize consumer satisfaction (e.g., a thinner
film may provide increased comfort to the user of a personal
hygiene product that includes the film). The basis weight of an
apertured elastic film 2 in accordance with the present disclosure
may be one of several different values or fall within one of
several different ranges. For example, it is within the scope of
the present disclosure to select a basis weight to be one of the
following values: about 30 gsm, 29 gsm, 28 gsm, 27 gsm, 26 gsm, 25
gsm, 24 gsm, 23 gsm, 22 gsm, 21 gsm, 20 gsm, 19 gsm, 18 gsm, 17
gsm, 16 gsm, 15 gsm, 14 gsm, 13 gsm, 12 gsm, 11 gsm, 10 gsm, 9 gsm,
8 gsm, 7 gsm, 6 gsm, or 5 gsm.
[0056] It is also within the scope of the present disclosure for
the basis weight of the apertured elastic film 2 to fall within one
of many different ranges. In a first set of ranges, the basis
weight of the apertured elastic film 2 is in one of the following
ranges: about 5 gsm to 30 gsm, 6 gsm to 30 gsm, 7 gsm to 30 gsm, 8
gsm to 30 gsm, 9 gsm to 30 gsm, 10 gsm to 30 gsm, 11 gsm to 30 gsm,
12 gsm to 30 gsm, 13 gsm to 30 gsm, and 14 gsm to 30 gsm. In a
second set of ranges, the basis weight of the apertured elastic
film is in one of the following ranges: about 5 gsm to 29 gsm, 5
gsm to 28 gsm, 5 gsm to 27 gsm, 5 gsm to 26 gsm, 5 gsm to 25 gsm, 5
gsm to 24 gsm, 5 gsm to 23 gsm, 5 gsm to 22 gsm, 5 gsm to 21 gsm, 5
gsm to 20 gsm, 5 gsm to 19 gsm, 5 gsm to 18 gsm, 5 gsm to 17 gsm, 5
gsm to 16 gsm, 5 gsm to 15 gsm, 5 gsm to 14 gsm, 5 gsm to 13 gsm, 5
gsm to 12 gsm, 5 gsm to 11 gsm, 5 gsm to 10 gsm, 5 gsm to 9 gsm, 5
gsm to 8 gsm, and 5 gsm to 7 gsm. In a third set of ranges, the
basis weight of the apertured elastic film 2 is in one of the
following ranges: about 6 gsm to 29 gsm, 7 gsm to 29 gsm, 7 gsm to
28 gsm, 7 gsm to 27 gsm, 7 gsm to 26 gsm, 7 gsm to 25 gsm, 7 gsm to
24 gsm, 7 gsm to 23 gsm, 7 gsm to 22 gsm, 7 gsm to 21 gsm, 7 gsm to
20 gsm, 7 gsm to 19 gsm, 7 gsm to 18 gsm, 7 gsm to 17 gsm, 7 gsm to
16 gsm, 7 gsm to 15 gsm, 7 gsm to 14 gsm, and 7 gsm to 13 gsm.
[0057] In illustrative embodiments, an apertured elastic film 2 in
accordance with the present disclosure exhibits a notched
elongation to break that is equal to or greater than a notched
elongation to break of a comparative apertured elastic film
prepared without the pre-stretching. The basis weight of an
apertured elastic film 2 in accordance with the present disclosure
may be varied based on a desired notched elongation to break. In
one example, an apertured elastic film 2 in accordance with the
present disclosure has a basis weight of about 30 gsm and a notched
elongation to break of at least about 50%. In another example, an
apertured elastic film 2 in accordance with the present disclosure
has a basis weight of about 30 gsm and a notched elongation to
break of at least about 60%. In a further example, an apertured
elastic film 2 in accordance with the present disclosure has a
basis weight of less than about 14 gsm and a notched elongation to
break of at least about 70%. In a further example, an apertured
elastic film 2 in accordance with the present disclosure has a
basis weight of less than about 14 gsm and a notched elongation to
break of at least about 70%. In a further example, an apertured
elastic film 2 in accordance with the present disclosure has a
basis weight of less than about 14 gsm and a notched elongation to
break of at least about 80%. In a further example, an apertured
elastic film 2 in accordance with the present disclosure has a
basis weight of less than about 14 gsm and a notched elongation to
break of at least about 90%. In a further example, an apertured
elastic film 2 in accordance with the present disclosure has a
basis weight of less than about 14 gsm and a notched elongation to
break of at least about 100%.
[0058] The notched elongation to break of an apertured elastic film
2 in accordance with the present disclosure may be one of several
different values or fall within one of several different ranges.
For example, for an apertured elastic film having a basis weight of
less than or equal to about 30 gsm--in some embodiments, less than
or equal to about 25 gsm or 20 gsm--it is within the scope of the
present disclosure to select a notched elongation to break to be
greater than or equal to one of the following values: about 75%,
76%, 77%, 78%, 79%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%,
89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, 100%, 101%,
102%, 103%, 104%, 105%, 106%, 107%, 108%, 109%, 110%, 111%, 112%,
113%, 114%, 115%, 116%, 117%, 118%, 119%, 120%, 121%, 122%, 123%,
124%, or 125%.
[0059] It is also within the scope of the present disclosure for
the notched elongation to break of the apertured elastic film 2 to
fall within one of many different ranges. In a first set of ranges,
the notched elongation to break for an apertured elastic film
having a basis weight of less than or equal to about 30 gsm--in
some embodiments, less than or equal to about 25 gsm or 20 gsm--is
in one of the following ranges: about 65% to 150%, 65% to 145%, 65%
to 140%, 65% to 135%, 65% to 130%, 65% to 125%, 65% to 120%, 65% to
115%, 65% to 110%, 65% to 105%, 65% to 100%, 65% to 95%, 65% to
90%, 65% to 85%, 65% to 80%, and 65% to 75%. In a second set of
ranges, the notched elongation to break for an apertured elastic
film 2 having a basis weight of less than or equal to about 30
gsm--in some embodiments, less than or equal to about 25 gsm or 20
gsm--is in one of the following ranges: about 66% to 150%, 67% to
150%, 68% to 150%, 69% to 150%, 70% to 150%, 71% to 150%, 72% to
150%, 73% to 150%, 74% to 150%, 75% to 150%, 76% to 150%, 77% to
150%, 78% to 150%, 79% to 150%, 80% to 150%, 81% to 150%, 82% to
150%, 83% to 150%, 84% to 150%, 85% to 150%, 86% to 150%, 87% to
150%, 88% to 150%, 89% to 150%, 90% to 150%, 91% to 150%, 92% to
150%, 93% to 150%, 94% to 150%, 95% to 150%, 96% to 150%, 97% to
150%, 98% to 150%, 99% to 150%, 100% to 150%, 101% to 150%, 102% to
150%, 103% to 150%, 104% to 150%, 105% to 150%, 106% to 150%, 107%
to 150%, 108% to 150%, 109% to 150%, 110% to 150%, 111% to 150%,
112% to 150%, 113% to 150%, 114% to 150%, 115% to 150%, 116% to
150%, 117% to 150%, 118% to 150%, 119% to 150%, 120% to 150%, 121%
to 150%, 122% to 150%, 123% to 150%, 124% to 150%, and 125% to
150%. In a third set of ranges, the notched elongation to break for
an apertured elastic film 2 having a basis weight of less than or
equal to about 30 gsm--in some embodiments, less than or equal to
about 25 gsm or 20 gsm--is in one of the following ranges: about
60% to 149%, 65% to 145%, 70% to 140%, 75% to 135%, 80% to 135%,
85% to 125%, 90% to 120%, 95% to 115%, 100% to 110%, and 105% to
109%.
[0060] In some embodiments, as shown in FIG. 1, the present
disclosure provides a multi-layer apertured elastic film 2. In
other embodiments, as noted above, the present disclosure provides
a monolayer apertured elastic film 2 (i.e., core layer 4 in FIG. 1
without the outer skin layers 6 and 8). In one example, the skin
layers may be independently selected from compositions designed to
minimize the levels of volatiles building up on the extrusion die.
In one example, a pair of skin layers sandwiching a core layer are
relatively thin and together account for no more than about 30% of
the total film thickness. In some embodiments, the skin layer may
be breathable even if perforation is not performed. For example,
the skin layer may include one or more discontinuities that are
introduced during the stretching process. The likelihood of
discontinuities forming in a skin layer may increase as the
thickness of the skin layer subjected to stretching decreases.
[0061] In one example, a multi-layer apertured elastic films in
accordance with the present disclosure may be manufactured by feed
block co-extrusion. In another example, a multi-layer apertured
elastic films in accordance with the present disclosure may be made
by blown film (tubular) co-extrusion. Methods for feed block and
blown film extrusion are described in The Wiley Encyclopedia of
Packaging Technology, pp. 233-238 (Aaron L. Brody et al. eds., 2nd
Ed. 1997), which is incorporated herein by reference, except that
in the event of any inconsistent disclosure or definition from the
present specification, the disclosure or definition herein shall be
deemed to prevail. Methods for film extrusion are also described in
U.S. Pat. No. 6,265,055, the entire contents of which are likewise
incorporated by reference herein, except that in the event of any
inconsistent disclosure or definition from the present
specification, the disclosure or definition herein shall be deemed
to prevail.
[0062] In some embodiments, as described above, the present
disclosure provides apertured elastic films (e.g., mono-layer or
multi-layer). In other embodiments, the present disclosure further
provides elastic films that are not apertured but which contain a
folded edge that provides tear-resistance to the film.
[0063] A non-apertured elastic film 76 comprising an elastomer is
shown in FIG. 6. The elastic film 76 includes a core layer 84, a
first skin layer 80, and a second skin layer 82. As shown in FIG.
6, at least one edge of the elastic film 76 is folded, thereby
providing at least one tear-resistant edge 78 to the elastic film
76. The elastic film has a basis weight of less than or equal to
about 30 gsm. Although the elastic film 76 is shown in FIG. 6 as
being multi-layer, a monolayer elastic film (not shown) may
likewise contain a folded edge in accordance with the present
disclosure. Moreover, although the elastic film 76 shown in FIG. 6
does not contain any apertures, the elastic film may, in some
embodiments, be subjected to a perforation process as described
above.
[0064] The at least one folded edge 78 shown in FIG. 6 may provide
one or more benefits to the elastic film 76. By way of example, the
at least one folded edge 78 shown in FIG. 6 may provide resistance
against web tear-offs. For example, web breaks that occur during
stretching in a machine direction typically initiate at one edge of
the web and then zip across to the other side. The breaks typically
do not start in the center of the web but rather occur when the
edge of the film is not smooth but contains small cracks or tears.
Thus, the folded edge 78 show in FIG. 6 faces inward and is
protected since the most significant MD strain is occurring at the
fold. The film 76 will be resistant to tear offs especially if the
edges of the film are folded on both sides. Moreover, an elastic
film 76 having the tear-resistant edge 78 may be subjected to
increased stretching forces if the ends of the film are folded
prior to stretching, thereby conferring protection against edge
tears to the film. In some embodiments, the total stretch of an
elastic film containing a folded edge in accordance with the
present disclosure may be about 5:1.
[0065] In addition, the at least one folded edge 78 may also
provide increased retroactive force, whereby the elastic film 76
may be used as a replacement for the synthetic fibers that are
conventionally used in the waistbands of incontinence briefs, such
as the fibers sold under the tradename LYCRA by Invista (Wichita,
Kans.). For example, by replacing the LYCRA strands that form the
"belly panel" of the incontinence pants with an elastic film in
accordance with the present disclosure, elastic panels with a much
flatter appearance may be generated.
[0066] The elastic film 76 shown in FIG. 6 may be prepared, for
example, using a stretcher of a type commonly used to elongate and
thin out stretch wrap film. A representative type of stretcher that
may be used in accordance with the present disclosure is the
stretcher available under the trade designation NoEL from
Davis-Standard (Pawcatuck, Conn.). For example, as shown in FIG. 7,
smooth metal folders 86 located on the sides of the elastic film
that running through the stretcher equipment may be used to push
against the edges of the film, thereby causing the edges to fold
in.
[0067] In some embodiments, a multi-layer film in accordance with
the present disclosure may contain one or a plurality of apertured
elastic film layers analogous to the core layer 4 shown in FIG. 1.
In other embodiments, a multi-layer film in accordance with the
present disclosure may contain one or a plurality of elastic film
layers having a folded edge as shown in FIG. 6. The individual film
layers in a multi-layer film structure in accordance with the
present disclosure may be monolayers or co-extrusions. Each of the
individual apertured elastic film layers or elastic film layers
having a folded edge may be placed in any order within the inner
layers of the multi-layer film structure. When a plurality of
individual apertured elastic film layers or elastic film layers
having a folded edge in accordance with the present disclosure is
used, the individual layers may differ from each other in thickness
and/or type of thermoplastic polymer.
[0068] Multi-layer films of a type described above are not limited
to any specific kind of film structure. Other film structures may
achieve the same or similar result as the three-layer apertured
elastic film layer 2 shown in FIG. 1 or the three-layered elastic
film layer having a folded edge shown in FIG. 6. Film structure is
a function of equipment design and capability. For example, the
number of layers in a film depends only on the technology available
and the desired end use for the film. Representative examples of
film structures that may be implemented in accordance with the
present disclosure include but are not limited to the following,
wherein "A" represents an apertured elastic film layer or an
elastic film layer having a folded edge in accordance with the
present disclosure, and "B" represents an additional film layer
(which, in some embodiments, is an additional apertured elastic
film layer or elastic film layer having a folded edge in accordance
with the present disclosure): [0069] A-B-A [0070] A-A-B-A [0071]
A-B-A-A [0072] A-A-B-A-A [0073] A-B-A-A-A [0074] A-B-A-B-A [0075]
A-B-A-A-A-A-A [0076] A-A-B-A-A-A-A [0077] A-A-A-B-A-A-A [0078]
A-B-A-A-A-B-A [0079] A-B-A-A-B-A-A [0080] A-B-A-B-A-A-A [0081]
A-B-A-B-A-B-A [0082] A-B-A-A-A-A-A-A [0083] A-A-B-A-A-A-A-A [0084]
A-A-A-B-A-A-A-A [0085] A-B-A-A-A-A-B-A.
[0086] In the above-described exemplary film structures, each of
the elastic film layers A may include two or more elastic film
layers in order to better control other film properties, such as
the ability to bond to nonwovens. For example, when there are two
apertured elastic film layers in one "A" elastic film layer, and
when "C" represents the second elastic film layer, some exemplary
film structures are as follows: [0087] A-C-B-C-A [0088]
A-C-A-C-B-C-A [0089] A-C-B-C-A-C-A [0090] A-C-A-C-B-C-A-C-A [0091]
A-C-B-C-A-C-A-C-A [0092] A-C-B-C-A-B-C-A
[0093] Additionally, die technology that allows production of
multiple layers in a multiplier fashion may be used. For example,
an ABA structure may be multiplied from about 10 to about 1000
times. The resulting 10-time multiplied ABA structure may be
expressed as follows: [0094]
A-B-A-A-B-A-A-B-A-A-B-A-A-B-A-A-B-A-A-B-A-A-B-A-A-B-A-A-B-A
[0095] In some embodiments, as described above, the present
disclosure provides apertured elastic films 2 (e.g., mono-layer or
multi-layer). In other embodiments, the present disclosure further
provides personal hygiene products containing one or more apertured
elastic films (e.g., mono-layer or multi-layer) in accordance with
the present disclosure.
[0096] In illustrative embodiments, as shown in FIG. 8, an
apertured elastic film 2 in accordance with the present disclosure
may be subjected to additional post-stretching (e.g., by an end
user of the film). In the exemplary process shown in FIG. 8, the
apertured elastic film 2 may be post-stretched in a machine
direction by further MD stretching from a series of additional
rollers moving at different speeds. For example, a first roller 90
(1.times.), a second roller 92 (2.times.), and a third roller 94
(3.times.) may be used to post-stretch the film in a machine
direction. In some embodiments, the resultant post-stretched film
91 may be ultrasonically bonded to a non-woven material 95 by the
ultrasonic bond horn 96.
[0097] As shown in FIG. 9, a multi-layer apertured elastic film 100
contains a core layer 108 interposed between a first skin layer 104
and a second skin layer 106, and one or more apertures 110. The
apertured elastic film 100 is bonded to a non-woven layer 102 to
form a multi-layer structure 98 which, in some embodiments, may be
used as a backsheet for a diaper, incontinence brief, and/or the
like. The multi-layer structure 98 shown in FIG. 9 may be formed
using a process as shown in FIG. 8, whereby an apertured elastic
film is attached to a nonwoven material using an ultrasonic bond
horn 96. In some embodiments, the non-woven layer 102 and at least
the second skin layer 106 to which it is adjacent include the same
polyolefin. For example, in some embodiments, the non-woven layer
102, the second skin layer 106, and/or the first skin layer 104
include polypropylene. In some embodiments, the non-woven layer
102, the second skin layer 106, and/or the first skin layer 104
include polypropylene, and the non-woven layer 102 is bonded to the
second skin layer 106 by an ultrasonic weld.
[0098] In some embodiments, a multi-layer structure in accordance
with the present teachings, such as the apertured elastic film 2
shown in FIG. 1 and/or the apertured elastic film 100 shown in FIG.
9, is a co-extrusion with a target layer ratio of about 7.5/85/7.5.
In other embodiments, the multi-layer structure is a co-extrusion
with a target layer ratio of about 10/80/10. In further
embodiments, the multi-layer structure is a co-extrusion with a
target layer ratio of about 5/90/5.
[0099] In illustrative embodiments, the core layer 4 shown in FIG.
2 and the core layer 108 shown in FIG. 9--either of which may be a
single layer or multiple co-extruded layers--contains an
elastomer-rich formula. The types of elastomers suitable for use in
the core layer 4 and the core layer 108 range from polyolefin to
block copolymer. Representative elastomers include but are not
limited to the polypropylene elastomer available under the trade
designation VISTAMAXX, the polyethylene block copolymer elastomer
available under the trade designation INFUSE, and/or a combination
thereof. In some embodiments, the core layer 4 and the core layer
108 contain a styrene-ethylene-butylene-styrene (SEBS) polymer.
[0100] For some embodiments in which the non-woven material 102
contains polypropylene homopolymer, the first skin layer 104 and/or
the second skin layer 106 may contain a blend of about 60% C702-20
and 40% Exceed 3518. In other embodiments, the first skin layer 104
and/or the second skin layer 106 may contain a blend of about 85%
35 MFR polypropylene homopolymer and about 15% of an LDPE, such as
Equistar NA334.
[0101] For some embodiments in which the non-woven material 102
contains bicomponent polyethylene/polypropylene non-woven material,
which is sometimes used for softness, the first skin layer 104
and/or the second skin layer 106 may contain a blend of about 60%
C702-20 and about 40% Exceed 3518. In other embodiments, the first
skin layer 104 and/or the second skin layer 106 may contain (a) a
blend of about 75% Exceed 3518 and about 25% of an LDPE, such as
Equistar NA334, or (b) 100% of an HDPE resin.
[0102] In illustrative embodiments, a personal hygiene product in
accordance with the present disclosure includes at least one inner
apertured elastic film 2 prepared by a process as described above
and at least one outer non-woven layer. The at least one inner
apertured elastic film 2 is configured for contacting skin and/or
clothing of a user of the personal hygiene product.
[0103] In one example, the at least one inner apertured elastic
film is bonded to the at least one outer non-woven layer without an
adhesive (e.g., via heat sealing, ultrasonic welding, and/or the
like). In some embodiments, each of the at least one inner
apertured elastic film 2 and the at least one outer non-woven layer
comprises polypropylene and/or polyethylene. In illustrative
embodiments, each of the at least one inner apertured elastic film
2 and the at least one outer non-woven layer comprises
polypropylene. In illustrative embodiments, the at least one
apertured elastic film is bonded to the at least one outer
non-woven layer via an ultrasonic bond.
[0104] For embodiments in which the apertured elastic film to be
ultrasonically bonded to a nonwoven material is a co-extrusion
analogous to that shown in FIG. 1, the outer skin layers of the
apertured elastic film 2 may include a material that will
ultrasonically bond with the non-woven material. For example, if
the apertured elastic film 2 shown in FIG. 1 is a co-extrusion with
a target layer ratio of about 7.5/85/7.5, at least the outer 7.5%
layers and the non-woven material may include a material such as
polypropylene.
[0105] In illustrative embodiments, the personal hygiene product in
accordance with the present disclosure is configured as an
incontinence brief, a surgical gown, or a feminine hygiene
product.
[0106] The following numbered clauses include embodiments that are
contemplated and non-limiting:
[0107] Clause 1. A process for making an apertured elastic film
comprising the steps of
[0108] extruding a composition comprising a polyolefin, a styrene
block copolymer, a non-styrene block copolymer, or a combination
thereof to form a molten web.
[0109] Clause 2. The process of clause 1, any other suitable
clause, or combination of suitable clauses, further comprising
casting the molten web against a surface of a chill roll using an
air knife, an air blanket, a vacuum box, or a combination thereof
to form a quenched film.
[0110] Clause 3. The process of clause 2, any other suitable
clause, or combination of suitable clauses, further comprising
stretching the quenched film in a machine direction in at least a
2:1 draw to form a stretched film.
[0111] Clause 4. The process of clause 3, any other suitable
clause, or combination of suitable clauses, further comprising
relaxing the stretched film to form a relaxed film.
[0112] Clause 5. The process of clause 4, any other suitable
clause, or combination of suitable clauses, further comprising
perforating the relaxed film to introduce at least one aperture
therein.
[0113] Clause 6. The process of clause 5, any other suitable
clause, or combination of suitable clauses, wherein the polyolefin
comprises polyethylene, polypropylene, or a combination
thereof.
[0114] Clause 7. The process of clause 5, any other suitable
clause, or combination of suitable clauses, wherein the polyolefin
comprises low density polyethylene, high density polyethylene,
linear low density polyethylene, ultra-low density polyethylene, or
a combination thereof.
[0115] Clause 8. The process of clause 5, any other suitable
clause, or combination of suitable clauses, wherein the polyolefin
comprises linear low density polyethylene.
[0116] Clause 9. The process of clause 5, any other suitable
clause, or combination of suitable clauses, wherein the polyolefin
comprises linear low density polyethylene and the linear low
density polyethylene comprises a metallocene polyethylene.
[0117] Clause 10. The process of clause 5, any other suitable
clause, or combination of suitable clauses, wherein the polyolefin
comprises polypropylene.
[0118] Clause 11. The process of clause 5, any other suitable
clause, or combination of suitable clauses, wherein the polyolefin
comprises polypropylene impact copolymer.
[0119] Clause 12. The process of clause 5, any other suitable
clause, or combination of suitable clauses, wherein the styrene
block copolymer comprises styrene-isoprene block copolymer,
styrene-(ethylene-butylene) block copolymer,
styrene-(ethylene-propylene) block copolymer, styrene-butadiene
block copolymer, or a combination thereof
[0120] Clause 13. The process of clause 5, any other suitable
clause, or combination of suitable clauses, wherein the molten web
is cast against the surface of the chill roll under negative
pressure by the vacuum box.
[0121] Clause 14. The process of clause 5, any other suitable
clause, or combination of suitable clauses, wherein the molten web
is cast against the surface of the chill roll under positive
pressure by the air knife.
[0122] Clause 15. The process of clause 5, any other suitable
clause, or combination of suitable clauses, wherein at least the
extruding and the casting are achieved via in-line processing.
[0123] Clause 16. The process of clause 5, any other suitable
clause, or combination of suitable clauses, wherein the extruding
and the casting are achieved via in-line processing, and wherein
one or more of the stretching, the relaxing, and the perforating is
achieved via post-processing of the quenched film.
[0124] Clause 17. The process of clause 5, any other suitable
clause, or combination of suitable clauses, wherein at least the
extruding, the casting, and the stretching are achieved via in-line
processing.
[0125] Clause 18. The process of clause 5, any other suitable
clause, or combination of suitable clauses, wherein at least the
extruding, the casting, the stretching, and the relaxing are
achieved via in-line processing.
[0126] Clause 19. The process of clause 5, any other suitable
clause, or combination of suitable clauses, wherein each of the
extruding, the casting, the stretching, the relaxing, and the
perforating is achieved via in-line processing.
[0127] Clause 20. The process of clause 5, any other suitable
clause, or combination of suitable clauses, wherein the stretching
in the machine direction is in at least a 3:1 draw.
[0128] Clause 21. The process of clause 5, any other suitable
clause, or combination of suitable clauses, wherein the stretching
in the machine direction is in at least a 4:1 draw.
[0129] Clause 22. The process of clause 5, any other suitable
clause, or combination of suitable clauses, wherein at least a
portion of the stretching is performed at room temperature.
[0130] Clause 23. The process of clause 5, any other suitable
clause, or combination of suitable clauses, wherein the perforating
is performed in a machine direction.
[0131] Clause 24. The process of clause 5, any other suitable
clause, or combination of suitable clauses, further comprising
co-extruding one or a plurality of additional compositions
substantially contemporaneously with the extruding of the
composition.
[0132] Clause 25. The process of clause 5, any other suitable
clause, or combination of suitable clauses, wherein the extruding
of the composition forms a first film layer, wherein the process
further comprises co-extruding at least a second composition to
form at least one second film layer and at least a third
composition to form at least one third film layer, the second
composition and the third composition being identical or different,
wherein the first film layer is disposed between the at least one
second film layer and the at least one third film layer.
[0133] Clause 26. The process of clause 25, any other suitable
clause, or combination of suitable clauses, wherein each of the
second composition and the third composition comprises a
polyolefin, wherein the first film layer is a core layer, and
wherein each of the at least one second film layer and the at least
one third film layer is an outer skin layer.
[0134] Clause 27. The process of clause 25, any other suitable
clause, or combination of suitable clauses, wherein each of the
second composition and the third composition comprises a
polyolefin, and wherein the polyolefin is polyethylene,
polypropylene, or a combination thereof.
[0135] Clause 28. The process of clause 5, any other suitable
clause, or combination of suitable clauses, wherein the apertured
elastic film has a basis weight of less than or equal to about 50
gsm.
[0136] Clause 29. The process of clause 5, any other suitable
clause, or combination of suitable clauses, wherein the apertured
elastic film has a basis weight of less than or equal to about 40
gsm.
[0137] Clause 30. The process of clause 5, any other suitable
clause, or combination of suitable clauses, wherein the apertured
elastic film has a basis weight of less than or equal to about 30
gsm.
[0138] Clause 31. The process of clause 5, any other suitable
clause, or combination of suitable clauses, wherein the apertured
elastic film has a basis weight of less than or equal to about 20
gsm.
[0139] Clause 32. A process for making an apertured elastic film
comprising the steps of
[0140] extruding a composition comprising an elastomer to form a
molten web.
[0141] Clause 33. The process of clause 32, any other suitable
clause, or combination of suitable clauses, further comprising
quenching the molten web to form a quenched film.
[0142] Clause 34. The process of clause 33, any other suitable
clause, or combination of suitable clauses, further comprising
ageing the quenched film to form an aged film.
[0143] Clause 35. The process of clause 34, any other suitable
clause, or combination of suitable clauses, wherein the aged film
has an increased elasticity relative to the quenched film.
[0144] Clause 36. The process of clause 35, any other suitable
clause, or combination of suitable clauses, further comprising
stretching the aged film in a machine direction in at least a 2:1
draw to form a stretched film.
[0145] Clause 37. The process of clause 36, any other suitable
clause, or combination of suitable clauses, further comprising
relaxing the stretched film to form a relaxed film.
[0146] Clause 38. The process of clause 37, any other suitable
clause, or combination of suitable clauses, further comprising
perforating the relaxed film to introduce at least one aperture
therein.
[0147] Clause 39. The process of clause 38, any other suitable
clause, or combination of suitable clauses, wherein the elastomer
comprises a polyolefin, a non-styrene block co-polymer, a styrene
block copolymer, or a combination thereof.
[0148] Clause 40. The process of clause 38, any other suitable
clause, or combination of suitable clauses, wherein the elastomer
comprises an ethylene copolymer, an ethylene/propylene copolymer, a
propylene copolymer, an ethylene/propylene/diene terpolymer, a
metallocene polyolefin, or a combination thereof.
[0149] Clause 41. The process of clause 38, any other suitable
clause, or combination of suitable clauses, wherein the elastomer
comprises a polypropylene copolymer.
[0150] Clause 42. The process of clause 38, any other suitable
clause, or combination of suitable clauses, wherein the extruding
and the quenching are achieved via a first in-line process, and
wherein one or more of the stretching, the relaxing, and the
perforating is achieved via a second in-line process.
[0151] Clause 43. The process of clause 38, any other suitable
clause, or combination of suitable clauses, wherein the stretching
in the machine direction is in at least a 3:1 draw.
[0152] Clause 44. The process of clause 38, any other suitable
clause, or combination of suitable clauses, wherein the stretching
in the machine direction is in at least a 4:1 draw.
[0153] Clause 45. The process of clause 38, any other suitable
clause, or combination of suitable clauses, wherein the perforating
is performed in a machine direction.
[0154] Clause 46. An apertured elastic film comprising
[0155] a polyolefin, a styrene block copolymer, a non-styrene block
copolymer, or a combination thereof.
[0156] Clause 47. The apertured elastic film of clause 46, any
other suitable clause, or combination of suitable clauses, wherein
the apertured elastic film is prepared by a process comprising
stretching a quenched film in a machine direction in at least a 2:1
draw to form a stretched film, relaxing the stretched film to form
a relaxed film, and perforating the relaxed film to introduce at
least one aperture therein.
[0157] Clause 48. The apertured elastic film of clause 47, any
other suitable clause, or combination of suitable clauses, wherein
the apertured elastic film has a basis weight of less than or equal
to about 30 gsm.
[0158] Clause 49. The aperture elastic film of clause 48, any other
suitable clause, or combination of suitable clauses, wherein a
notched elongation to break of the apertured elastic film is equal
to or greater than a notched elongation to break of a comparative
apertured elastic film prepared without the stretching.
[0159] Clause 50. The apertured elastic film of clause 49, any
other suitable clause, or combination of suitable clauses, wherein
the basis weight is less than or equal to about 25 gsm.
[0160] Clause 51. The apertured elastic film of clause 49, any
other suitable clause, or combination of suitable clauses, wherein
the basis weight is less than or equal to about 20 gsm.
[0161] Clause 52. The apertured elastic film of clause 49, any
other suitable clause, or combination of suitable clauses, wherein
the film has a multi-layer structure comprising at least one core
film layer interposed between at least a first skin layer and at
least a second skin layer.
[0162] Clause 53. The apertured elastic film of clause 52, any
other suitable clause, or combination of suitable clauses, wherein
the multi-layer structure has a layer ratio of about
7.5/85/7.5.
[0163] Clause 54. The apertured elastic film of clause 52, any
other suitable clause, or combination of suitable clauses, wherein
the multi-layer structure has a layer ratio of about 10/80/10.
[0164] Clause 55. The apertured elastic film of clause 52, any
other suitable clause, or combination of suitable clauses, wherein
the multi-layer structure has a layer ratio of about 5/90/5.
[0165] Clause 56. An apertured elastic film comprising
[0166] an elastomer.
[0167] Clause 57. The apertured elastic film of clause 56, any
other suitable clause, or combination of suitable clauses, wherein
the apertured elastic film comprises at least one slit that extends
from a top surface of the film through to a bottom surface of the
film.
[0168] Clause 58. The apertured elastic film of clause 57, any
other suitable clause, or combination of suitable clauses, wherein
at least one edge of the apertured elastic film is folded, thereby
providing at least one tear-resistant edge to the apertured elastic
film.
[0169] Clause 59. The apertured elastic film of clause 58, any
other suitable clause, or combination of suitable clauses, wherein
the apertured elastic film has a basis weight of less than or equal
to about 30 gsm.
[0170] Clause 60. The apertured elastic film of clause 59, any
other suitable clause, or combination of suitable clauses, wherein
the film has a multi-layer structure comprising at least one core
film layer interposed between at least a first skin layer and at
least a second skin layer.
[0171] Clause 61. The apertured elastic film of clause 60, any
other suitable clause, or combination of suitable clauses, wherein
the multi-layer structure has a layer ratio of about
7.5/85/7.5.
[0172] Clause 62. The apertured elastic film of clause 60, any
other suitable clause, or combination of suitable clauses, wherein
the multi-layer structure has a layer ratio of about 10/80/10.
[0173] Clause 63. The apertured elastic film of clause 60, any
other suitable clause, or combination of suitable clauses, wherein
the multi-layer structure has a layer ratio of about 5/90/5.
[0174] Clause 64. The apertured elastic film of clause 59, any
other suitable clause, or combination of suitable clauses, wherein
the basis weight is less than or equal to about 25 gsm.
[0175] Clause 65. The apertured elastic film of clause 60, any
other suitable clause, or combination of suitable clauses, wherein
the basis weight is less than or equal to about 20 gsm.
[0176] Clause 66. An elastic film comprising
[0177] an elastomer,
[0178] wherein at least one edge of the elastic film is folded,
thereby providing at least one tear-resistant edge to the elastic
film.
[0179] Clause 67. The elastic film of clause 66, any other suitable
clause, or combination of suitable clauses, wherein the elastic
film has a basis weight of less than or equal to about 30 gsm.
[0180] Clause 68. The elastic film of clause 67, any other suitable
clause, or combination of suitable clauses, wherein the film has a
multi-layer structure comprising at least one core film layer
interposed between at least a first skin layer and at least a
second skin layer.
[0181] Clause 69. The elastic film of clause 68, any other suitable
clause, or combination of suitable clauses, wherein the multi-layer
structure has a layer ratio of about 7.5/85/7.5.
[0182] Clause 70. The elastic film of clause 68, any other suitable
clause, or combination of suitable clauses, wherein the multi-layer
structure has a layer ratio of about 10/80/10.
[0183] Clause 71. The elastic film of clause 68, any other suitable
clause, or combination of suitable clauses, wherein the multi-layer
structure has a layer ratio of about 5/90/5.
[0184] Clause 72. The elastic film of clause 68, any other suitable
clause, or combination of suitable clauses, wherein the basis
weight is less than or equal to about 25 gsm.
[0185] Clause 73. The elastic film of clause 68, any other suitable
clause, or combination of suitable clauses, wherein the basis
weight is less than or equal to about 20 gsm.
[0186] Clause 74. A personal hygiene product comprising
[0187] at least one apertured elastic film prepared by the process
of clause 5, any other suitable clause, or combination of suitable
clauses, the at least one apertured elastic film being configured
for contacting skin and/or clothing of a user of the personal
hygiene product, and
[0188] at least one outer non-woven layer.
[0189] Clause 75. The personal hygiene product of clause 74, any
other suitable clause, or combination of suitable clauses, wherein
the at least one apertured elastic film is bonded to the at least
one outer non-woven layer without an adhesive.
[0190] Clause 76. The personal hygiene product of clause 74, any
other suitable clause, or combination of suitable clauses, wherein
each of the at least one apertured elastic film and the at least
one outer non-woven layer comprises polypropylene.
[0191] Clause 77. The personal hygiene product of clause 74, any
other suitable clause, or combination of suitable clauses, wherein
the product is configured as an incontinence brief.
[0192] Clause 78. The personal hygiene product of clause 74, any
other suitable clause, or combination of suitable clauses, wherein
the product is configured as a feminine hygiene product.
[0193] Clause 79. The personal hygiene product of clause 74, any
other suitable clause, or combination of suitable clauses, wherein
the at least one apertured elastic film is bonded to the at least
one outer non-woven layer via an ultrasonic bond.
[0194] The following examples and representative procedures
illustrate features in accordance with the present disclosure, and
are provided solely by way of illustration. They are not intended
to limit the scope of the appended claims or their equivalents.
EXAMPLES
General
[0195] For production of the example films, an extrusion cast line
with up to 3 extruders was used. The "A" and "B" extruders are 21/2
in diameter, and the "C" extruder is 13/4 in diameter. The
extruders feed into a combining feedblock manufactured by Cloeren
Corporation of Orange, Tex., which can layer the A, B and C
extruder outputs in a variety of configurations. From the
feedblock, the molten polymer proceeds into a monolayer cast die
(manufactured by Cloeren) that is about 36'' wide. The die has an
adjustable gap. For the samples described herein, the adjustable
gap was maintained between 10 and 40 mils. The molten polymer drops
down to a chill roll. For the samples described herein, the chill
roll had an embossed pattern FST-250 which was engraved by Pamarco
of Roselle, N.J. as their pattern P-2739. The embossed pattern
P-2739 is a square pattern (e.g., with lines nearly aligned with
the Machine Direction) with 250 squares per inch and a depth of
about 31 microns. The roll itself has an 18'' diameter with
internal water cooling. The engrave roll pattern may be replaced
with other patterns that are shallow enough not to interfere with a
vacuum box quench. One alternative is a 40 Ra pattern (40
micro-inch average roughness) generated by a sand-blasting process
on a chrome plated roll.
Example 1
Polypropylene-Based Elastic Films
[0196] In this experiment, elastic films were made from the
formulation XC3-828-2358.0 shown in Table 1, the formulation
XC3-828-2358.1 shown in Table 2, the formulation XC3-828-2358.5
shown in Table 3, and the formulation XC3-828-2358.6 shown in Table
4.
TABLE-US-00001 TABLE 1 Composition of XC3-828-2358.0. Amount of
Layer % Component EXTRUDER (Total) COMPONENT (Weight %) B 85.0
INFUSE .TM. 9107 100 (Dow Chemical Company, olefin block copolymer
C 7.5/7.5 CP360 60 (split) (Braskem, homopolymer polypropylene,
narrow MWD) PETROTHENE .RTM. 40 NA334000 (LyondellBasell, low
density polyethylene)
TABLE-US-00002 TABLE 2 Composition of XC3-828-2358.1. Amount of
Layer % Component EXTRUDER (Total) COMPONENT (Weight %) B 85.0
INFUSE .TM. 9507 100 (Dow Chemical Company, olefin block copolymer)
C 7.5/7.5 C702-20 60 (split) (Braskem, impact copolymer
polypropylene) EXCEED LL3518 40 (ExxonMobil, metallocene
polyethylene resin, narrow MWD, density = 0.918 g/cm.sup.3)
TABLE-US-00003 TABLE 3 Composition of XC3-828-2358.5. Amount of
Layer % Component EXTRUDER (Total) COMPONENT (Weight %) B 85.0
VISTAMAXX .TM. 6102 100 (ExxonMobil, propylene-based elastomer C
7.5/7.5 C702-20 60 (split) (Braskem, impact copolymer
polypropylene) EXCEED LL3518 40 (ExxonMobil, metallocene
polyethylene resin, narrow MWD, density = 0.918 g/cm.sup.3)
TABLE-US-00004 TABLE 4 Composition of XC3-828-2358.6 Amount of
Layer % Component EXTRUDER (Total) COMPONENT (Weight %) B 85.0
VISTAMAXX .TM. 6102 91.70 (ExxonMobil, propylene-based elastomer
C702-20 5.00 (Braskem, Impact Copolymer Polypropylene) EXCEED
LL3518 3.30 (ExxonMobil, metallocene polyethylene resin, narrow
MWD, density = 0.918 g/cm.sup.3) C 7.5/7.5 C702-20 60 (split)
(Braskem, Impact Copolymer Polypropylene) EXCEED LL3518 40
(ExxonMobil, metallocene polyethylene resin, narrow MWD, density =
0.918 g/cm.sup.3)
Example 2
Notched Tensile Test Data
[0197] Tensile strength of notched films prepared from the
formulation XC3-828-2358.0 shown in Table 1, the formulation
XC3-828-2358.1 shown in Table 2, the formulation XC3-828-2358.5
shown in Table 3, and the formulation XC3-828-2358.6 shown in Table
4 were evaluated using the Standard Tensile Test (ASTM D882). A
rectangular sample one-inch wide was placed in Tensile tester grips
that were two inches apart. A one-eighth-inch notch was made at the
midpoint on one side of each of the film samples. In the test, the
upper jaw moves at 20 inches per minute and proceeds until the
sample breaks.
[0198] The tensile test data for films prepared from formulation
XC3-828-2358.0 are summarized in Table 5 below.
[0199] The tensile test data for films prepared from formulation
XC3-828-2358.1 are summarized in Table 6 below.
[0200] The tensile test data for films prepared from formulation
XC3-828-2358.5 are summarized in Table 7 below.
[0201] The tensile test data for films prepared from formulation
XC3-828-2358.6 are summarized in Table 8 below.
TABLE-US-00005 TABLE 5 Tensile test data for films prepared from
formulation XC3-828-2358.0. MD MD Tensile Tensile Prestretch
Prestretched MD Properties Elong. % Std. Elong. % Notched Elong. %
MD Tensile Elong. % Tensile Notched Gauge 1.38 1.39 1.38 1.38
(mils) MD5 5 762 5 102 5 661 5 29 MD10 10 780 10 252 10 768 10 62
MD25 25 840 25 301 25 1026 25 111 MD50 50 954 50 311 50 1451 50 163
MD100 100 1231 100 270 100 2594 100 336 Force at Peak 350 3204 57
312 131 3326 96 344 (grams/inch) Force at Break 351 3193 91 282 131
3313 105 314 (grams/inch) Total Energy 2165 69 706 53 Absorbed
(ft-lb/in.sup.2) No REDUCTION BY NOTCH Prestretch Prestretch Peak
Elongation 84% 27% Break Elongation 74% 20% Total Energy 97%
92%
TABLE-US-00006 TABLE 6 Tensile test data for films prepared from
formulation XC3-828-2358.1. MD MD Tensile Tensile Prestretch
Prestretched MD Properties Elong. % Std. Elong. % Notched Elong. %
MD Tensile Elong. % Tensile Notched Gauge 1.35 1.35 1.35 1.35
(mils) MD5 5 309 5 134 5 160 5 23 MD10 10 312 10 188 10 190 10 44
MD25 25 324 25 237 25 290 25 75 MD50 50 346 50 247 50 446 50 108
MD100 100 401 100 255 100 818 100 Force at Peak 519 1343 159 277
154 1174 96 242 (grams/inch) Force at Break 520 1237 184 251 154
1174 101 238 (grams/inch) Total Energy 1197 124 290 35 Absorbed
(ft-lb/in.sup.2) No REDUCTION BY NOTCH Prestretch Prestretch Peak
Elongation 69% 38% Break Elongation 65% 34% Total Energy 90%
88%
TABLE-US-00007 TABLE 7 Tensile test data for films prepared from
formulation XC3-828-2358.5. MD MD Tensile Tensile Prestretch
Prestretched MD Properties Elong. % Std. Elong. % Notched Elong. %
MD Tensile Elong. % Tensile Notched Gauge 1.3 1.3 1.3 1.3 (mils)
MD5 5 805 5 125 5 800 5 29 MD10 10 823 10 187 10 890 10 59 MD25 25
876 25 258 25 1104 25 99 MD50 50 978 50 282 50 1448 50 139 MD100
100 1228 100 247 100 2360 100 248 Force at Peak 302 2801 78 292 132
3088 93 264 (grams/inch) Force at Break 302 2801 99 269 133 2968
102 239 (grams/inch) Total Energy 1850 72 758 43 Absorbed
(ft-lb/in.sup.2) No REDUCTION BY NOTCH Prestretch Prestretch Peak
Elongation 74% 30% Break Elongation 67% 23% Total Energy 96%
94%
TABLE-US-00008 TABLE 8 Tensile test data for films prepared from
formulation XC3-828-2358.6. MD MD Tensile Tensile Prestretch
Prestretched MD Properties Elong. % Std. Elong. % Notched Elong. %
MD Tensile Elong. % Tensile Notched Gauge 1.35 1.35 1.35 1.35
(mils) MD5 5 1200 5 179 5 961 5 38 MD10 10 1230 10 258 10 1113 10
77 MD25 25 1332 25 359 25 1586 25 147 MD50 50 1524 50 404 50 2278
50 241 MD100 100 1981 100 245 100 100 Force at Peak 224 3777 59 407
107 4517 79 369 (grams/inch) Force at Break 224 3777 59 369 107
4363 88 334 (grams/inch) Total Energy 1986 77 827 52 Absorbed
(ft-lb/in.sup.2) No REDUCTION BY NOTCH Prestretch Prestretch Peak
Elongation 74% 26% Break Elongation 74% 18% Total Energy 96%
94%
[0202] The physical properties of the resultant films prepared from
formulations XC3-828-2358.0, XC3-828-2358.1, XC3-828-2358.5, and
XC3-828-2358.6 are shown in Table 9 below. All of the films had a
7.5/85/7.5 A/B/A layering.
TABLE-US-00009 TABLE 9 Physical Properties of Elastic Films
Prepared from Formulations XC3-828-2358.0, XC3-828-2358.1,
XC3-828-2358.5, and XC3-828-2358.6. XC3-828- XC3-828- XC3-828-
XC3-828- Properties Units 2358.0 2358.1 2358.5 2358.6 Basis Weight
g/m.sup.2 30 30 29 29 Tensile mil 1.34 1.39 1.26 1.37 Gauge MD
Force @ Peak g/in 3,573 1,318 2,467 4,171 MD Strain @ Peak % 776
679 649 626 MD Force @ Break g/in 3,566 1,315 2,464 4,166 MD Strain
@ Break % 776 679 649 626 MD Force @ Yield g/in 241 234 175 237 MD
Strain @ Yield % 11 16 11 11 MD Force @ 5% g/in 152 122 95 130
Strain MD Force @ 10% g/in 231 193 165 228 Strain MD Force @ 25%
g/in 296 258 243 338 Strain MD Force @ 50% g/in 312 265 268 393
Strain MD Force @ 100% g/in 336 274 295 441 Strain MD TEA MD FtLb/
2,561 1,095 1,640 2,284 in.sup.2 Elmendorf Tear g 400 200 200 200
MD Arm .dagger..dagger..dagger..dagger.Elmendorf gf 161 135 152 110
Tear MD Tensile Gauge mil 1.36 1.33 1.30 1.29 TD Force @ Peak g/in
815 503 2,148 2,050 TD Strain @ Peak % 818 757 994 957 TD Force @
Break g/in 815 503 2,148 2,048 TD Strain @ Break % 817 759 994 957
TD Force @ Yield g/in 269 192 190 249 TD Strain @ Yield % 18 19 15
17 TD Force @ 5% g/in 151 99 97 116 Strain TD Force @ 10% g/in 231
161 158 199 Strain TD Force @ 25% g/in 277 197 220 276 Strain TD
Force @ 50% g/in 280 202 242 296 Strain TD Force @ 100% g/in 280
206 253 303 Strain TD TEA TD FtLb/ 995 636 1,993 2,045 in.sup.2
Elmendorf Tear g 1,600 800 800 800 TD Arm Elmendorf Tear gf 458 306
200 265 TD .sctn. Slow gf 1,071 864 973 -- Puncture - 1/4'' (D3)
.sctn. Slow gf 535 Puncture - 1/8'' -- CD 100% Hysteresis 1st Cycle
Load gf 290 216 399 339 at Peak 1st Cycle Load gf 288 213 377 334
at 50% 1st Cycle gf 22 18 42 45 Unload at 50% Extension Set, inches
0.253 0.259 0.089 0.156 second load % 12.65 12.95 4.45 7.8 second
unload inches 0.492 0.515 0.383 0.377 % 24.6 25.75 19.15 18.85
[0203] Films prepared from the formulations XC3-828-2358.0,
XC3-828-2358.1, XC3-828-2358.5, and XC3-828-2358.6 were subjected
to machine direction prestretching. The MD 100% hysteresis testing
data are summarized in Table 10 below.
TABLE-US-00010 TABLE 10 MD 100% Hysteresis Testing Data For Films
After MD Stretching. Prestretch - From 1'' to 4'' XC3-828- XC3-828-
XC3-828- XC3-828- Units 2358.0 2358.1 2358.5 2358.6 Final Length
inches 1.9375 1.708 1.5625 1.79 MD 100% Hysteresis 1st Cycle Load
gf 402 132 178 422 at Peak 1st Cycle Load gf 212 84 115 191 at 50%
1st Cycle gf 56 26 46 53 Unload at 50% Extension Set, inches 0.097
0.063 0.126 0.083 second load % 4.85 3.15 6.3 4.15 second unload
inches 0.327 0.424 0.259 0.262 % 16.35 21.2 12.95 13.1
[0204] The MD 100% Hysteresis testing data for the films prepared
from the formulations XC3-828-2358.0, XC3-828-2358.1,
XC3-828-2358.5, and XC3-828-2358.6 that were not subjected to
machine direction prestretching are summarized in Table 11
below.
TABLE-US-00011 TABLE 11 MD 100% Hysteresis Testing Data For Films
Without MD Stretching. MD 100% XC3-828- XC3-828- XC3-828- XC3-828-
Hysteresis Units 2358.0 2358.1 2358.5 2358.6 1st Cycle Load gf 367
274 359 490 at Peak 1st Cycle Load gf 345 267 327 436 at 50% 1st
Cycle gf 47 25 49 61 Unload at 50% Extension Set, inches 0.196
0.216 0.149 0.133 second load % 9.8 10.8 7.45 6.65 second unload
inches 0.375 0.465 0.36 0.337 % 18.75 23.25 18 16.85
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