U.S. patent application number 17/159973 was filed with the patent office on 2021-08-05 for artificial leather of ethylene-propylene copolymer and manufacturing method thereof.
The applicant listed for this patent is SAN FANG CHEMICAL INDUSTRY CO., LTD.. Invention is credited to CHI-WEI CHANG, KUO-KUANG CHENG, CHI-CHIN CHIANG, CHIH-YI LIN.
Application Number | 20210238798 17/159973 |
Document ID | / |
Family ID | 1000005383078 |
Filed Date | 2021-08-05 |
United States Patent
Application |
20210238798 |
Kind Code |
A1 |
LIN; CHIH-YI ; et
al. |
August 5, 2021 |
ARTIFICIAL LEATHER OF ETHYLENE-PROPYLENE COPOLYMER AND
MANUFACTURING METHOD THEREOF
Abstract
The present disclosure provides an artificial leather including
a fabric layer and an ethylene-propylene copolymer (EPM) layer
attached to the fabric layer. The EPM layer is an EPM composite
layer including an EPM foaming layer and an EPM surface layer. The
present disclosure further provides a method for manufacturing the
artificial leather, and a shoe structure including the artificial
leather.
Inventors: |
LIN; CHIH-YI; (KAOHSIUNG
CITY, TW) ; CHENG; KUO-KUANG; (KAOHSIUNG CITY,
TW) ; CHIANG; CHI-CHIN; (KAOHSIUNG CITY, TW) ;
CHANG; CHI-WEI; (KAOHSIUNG CITY, TW) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SAN FANG CHEMICAL INDUSTRY CO., LTD. |
Kaohsiung City |
|
TW |
|
|
Family ID: |
1000005383078 |
Appl. No.: |
17/159973 |
Filed: |
January 27, 2021 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
D06N 3/045 20130101;
D06N 2211/106 20130101; D06N 2203/042 20130101; D06N 3/183
20130101 |
International
Class: |
D06N 3/04 20060101
D06N003/04; D06N 3/18 20060101 D06N003/18 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 31, 2020 |
TW |
109103114 |
Claims
1. An artificial leather, comprising: a fabric layer; and an
ethylene-propylene copolymer (EPM) layer attached to the fabric
layer, wherein the EPM layer is an EPM composite layer comprising
an EPM foaming layer and an EPM surface layer.
2. The artificial leather of claim 1, wherein the fabric layer is
attached to the EPM foaming layer, and the EPM surface layer is
disposed on a surface of the EPM foaming layer opposite to the
fabric layer.
3. The artificial leather of claim 1, wherein the EPM surface layer
presents a texture on a surface opposite to the EPM foaming
layer.
4. The artificial leather of claim 1, wherein the EPM composite
layer further comprises an EPM adhesive layer, and the fabric layer
is attached to the EPM composite layer through the EPM adhesive
layer.
5. The artificial leather of claim 1, further comprising a covering
layer disposed on a surface of the EPM layer opposite to the fabric
layer.
6. A method for manufacturing the artificial leather of claim 1,
comprising: providing the fabric layer; providing the EPM layer;
and attaching the EPM layer to the fabric layer.
7. The method of claim 6, comprising forming the EPM foaming layer
and the EMP surface layer concurrently.
8. The method of claim 6, comprising co-extruding the EPM foaming
layer and the EPM surface layer.
9. The method of claim 6, wherein the EMP composite layer further
comprises an EPM adhesive layer, and the method comprises
co-extruding the EPM foaming layer, the EPM surface layer and the
EPM adhesive layer.
10. The method of claim 9, wherein the EPM adhesive layer is a
hot-melt adhesive, and the method comprises heat press laminating
the EPM adhesive layer to the fabric layer, such that the EPM
composite layer is attached to the fabric layer through the EPM
adhesive layer.
11. The method of claim 6, comprising extrusion laminating the EPM
foaming layer to the fabric layer.
12. The method of claim 6, further comprising providing a covering
layer, and attaching the covering layer to a surface of the EPM
layer opposite to the fabric layer.
13. A shoe structure comprising the artificial leather of claim
1.
14. A shoe structure comprising the artificial leather of claim
2.
15. A shoe structure comprising the artificial leather of claim
3.
16. A shoe structure comprising the artificial leather of claim
4.
17. A shoe structure comprising the artificial leather of claim 5.
Description
BACKGROUND
1. Field of the Disclosure
[0001] The present disclosure relates to an artificial leather and
a manufacturing method, and more particularly to an artificial
leather made by environmentally-friendly processes, and a
manufacturing method thereof.
2. Description of the Related Art
[0002] Conventional artificial leather may be manufactured by a dry
process or a wet process. The wet process involves impregnating or
coating a textile with a resin solution including resin (e.g.,
polyurethane), organic solvent (e.g., dimethylformamide),
surfactant, colorant, filler, etc. Then, the organic solvent may be
replaced by water, so as to form pores in the resin. The resin is
then solidified, thus forming the conventional artificial leather.
In the dry process, a resin solution is coated on a release
material. After it is dried, a paste is applied on the resin, and
the resin is attached to a textile. The resin is then matured at a
specific temperature, and the release material is removed to obtain
the conventional artificial leather. However, both dry and wet
processes involve the use of organic solvents such as
dimethylformamide. Although these organic solvents can be recycled
and reused, the recycling equipment is quite expensive, while the
recovery rate may not be high. Moreover, conventional artificial
leather cannot meet the requirement of zero detection of organic
solvents.
[0003] An improvement of the aforementioned processes may include
heat press laminating or extrusion laminating polyurethane onto a
textile. However, the resultant artificial leather is heavy, and
has a stiff hand feel and rubber-like appearance. It is also
uncomfortable to wear, and not completely recyclable.
SUMMARY
[0004] To address at least some of the aforementioned issues, the
present disclosure provides an artificial leather which can be
manufactured by environmentally-friendly processes. The artificial
leather is light-weight, and provides a favorable hand feel and
leather-like appearance. The artificial leather is also comfortable
to wear, and is completely recyclable.
[0005] The present disclosure provides an artificial leather
including a fabric layer and an ethylene-propylene copolymer (EPM)
layer attached to the fabric layer. The EPM layer is an EPM
composite layer including an EPM foaming layer and an EPM surface
layer.
[0006] The present disclosure further provides a method for
manufacturing the aforementioned artificial leather including:
providing the fabric layer; providing the EPM layer; and attaching
the EPM layer to the fabric layer.
[0007] The present disclosure further provides a shoe structure
including the aforementioned artificial leather.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 illustrates a cross-sectional view of an artificial
leather according to a first embodiment of the present
disclosure.
[0009] FIG. 2 illustrates a cross-sectional view of an artificial
leather according to a second embodiment of the present
disclosure.
[0010] FIG. 3 illustrates a cross-sectional view of an artificial
leather according to a third embodiment of the present
disclosure.
[0011] FIG. 4 illustrates a cross-sectional view of an artificial
leather according to a fourth embodiment of the present
disclosure.
DETAILED DESCRIPTION
[0012] FIG. 1 illustrates a cross-sectional view of an artificial
leather 1 according to a first embodiments of the present
disclosure. The artificial leather 1 includes a fabric layer 11 and
an ethylene-propylene copolymer (EPM) layer 12 attached to the
fabric layer 11.
[0013] For example, the artificial leather of the present
disclosure may be used in clothing, shoes, hats, accessories,
furniture, wall decorations, etc., or raw materials or
semi-finished products. Alternatively, the artificial leather may
be used in handicrafts or for other purposes, which are not limited
by the present disclosure. In one embodiment, the artificial
leather may be a part of a shoe structure, such as a part of or the
entire shoe upper in the shoe structure.
[0014] In one embodiment of the present disclosure, the fabric
layer may be any type of fabrics, such as woven fabrics or nonwoven
fabrics. In one embodiment, the fabric layer is a nonwoven fabric.
The term "nonwoven fabric" used in the present disclosure refers to
a sheet, web or bat manufactured by directionally or randomly
oriented fibers, bonded by friction, and/or cohesion and/or
adhesion, excluding paper or products which are woven, knitted,
tufted stitch bonded incorporating binding yarns or filaments, or
felted by wet milling, whether or not additionally needled. The
fibers may be of natural or man-made origin. They may be staple or
continuous filaments or may be formed in situ. Depending on the
method for forming the web, the nonwoven fabric usually includes a
composite nonwoven fabric, a needle-punched nonwoven fabric, a
melt-blown nonwoven fabric, a spun bonded nonwoven fabric, a
dry-laid nonwoven fabric, a wet-laid nonwoven fabric, a
stitch-bonded nonwoven fabric, or a spun lace nonwoven fabric. The
fabric layer provides a soft hand feel similar to real leather.
[0015] In one embodiment of the disclosure, the fiber layer
comprises a plurality of fibers. Preferably, the fibers are made of
at least one material selected from the group consisting of
polyene, polyamide, poly(p-phenylene terephthalamide), polyolefin,
polymethyl methacrylate (PMMA), polyethylene terephthalate (PET),
polytrimethylene terephthalate (PTT), polybutylene terephthalate
(PBT), polyacrylonitrile (PAN), and a mixture thereof.
[0016] FIG. 2 illustrates a cross-sectional view of an artificial
leather 2 according to a second embodiment of the present
disclosure. The artificial leather 2 also includes a fabric layer
21 and an EPM layer, while the EPM layer is an EPM composite layer
22. The EPM composite layer 22 includes an EPM foaming layer 221
and an EPM surface layer 222. The fabric layer 21 is attached to
the EPM foaming layer 221. The EPM surface layer 222 is disposed on
a surface of the EPM foaming layer 221 opposite to the fabric layer
21. That is, the EPM foaming layer 221 has a first surface and a
second surface opposite to the first surface. The fabric layer 21
is attached to the first surface of the EPM foaming layer 221, and
the EPM surface layer 22 is disposed on the second surface of the
EPM foaming layer 221.
[0017] In one preferred embodiment of the present disclosure, a
manner of foaming the EPM foaming layer may be chemically foaming
or physically foaming, wherein the chemically foaming manner uses
an agent capable of conducting a chemical reaction to yield gas,
with the gas evenly distributed in the EPM. In another aspect, the
physically foaming manner includes infiltrating gas or
supercritical carbon dioxide into the EPM, and making the gas
evenly distributed in the EPM by stirring to form the EPM foaming
layer. Since the EPM foaming layer includes foaming pores, it is
capable of replacing the polyurethane used in the conventional
artificial leather, especially the wet-process polyurethane. The
EPM foaming layer can provide a thick and rich hand feel similar to
the wet-process polyurethane. In another aspect, since the density
of the EPM is less than the density of the polyurethane used in
conventional artificial leather, the EPM is lighter in weight at
the same thickness. Preferably, the foaming density reduction rate
(density after foaming/density before foaming) of the EPM foaming
layer is about 40% to about 90%.
[0018] In one preferred embodiment of the present disclosure, the
EPM foaming layer includes a plurality of independent pores. In
another aspect, a diameter of the pores in the EPM foaming layer is
about 20 .mu.m to about 150 .mu.m, preferably about 50 .mu.m to
about 120 .mu.m, and more preferably about 70 .mu.m to about 100
.mu.m. As such, the EPM foaming layer is capable of providing a
thick, rich and bouncy hand feel similar to real leathers.
[0019] In one preferred embodiment of the present disclosure, the
EPM foaming layer has a thickness of about 0.10 mm to about 0.70
mm, preferably 0.25 mm to about 0.55 mm, and more preferably about
0.30 mm to about 0.40 mm. A hardness of the EPM foaming layer is
about 50 A to about 80 A, preferably about 55 A to about 75 A, and
more preferably about 60 A to about 70 A. A melting point of the
EPM foaming layer is about 60.degree. C. to about 200.degree. C.,
preferably about 100.degree. C. to about 190.degree. C., and more
preferably about 130.degree. C. to about 170.degree. C.
[0020] In one preferred embodiment of the present disclosure, the
EPM surface layer presents a texture on a surface opposite to the
EPM foaming layer. That is, the EPM surface layer has a first
surface facing the EPM foaming layer and a second surface opposite
to the first surface. The texture is presented on the second
surface of the EPM surface layer. A method for forming the texture
may include transfer printing using a release material or a mold
having a corresponding texture, but is not limited thereto.
[0021] In one preferred embodiment of the present disclosure, a
thickness of the EPM surface layer is about 0.10 mm to about 0.50
mm, preferably about 0.20 mm to about 0.40 mm, and more preferably
0.30 mm to about 0.35 mm. A hardness of the EPM surface layer is 50
A to about 95 A, preferably about 55 A to about 80 A, and more
preferably about 65 A to about 75 A. A melting point of the EPM
surface layer is about 60.degree. C. to about 200.degree. C.,
preferably about 100.degree. C. to about 190.degree. C., and more
preferably about 130.degree. C. to about 170.degree. C.
[0022] In one preferred embodiment of the present disclosure, a
ratio of the thickness of the EPM surface to the thickness of the
EPM foaming layer is about 9:1 to about 1:9, preferably about 5:1
to about 1:5, and more preferably about 3:1 to about 1:3.
[0023] In one preferred embodiment of the present disclosure, the
EPM layer further includes an EPM adhesive layer, and the fabric
layer is attached to the EPM layer through the EPM adhesive layer.
FIG. 3 illustrates a cross-sectional view of an artificial leather
3 according to a third embodiment of the present disclosure. The
artificial leather 3 also includes a fabric layer 31 and an EPM
layer, while the EPM layer is an EPM composite layer 32. The EPM
composite layer 32 includes an EPM foaming layer 321, an EPM
surface layer 322, and an EPM adhesive layer 323. The fabric layer
31 is attached to the EPM layer (e.g., the EPM composite layer 32)
through the EPM adhesive layer 323. For example, the fabric layer
31 is attached to the EPM foaming layer 321 by the EPM adhesive
layer 323, and the EPM surface layer 322 is disposed on a surface
of the EPM foaming layer 321 opposite to the fabric layer 31. That
is, the EPM adhesive layer 323 and the EPM surface layer 322 are
respectively disposed on two opposite surfaces of the EPM foaming
layer 321. Preferably, the EPM adhesive layer 323 is a hot-melt
adhesive.
[0024] In one preferred embodiment of the present disclosure, a
hardness of the EPM adhesive layer is about 50 A to about 85 A,
preferably about 55 A to about 80 A, and more preferably about 60 A
to about 75 A. A melting point of the EPM adhesive layer is about
50.degree. C. to about 140.degree. C., preferably about 55.degree.
C. to about 130.degree. C., and more preferably about 60.degree. C.
to about 110.degree. C.
[0025] In another preferred embodiment of the present disclosure,
the fabric layer is attached to the EPM foaming layer by another
adhesive layer. Preferably, the other adhesive layer is a hot-melt
adhesive, more preferably a hot-melt adhesive of EPM. That is, the
adhesive layer may not be a part of the EPM layer or the EPM
composite layer.
[0026] In one preferred embodiment of the present disclosure, the
artificial leather further includes a covering layer disposed on a
surface of the EPM layer opposite to the fabric layer. That is, the
EPM layer has a first surface and a second surface opposite to the
first surface. The fabric layer is attached to the first surface of
the EPM layer, and the covering layer is disposed on the second
surface of the EPM layer. FIG. 4 illustrates a cross-sectional view
of an artificial leather according to a fourth embodiment of the
present disclosure. The artificial leather 4 includes a fabric
layer 41, an EPM layer (e.g., an EPM composite layer 42) and a
covering layer 43. The EPM composite layer 42 includes an EPM
foaming layer 421, an EPM surface 422, and an EPM adhesive layer
423. The fabric layer 41 is attached to the EPM foaming layer 421
by the EPM adhesive layer 423, and the EPM surface layer 422 is
disposed on a surface of the EPM foaming layer 421 opposite to the
fabric layer 41. The covering layer 43 is disposed on a surface of
the EPM surface layer 422 opposite to the EPM foaming layer 421 or
the fabric layer 41. In another embodiment of the present
disclosure, the EPM composite layer may only include, or be
composed of, an EPM foaming layer and an EPM surface layer.
[0027] The covering layer of the present disclosure includes, but
is not limited to, polyurethane, thermoplastic polyurethane,
polyolefin or thermoplastic polyolefin. Preferably, the
polyurethane is an aqueous polyurethane. The covering layer may
optionally present textures or have microstructures on its surface,
or may include pigments.
[0028] As described above, the artificial leather of the present
disclosure is mainly made of EPM. When the fabric layer made of
polyolefin is used, the artificial leather is completely made of
polyolefin materials, and thus is completely recyclable.
Furthermore, the artificial leather of the present disclosure has
leather-like hand feel, and excellent physical properties and
abrasion resistance. The torsion resistance strength of the
artificial leather can reach 2.5 kgf/cm or more. Compared with
natural leather or conventional artificial leather, the artificial
leather of the present disclosure is light-weight and soft, and is
suitable for all kinds of applications, especially shoes.
[0029] The present disclosure further provides a method for
manufacturing the aforementioned artificial leather, including:
providing the fabric layer; providing the EPM layer; and attaching
the EPM layer to the fabric layer.
[0030] In one preferred embodiment of the present disclosure, the
EPM layer is an EPM composite layer including an EPM foaming layer
and an EPM surface layer. The method includes forming the EPM
foaming layer and the EMP surface layer concurrently.
[0031] In one embodiment of the present disclosure, "forming the
EPM foaming layer and the EMP surface layer concurrently" may be
achieved by co-extruding the EPM foaming layer and the EPM surface
layer. The co-extrusion process includes, but is not limited to,
drying the materials of the EPM foaming layer and/or the EPM
surface layer; melting the aforementioned materials; co-extruding
the materials using a die (e.g., a T-die); and cooling the
materials to a predetermined thickness. In one embodiment of the
present disclosure, a release material may be applied to a surface
of the EPM layer during the co-extrusion process (e.g., before the
cooling step), such that the surface texture of the release
material can be transfer printed on the EPM surface layer.
[0032] In one preferred embodiment of the present disclosure, the
EPM composite layer further includes an EPM adhesive layer.
Accordingly, the method may include co-extruding the EPM foaming
layer, the EPM surface layer and the EPM adhesive layer.
[0033] In one preferred embodiment of the present disclosure, the
EPM adhesive layer is a hot-melt adhesive. The method includes heat
press laminating the EPM adhesive layer to the fabric layer, such
that the EPM composite layer is attached to the fabric layer
through the EPM adhesive layer.
[0034] In one preferred embodiment of the present disclosure, the
method includes extrusion laminating the EPM foaming layer to the
fabric layer, such that the EMP layer (e.g., the EPM composite
layer) is attached to the fabric layer.
[0035] In one preferred embodiment of the present disclosure, the
method includes attaching the EPM layer to the fabric layer by
another adhesive layer. Preferably, the other adhesive layer is a
hot-melt adhesive, more preferably a hot-melt adhesive of EPM.
[0036] In one preferred embodiment of the present disclosure, the
method further includes providing a covering layer, and attaching
the covering layer to a surface of the EPM layer opposite to the
fabric layer.
[0037] The method of the present disclosure can avoid the use of
organic solvents in the manufacturing process of the conventional
artificial leather. Hence, the method of the present disclosure
meets the 2020 ZDHC (Zero Discharge of Hazardous Chemicals)
requirements. Furthermore, the method of the present disclosure is
simpler and faster than the conventional wet process.
[0038] The present disclosure further provides a shoe structure
including the aforementioned artificial leather. For example, the
artificial leather may be a part of or the entire shoe upper in the
shoe structure. That is, the artificial leather a can be combined
with the sole and other parts to form the shoe structure.
[0039] The following examples are given to illustrate the method
for manufacturing the conjugated fiber of the present disclosure,
but are not intended to limit the scope of the present
invention.
Example 1
[0040] Drying condition: The EPM was dried to a moisture content of
about 300 ppm or lower.
[0041] Extruder Temperature:
[0042] EPM surface layer (component A): 170.degree. C., 200.degree.
C., 200.degree. C.
[0043] The temperature of the T-die was set at 185.degree. C.
[0044] The EPM surface layer was extrusion laminated to a nonwoven
fabric, and was cooled by cooling rollers. The speed of the
laminating rollers was set at 3.0 m/min, thus forming an artificial
leather of EPM having a thickness of about 0.8 mm.
[0045] Then, the artificial leather was pressed by embossing
rollers having a surface temperature of 100.degree. C., thus
forming the surface-textured artificial leather of EPM.
Example 2
[0046] Drying condition: The EPM was dried to a moisture content of
about 300 ppm or lower.
[0047] Extruder Temperature:
[0048] EPM surface layer (component A): 170.degree. C., 200.degree.
C., 200.degree. C.
[0049] EPM foaming layer (component B): 150.degree. C., 195.degree.
C., 190.degree. C., with 1% to 5% microsphere foaming agent
added.
[0050] The temperature of the T-die was set at 185.degree. C.
[0051] The metering pumps of the component A and the component B
were set so that the thickness ratio of the EPM surface layer and
the EPM foaming layer was 1:3.
[0052] The EPM surface layer and the EPM foaming layer were cooled
by laminating rollers. The speed of the laminating rollers was set
at 3.0 m/min, thus forming an EPM composite layer (including the
EPM surface layer and the EPM foaming layer) having a thickness of
about 0.4 mm. The thickness of the EPM surface layer was about 0.1
mm, and the thickness of the EPM foaming layer was about 0.3
mm.
[0053] The EPM composite layer was attached to a polyolefin
nonwoven fabric by 0.1 mm EPM hot-melt adhesive, thus forming the
artificial leather. The attaching process was conducted using a
heat roll laminator with a roll surface temperature of 100.degree.
C.
Example 3
[0054] Drying condition: The EPM was dried to a moisture content of
about 300 ppm or lower.
[0055] Extruder Temperature:
[0056] EPM surface layer (component A): 170.degree. C., 200.degree.
C., 200.degree. C.
[0057] EPM foaming layer (component B): 150.degree. C., 195.degree.
C., 190.degree. C., with 1% to 5% microsphere foaming agent
added.
[0058] EPM adhesive layer (component C): 150.degree. C.,
185.degree. C., 180.degree. C.
[0059] The temperature of the T-die was set at 185.degree. C.
[0060] The metering pumps of the component A, the component B and
the component C were set, so that the thickness ratio of the EPM
surface layer, the EPM foaming layer and the EPM adhesive layer is
1:7:1.
[0061] The EPM surface layer, the EPM foaming layer and the EPM
adhesive layer were cooled by laminating rollers. The speed of the
laminating rollers was set at 2.5 m/min, thus forming an EPM
composite layer (including the EPM surface layer, the EPM foaming
layer and the EPM adhesive layer) having a thickness of about 0.9
mm. The thickness of the EPM surface layer was about 0.1 mm, the
thickness of the EPM foaming layer was about 0.7 mm, and the
thickness of the EPM adhesive layer was about 0.1 mm.
[0062] A water-based polyurethane covering layer was applied to the
EPM surface layer.
[0063] The EPM composite layer was attached to a polyolefin
nonwoven fabric through the 0.1 mm EPM adhesive layer, thus forming
the artificial leather. The attaching process was conducted using a
heat roll laminator with a roll surface temperature of 100.degree.
C.
Example 4
[0064] Extruder Temperature:
[0065] EPM surface layer (component A), containing 0%, 10%, 20%,
30%, 50% thermoplastic vulcanize (TPV): 180.degree. C., 210.degree.
C., 210.degree. C.
[0066] The temperature of the T-die was set at 195.degree. C.
[0067] The EPM surface layer was extrusion laminated to a nonwoven
fabric, and was cooled by cooling rollers. The speed of the
laminating rollers was set at 3.0 m/min, thus forming an artificial
leather of EPM having a thickness of about 0.8 mm.
[0068] The artificial leather was further pressed by embossing
rollers having a surface temperature of 100.degree. C., thus
forming the surface-textured artificial leather of EPM.
[0069] The EPM containing TPV with different contents (as shown
below) can provide the artificial leather with improved mechanical
properties and hand feel.
[0070] Test Result of Example 4
TABLE-US-00001 TPV content 0% 10% 70% 30% 50% Peel strength 3.2 3.5
3.7 3.4 3.8 (kg/cm) Flex fatigue 5,000 20,000 50,000 80,000 100,000
resistance (cycles)
[0071] While the present disclosure has been described and
illustrated with reference to specific embodiments thereof, these
descriptions and illustrations are not limiting. It should be
understood by those skilled in the art that various changes may be
made and equivalents may be substituted without departing from the
true spirit and scope of the present disclosure as defined by the
appended claims. The illustrations may not necessarily be drawn to
scale. There may be distinctions between the artistic renditions in
the present disclosure and the actual apparatus due to
manufacturing processes and tolerances. There may be other
embodiments of the present disclosure which are not specifically
illustrated. The specification and drawings are to be regarded as
illustrative rather than restrictive. Modifications may be made to
adapt to a particular situation, material, composition of matter,
method, or process in accordance with the objective, spirit and
scope of the present disclosure. All such modifications are
intended to be within the scope of the claims appended hereto.
While the methods disclosed herein have been described with
reference to particular operations performed in a particular order,
it will be understood that these operations may be combined,
sub-divided, or re-ordered to form an equivalent method without
departing from the teachings of the present disclosure.
Accordingly, unless specifically indicated herein, the order and
grouping of the operations are not limitations of the present
disclosure.
* * * * *