U.S. patent application number 13/787098 was filed with the patent office on 2013-09-12 for strobel footwear construction.
This patent application is currently assigned to W.L. GORE & ASSOCIATES, INC.. The applicant listed for this patent is W.L. GORE & ASSOCIATES, INC.. Invention is credited to Robert J. Wiener.
Application Number | 20130232818 13/787098 |
Document ID | / |
Family ID | 49112750 |
Filed Date | 2013-09-12 |
United States Patent
Application |
20130232818 |
Kind Code |
A1 |
Wiener; Robert J. |
September 12, 2013 |
Strobel Footwear Construction
Abstract
Waterproof footwear having a liner material, insole, and sealing
carrier are described herein. The sealing carrier includes one or
more layers containing a flowable polymer adapted to flow upon
application of energy in order to impart a waterproof seal.
Inventors: |
Wiener; Robert J.;
(Middletown, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
W.L. GORE & ASSOCIATES, INC. |
NEWARK |
DE |
US |
|
|
Assignee: |
W.L. GORE & ASSOCIATES,
INC.
NEWARK
DE
|
Family ID: |
49112750 |
Appl. No.: |
13/787098 |
Filed: |
March 6, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61607923 |
Mar 7, 2012 |
|
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|
Current U.S.
Class: |
36/84 ; 12/142R;
36/102; 36/7.1R; 36/83 |
Current CPC
Class: |
A43B 7/125 20130101 |
Class at
Publication: |
36/84 ; 36/83;
36/102; 36/7.1R; 12/142.R |
International
Class: |
A43B 7/12 20060101
A43B007/12 |
Claims
1. Waterproof footwear comprising: a liner material comprising at
least a waterproof, water vapor permeable functional layer, and
perimeter edge portion, the liner material further being secured to
an upper material; an insole attached to the perimeter edge
portion; and a sealing carrier adapted for closing the upper
material and waterproofing the footwear article, said sealing
carrier comprising a top surface wherein the top surface is
attached to at least a portion of the bottom perimeter edge portion
of the liner material, and further wherein at least a portion of
the top surface is adapted to flow upon application of energy to
form a waterproof seal with the upper material.
2. The footwear of claim 1, wherein the sealing carrier comprises
at least two layers.
3. The footwear of claim 2, wherein at least one of the at least
two layers comprises a polymeric layer comprising a melting point
greater than the other layer or layers.
4. The footwear of claim 2, wherein at least one of the at least
two layers comprises a polymeric layer comprising a melting point
lower than the other layer or layers.
5. The footwear of claim 1, wherein the waterproof, water vapor
permeable functional layer comprises a polymeric membrane
material.
6. The footwear of claim 5, wherein the polymeric membrane material
is selected from the group consisting of polyurethane, polyester,
polyether, polyamide, polyacrylate, copolyether ester, and
copolyether amide.
7. The footwear of claim 5, wherein the polymeric membrane material
comprises microporous, expanded polytetrafluoroethylene.
8. The footwear of claim 3, wherein the polymeric layer is a
polyurethane.
9. The footwear of claim 4, wherein the polymeric layer is a
polyurethane.
10. The footwear of claim 1, wherein the liner material comprises
at least one waterproof, water vapor permeable functional layer and
at least one textile layer.
11. The footwear of claim 1, wherein an outer sole is secured to
the footwear.
12. The footwear of claim 1, wherein the sealing carrier is
stretchable.
13. The footwear of claim 1, wherein the insole is stretchable.
14. Waterproof footwear comprising: a liner material comprising at
least a waterproof, water vapor permeable functional layer and a
textile layer, the liner material further being secured to an upper
material and comprising a perimeter edge portion; an insole
attached to the perimeter edge portion; and a sealing carrier
adapted for closing the upper material and waterproofing the
footwear article, said sealing carrier comprising a first layer
with a top surface wherein the top surface is attached to at least
a portion of the bottom perimeter edge portion of the liner
material, and further wherein at least a portion of the top surface
is adapted to flow upon application of energy to form a waterproof
seal with the upper material, and comprising a second layer
comprising a melting point greater than the first layer.
15. A bootie for use within waterproof footwear, the bootie
comprising a liner material comprising at least a waterproof, water
vapor permeable functional layer, and a perimeter edge portion; an
insole attached to the perimeter edge portion; and a sealing
carrier, said sealing carrier comprising a top surface wherein the
top surface is attached to at least a portion of the bottom
perimeter edge portion of the liner material, and further wherein
at least a portion of the top surface is adapted to flow upon
application of energy.
16. The bootie of claim 15 wherein the liner material further
comprises a textile.
17. The footwear of claim 15, wherein the sealing carrier comprises
at least two layers.
18. The footwear of claim 17, wherein at least one of the at least
two layers comprises a polymeric layer comprising a melting point
greater than the other layer or layers.
19. The footwear of claim 17, wherein at least one of the at least
two layers comprises a polymeric layer comprising a melting point
lower than the other layer or layers.
20. The footwear of claim 15, wherein the waterproof, water vapor
permeable functional layer comprises a polymeric membrane
material.
21. The footwear of claim 20, wherein the polymeric membrane
material is selected from the group consisting of polyurethane,
polyester, polyether, polyamide, polyacrylate, copolyether ester,
and copolyether amide.
22. The footwear of claim 20, wherein the polymeric membrane
material comprises microporous, expanded
polytetrafluoroethylene.
23. The footwear of claim 18, wherein the polymeric layer is a
polyurethane.
24. The footwear of claim 19, wherein the polymeric layer is a
polyurethane.
25. A method for making waterproof footwear comprising: Providing
upper material; providing a liner material comprising at least a
waterproof, water vapor permeable functional layer and a non
waterproof bottom portion; securing an insole material to the non
waterproof bottom portion of the laminate liner material to form a
bootie; locating a shoe last within the bootie to form a bottom
portion of the bootie which includes the insole material and a
perimeter edge portion of the laminate liner material; providing a
sealing carrier comprising a top surface and a bottom surface, and
further wherein at least a portion of the top surface is adapted to
flow upon application of energy to form a waterproof seal with the
upper material; attaching the top surface of the sealing laminate
to the bottom portion of the bootie, the sealing laminate covering
the surface of the first insole material and at least a portion of
the perimeter edge portion of the laminate liner material to form a
waterproof bootie; applying energy to the sealing laminate at the
bottom surface to form a waterproof seal with the waterproof, water
vapor permeable functional layer; and attaching an outsole to the
bottom surface to form waterproof footwear.
Description
RELATED APPLICATION
[0001] The present application is a non-provisional application
which claims the benefit of U.S. Provisional Application No.
61/607,923 filed Mar. 7, 2012.
BACKGROUND
[0002] The art is replete with attempts at making waterproof,
breathable footwear. Early attempts for making such footwear
included making footwear consisting of upper materials such as
leather treated to make it water resistant and soles made of
rubber. Thus, some breathability was achieved. However, several
problems arose with this type of footwear construction. If the
upper material was to be made truly waterproof, it would lose its
ability to breathe. Moreover, the connecting region between the
waterproof sole and the upper became a major source of leakage as
there was no effective way to make the connecting region
waterproof.
[0003] An alternative approach to the goal of achieving comfortable
waterproof footwear involved employing a waterproof insert or
bootie into the shoe. This method is particularly useful in machine
lasted footwear, as known in the art. This waterproof insert, if
constructed of appropriate materials had the additional advantage
of being permeable to water vapor so that there was no buildup of
water vapor within the shoe over the time when the shoe was being
worn. In the footwear art materials which are both waterproof and
water vapor permeable are commonly referred to as "functional"
materials. Exemplary of such a functional material is a
microporous, expanded polytetrafluoroethylene membrane material
available from W. L. Gore and Associates, Inc., Elkton, Md., under
the tradename GORE-TEX.RTM.. Other functional materials have also
been developed and are well known in the art.
[0004] Further approaches have included securing, by a lasting
process, a waterproof, breathable liner material to the inside of
the footwear upper and sealing the liner material to a waterproof
gasket or insole. There have been many different attempts at
providing a durable, waterproof seal or connection at the region
where the liner material is joined with the waterproof gasket or
insole. These attempts have resulted in varying degrees of
success.
[0005] One problem which often results when forming such
waterproof, breathable footwear is that the insertion of the liner
or bootie will often result in a poor fitting shoe (i.e., a smaller
fit due to the liner being inserted into the already sized shoe
upper) and/or poor attachment between the liner or bootie and the
shoe upper material, which results in, among other things, a less
than desirable appearance of the inside of the footwear (i.e., the
liner appears wrinkled or pulls away from the upper).
[0006] An additional problem is that because of the multiple extra
layers typically needed for manufacturing an article of waterproof
footwear, flexibility may be severely compromised. In other words,
the typical prior art waterproof shoe is much less flexible than
prior art non-waterproof footwear.
[0007] Thus, the search continues for waterproof breathable
footwear that is both durably sealed and flexible, yet economical
to manufacture.
SUMMARY OF INVENTION
[0008] Various constructions and methods of manufacture of
waterproof footwear and booties are described herein. The
waterproof footwear include a liner material having at least a
waterproof, water vapor permeable functional layer and perimeter
edge portion, and optionally at least one textile layer. During
construction, the liner material is secured to an upper material.
Additionally, the waterproof footwear construction includes an
insole attached to the perimeter edge portion. Further, the
waterproof footwear construction includes a sealing carrier adapted
for closing the upper material and waterproofing the footwear
article. The sealing carrier has a top surface wherein the top
surface is attached to at least a portion of the bottom perimeter
edge portion of the liner material. Further wherein at least a
portion of the top surface is adapted to flow upon application
energy to form a waterproof seal with the upper material. Further,
upon completion of construction an outer sole is secure to the
footwear.
[0009] In an embodiment, the sealing carrier includes at least two
layers, an upper layer 60 having the top surface 110 previously
described and a lower layer 70. At least one of the at least two
layers includes a polymeric layer having a melting point greater
than the other layer or layers (i.e. the lower layer). Conversely,
at least one of the other at least two layers includes a polymeric
layer having a melting point lower than the other layer or layers
(i.e. the upper layer). The polymeric layer may be polyurethane,
for example. Of note, when the upper layer has a melting point
lower than the other layer or layers, the top surface 110 or the
upper layer 60 is may be adapted to flow as described above as well
as other portions of the upper layer.
[0010] In an embodiment, the waterproof, water vapor permeable
functional layer is a polymeric membrane material. Suitable
polymeric membrane material include polyurethane, polyester,
polyether, polyamide, polyacrylate, copolyether ester, and
copolyether amide. Further, the polymeric membrane material could
be microporous, expanded polytetrafluoroethylene.
[0011] In an embodiment the sealing carrier and/or the insole may
be stretchable in the machine direction and in the cross machine
direction.
[0012] Booties for use within waterproof, footwear constructions
are also described. The booties include a liner material having at
least a waterproof, water vapor permeable functional layer and
perimeter edge portion, and optionally at least one textile layer.
Additionally, the bootie includes an insole attached to the
perimeter edge portion. Further, a sealing carrier adapted for use
in waterproofing a footwear article is provided. The sealing
carrier has a top surface wherein the top surface is attached to at
least a portion of the bottom perimeter edge portion of the liner
material. At least a portion of the top surface is adapted to flow
upon application energy to form a waterproof seal with the upper
material.
[0013] Methods for making waterproof footwear are also described
herein. The method includes providing upper material, providing a
liner material having at least a waterproof, water vapor permeable
functional layer and an open bottom portion 210. The method also
includes securing an insole material to the open bottom portion 210
of the liner material 20 to form a bootie and subsequently locating
a shoe last within the bootie to form a bottom portion of the
bootie which includes the insole material 80 and a perimeter edge
portion 90 of the liner material 20. The method further includes
providing a sealing carrier 50 having an upper layer 60 and a lower
layer 70, attaching the upper layer 60 of the sealing carrier 50 to
the bottom portion of the bootie to cover the insole material and
perimeter edge portion, and applying energy to a bottom surface of
the sealing carrier to form a waterproof seal with the upper
material. Finally, an outsole 100 is attached to the bottom surface
of the sealing carrier to form waterproof footwear.
BRIEF DESCRIPTION OF DRAWINGS
[0014] FIG. 1 is a cross-sectional view of waterproof footwear
containing a sealing carrier.
[0015] FIG. 2 is an exploded view of waterproof footwear containing
a sealing carrier.
[0016] FIG. 3 is a perspective view of waterproof footwear
containing a sealing carrier.
[0017] FIG. 4 illustrates viscosity differences within a sealing
carrier.
[0018] FIG. 5 illustrates the attachment of a sealing carrier to a
bootie and a bootie to an upper.
[0019] FIG. 6 illustrates viscosity differences within a sealing
carrier.
DETAILED DESCRIPTION
[0020] The disclosure relates to waterproof footwear and methods
for making the same. The footwear utilizes a special sealing
carrier 50 rather than a traditional waterproof gasket. The sealing
carrier 50 incorporates flowable polymer within one or more layers
to make applying adhesive on the bottom of a bootie for securing a
waterproof gasket thereto unnecessary. This increases factory
efficiency by lowering manufacturing costs.
[0021] In this regard, manufacturing costs are lowered because
traditional strobel board/waterproof gasket combination and
necessary adhesives used therewith are not needed to provide
stability and facilitate waterproofness of the shoe. Instead the
sealing carrier adheres to the liner and upper to create a
waterproof seal by utilization of flowable sealing polymer rather
than by a traditional waterproof gasket/strobel board.
[0022] Turning to FIGS. 1-3, as a preliminary matter, the
waterproof footwear described herein includes a liner material 20
having a perimeter edge portion 90. It also includes an insole 80
attached to the perimeter edge portion 90. Further, it includes a
sealing carrier 50 adapted for closing upper material 10 and
waterproofing a footwear article.
[0023] Turning to FIG. 5, described herein is a liner material 20
having an open top portion 200 and an open bottom portion 210.
Optionally, seams may be joined together to form the liner material
into the general corresponding shape of a shoe upper. Pieces of
liner material can be joined together by sewing, welding, gluing,
etc. When pieces of liner are sewn together, the seams can be made
waterproof by sealing the seams with known sealing materials, such
as GORE-SEAM.RTM. tape (available from W. L. Gore and Associates,
Inc.). Other sealants may be applied to the seams to render them
waterproof if they are not inherently waterproof due to welding or
gluing. The liner material 20 includes at least one layer of
material which is waterproof and water vapor permeable (i.e., a
functional material), such as a breathable polymeric membrane. As
used herein, "water vapor permeable" and "breathable" are used
interchangeably and mean that the functional layer has a water
vapor coefficient Ret of less than 200 m.sup.2 Pa W.sup.-1.
[0024] Breathable polymeric membranes may be breathable by virtue
of pores in the membrane or through a solution diffusion mechanism.
Breathable polymeric membranes may be selected from polyurethane,
polyester, polyether, polyamide, polyacrylate, copolyether ester
and copolyether amides. In an aspect of the invention the
waterproof, water vapor permeable membrane is a membrane of
microporous polytetrafluoroethylene. In a further aspect of the
invention, the microporous polytetrafluoroethylene membrane is a
membrane of expanded polytetrafluoroethylene as taught in U.S. Pat.
Nos. 3,953,566 and 4,187,390, to Gore. Such membranes of expanded
polytetrafluoroethylene are commercially available from W. L. Gore
and Associates, Inc., Elkton, Md., under the tradename
GORE-TEX.RTM. fabric.
[0025] The liner material will contain at least the above described
functional material. Optionally, it may contain at least one other
material attached thereto. In this regard, the liner can include
the functional material 30 and a textile material 40 laminated or
otherwise joined to at least one side, and often times joined to
both sides thereof. Lamination is generally carried out with the
use of a discontinuous pattern of suitable adhesive. Thus, water
vapor permeability is not significantly affected. The at least one
other material can be a textile fabric. Textile fabrics can be
woven, knit, mesh, nonwoven, felt constructions, etc. Textiles can
be produced from natural fibers such as cotton, or from synthetic
fibers such as polyesters, polyamides, polypropylenes, polyolefins,
or blends thereof. In an aspect of the invention a textile fabric
is laminated to the side of the functional material which will be
in contact with the upper material. In a further aspect of the
invention a textile fabric is laminated to the side of the
functional material which will face the inside of the footwear. In
a still further aspect of the invention, textile fabric is
laminated to both sides of the functional material, thus providing
a three layer liner material.
[0026] An insole material 80 is also described herein. The insole
material is in the shape, generally, of the bottom of a foot. The
insole material can be any suitable material which is capable of
being secured to the bottom portion of the laminate liner material
to form a bootie. The insole material can be a woven or nonwoven
material; or EVA or other polymer foam materials. For example, the
first insole material can be polyester, nylon, polyacrylic,
polyolefin, polyurethane, polyvinyl, cotton, acetate, rayon,
olefin, acrylic, wool, spandex, metallic, etc.
[0027] The insole material 80 could also be made from a stretchable
material made from at least one substrate and at least one film and
is in the shape, generally, of the bottom of a foot. The substrate
may be composed of a variety of materials. Non-limiting examples
include polyester, nylon, polyacrylic, polyolefin, polyurethane,
polyvinyl, cotton, acetate, rayon, olefin, acrylic, wool, spandex,
metallic.
[0028] A film may optionally be included as part of the insole. The
film is desirably an extruded film, PVC, rubbers, neoprene, or any
other film capable of being stretched in the machine direction to
impart flexibility in the insole.
[0029] The insole material 80 can be secured to the perimeter edge
90 of the liner material by any suitable means. For example, the
insole material can be secured to the perimeter edge 90 of the
laminate material by stitching, stapling, ultra sonic welding,
etc., with stitching being preferred. Upon securing the insole
material to the bottom portion of laminate liner material, a bootie
is obtained which is formed to be capable of accepting a wearer's
foot.
[0030] Thereafter, the bootie can be secured to the shoe upper
shown in FIG. 5. Any suitable durable material can be used to form
shoe upper such as leather or fabric. Any suitable means can be
used for securing the bootie to the shoe upper. In an aspect of the
invention, the open top portion 200 of the bootie is secured to a
collar portion or any other suitable portion of the shoe upper by
stitching.
[0031] Upon attaching the bootie to a shoe upper, a sealing carrier
50 is then applied to the bottom surface of the construction. The
sealing carrier may include a single film layer, two film layers,
multiple film layers, and/or multiple film layers with textile.
Regardless of the configuration, the sealing carrier includes at
least one layer containing a flowable polymer therein. Exemplary,
non-limiting polymers include polyurethane, copolyether polyester,
polyester, or polyamide but any polymer that is adapted to flow
upon application of energy, for example, heat, pressure, or
ultrasonic energy may be used.
[0032] In an embodiment of the invention involving a sealing
carrier with two layers, an upper layer 60 and a lower layer 70,
the top surface 110 of the upper layer 60 will be placed underneath
the insole and the upper layer 60 and lower layer 70 will work
together to create a waterproof seal because of differences in
viscosity of the layers. For example, upon application of energy to
the lower layer 70 of the sealing carrier, the upper layer 60 will
flow and will bond with the perimeter edge of the liner material 20
and the upper 10 to form a waterproof seal. As illustrated in FIG.
4, this works because the lower layer will have a higher melting
point than the upper layer and will be more viscous than the upper
layer. In other words, the lower layer will be more resistant to
flow and will provide stability to the sealing carrier 50. For
example, in an embodiment, the lower layer will have a melting
point greater than about 120 C and the upper layer will have a
melting point lower than about 120 C.
[0033] Upon completion of this step, outer sole is attached using
conventional methods known in the art.
[0034] In marked contrast to prior art constructions, this
construction does not require a traditional waterproof gasket to
impart a waterproof seal to the footwear construction.
Additionally, because there are fewer layers involved in this
construction, the footwear construction advantageously provides
flexibility believed to previously be found in only non-waterproof
footwear.
[0035] In an alternative embodiment, the liner material can be
constructed such that the liner material is the entire upper
without a separate upper material to attach to. In this case, the
sealing carrier is secured to the liner material as described above
and energy is applied to activate the flowable polymer in the
sealing carrier to create a waterproof seal.
EXAMPLES
Test Methods
Whole Boot Moisture Vapor Transmission Rate Test
[0036] The Whole Boot Moisture Vapor Transmission Rate for each
sample was determined in accordance with Department of Defense Army
Combat Boot Temperate Weather Specifications. The specifications
are as follows:
4.5.4 Whole boot breathability. The boot breathability test shall
be designed to indicate the Moisture Vapor Transmission Rate (MVTR)
through the boot by means of a difference in concentration of
moisture vapor between the interior and the exterior
environment.
4.5.4.1 Apparatus.
[0037] a. The external test environment control system shall be
capable of maintaining 23 (.+-.1) C and 50%.+-.2% relative humidity
throughout the test duration. b. The weight scale shall be capable
of determining weight of boots filled with water to an accuracy of
(.+-.0.01) gram. c. The water holding bag shall be flexible so that
it can be inserted into the boot and conform to the interior
contours; it must be thin enough so that folds do not create air
gaps; it must have much higher MVTR than the footwear product to be
tested; and it must be waterproof so that only moisture vapor
contacts the interior of the footwear product rather than liquid
water. d. The internal heater for the boot shall be capable of
controlling the temperature of the liquid water uniformly in the
boot to 35 (.+-.1) C. e. The boot plug shall be impervious to both
liquid water and water vapor.
4.5.4.2 Procedure.
[0038] a. Place boot in test environment. b. Insert holding bag
into boot opening and fill with water to a height of 12.5 cm (5 in)
measured from inside sole. c. Insert water heater and seal opening
with boot plug. d. Heat water in boot to 35 C. e. Weigh boot sample
and record as Wi. f. Hold temperature in boot after weighing for a
minimum of 6 hours. g. After 6 hours, reweigh boot sample. Record
weight as Wf and test duration as Td. h. Compute whole boot MVTR in
grams/hour from the equation below:
MVTR=(Wi-Wf)/Td
4.5.4.3 Method of Inspection. Each boot shall be tested in
accordance with the method described in paragraph 4.5.4.2. The
average whole boot MVTR from the 5 boots tested shall be greater
than 3.5 grams/hour.
Centrifuge Waterproofness Test
[0039] Waterproofness for each sample was determined by use of the
Centrifuge test described in U.S. Pat. No. 5,329,807 assigned to
W.L. Gore and Associates, Inc. and incorporated by reference herein
in its entirety. The centrifuge tests were carried out for 30
minutes.
Flexibility Testing
[0040] Flexibility testing for each sample was carried out in
accordance with International Sports Engineering Association's
flexibility test described in the article entitled "Development and
reliability quantification of a novel set-up for measuring footwear
bending stiffness.
Viscosity Testing
[0041] Viscosity of various samples suitable for use in a sealing
carrier was tested. These samples included a polyurethane barrier
film suitable for use in the lower layer of a sealing carrier, and
it includes polyurethane sealing films suitable for use in the
upper layer of a sealing carrier. The barrier film is commercially
available from Worthen Industries, Richmond, Va., part number
WPS24. Additionally two of the sealing films are commercially
available from Worthen Industries, Richmond, Va. These sealing
films are Upaco 156 and Upaco 450, known as part numbers Film 450
and Film 156. Additionally polyurethane sealing films referenced as
LB25L, LB25M, TBO37, and HM339 are available from W.L. Gore and
Associates, Inc. in Elkton, Md.
[0042] The testing results as illustrated in FIGS. 4 and 6 show a
marked difference in viscosity between polymers suitable for use in
the upper layer of a sealing carrier and the lower layer.
[0043] A sample of each polyurethane was dried at 70.degree. C. in
a vacuum oven under approximately 28'' Hg vacuum for approximately
24 hours (LB25L, LB25M, TBO37) or 65 hours (Upaco 156 and 450,
HM339, and WPS24 barrier film). The dried samples were then pressed
into plaques approximately 75 mm.times.75 mm.times.1.5 mm in a
press at 130.degree. C. (LB25L), 130.degree. C. or 140.degree. C.
(LB25M), 125.degree. C. or 130.degree. C. (TBO37), or 120.degree.
C. (Upaco 156 and 450, HM339, and WPS24 barrier film); the plaques
were then stored in a dry nitrogen atmosphere.
[0044] Each sample was tested on the TA Instruments Ares G2
rheometer available from TA Instruments, New Castle, Del. using 25
mm diameter stainless steel parallel plates under nitrogen
atmosphere. A thermocouple was attached to each parallel plate; the
readout from these thermocouples was used to measure and control
sample temperature. The rheometer plates were zeroed at 160.degree.
C. Prior to loading each sample, the rheometer oven and test
fixture were pre-heated to 160.degree. C. For each rheometer test
performed in this study, a sample plaque was removed from the dry
nitrogen atmosphere, a 26 mm disc was punched from the sample
plaque, and the remaining sample plaque was returned to the dry
nitrogen atmosphere. The rheometer oven was then opened, the 26 mm
disc loaded into the test fixture as quickly as possible at
approximately 160.degree. C., and the rheometer oven closed. The
sample was then held for one minute to allow the sample temperature
to equilibrate at 160.degree. C. The top parallel plate was then
lowered at 0.02 mm/sec until a sample thickness of 1.25 mm was
achieved. The rheometer oven was then opened, excess sample trimmed
from the test fixture, and the rheometer oven closed. The sample
was then held for approximately one minute prior to experimental
run initiation to allow the sample temperature to re-equilibrate at
160.degree. C. Upon experimental run initiation, the rheometer
ramped the sample temperature to the initial test temperature of
180.degree. C. in approximately one minute. An initial test
temperature of 180.degree. C. was used to (i) sufficiently melt the
sample to ensure the sample was adequately adhered to the rheometer
test plates, and (ii) eliminate any sample crystallinity (and thus
erase any sample thermal history). For temperature sweeps, the
sample was held at 180.degree. C. for thirty seconds prior to
initiation of sinusoidally oscillating sample deformation and
temperature ramping. For all other tests, sinusoidally oscillating
sample deformation was initiated once the sample temperature
reached the initial test temperature of 180.degree. C. During each
experimental run, the rheometer recorded a data point approximately
every six seconds. A rheometer gap (i.e., sample thickness)
coefficient of thermal expansion correction factor of 2.34
.mu.m/.degree. C. was used for all runs. Testing parameters were as
follows:
Nitrogen atmosphere Sample diameter: 25 mm Sample thickness: 1.25
mm nominal Oscillation strain: 5% nominal Oscillation frequency: 2
radians/second typically, 0.1 628 rad/sec during frequency sweeps
Axial force control range: 5 g.+-.10 g Strain control parameters:
strain range 0.01%-5.0%, torque range 2.0-1,000 gcm (temperature
sweeps), 2.0 200 gcm (all other tests)
[0045] For each temperature sweep test, sample temperature was
ramped from 180.degree. C. to 40.degree. C. at 5.degree. C./minute,
then from 40.degree. C. to 180.degree. C. at 5.degree. C./minute.
Graphs of complex viscosity versus temperature for each
polyurethane examined in this study while cooling from 180.degree.
C. to 40.degree. C. at 5.degree. C./minute and while heating from
40.degree. C. to 180.degree. C. after being cooled from 180.degree.
C. to 40.degree. C. at 5.degree. C./minute are presented in FIG.
6.
Example 1
[0046] Waterproof footwear was made with upper material available
from God Speed, DONGGUAN CITY, China, part number GS14-721 Mesh
non-wicking. The upper materials were stitched together to form the
upper of the waterproof footwear. Liner materials were then made.
The liner materials were made of expanded polytetrafluroroethylene
and a textile, part number KBHX 600A available from W.L. Gore and
Associates, Inc in Elkton, Md. The liner parts were stitched
together to form a partial bootie. A 0.8 mm polyester insole
material made from available from Jiu Run, DONGGUAN CITY, China
part number J018 was attached to the bottom of the partial bootie
to form a bootie construction.
[0047] The bootie was then joined to the upper by stitching the
bootie to the upper at the collar portion of the upper.
[0048] A two layer sealing carrier was then stitched to the bottom
of the upper to form a closed upper to form a partial footwear
construction. The first layer of the sealing carrier was made from
polyurethane Upaco part number WPS24 and had a melting point in the
range of about 160 to 170 C. The second layer of the sealing
carrier was made from polyurethane, Upaco Film 450, and had a
melting point in the range of about 85-125 C.
[0049] A shoe last, as known in the art, was then placed inside the
partial footwear construction. The sealing carrier was then heated
and placed into a hydraulic sole press to drive flowable
polyurethane into the bottom of the bootie including the perimeter
edge region to form a waterproof seal. The hydraulic system of the
sole press was set at 40 kg/cm.sup.2 and had a silicon pad to
conform to the shape of the bottom of the upper. The sole press was
actuated.
[0050] Finally an outsole 100 made of rubber available from Zhanhui
in DONGGUAN CITY, China, part number MRS-865-1 rubber outsole was
attached to the bottom of the upper by use of adhesive available
from Nanpao in Huang Jiang Town, China, part number WA17 Adhesive
Cement Glue.
[0051] The footwear construction was tested utilizing the Whole
Boot Moisture Vapor Transmission test method described above and it
achieved a breathability of 7.4/g/m.sup.2/h.
[0052] The footwear construction tested for waterproofness
according to the test for waterproofness described above. The
footwear construction passed the test.
[0053] The footwear was then tested for flexibility according to
the test for flexibility described above. Test results indicated a
mean stiffness of 0.0699993989 Nm/.degree. which is similar to the
mean stiffness described below in Comparative Example 1 which is a
non-waterproof shoe. Conversely, the waterproof shoe described in
Comparative Example 2 below was substantially stiffer than the shoe
described in the Example or Comparative Example 1. This
demonstrates that the current construction achieves high
flexibility while maintaining breathability and waterproofness.
Comparative Example 1
[0054] Non-waterproof footwear was made with upper material
available from God Speed, DONGGUAN CITY, China, part number
GS14-721 Mesh non-wicking. The upper materials were stitched
together to form the upper of the non-waterproof footwear. Liner
materials were then made. The liner materials were made of textile,
part number GS11-C+2 mm Foam+20 gram Tricot available from Godspeed
Industrial Group, Dongguan, China. The liner is stitched
together.
[0055] The liner was then joined to the upper by stitching the
liner to the upper at the collar portion of the upper.
[0056] A strobel board 180 grams/m 2 Vidona Strobel available from
Jinjiang Chenxu Shoes Material Trade Co., Ltd, Jinjiang City,
Fujian Province, China was then stitched to the bottom of the upper
to form a closed upper A shoe last, as known in the art, was then
placed inside the partial footwear construction.
[0057] Finally an outsole made of rubber available from Zhanhui in
DONGGUAN CITY, China, part number MRS-865-1 rubber outsole was
attached to the bottom of the upper by use of adhesive available
from Nanpao in Huang Jiang Town, China, part number WA17 Adhesive
Cement Glue.
[0058] The footwear was tested for flexibility according to the
test for flexibility described above. Test results indicated a mean
stiffness of 0.067304555.
Comparative Example 2
[0059] Waterproof footwear were made substantially in accordance
with the teachings of U.S. Pat. No. 6,935,053 assigned to W.L. Gore
and Associates, Inc and hereby incorporated by reference in its
entirety. The footwear was tested for flexibility according to the
test for flexibility described above. Test results indicated a mean
stiffness of 0.082768711.
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