U.S. patent application number 15/415449 was filed with the patent office on 2017-05-11 for composite laminated structure for shoe stiffener and preparing method thereof.
The applicant listed for this patent is Yung-Chang HUANG, Shu-Chieh WANG. Invention is credited to Yung-Chang HUANG, Shu-Chieh WANG.
Application Number | 20170127761 15/415449 |
Document ID | / |
Family ID | 58668186 |
Filed Date | 2017-05-11 |
United States Patent
Application |
20170127761 |
Kind Code |
A1 |
WANG; Shu-Chieh ; et
al. |
May 11, 2017 |
COMPOSITE LAMINATED STRUCTURE FOR SHOE STIFFENER AND PREPARING
METHOD THEREOF
Abstract
The present invention is related to a composite laminated
structure for shoe stiffeners and preparing method thereof. The
composite laminated structure comprises: a fabric core layer, and a
hot-melt-adhesive layer covering and interpenetrating the fabric
core layer, wherein the fabric core layer comprises a fabric having
a fabric count of about 61 to 13 wpi and about 60 to 30 fpi and a
weight more than or equal to 100 g/m.sup.2. Preparing methods for
said composite laminated structure are very simple processes. With
the fabric core layer, proper performances could be achieved with
simple hot-melt-adhesives. High level of cheap fillers, such as
recycled materials, inorganic fillers or the mixture thereof, could
be added while still maintaining excellent split tear strength,
resilience and bending stiffness. Thus, the use of virgin materials
and the overall cost could be greatly reduced for shoe
stiffeners.
Inventors: |
WANG; Shu-Chieh; (Taichung
City, TW) ; HUANG; Yung-Chang; (Miaoli County,
TW) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
WANG; Shu-Chieh
HUANG; Yung-Chang |
Taichung City
Miaoli County |
|
TW
TW |
|
|
Family ID: |
58668186 |
Appl. No.: |
15/415449 |
Filed: |
January 25, 2017 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
14024762 |
Sep 12, 2013 |
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15415449 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A43B 23/16 20130101;
A43B 23/17 20130101; D06M 15/564 20130101; Y10T 442/2746 20150401;
A43B 23/086 20130101; A43B 23/087 20130101 |
International
Class: |
A43B 23/08 20060101
A43B023/08; D06M 15/564 20060101 D06M015/564 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 8, 2013 |
TW |
102105063 |
Claims
1. A composite laminated structure for a shoe stiffener,
comprising: a fabric core layer; a hot-melt-adhesive layer, which
covers and interpenetrates the fabric core layer; wherein the
fabric core layer comprises a fabric having a fabric count of about
61 to 13 warp yarns per inch (wpi) and about 60 to 30 filling yarns
per inch (fpi) and a weight more than or equal to 100
g/m.sup.2.
2. The composite laminated structure of claim 1, wherein the
composite laminated structure without a filler has a split tear
strength greater than or equal to 87.5 kgf/cm.
3. The composite laminated structure of claim 1, wherein the
composite laminated structure has a resilience greater than or
equal to 5.0 kgf.
4. The composite laminated structure of claim 1, wherein the fabric
core layer has a bending stiffness greater than 2000 mgcm.
5. The composite laminated structure of claim 1, wherein the fabric
core layer has a bending stiffness of about 2000 to about 25000
mgcm.
6. The composite laminated structure of claim 4, wherein the
bending stiffness is determined by using standard ISO 9073 and GB
18318 test methods.
7. The composite laminated structure of claim 1, wherein the fabric
core layer comprises: cloth about 61 warp yarns per inch (wpi) and
about 60 filling yarns per inch (fpi) for cap interlining and cloth
about 40 warp yarns per inch (wpi) and about 40 filling yarns per
inch (fpi) for cap interlining.
8. The composite laminated structure of claim 1, wherein the
hot-melt-adhesive layer is a low application temperature
hot-melt-adhesive layer having a softening temperature lower than
90.degree. C. and a solidification time greater than one
minute.
9. The composite laminated structure of claim 1, wherein the
hot-melt-adhesive layer comprises thermoplastic polyurethane (TPU)
or polycaprolactone (CAPA).
10. The composite laminated structure of claim 1, wherein the
composite laminated structure further comprises at least an
adhesive layer.
11. The composite laminated structure of claim 1, wherein the
hot-melt-adhesive layer further comprises a filler and a percentage
of the filler in the hot-melt-adhesive layer is up to 90%.
12. The composite laminated structure of claim 11, wherein the
percentage of the filler in the hot-melt-adhesive layer is up to
80%.
13. The composite laminated structure of claim 11, wherein the
filler comprises: an inorganic filler material, an organic polymer
material, or a combination thereof.
14. The composite laminated structure of claim 13, wherein the
organic polymer material is a recycled plastic material.
15. The composite laminated structure of claim 14, wherein the
organic polymer material is a recycled plastic material comprising:
polycarbonate (PC), thermoplastic polyurethane (TPU), polyethylene
terephthalate (PET), phenol-formaldehyde resin, urea-formaldehyde
resin, melamine-formaldehyde resin, epoxy resin, unsaturated
polyester resin, polyurethane, or a mixture thereof.
16. A method for preparing the composite laminated structure of
claim 1, comprising: providing a first hot-melt-adhesive material
in a molten state; providing a fabric, wherein the fabric is placed
onto the first hot-melt-adhesive material in the molten state;
providing a second hot-melt-adhesive material in a molten state,
wherein the second hot-melt-adhesive material in the molten state
is placed onto the fabric; and co-extruding and laminating the
first hot-melt-adhesive material in the molten state, the fabric
and the second hot-melt-adhesive material in the molten state to
form the composite laminated structure.
17. The method of claim 16, wherein the method further comprises a
step of coating an adhesive layer onto a surface of the composite
laminated structure.
18. A method for preparing the composite laminated structure of
claim 1, comprising: providing a first hot-melt-adhesive material
in a preheated mold; providing a fabric, wherein the fabric is
placed onto the first hot-melt-adhesive material; providing a
second hot-melt-adhesive material, wherein the second
hot-melt-adhesive material is placed onto the fabric; and forming
the first hot melt adhesive material and the second hot melt
adhesive material to be in a molten state in the mold, and pressing
the first hot melt adhesive material in the molten state, the
second hot melt adhesive material in the molten state and the
fabric together to form the composite laminated structure.
19. The method of claim 18, wherein the method further comprises a
step of coating an adhesive layer onto a surface of the composite
laminated structure.
20. A method for preparing the composite laminated structure of
claim 1, comprising: providing a hot-melt-adhesive material in a
molten state; providing a fabric, wherein the fabric is placed onto
the hot-melt-adhesive material in the molten state; and extruding
and laminating the hot melt adhesive material in the molten state
and the fabric to form the composite laminated structure.
21. The method of claim 20, wherein the method further comprises a
step of coating an adhesive layer onto a surface of the composite
laminated structure.
22. A method for preparing the composite laminated structure of
claim 1, comprising: providing a hot-melt-adhesive material in a
preheated mold; providing a fabric, wherein the fabric is placed
onto the hot-melt-adhesive material; and forming the hot melt
adhesive material to be in the molten state in the mold, and
pressing the hot melt adhesive material in the molten state and the
fabric together to form the composite laminated structure.
23. The method of claim 22, wherein the method further comprises a
step of coating an adhesive layer onto a surface of the composite
laminated structure.
24. A composite laminated structure for a shoe stiffener,
comprising: a fabric core layer; a first hot-melt-adhesive layer
and a second hot-melt-adhesive layer, which cover opposite surfaces
of the fabric core layer and interpenetrate the fabric core layer;
wherein the fabric core layer comprises a fabric having a fabric
count of about 61 to 13 warp yarns per inch (wpi) and about 60 to
30 filling yarns per inch (fpi) and a weight more than or equal to
100 g/m.sup.2.
25. The composite laminated structure of claim 5, wherein the
bending stiffness is determined by using standard ISO 9073 and GB
18318 test methods.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part of U.S. patent
application Ser. No. 14/024,762, filed on Sep. 12, 2013, which
claims foreign priority to Taiwan Patent Application No. 102105063,
filed on Feb. 8, 2013. All of the above-referenced applications are
hereby incorporated herein by reference in their entirety.
FIELD OF THE INVENTION
[0002] The present invention relates to a composite laminated
structure for shoe stiffeners and the preparing methods thereof.
More particularly, the present invention relates to a composite
laminated structure using fabrics as its core.
BACKGROUND OF THE INVENTION
[0003] In shoe industry, stiffeners are usually used in the toe
part or the heel part, known as toe puffs and counters,
respectively. The use of stiffeners is aimed at providing support
to shoe upper materials. Thus, materials for toe puffs and counters
usually require proper split tear strength and resilience. Split
tear strength is defined to represent the desired durability of
shoe uppers, while resilience is defined to represent the recovery
of the original shape upon deformation for any factors.
[0004] There are various stiffeners used in shoe industry,
including: impregnated stiffeners, premolded stiffeners, powder
coated stiffeners, extruded stiffeners, or the like. Here,
impregnated stiffeners can be made stiff, but the ones with high
stiffness usually do not have high resilience and operability under
low temperature or long time. Impregnated stiffeners, premolded
stiffeners and extruded stiffeners all require expensive processing
steps. For example, extruded stiffeners are made via extrusion of
resins such as ionomers or other thermoplastic polymers, followed
by extrusion coating of binders onto polymer sheets, so that the
desired resilience and split tear strength can be achieved. Such a
process leads to increased processing steps and cost. Furthermore,
it takes long time if not forever for these materials to be
decomposed. Lots of waste is generated accordingly. To improve,
there is a strong need for cheaper, better, and environmentally
friendly stiffeners, which provide good split tear strength,
resilience, and bending stiffness while using less virgin plastic
materials.
SUMMARY OF THE INVENTION
[0005] In light of the deficiencies in prior art, a composite
laminated structure for a shoe stiffener is provided herein,
comprising:
[0006] a fabric core layer;
[0007] a hot-melt-adhesive layer, covering and interpenetrating the
fabric core layer;
[0008] wherein the fabric core layer comprises a fabric having a
fabric count of about 61 to 13 warp yarns per inch (wpi) and about
60 to 30 filling yarns per inch (fpi) and a weight more than or
equal to 100 g/m.sup.2.
[0009] A permanent interlocking structure will be formed among the
fibers in the fabric core layer via interpenetration of the
hot-melt-adhesive layer into the fabric core layer, and thus, the
composite laminated structure will have excellent split tear
strength and resilience.
[0010] In one embodiment, the composite laminated structure without
a filler may have a split tear strength greater than or equal to
87.5 kgf/cm.
[0011] In another embodiment, the composite laminated structure may
have a resilience greater than or equal to 5.0 kgf.
[0012] In one embodiment, the fabric core layer may have a bending
stiffness greater than 2000 mgcm. In one preferred embodiment, the
fabric core layer may have a bending stiffness of about 2000 to
about 25000 mgcm.
[0013] In another embodiment, the bending stiffness for the fabric
core layer can be determined by using standard ISO 9073 and GB
18318 test methods but not limited hereto.
[0014] In a specific embodiment, the fabric core layer may
comprise, but is not limited to, fine cloth for cap interlining and
cloth (40 (wpi).times.40 (fpi)) for cap interlining, or the
like.
[0015] In one embodiment, the hot-melt-adhesive layer may be a low
application temperature hot-melt-adhesive layer having a softening
temperature lower than 90.degree. C. and a solidification time
greater than one minute. In a specific embodiment, the low
application temperature hot-melt-adhesive layer may comprise, but
is not limited to, thermoplastic polyurethane (TPU),
polycaprolactone (CAPA), or the like.
[0016] In one embodiment, the composite laminated structure may
further comprise at least an adhesive layer to enhance its
adhesion, such that the composite laminated structure can be
connected to an upper or a lining and better laminated to more
inert materials, e.g. greasy leathers.
[0017] In one embodiment, the composite laminated structure may
further comprise a filler. And the percentage of the filler in the
hot-melt-adhesive layer may be up to 90%. In another embodiment,
the percentage of the filler in the hot-melt-adhesive layer may be
up to 80%.
[0018] In a specific embodiment, the filler may comprise, but is
not limited to, an inorganic filler material, such as inorganic
mineral powders (e.g. calcium carbonate powders, silica powders, or
the like); an organic polymer material, such as recycled plastic
materials; or a combination thereof. One skilled in the art can
optionally select the filler material as needed.
[0019] In a specific embodiment, the recycled plastic material may
comprise, but is not limited to, polycarbonate (PC), thermoplastic
polyurethane (TPU), polyethylene terephthalate (PET),
phenol-formaldehyde resin, urea-formaldehyde resin,
melamine-formaldehyde resin, epoxy resin, unsaturated polyester
resin, polyurethane, a mixture thereof, or the like.
[0020] A method for preparing the composite laminated structure is
also provided herein, including steps of:
[0021] providing a first hot-melt-adhesive material in a molten
state;
[0022] providing a fabric, wherein the fabric is placed onto the
first hot-melt-adhesive material in the molten state;
[0023] providing a second hot-melt-adhesive material in a molten
state, wherein the second hot-melt-adhesive material in the molten
state is placed onto the fabric; and
[0024] co-extruding and laminating the first hot-melt-adhesive
material in the molten state, the fabric and the second
hot-melt-adhesive material in the molten state to form the
composite laminated structure.
[0025] The present invention further provides a method for
preparing the composite laminated structure, including steps
of:
[0026] providing a first hot-melt-adhesive material in a preheated
mold;
[0027] providing a fabric, wherein the fabric is placed onto the
first hot-melt-adhesive material;
[0028] providing a second hot-melt-adhesive material, wherein the
second hot-melt-adhesive material is placed onto the fabric;
[0029] forming the first hot melt adhesive material and the second
hot melt adhesive material to be in a molten state in the mold, and
pressing the first hot melt adhesive material in the molten state,
the second hot melt adhesive material in the molten state and the
fabric together to form the composite laminated structure.
[0030] In one embodiment, the first hot-melt-adhesive material and
the second hot-melt-adhesive material may be the same. Optionally,
in another embodiment, the first hot-melt-adhesive material and the
second hot-melt-adhesive material may be different.
[0031] In one embodiment, the method for preparing the composite
laminated structure may further comprise a step of coating an
adhesive layer onto a surface of the composite laminated
structure.
[0032] The present invention provides another method for preparing
the composite laminated structure, including steps of:
[0033] providing a hot-melt-adhesive material in a molten
state;
[0034] providing a fabric, wherein the fabric is placed onto the
hot-melt-adhesive material in the molten state; and
[0035] extruding and laminating the hot melt adhesive material in
the molten state and the fabric to form the composite laminated
structure.
[0036] The present invention provides still another method for
preparing the composite laminated structure, including steps
of:
[0037] providing a hot-melt-adhesive material in a preheated
mold;
[0038] providing a fabric, wherein the fabric is placed onto the
hot-melt-adhesive material;
[0039] forming the hot melt adhesive material to be in the molten
state in the mold, and pressing the hot melt adhesive material in
the molten state and the fabric together to form the composite
laminated structure.
[0040] In one embodiment, the method for preparing the composite
laminated structure may further comprise a step of coating an
adhesive layer onto a surface of the composite laminated
structure.
[0041] The present invention further provides a composite laminated
structure for a shoe stiffener, comprising:
[0042] a fabric core layer;
[0043] a first hot-melt-adhesive layer and a second
hot-melt-adhesive layer, which cover opposite surfaces of the
fabric core layer and interpenetrate the fabric core layer;
[0044] wherein the fabric core layer comprises a fabric having a
fabric count of about 61 to 13 warp yarns per inch (wpi) and about
60 to 30 filling yarns per inch (fpi) and a weight more than or
equal to 100 g/m.sup.2.
BRIEF DESCRIPTION OF THE DRAWINGS
[0045] FIG. 1 illustrates a cross-sectional view of a composite
laminated structure of a shoe stiffener according to Example 1 of
the present invention.
[0046] FIG. 2 illustrates a cross-sectional view of a composite
laminated structure of a shoe stiffener according to Example 2 of
the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0047] Preferred embodiments of the present invention will be
described below in more detail with reference to the accompanying
drawings. The present invention may, however, be embodied in
different forms and should not be construed as limited to the
embodiments set forth herein. Other objectives, advantages, and
novel features of the invention will become more apparent from the
following detailed description when taken in conjunction with the
accompanying drawings.
Example 1
[0048] FIG. 1 shows a cross-sectional view of a composite laminated
structure of a shoe stiffener according to Example 1 of the present
invention. The composite laminated structure 1 comprises, in order:
a first hot-melt-adhesive layer 11, a fabric core layer 12, and a
second hot-melt-adhesive layer 13, wherein the first
hot-melt-adhesive layer 11 and the second hot-melt-adhesive layer
13 cover and interpenetrate the fabric core layer 12. In this
example, the first hot-melt-adhesive layer 11 and the second
hot-melt-adhesive layer 13 are made with the same materials. In
other examples, the composite laminated structure 1 may comprise
only one hot-melt-adhesive layer (i.e. the first hot-melt-adhesive
layer 11 or the second hot-melt-adhesive layer 13) and a fabric
core layer 12.
[0049] In this example, the first hot-melt-adhesive layer 11 and
the second hot-melt-adhesive layer 13 are low application
temperature hot-melt-adhesive layers of TPU, having a softening
temperature lower than 90.degree. C. and a solidification time
greater than one minute. The first hot-melt-adhesive layer 11 and
the second hot-melt-adhesive layer 13 may optionally comprise a
filler of up to 90% or 80%, such as an inorganic filler material,
an organic polymer material or the like. One skilled in the art may
optionally select the filler material as needed. In this example,
the organic polymer material used is a recycled plastic material,
comprising, but not limited to, polycarbonate (PC), thermoplastic
polyurethane (TPU), polyethylene terephthalate (PET),
phenol-formaldehyde resin, urea-formaldehyde resin,
melamine-formaldehyde resin, epoxy resin, unsaturated polyester
resin, polyurethane or a mixture thereof.
[0050] The above-mentioned fabric core layer 12 may be made of a
fabric having a fabric count of about 61 to 13 warp yarns per inch
(wpi) and about 60 to 30 filling yarns per inch (fpi) and a weight
more than or equal to 100 g/m.sup.2, for instance, fine cloth for
cap interlining, cloth (40 (wpi).times.40 (fpi)) for cap
interlining, or the like, and its characteristics will be detailed
with the tests described below.
[0051] In addition, the composite laminated structure 1 as in
Example 1 may optionally comprise two adhesive layers 14, which are
provided onto the surfaces of the first hot-melt-adhesive layer 11
and the second hot-melt-adhesive layer 13 respectively, to enhance
its adhesion, such that the composite laminated structure 1 can be
adhered to an upper or a lining and better laminated to more inert
materials, e.g. greasy leathers.
[0052] The above-mentioned composite laminated structure 1 may be
prepared via extrusion molding, but is not limited to this method.
Any suitable plastic processing method may be used as well. In the
present example, the composite laminated structure 1 is prepared
via a co-extrusion/lamination process. Particularly, the
hot-melt-adhesive materials and the optional recycled plastic
material are added into the extruders, where the hot-melt-adhesive
material is melted to a molten state. The co-extrusion process is
followed by lamination of the hot-melt-adhesive material onto the
fabric to form the composite laminated structure 1. After the
composite laminated structure 1 is cooled and solidified, it is cut
to the desired shape and size.
Example 2
[0053] FIG. 2 shows a cross-sectional view of a composite laminated
structure of a shoe stiffener according to Example 2 of the present
invention. The composite laminated structure 1a comprises, in
order: a first hot-melt-adhesive layer 11a, a fabric core layer
12a, and a second hot-melt-adhesive layer 13a, wherein the first
hot-melt-adhesive layer 11a and the second hot-melt-adhesive layer
13a cover and interpenetrate the fabric core layer 12a. In this
example, the first hot-melt-adhesive layer 11a and second
hot-melt-adhesive layer 13a are made of the same material. Also,
the composite laminated structure 1a forms a tapered-off fringe
111a in the first hot-melt-adhesive layer 11a. In addition, the
composite laminated structure 11a may optionally comprise two
adhesive layers 14a, which are provided on the surfaces of the
first hot-melt-adhesive layer 11a and the second hot-melt-adhesive
layer 13a respectively, to enhance its adhesion, such that the
composite laminated structure 1a can be adhered to an upper or a
lining and better laminated to more inert materials, e.g. greasy
leathers.
[0054] The above-mentioned composite laminated structure 1a may be
prepared via a molding process, but is not limited to this method.
In this example where a molding process was adopted, the mold had a
upper die and a corresponding lower die (not shown), and part of
the hot-melt-adhesive material was flattened in the mold cavity of
the lower die of the preheated mold. The fabric is then placed onto
the hot-melt-adhesive material in the mold. Next, the remainder of
the hot-melt-adhesive material is placed onto the fabric and
flattened in the mold. Then, the upper die is placed on top and
followed by heating and pressing. After the process is done by a
hand press, the upper die was removed. Then, the molded products
are taken out after they are cooled and solidified. By the molding
process, different mold shapes can be designed depending on users'
needs. That is, the product may be molded into the final shape
without additional cutting, and thus the waste from cutting the
product into a specific shape can be reduced and the manufacturing
cost may be reduced.
Test Example 1: Characteristic Tests of the Fabric Core Layer
[0055] The samples of the fabric core layer 12, 12a are fine cloth
for cap interlining, cloth for cap interlining 40 (wpi).times.40
(fpi) and oxford. These samples are cut to strips of 2 cm.times.20
cm, held onto a clamp of a fully automatic fabric stiffness tester
(Model YG022D, Wenzhou Jigao Testing Instrument Co. Ltd) and moved
forward in the rate according to the operational manual of the
tester. The tests are conducted by the test methods of ISO 9073 and
GB 18318. When each sample passed through a bending angle, the
bending stiffness (mgcm) is automatically calculated. These data
are shown in the following Table 1.
[0056] It is noteworthy that the bending stiffnesses of the spandex
fabric sold under the trademark Lycra.RTM. and muslin are lower
than the detection limit of the tester, thus the bending
stiffnesses of the spandex fabric sold under the trademark
Lycra.RTM. and muslin are shown as <500 mgcm, which is the
detection limit of the tester.
TABLE-US-00001 TABLE 1 Characteristic data of the fabric core
layers fabric Bending count stiffness Weight (wpi .times. fpi) (mg
cm) Working fine cloth for cap 100 g/m.sup.2 61 .times. 60 2346
Examples interlining cloth for cap 180 g/m.sup.2 32 .times. 30 6544
interlining 40 .times. 40 (wpi .times. fpi) Comparative spandex
fabric sold 190 g/m.sup.2 non- <500 Examples under the trademark
specified Lycra .RTM. muslin 80 g/m.sup.2 45 .times. 46 <500
nonwoven 120 g/m.sup.2 non- 4891 specified
Test Example 2: Characteristic Tests of the Composite Laminated
Structure for a Shoe Stiffener without Recycled Plastics
[0057] 1. Process of Manufacturing the Composite Laminated
Structure for a Shoe Stiffener without Recycled Plastics
[0058] A mold having an upper die and a lower die is placed on an
electric hot plate and heated to 100.degree. C. Part of the TPU
hot-melt-adhesive powder was positioned in the mold cavity of the
lower die, and then scraped flatly back and forth with a scraper.
After the TPU powder is scraped evenly, samples of the fabric core
layer are cut into smaller pieces (i.e. a fringe 111a of each
sample was tapered-off) and positioned at a proper position in the
mold cavity. Furthermore, the TPU powder is added evenly onto the
fabric core layer in the mold cavity and scraped flatly again. A
release paper is put in after the TPU powder became flat, followed
by covering the upper die on top. At the time, the TPU powder is in
a molten state and flattened by a hand press. After the pressing is
done, the upper die and the release paper were removed. Each
product is taken out after sufficient cooling.
[0059] 2. Tests for Strength of Split Tear Strength
[0060] The above-mentioned composite laminated structures are cut
to strips of 2 cm (width).times.8 cm (length) with a thickness of
0.12 cm. Each of the strips is further cut at the middle to form a
slit of 1.5 cm, and is then fixed between the upper retaining clamp
and the lower retaining clamp of a universal tensile testing
machine (SATRA TM65, at a rate of 100 mm/min). The maximum value
measured by the machine is recorded as the strength of split tear
strength. The test results are shown in Table 2.
[0061] 3. Tests for Collapse Force and Compression Resilience
[0062] A pneumatic cylinder having a diameter of 16 mm is stood
upright and comprises a gas pressure regulator having a ball head
of 10 mm at the front. For making samples of proper size and shape,
an outer frame having a diameter of 60 mm and a hemispherical
fixture having an upper die and a lower die with a diameter of 47
mm and a height of 9.5 mm are prepared. Each sample of the
composite laminated structure is cut into a 70 mm-diameter circle,
which is further softened in hot water and shaped into a hemisphere
by the hemispherical fixture. The hemispherical sample is placed
under the pneumatic cylinder. The ball head at the front of the
pneumatic cylinder is pointed at the central convex point of the
hemispherical sample at a distance about 1 cm to start the
tests.
[0063] The gas pressure regulator is set to zero, and then adjusted
with visual observation of the value on the gas pressure regulator.
When the ball head of the pneumatic cylinder collapses the
hemispherical sample, the maximum value is recorded as the collapse
pressure or collapse force. The rebound height is also measured,
wherein the ratio of the rebound height to the initial height
represented the shape retention. The experiment is repeated ten
times. The ratio of the final to the initial pressure/force
represents the resilience. The test results are shown in Table
2.
TABLE-US-00002 TABLE 2 Data for split tear strength, collapse force
and resilience of the composite laminated structure for a shoe
stiffener without recycled plastics Initial Final Split tear
Initial Final shape shape The first The tenth strength height
height retention retention collapse collapse Resilience No. Item
(kgf/cm) (mm) (mm) (%) (%) (kgf) (kgf) (%) 1 pure hot-melt-adhesive
87.5 9.4 9.4 >98 >98 5.7 5.5 96 2 pure hot-melt-adhesive +
125 9.4 9.4 >98 >98 9 8.3 92 fine cloth for cap interlining 3
pure hot-melt-adhesive + 125 9.4 9.4 >98 >98 9.5 8.7 92 cloth
for cap interlining 40 .times. 40 (wpi .times. fpi) 4 pure
hot-melt-adhesive + 103 9.4 9.4 >98 >98 7.5 7 93 spandex
fabric sold under the trademark Lycra .RTM. 5 pure
hot-melt-adhesive + 62.5 9.4 9.4 >98 >98 6.5 6 92 muslin 6
pure hot-melt-adhesive + 89.2 Incomplete Incomplete Incomplete
nonwoven(120 g) rebound rebound Rebound
[0064] As shown in the table above, better split tear strength and
collapse force could be achieved depending on the fabric used.
Particularly, the composite laminated structures comprising the
fabric core layers having a fabric count of about 61 to 13 wpi and
about 60 to 30 fpi and a weight more than or equal to 100
g/m.sup.2, such as fine cloth for cap interlining and cloth for cap
interlining 40.times.40 (wpi.times.fpi), are provided with higher
split tear strength and resistant to the collapse, i.e. requiring
more force to collapse the laminate structure, by the ball head of
the pneumatic cylinder. Namely, with the fabric core layers having
a fabric count of about 61 to 13 wpi and about 60 to 30 fpi and a
weight more than 100 g/m.sup.2, for example, No. 2 and 3 in Table
2, the strength of the composite laminated structures is stronger
comparing to No. 1 and 4-6 for that more force is needed to
collapse the composite laminated structure.
[0065] In fact, the present application provides a composite
laminate structure to keep shoes in good shape by preventing toe
and counter from collapse under pressure. If the toe and counter
collapse, they need to bounce back to the original shape to
maintain their function, which is shown in the tests of the force
for collapses and the resilience for the dome in the Tests for
compression resilience described above.
[0066] Those effects may be due to the formation of interlocking
structures in the fabric core layers via the interpenetration of
the hot-melt-adhesive through the fabric core layer having a fabric
count of about 61 to 13 wpi and about 60 to 30 fpi and a weight
more than or equal to 100 g/m.sup.2. The production method for the
composite laminated structures is simple, and thus the cost for
shoe stiffeners could be lowered. Materials for the fabric core
layer are cheap and readily available. With different fabric, one
can achieve different split tear strength, collapse force and
resilience. Furthermore, in the preferred examples as provided
herein, the cutting step is no longer needed since the stiffeners
were prepared via molding. Wastes generated from cutting the
stiffeners to a specific shape could be greatly reduced.
Test Example 3: Characteristic Tests of the Composite Laminated
Structure for a Shoe Stiffener with Recycled Plastics
[0067] 1. Process of Manufacturing the Composite Laminated
Structure for a Shoe Stiffener with Recycled Plastics
[0068] Recycled plastics are grounded into particles of about 30 to
about 50 meshes in size. The hot-melt-adhesive (i.e. TPU powder)
and the recycled plastic powder are weighed respectively according
to the ratio shown in the following Table 3. The weighed powders
are put into plastic bags, and then shaken for well mixing. A mold
having an upper die and a lower die is placed onto an electric hot
plate and heated to 100.degree. C. Part of the TPU powder and the
recycled plastic powder are positioned in the mold cavity of the
lower die and then flattened back and forth with a scraper. After
the mixture powder is scraped evenly, samples of the fabric core
layer are cut to smaller pieces (i.e. a fringe 111a of each sample
was tapered-off) and positioned on top. The remainder of the
mixture powder is added evenly onto the fabric core layer and
scraped flat again. A release paper is put in after the mixture
powder became flat, followed by covering the upper die on top. At
the time, the mixture powder is in a molten state and is then
flattened by a hand press. After the pressing was done, the upper
die and the release paper are removed. Each product is then taken
out after cooled down. Tests for split tear strength and resilience
are conducted respectively according to the above-mentioned method,
which is not repeated here. The test results are shown in Table
3.
TABLE-US-00003 TABLE 3 Data for split tear strength, collapse force
and resilience of the composite laminated structure for a shoe
stiffener with recycled plastics Initial Final Split tear Initial
Final shape shape The first The tenth strength height height
retention retention collapse collapse Resilience No. Item (kgf/cm)
(mm) (mm) (%) (%) (kgf) (kgf) (%) 1 85% RPC + 15% 35 9.4 9.2 >98
96 2.2 1.7 77 hot-melt-adhesive + fine cloth for cap interlining 2
85% RPC + 15% 46.7 9.4 9.2 >98 96 2.2 1.7 77 hot-melt-adhesive +
cloth for cap interlining 40 .times. 40 (wpi .times. fpi) 3 85% RPC
+ 15% <5 <0.2 <0.2 <0.2 hot-melt-adhesive (without the
fabric core layer) 4 85% RTPU + 15% 29.2 9.4 9.2 >98 96 2.2 1.7
77 hot-melt-adhesive + fine cloth for cap interlining 5 85% RTPU +
15% 43.3 9.4 9.2 >98 96 2.25 1.7 77 hot-melt-adhesive + cloth
for cap interlining 40 .times. 40 (wpi .times. fpi) 6 85% RTPU +
15% <5 <0.2 <0.2 <0.2 hot-melt-adhesive (without the
fabric core layer) 7 60% RPC + 40% 42.5 9.4 9.2 >98 96 6 5.3 85
hot-melt-adhesive + fine cloth for cap interlining 8 60% RPC + 40%
45 9.4 9.2 >98 96 6.2 4.6 75 hot-melt-adhesive + cloth for cap
interlining 40 .times. 40 (wpi .times. fpi) 9 60% RPC + 40% 30.8
9.4 8.9 >98 92 5 3.2 65 hot-melt-adhesive + nonwoven (120 g) 10
60% RPET + 40% 49.2 9.4 9.1 >98 95 7 6.5 90 hot-melt-adhesive +
fine cloth for cap interlining 11 60% RPET + 40% 55.8 9.4 9.1
>98 95 7 6.5 90 hot-melt-adhesive + cloth for cap interlining 40
.times. 40 (wpi .times. fpi) 12 60% RTPU + 40% 59.2 9.4 9.2 >98
96 5 4.5 90 hot-melt-adhesive + fine cloth for cap interlining 13
60% RTPU + 40% 61.7 9.4 9.2 >98 96 5 4.5 90 hot-melt-adhesive +
cloth for cap interlining 40 .times. 40 (wpi .times. fpi) 14 60%
RTPU + 40% 36.7 9.4 9.2 >98 96 3.8 2.6 75 hot-melt-adhesive +
nonwoven (120 g) *Note: Plastics with the "R" initial refers to
recycled plastic raw materials (e.g. from post-industrial or
post-consumer wastes), which are grounded at a low temperature into
plastic powders in this example. A #30 mesh steel screen is used.
The plastic powders have a particle size of about 30 to about 40
meshes.
[0069] As shown in the above table, the composite laminated
structures with the fabric core layer having a fabric count of
about 61 to 13 wpi and about 60 to 30 fpi and a weight more than or
equal to 100 g/m.sup.2, for example No. 1-2, 4-5, 7-8 and 10-13 in
Table 3, have a significantly better split tear strength and
resilience as compared to those without fabric core layer (see data
for No. 3 and 6 of Table 3) or those with nonwoven as the fabric
core layer (see data for No. 9 and 14 of Table 3). The composite
laminated structures are environmentally friendly since the virgin
material usage could be drastically reduced. The examples indicate
that the desired split tear strength and resilience could be
obtained by a simple process without the need of complicated
treatments. The cost for shoe stiffeners could be lowered as well.
In addition, in the preferred examples as provided herein, the
cutting step is no longer needed since the stiffeners were prepared
via molding. Wastes generated from cutting the stiffeners to
specific shapes could be greatly reduced.
[0070] The above-disclosed subject matter is to be considered
illustrative, and not restrictive, and the appended claims are
intended to cover all such modifications, enhancements, and other
embodiments, which fall within the true spirit and scope of the
present invention. Thus, to the maximum extent allowed by law, the
scope of the present invention is to be determined by the broadest
permissible interpretation of the following claims and their
equivalents, and shall not be restricted or limited by the
foregoing detailed description.
* * * * *