U.S. patent application number 14/024762 was filed with the patent office on 2014-08-14 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 | 20140227926 14/024762 |
Document ID | / |
Family ID | 51268874 |
Filed Date | 2014-08-14 |
United States Patent
Application |
20140227926 |
Kind Code |
A1 |
WANG; SHU-CHIEH ; et
al. |
August 14, 2014 |
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 fiber fabric core layer,
and a hot-melt-adhesive layer covering and interpenetrating the
fiber fabric core layer, whereby the composite laminated structure
has a tear resistance greater than 3.0 kg or a resilience greater
than 2.0 kg. Preparing methods for said composite laminated
structure are very simple processes, which are also provided
herein. With the fiber 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
tear resistance and resilience. 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: |
51268874 |
Appl. No.: |
14/024762 |
Filed: |
September 12, 2013 |
Current U.S.
Class: |
442/150 ;
264/129; 264/240 |
Current CPC
Class: |
A43B 23/086 20130101;
A43B 23/16 20130101; Y10T 442/2746 20150401 |
Class at
Publication: |
442/150 ;
264/240; 264/129 |
International
Class: |
A43B 23/16 20060101
A43B023/16 |
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; whereby the
composite laminated structure has a tear resistance greater than
3.0 kg or a resilience greater than 2.0 kg.
2. The composite laminated structure of claim 1, wherein the
composite laminated structure has a tear resistance greater than
10.5 kg.
3. The composite laminated structure of claim 1, wherein the
composite laminated structure has a resilience greater than 5.0
kg.
4. The composite laminated structure of claim 1, wherein the fabric
core layer has a bending stiffness greater than 500 mgcm.
5. The composite laminated structure of claim 1, wherein the fabric
core layer has a bending stiffness of about 500 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: fine cloth for cap interlining, cloth (about
40 warp yarns per inch (wpi) and about 40 filling yarns per inch
(fpi)) for cap interlining, Oxford, Lycra fabric, muslin or
nonwoven.
8. The composite laminated structure of claim 1, 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 80 g/m.sup.2.
9. 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.
10. The composite laminated structure of claim 1, wherein the
hot-melt-adhesive layer comprises thermoplastic polyurethane (TPU)
or polycaprolactone (CAPA).
11. The composite laminated structure of claim 1, wherein the
composite laminated structure further comprises at least an
adhesive layer.
12. 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%.
13. The composite laminated structure of claim 12, wherein the
percentage of the filler in the hot-melt-adhesive layer is up to
80%.
14. The composite laminated structure of claim 12, wherein the
filler comprises: an inorganic filler material, an organic polymer
material, or a combination thereof.
15. The composite laminated structure of claim 14, wherein the
organic polymer material is a recycled plastic material.
16. The composite laminated structure of claim 15, 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.
17. 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.
18. The method of claim 17, wherein the method further comprises a
step of coating an adhesive layer onto a surface of the composite
laminated structure.
19. 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.
20. The method of claim 19, wherein the method further comprises a
step of coating an adhesive layer onto a surface of the composite
laminated structure.
21. 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.
22. The method of claim 21, wherein the method further comprises a
step of coating an adhesive layer onto a surface of the composite
laminated structure.
23. 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.
24. The method of claim 23, wherein the method further comprises a
step of coating an adhesive layer onto a surface of the composite
laminated structure.
Description
FIELD OF THE INVENTION
[0001] 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
[0002] 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 tear resistance and resilience. Tear
resistance is needed for keeping the desired durability of shoe
uppers, while resilience is needed for recovering to the original
shape upon deformation for any factors.
[0003] 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 grades usually do not have high resiliency and
low-temperature operability or long-time operability. 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, tear
resistance, and adhesion 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 are generated accordingly. To improve, there is a strong need
for cheaper, better, and environmentally friendly stiffeners, which
provide good tear resistance, resilience, and adhesion while using
less virgin plastic materials.
SUMMARY OF THE INVENTION
[0004] In light of the deficiencies in prior art, a composite
laminated structure for a shoe stiffener is provided herein,
comprising:
[0005] a fabric core layer;
[0006] a hot-melt-adhesive layer, covering and interpenetrating the
fabric core layer;
[0007] whereby the composite laminated structure has a tear
resistance greater than 3.0 kg or a resilience greater than 2.0
kg.
[0008] 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 tear resistance
and resilience.
[0009] In one embodiment, the composite laminated structure may
have a tear resistance greater than 10.5 kg.
[0010] In another embodiment, the composite laminated structure may
have a resilience greater than 5.0 kg.
[0011] In one embodiment, the fabric core layer may have a bending
stiffness greater than 500 mgcm. In one preferred embodiment, the
fabric core layer may have a bending stiffness of about 500 to
about 25000 mgcm.
[0012] 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.
[0013] In a further embodiment, the fabric core layer may comprise
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 80 g/m.sup.2.
[0014] In a specific embodiment, the fabric core layer may
comprise, but is not limited to, fine cloth for cap interlining,
cloth (40 (wpi).times.40 (fpi)) for cap interlining, Oxford, Lycra
fabric, muslin, nonwoven, 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.
BRIEF DESCRIPTION OF THE DRAWINGS
[0041] FIG. 1 illustrates a cross-sectional view of a composite
laminated structure of a shoe stiffener according to Example 1 of
the present invention.
[0042] 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
[0043] 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 constructed 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
[0044] 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 comprised, 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 covered and interpenetrated the fabric core layer 12. In this
example, the first hot-melt-adhesive layer 11 and second
hot-melt-adhesive layer 13 used the same materials. In other
examples, the composite laminated structure 1 may comprise only a
single 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.
[0045] In this example, the first hot-melt-adhesive layer 11 and
the second hot-melt-adhesive layer 13 were 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 was 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.
[0046] The above-mentioned fabric core layer 12 may be made of fine
cloth for cap interlining, cloth (40 (wpi).times.40 (fpi)) for cap
interlining, Oxford, Lycra fabric, muslin, nonwoven, or the like,
and its characteristics will be detailed with the tests described
below.
[0047] 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
connected to an upper or a lining and better laminated to more
inert materials, e.g. greasy leathers.
[0048] The above-mentioned composite laminated structure 1 may be
prepared via extrusion, but is not limited to this method. Any
suitable plastic processing method may be used as well. For this
example, the composite laminated structure 1 was prepared via a
co-extrusion/lamination process. First, the hot-melt-adhesive
material and the optional recycled plastic material were added into
the extruders, where the hot-melt-adhesive material was then melted
to a molten state. The co-extrusion process was 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 was cooled and solidified, it was cut to the
desired shape and size.
EXAMPLE 2
[0049] 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 comprised, 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 covered and interpenetrated the fabric core layer 12a. In this
example, the first hot-melt-adhesive layer 11a and second
hot-melt-adhesive layer 13a used the same material. Also, the
composite laminated structure 1a formed 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 onto 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 connected to an upper or a
lining and better laminated to more inert materials, e.g. greasy
leathers.
[0050] 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 was then placed
onto the hot-melt-adhesive material in the mold. Next, the
remainder of the hot-melt-adhesive material was placed onto the
fabric and flattened in the mold. Then, the upper die was placed on
top; heated and pressed. After the pressing was done by a hand
press, the upper die was removed. Then, the molded products were
taken out after they were cooled and solidified. By using the
molding process, different mold shapes can be designed depending on
user's needs. 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 manufacuturing
cost may be saved.
TEST EXAMPLE 1
Characteristic Tests of the Fabric Core Layer
[0051] The samples of the fabric core layer 12, 12a were fine cloth
for cap interlining, cloth for cap interlining 40 (wpi).times.40
(fpi), Oxford, a Lycra fabric, muslin, and nonwoven. These samples
were 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 of
the tester. The tests were conducted using standard ISO 9073 and GB
18318 test methods. The ratio of bending angle was calculated by
the tester when each sample passed through a bending angle. Also,
the bending stiffness (mgcm) was calculated. These data were shown
in the following Table 1.
TABLE-US-00001 TABLE 1 Characteristic data of the fabric core layer
fabric Bending count stiffness Weight (wpi .times. fpi) (mg cm)
fine cloth for cap 100 g/m.sup.2 61 .times. 60 2346 interlining
cloth for cap 180 g/m.sup.2 32 .times. 30 6544 interlining 40
.times. 40 (wpi .times. fpi) Oxford 220 g/m.sup.2 13 .times. 45
8855 Lycra fabric 190 g/m.sup.2 non-specified <2000 muslin 80
g/m.sup.2 45 .times. 46 <1000 nonwoven 120 g/m.sup.2
non-specified 4891
TEST EXAMPLE 2
Characteristic Tests of the Composite Laminated Structure for a
Shoe Stiffener Without Recycled Plastics
[0052] 1. Process of Manufacturing the Composite Laminated
Structure for a Shoe Stiffener Without Recycled Plastics
[0053] A mold having an upper die and a lower die was 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 was scraped evenly, samples of the fabric core
layer were cut into smaller pieces (i.e. a fringe 111a of each
sample was tapered-off) and positioned as desired in the mold
cavity. The remainder of the TPU powder was added evenly onto the
fabric core layer in the mold cavity and scraped flatly again. A
release paper was put in after the TPU powder became flat, followed
by covering the upper die on top. At the time, the TPU powder was
in a molten state and was then flattened by a hand press. After the
pressing was done, the upper die and the release paper were
removed. Each product was taken out after sufficient cooling.
[0054] 2. Tests for Strength of Tear Resistance
[0055] The above-mentioned composite laminated structures were cut
to strips of 2 cm (width).times.8 cm (length). Each of the strips
was further cut at the middle to form a slit of 1.5 cm, and was
then fixed between the upper retaining clamp and the lower
retaining clamp of a universal tensile testing machine for testing
(SATRA TM65, at a rate of 100 mm/min). The maximum tensile strength
measured by the machine was recorded as the strength of tear
resistance. The test results are shown in Table 2.
[0056] 3. Tests for Compression Resilience
[0057] A pneumatic cylinder having a diameter of 16 mm was stood
upright and comprised 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 fixture having an
upper die and a lower die with a diameter of 47 mm and a height of
9.5 mm were prepared. Each sample of the composite laminated
structure was first cut to a 70 mm-diameter circle, then softened
in hot water and shaped to a hemisphere by the just mentioned
hemispherical fixture. The hemispherical sample was placed under
the pneumatic cylinder. The ball head at the front of the pneumatic
cylinder was pointed at the central convex point of the
hemispherical sample at a distance about 1 cm to start the
tests.
[0058] The gas pressure regulator was first set to zero, then
rotated for visual observation of the value on the gas pressure
regulator. When the ball head of the pneumatic cylinder collapsed
the hemispherical sample, the maximum value was recorded as the
collapse pressure or resilience force. The rebound height was also
measured, wherein the ratio of the rebound height to the initial
height represented the shape retention. The measurement was
repeated ten times to observe the change, wherein the ratio of the
final to the initial pressure/resilience force represented the
resiliency. The test results are shown in Table 2.
TABLE-US-00002 TABLE 2 Data for tear resistance and resilience of
the composite laminated structure for a shoe stiffener without
recycled plastics Tear Initial Final Initial shape Final shape The
first The tenth resistance height height retention retention
collapse collapse Resiliency No. Item (KG) (mm) (mm) (%) (%) (kg)
(kg) (%) 1 pure hot-melt-adhesive 10.5 9.4 9.4 >98 >98 5.75
5.5 96 2 pure hot-melt-adhesive + 15 9.4 9.4 >98 >98 9 8.3 92
fine cloth for cap interlining 3 pure hot-melt-adhesive + 15 9.4
9.4 >98 >98 9.5 8.75 92 cloth for cap interlining 40 .times.
40 (wpi .times. fpi) 4 pure hot-melt-adhesive + 8 9.4 9.4 >98
>98 9.5 8.75 92 Oxford 5 pure hot-melt-adhesive + 12.4 9.4 9.4
>98 >98 7.5 7 93 Lycra fabric 6 pure hot-melt-adhesive + 7.5
9.4 9.4 >98 >98 6.5 6 92 muslin 7 pure hot-melt-adhesive +
10.7 Incomplete Incomplete Incomplete nonwoven(120 g) rebound
rebound Rebound
[0059] As shown in the above table, significantly better tear
resistance and resilience force could be achieved depending on the
fabric used. This was 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. The production
method for the composite laminated structures was simple, and thus
the cost for shoe stiffeners could be lowered. Materials for the
fabric core layer were cheap and readily available. With different
fabric, one can achieve different tear resistance and resilience.
Furthermore, in the preferred examples as provided herein, the
cutting step was 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
[0060] 1. Process of Manufacturing the Composite Laminated
Structure for a Shoe Stiffener With Recycled Plastics
[0061] Recycled plastics were ground into particles of about 30 to
about 50 mesh in size. The hot-melt-adhesive (i.e. TPU powder) and
the recycled plastic powder were weighed respectively according to
the ratio shown in the following Table 3. The weighed powders were
put into plastic bags, then shaken for well mixing. A mold having
an upper die and a lower die was placed onto an electric hot plate
and heated to 100.degree. C. Part of the TPU powder and the
recycled plastic powder was positioned in the mold cavity of the
lower die and then flattened back and forth with a scraper. After
the mixture powder was scraped evenly, samples of the fabric core
layer were 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 was added evenly onto the fabric core layer and
scraped flat again. A release paper was put in after the mixture
powder became flat, followed by covering the upper die on top. At
the time, the mixture powder was in a molten state and was then
flattened by a hand press. After the pressing was done, the upper
die and the release paper were removed. Each product was then taken
out after cooled down. Tests for strength of tear resistance and
compression resilience were conducted respectively according to the
above-mentioned method, which is not to be repeated here. The test
results are shown in Table 3.
TABLE-US-00003 TABLE 3 Data for tear resistance and resilience of
the composite laminated structure for a shoe stiffener with
recycled plastics Tear Initial Final Initial shape Final shape The
first The tenth resistance height height retention retention
collapse collapse Resiliency No. Item (KG) (mm) (mm) (%) (%) (kg)
(kg) (%) 1 85% RPC + 15% 4.2 9.4 9.2 >98 96 2.25 1.75 77
hot-melt-adhesive + fine cloth for cap interlining 2 85% RPC + 15%
5.6 9.4 9.2 >98 96 2.25 1.75 77 hot-melt-adhesive + cloth for
cap interlining 40 .times. 40 (wpi .times. fpi) 3 85% RTPU + 15%
3.5 9.4 9.2 >98 96 2.25 1.75 77 hot-melt-adhesive + fine cloth
for cap interlining 4 85% RTPU + 15% 5.2 9.4 9.2 >98 96 2.25
1.75 77 hot-melt-adhesive + cloth for cap interlining 40 .times. 40
(wpi .times. fpi) 5 85% RPET + 15% Incomplete hot-melt-adhesive +
rebound fine cloth for cap interlining 6 85% RPET + 15% Incomplete
hot-melt-adhesive + rebound Oxford 7 85% RTPU + 15% <0.5 <0.2
<0.2 <0.2 hot-melt-adhesive (without the fabric core layer) 8
85% RPC + 15% <0.5 <0.2 <0.2 <0.2 hot-melt-adhesive
(without the fabric core layer) 9 60% RPC + 40% 5.1 9.4 9.2 >98
96 6 5.3 85 hot-melt-adhesive + fine cloth for cap interlining 10
60% RPC + 40% 6.7 9.4 8.9 >98 92 6.2 5.3 85 hot-melt-adhesive +
Oxford 11 60% RPC + 40% 5.4 9.4 9.2 >98 96 6.2 4.6 75
hot-melt-adhesive + cloth for cap interlining 40 .times. 40 (wpi
.times. fpi) 12 60% RPET + 40% 5.9 9.4 9.1 >98 95 7 6.5 90
hot-melt-adhesive + fine cloth for cap interlining 13 60% RPET +
40% 6.7 9.4 9.1 >98 95 7 6.5 90 hot-melt-adhesive + cloth for
cap interlining 40 .times. 40 (wpi .times. fpi) 14 60% RPET + 40%
5.8 9.4 8.8 >98 92 7 6.5 90 hot-melt-adhesive + Oxford 15 60%
RTPU + 40% 7.1 9.4 9.2 >98 96 5 4.5 90 hot-melt-adhesive + fine
cloth for cap interlining 16 60% RTPU + 40% 7.4 9.4 9.2 >98 96 5
4.5 90 hot-melt-adhesive + cloth for cap interlining 40 .times. 40
(wpi .times. fpi) 17 60% RTPU + 40% 8 9.4 8.9 >98 92 4.5 4.2 90
hot-melt-adhesive + Oxford 18 60% RTPU + 40% 4.4 9.4 9.2 >98 96
3.8 2.65 75 hot-melt-adhesive + nonwoven (120 g) 19 60% RPC + 40%
3.7 9.4 8.9 >98 92 5 3.25 65 hot-melt-adhesive + nonwoven (120
g) 20 86% RTPU + 14% 5.4 2.2 1.7 75 hot-melt-adhesive + (occasional
(occasional Oxford incomplete incomplete rebound) rebound) *Note:
Plastics with the "R" initial referred to recycled plastic raw
materials (e.g. from post-industrial or post-consumer wastes),
which were ground at a low temperature into plastic powders in this
example. A #30 mesh steel screen was used. The plastic powders had
a particle size of about 30 to about 40 mesh.
[0062] As shown in the above table, the composite laminated
structures with the fabric core layer had a significantly better
tear resistance and resilience as compared to those without (see
data for items 7 and 8 of Table 3). The composite laminated
structures were environmentally friendly since the virgin material
usage could be drastically reduced. The example provided a simple
process without the need of complicated treatments, such as adding
an impregnated nonwoven or compounding various ingredients, yet the
desired tear resistance and resilience could be obtained. The cost
for shoe stiffeners could be lowered. In addition, in the preferred
examples as provided herein, the cutting step was no longer needed
since the stiffeners were prepared via molding. Wastes generated
from cutting the stiffeners to specific shapes could be greatly
reduced.
[0063] 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.
* * * * *