U.S. patent application number 16/126733 was filed with the patent office on 2019-03-14 for woven shoe upper.
The applicant listed for this patent is adidas AG. Invention is credited to Thomas HENWOOD, Tom O'HAIRE, Andrew YIP.
Application Number | 20190075888 16/126733 |
Document ID | / |
Family ID | 63517735 |
Filed Date | 2019-03-14 |
United States Patent
Application |
20190075888 |
Kind Code |
A1 |
YIP; Andrew ; et
al. |
March 14, 2019 |
Woven Shoe Upper
Abstract
The present invention concerns a shoe upper comprising a woven
portion, wherein the woven portion comprises a plurality of warp
yarns; a plurality of weft yarns; at least one stitching yarn,
wherein the stitching yarn is integrally woven into the fabric
during the weaving process by laterally displacing the stitching
yarn substantially along the weft direction and moving the
stitching yarn in and out of at least one open reed gap in a
reed.
Inventors: |
YIP; Andrew; (Nuremberg,
DE) ; O'HAIRE; Tom; (Nuremberg, DE) ; HENWOOD;
Thomas; (Nuremberg, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
adidas AG |
Herzogenaurach |
|
DE |
|
|
Family ID: |
63517735 |
Appl. No.: |
16/126733 |
Filed: |
September 10, 2018 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
D03D 15/00 20130101;
A43D 999/00 20130101; D10B 2401/024 20130101; D10B 2101/12
20130101; A43B 3/0078 20130101; A43B 13/28 20130101; A43B 1/04
20130101; A43B 23/0205 20130101; D10B 2331/10 20130101; D03D 15/06
20130101; D03D 13/004 20130101; D03D 31/00 20130101; D10B 2401/041
20130101; D10B 2331/02 20130101; D03D 1/00 20130101; A43B 23/0255
20130101; D03D 21/00 20130101; D10B 2501/043 20130101; A43B 23/025
20130101; D03D 2700/0174 20130101 |
International
Class: |
A43B 23/02 20060101
A43B023/02; A43D 999/00 20060101 A43D999/00; A43B 13/28 20060101
A43B013/28; D03D 1/00 20060101 D03D001/00; D03D 13/00 20060101
D03D013/00 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 12, 2017 |
DE |
10 2017 216 026.8 |
Claims
1. A shoe upper comprising a woven portion, wherein the woven
portion comprises: a plurality of warp yarns; a plurality of weft
yarns; at least one stitching yarn, wherein the stitching yarn is
integrally woven into the fabric during the weaving process by
laterally displacing the stitching yarn substantially along the
weft direction and moving the stitching yarn in and out of at least
one open reed gap in a reed.
2. The shoe upper according to claim 1, wherein the stitching yarn
has a tensile modulus greater than the tensile modulus of the warp
yarns and/or the weft yarns.
3. The shoe upper according to claim 1, wherein the stitching yarn
comprises a meltable component.
4. The shoe upper according to claim 1, wherein the stitching yarn
is located in a midfoot region of the shoe.
5. The shoe upper according to claim 1, wherein the stitching yarn
is located within 2 cm from at least one lace eyelet.
6. The shoe upper according to claim 1, wherein the stitching yarn
is located in a sole region of the shoe upper.
7. The shoe upper according to claim 1, wherein at least one
stitching yarn makes an angle of between 30.degree. and 60.degree.
with the warp or weft yarns between at least two different
interlacing points.
8. The shoe upper according to claim 1, wherein at least one
stitching yarn and/or one weft yarn and/or one warp yarn is
dissolvable in a solvent.
9. The shoe upper according to claim 8, wherein the solvent is
water.
10. The shoe upper according to claim 1, wherein at least one
stitching yarn comprises carbon fiber.
11. A method of making a woven portion for a shoe upper,
comprising: providing a plurality of warp yarns and a plurality of
weft yarns; interweaving the plurality of weft yarns and the
plurality of warp yarns; providing at least one stitching yarn,
arranged substantially parallel to the warp yarns; and
simultaneously interweaving the stitching yarn during the weaving
process by laterally displacing the stitching yarn substantially
along the weft direction and moving the stitching yarn in and out
of at least one open reed gap in a reed.
12. The method according to claim 11, wherein the reed comprises at
least two groups of reed gaps, wherein a reed gap of the first
group is at least partially covered by an insertion bevel, and
wherein a reed gap of the second group is not covered by an
insertion bevel.
13. The method according to claim 11, wherein the stitching yarn
comprises a meltable component.
14. The method according to claim 11, wherein the stitching yarn is
located within 2 cm from at least one lace eyelet.
15. The method according to claim 11, wherein at least one
stitching yarn is interwoven at an angle of between 30.degree. and
60.degree. with the warp or weft yarns between at least two
different interlacing points.
16. The method according to claim 11, wherein the method further
comprises forming a reinforcement region comprising: stitching at
least one stitching yarn along a first direction; changing the
direction of the stitching yarn to a second direction, which is at
an angle of at least 30 degrees to the first direction; changing
the direction of the stitching yarn to a third direction which is
at an angle of at least 30 degrees to the second direction; and
changing the direction of the stitching yarn to a fourth direction
which is at an angle of less than 30 degrees to the first
direction.
17. The method according to claim 11, further comprising
configuring at least one stitching yarn as a lacing yarn,
comprising: extending at least one stitching yarn beyond the edge
of the woven portion and configuring said stitching yarn to be
moveable within the woven portion.
18. The method according to claim 11, wherein providing a plurality
of warp and weft yarns, and at least one stitching yarn comprises
providing at least one stitching yarn and/or one weft yarn and/or
one warp yarn that is dissolvable in a solvent and dissolving the
dissolvable warp, weft, and/or stitching yarn in the solvent.
19. The method according to claim 18, wherein the solvent is
water.
20. The method according to claim 1, wherein at least one stitching
yarn comprises carbon fiber.
Description
TECHNICAL FIELD
[0001] The present invention relates to a shoe upper comprising a
woven portion with an integrally woven stitching yarn and methods
for production thereof.
PRIOR ART
[0002] Knitting offers a great amount of flexibility for varying
the stiffness and elasticity of a shoe upper by varying local yarn
content and knit structure. Therefore, a knitted shoe upper allows
for a good fit and conformation to a wearer's foot. However, for
demanding applications, such as running, playing football, or a
number of other sports activities, the knit requires extra
reinforcement, for example from tape, a heel counter, or an
external cage system, which adds to the complexity and cost of the
production process. For this reason, woven materials are an
alternative for such applications because they have a lighter
weight and higher tensile strength than knits.
[0003] Unfortunately, conventional weaving techniques do not offer
the same flexibility for engineering a fabric as knitting. For a
woven material produced on a conventional loom, the woven fabric
may be engineered primarily by altering warp and weft yarns. The
technical limitations resulting from compatibility issues of
different materials on a warp beam are more severe than for
knitting. A further important limitation is that any engineering
based on introducing different warp or weft yarns is done in a
strictly linear fashion. Therefore, reinforcement, for example by
using stronger yarns, can only be achieved along the warp
(0.degree.) or weft (90.degree.) direction and therefore woven
materials are often unstable along a "bias direction" substantially
along +/-45.degree. to the warp direction.
[0004] Therefore, in conventional weaving, the mechanical
properties of the textile are governed by the interaction of the
warp and weft yarns and the stability of the fabric is governed by
the sum total of frictional contact of warp and weft yarns. This
relationship limits the stability of certain open structures as
well as the range of achievable differences between traditionally
engineered zones since typically most zones on a single textile
will have similar densities and common warp yarns.
[0005] It is known that additional yarns can be incorporated in a
second process step, for example by embroidery, after the weaving.
However, this method requires additional handling and is therefore
time-consuming. Furthermore, the accuracy and reproducibility in
adding the additional yarn is naturally limited in this method.
[0006] It is also known that conventional weaving techniques, such
as, for example, a Jacquard loom, can be used to form intricate
patterns on a woven fabric. However, these techniques are
technically complex, produce waste yarns at the back of the fabric,
and increase the area weight of the fabric significantly.
[0007] Therefore, a problem addressed in the present invention is
to provide a light-weight, woven portion for a shoe upper that
provides sufficient stability for demanding applications, that can
be produced in a simple, accurate, and reproducible way and that
can be engineered in a more flexible way than conventional woven
fabric. A further problem addressed in the present invention is to
increase the stability of woven fabric used for shoe uppers along
directions significantly different to the warp and weft
direction.
[0008] The US 2014/0173932 discloses a shoe upper that is formed as
a substantially planar woven article with varied functional zones
and lockout strands integrated therein. The lockout strands may be
integrally incorporated with the woven shoe upper to provide
functional characteristics that differ from those characteristics
provided by the woven upper.
[0009] It is a further object of the present invention to provide a
shoe upper utilizing a woven portion with specific engineered zones
created by an integrated one-step weaving process.
SUMMARY OF THE INVENTION
[0010] The invention concerns a shoe upper comprising a woven
portion, wherein the woven portion comprises: a plurality of warp
yarns; a plurality of weft yarns; at least one stitching yarn,
wherein the stitching yarn is integrally woven into the fabric
during the weaving process by laterally displacing the stitching
yarn substantially along the weft direction and moving the
stitching yarn in and out of at least one open reed gap in a
reed.
[0011] The woven portion may be only a component for the upper,
such as a tongue or a vamp, or it may make up substantially the
entire upper. This shoe upper can be generally light-weight and
durable. The upper can be engineered to have desired performance
requirements concerning, for example, stretch, durability, support,
haptic, etc. The properties of specific regions can be engineered
by locally incorporating at least one stitching yarn during the
weaving process without increasing the weight of the upper
significantly.
[0012] The displacement of the stitching yarn is in a direction
substantially parallel to the weft yarns, which effects that two
subsequent interlacing points between the weft yarns and the
stitching yarn may occur diagonally from each other. The stitching
yarns are separate from the warp yarns and are controlled
individually or as a group by needle eyelets. The stitching yarn
feeder is able to move laterally between weaving cycles. The action
of the feeding needles is "non-orthogonal", meaning that the
stitching yarn is able to change direction, i.e. change the angle
it makes with the warp and weft direction. The feeding needles are
controlled electronically or via a mechanical cam or dobby system.
A displacement mechanism provides sufficient lateral displacement
to cover at least a half width of a shoe upper, typically up to 10
cm. Since the stitching yarn is added during the weaving, the
process has a reduced complexity compared to a two-step process
where a stitching yarn is incorporated in a second step either
manually or by a machine. In conventional weaving, the reed is
closed at the top and the yarns are not free to leave the read
through either vertical or horizontal movement. For the present
invention, an open reed is required, wherein the reed has openings
at the top where the stitching yarn can move out of the reed and
re-enter at a different lateral position within the reed.
[0013] It is possible that in some regions of the shoe upper, the
stitching yarns run in a linear, warp-wise direction.
[0014] Compared to the two-step process, the stitching yarn can be
arranged in a more accurate and reproducible manner. Since a needle
is not required for incorporating the stitching yarn, there is also
less risk of damage to the warp or weft yarns which could be
damaged by a needle in a second step comprising an embroidery
process.
[0015] The present invention allows for a full digital design and
customization of an upper at the development stage, allowing for
mechanical properties, design, size, and fit to be determined at
this early creation stage.
[0016] In conventional weaving techniques, incorporating a complex
pattern would result in waste yarns at the back of the woven fabric
and hence an increased average area weight of the fabric. The
reason for this is that with conventional techniques, a localized
pattern can only be created by moving a yarn to the top of the
weave at those positions where it is supposed to show and hiding
said yarn at the back of the weave over the whole length or width
of the weave in those positions where it is not supposed to be
visible. The present invention prevents waste yarns at the back of
the fabric as the stitching yarn allows localized patterns to be
incorporated into a textile without the need to hide the yarn at
the back of the textile in portions of the fabric where it is not
supposed to be visible. As a consequence, the average area weight
of the woven fabric may be reduced, thereby improving the
performance of the shoe upper. Note that with the present
invention, the area weight of the fabric may also be engineered to
vary locally (the area weight in regions comprising the stitching
yarn may be higher than in regions without the stitching yarn) more
specifically than with conventional methods, thus allowing
reinforcement regions to be engineered into some portions of the
fabric while keeping other portions more lightweight.
[0017] The stitching yarn can have a tensile modulus greater than
the tensile modulus of the warp yarns and/or the weft yarns. By
using an elastic material for the warp and/or weft yarns and a less
elastic material for the stitching yarn, the upper may have a good
and comfortable fit but still provides the required level of
support in regions where increased support is required due to the
presence of the less elastic stitching yarn.
[0018] The stitching yarn may comprise a meltable component. The
stitching yarn can be either coated or comprised entirely of low
temperature melt, typically with melting temperatures between
40.degree. and 200.degree. C. By melting the meltable component, it
is possible to locally fix the structure permanently, for example
to prevent unravelling during further processing or when the shoe
is worn. In particular, the use of a yarn comprising a meltable
component enables the additional stiffness that is introduced by
the stitching yarn to be spread over a whole region rather than
just along the stitching yarn. The step of melting the meltable
component can be conducted in a 2-D form, for example with a stent
frame heat setting, or in a 3-D form, or when the upper is arranged
on a last. This has the advantage that the shoe upper obtains a
shape specific to the mold or lasting geometry.
[0019] It is also possible that melt yarns are incorporated into
the woven portion outside of the boundary of a normal 2-D shoe
upper. Therefore, when it 2-D upper is lasted to bring it to a 3-D
form, these excess melt yarns could be used to close the shoe upper
around the last.
[0020] The stitching yarn may be located in a midfoot region of the
shoe. Typically, the midfoot region requires an increased level of
support, for example for running or playing football. Therefore, a
stitching yarn that is located in the midfoot region of the upper,
may facilitate the required level of support, without adding much
weight to the upper.
[0021] The stitching yarn may be located within 2 cm from at least
one lace eyelet. The region around the lace eyelet is subject to
increased wear and tear in normal everyday use of a shoe.
Therefore, by incorporating the at least one stitching yarn in the
area around the lace eyelets it is possible to add support locally
in this area as required but without increasing the weight of the
upper significantly.
[0022] The stitching yarn may be located around a heel counter. The
region around the heel counter requires additional support in
normal everyday use of a shoe. Therefore, by incorporating the at
least one stitching yarn in the area around the heel counter it is
possible to add support locally in this area as required but
without increasing the weight of the upper significantly.
[0023] The stitching yarn may be located in a sole region of the
shoe upper. When a shoe comprising a midsole and an upper is
formed, a sole region of the shoe upper is at the interface between
the midsole and the upper. Incorporating the at least one stitching
yarn in a sole region of the upper is functional as it increases
the stability in this area and reduces the risk of the upper
detaching from the midsole or tearing at this point.
[0024] In particular, in combination with the use of a meltable
component, the meltable component could be melted, partly or fully,
such as to facilitate a strong bond to be formed between the
midsole and the upper. For example, the midsole could be a football
plate comprising thermoplastic polyurethane and the meltable
component in the stitching yarn could comprise thermoplastic
polyurethane. Therefore, a particularly strong bond would be formed
between the midsole and the upper without the use of any additional
adhesive. Connecting the midsole and the upper may comprise
activating at least one portion of a first connection surface by
providing heat energy without contact, for example by infrared
radiation and connecting the midsole with the upper by joining the
connection surfaces of the midsole and the upper. This process is
sometimes called infrared welding.
[0025] The woven portion may comprise at least a first and a second
stitching yarn, wherein the second stitching yarn is incorporated
substantially parallel to the first stitching yarn. The first or
the second stitching yarn or both the first and the second
stitching yarn may have the properties of the "at least one
stitching yarn" described herein. Substantially parallel in this
context means parallel within +/-10 degrees to allow for
manufacturing imperfections. In many cases, it may not be
sufficient to include a single stitching yarn. By incorporating a
second stitching yarn that is substantially parallel to the first
stitching yarn, the effect of incorporating the first stitching
yarn is enhanced by the second stitching yarn and thus a greater
amount of stiffness can be achieved.
[0026] At least one stitching yarn may make an angle of between
30.degree. and 60.degree. with the warp or weft yarns between at
least two different interlacing points. A conventional woven fabric
is most stable along the warp (0.degree.) or weft (90.degree.)
directions. Woven materials are often unstable along a "bias
direction" substantially along +/-45.degree. to the warp direction.
If the stitching yarn is added at an angle of between 30.degree.
and 60.degree. to the warp direction, the mechanical properties in
this angular range reflect the properties of the stitching yarn.
Therefore, for example, by using a strong stitching yarn it is
possible to add support that reduces strains when mechanical
stresses, or forces, are present at an angle of between
approximately 30.degree. and 60.degree. to the warp direction. It
is also possible to engineer a woven portion that is "locked" by
the stitching yarn and has only very little elasticity in a
specific direction or region. Furthermore, by arranging the
stitching yarn at such angles, it is possible for the stitching
yarn to follow the natural contours of a shoe upper to improve the
fit and aesthetic aspects of the upper.
[0027] Said two interlacing points may be located in a midfoot
region of the upper. As disclosed herein, when the stitching yarn
makes an angle of between 30.degree. and 60.degree. with the warp
or weft yarns, it is possible to engineer additional support
against distortions in this direction. The midfoot region of an
upper is frequently subject to the large stresses and forces in a
range of directions during physical activity. Therefore, it is
often preferable that additional support is provided in the midfoot
region of the upper, especially along the frequently weakest
directions of the fabric.
[0028] Said two interlacing points may be located within 2 cm from
at least one lace eyelet. The region around the lace eyelets is
often subject to large stresses and forces in a range of directions
during physical activity. Therefore, it is preferable to engineer
additional support for the region around the lace eyelets by
incorporating the stitching yarn at an angle of between 30.degree.
and 60.degree. with the warp yarns or weft yarns.
[0029] The shoe upper may further comprise a reinforcement region
comprising: a. at least one stitching yarn along a first direction;
b. the stitching yarn then changes to a second direction, which is
at an angle of at least 30 degrees to the first direction; c. the
stitching yarn then changes to a third direction which is at an
angle of at least 30 degrees to the second direction; and d. the
stitching yarn then changes to a fourth direction which is at an
angle of less than 30 degrees to the first direction. In other
words, the reinforcement region comprises at least one stitching
yarn that starts off along a first direction and follows a zigzag
path before it returns approximately back to the first direction.
The advantageous effect is that specific regions where additional
strength is required can be reinforced without the need to
incorporate a different type of yarn. This type of reinforcement
region is not possible in conventional weaving.
[0030] At least one stitching yarn may be a lacing yarn, wherein a
lacing yarn extends beyond the edge of the woven portion and is
configured to be moveable within the woven portion. The lacing yarn
may be a strand and/or a ribbon.
[0031] An advantage of incorporating a stitching yarn that is
configured as a lacing yarn, is that the speed of production of the
upper may be increased significantly as in conventional shoe
manufacturing the step of lacing an upper is still manual and thus
time consuming and expensive. Another advantage of incorporating a
stitching yarn that is a lacing yarn is that much more elaborate
and effective lacing systems can be developed.
[0032] The lacing yarn can be configured to be moveable within the
woven portion for example by having a relatively small number of
points at which it is interwoven with the warp and weft yarns. The
lacing yarn may be chosen from a stronger material such as
high-tenacity polyester or nylon to prevent tearing. The lacing
yarn can be provided to extend beyond the edge of the woven portion
for example by interweaving the lacing yarn in a sheet from which
the woven portion is later cut but extending the lacing yarn beyond
the edges of the woven portion in the sheet.
[0033] The lacing yarn may change direction in a ripstop region,
which has a similar function as a lacing eyelet. A ripstop region
can be formed using any method known in the art and may comprise
tear-resistant yarn such as high tenacity polyester or nylon. This
way, the lacing yarn may be used to adjust the fit of the upper
without risking tearing the upper in those regions, where the
pulling force on the upper exerted by the lacing yarn would be
greatest.
[0034] There may be two or more lacing yarns instead of just one
lacing yarn. This way, it is easier to design a lacing system as
the two or more lacing yarns may be connected.
[0035] At least one lacing yarn may comprise a meltable component.
The meltable component can be activated by heat so that the lacing
yarn can be fixedly attached to the warp and weft yarns at a
desired end point of the lacing yarn. Alternatively or
additionally, two lacing yarns may be fixedly attached to each
other by activating the meltable component at a chosen connection
point.
[0036] At least one stitching yarn and/or one weft yarn and/or one
warp yarn may be dissolvable in a solvent. This way it is possible
to create gaps, i.e. areas that provide improved ventilation and
flexibility, in the woven portion. It is not feasible to create
these gaps in conventional weaving, as the warp and weft yarns will
slide across each other to close any gaps. Here, the dissolvable
yarn keeps a space clear from non-dissolvable yarns during weaving.
After weaving, the dissolvable yarn is dissolved and a gap is
created. This process may include fixing the woven portion before
dissolving the dissolvable yarns, for example by melting selected
melt yarns in order to improve the stability of the gap. The
dissolvable yarn may be dissolved prior to lasting of the upper or
it may be dissolved after lasting of the upper. Dissolving the
dissolvable yarn may be performed prior to sale or after sale of
the shoe, i.e. it is also possible that the decision whether or not
to dissolve the dissolvable yarns is left up to the customer.
[0037] Dissolving the dissolvable yarn may be done at temperatures
of 70.degree.-100.degree. C. to increase the solubility of the
dissolvable yarn in the solvent.
[0038] The solvent may be water. Water is non-toxic and safe to use
even on a large scale. A water-dissolvable yarn could comprise
poly(vinyl alcohol), which has the advantage that it is not toxic
and has a high solubility in water.
[0039] However, many combinations of dissolvable yarn and solvent
are suitable. It is only important that the dissolvable yarn is
soluble in the solvent. The solvent may be an ionic liquid or an
organic solvent, depending on the material of the dissolvable yarn.
For example, alternatively, the dissolvable yarn may comprise
polycaprolactone for which a suitable solvent would be chloroform
or dichloromethane, or a mixture of both. Alternatively, the
dissolvable yarn could be made from nylon for which a suitable
solvent would be acetic acid.
[0040] The warp yarns and/or the weft yarns may contain a volume
fraction of at least 0.1% of elastane. Preferably, the warp yarns
and/or the weft yarns contain a volume fraction of between 0.1 and
30%, more preferably the warp yarns and/or the weft yarns contain a
volume fraction of between 0.5 and 20%. By incorporating a
significant volume fraction of elastane, the upper conforms well to
a wearer's foot and the upper can be lightweight and comfortable to
wear. In particular, the basic fabric formed by the warp and weft
yarns has an inherent amount of stretch and elasticity, deforming
and recovering from strains of up to 20% in at least one direction.
The person skilled in the art will recognize that this value is
significantly higher than for conventional woven or knitted fabric,
which typically experience irreversible damage at strains of about
4% or higher. However, the basic fabric formed by the warp and weft
yarns may also have no inherent elasticity.
[0041] A base fabric, comprising the warp yarns and the weft yarns
but excluding the stitching yarn(s), of the woven portion may have
a mass of 15-700 grams per square meter, more preferably between 50
and 350 grams per square meter. A lightweight fabric improves the
performance and wearing comfort of the upper. The mass per unit
area (also known as area weight) of the woven portion comprising
the warp yarns and the weft yarns, but excluding the stitching yarn
may be measured by cutting out a portion of the fabric that does
not comprise a stitching yarn, weighing said portion and
normalizing the measured weight (or mass) by the area of the
cut-out portion. Of course, an analogous procedure allows measuring
the area weight of portions of the fabric that also comprise the
stitching yarn.
[0042] At least one stitching yarn may have a tensile modulus of at
least 3 GPa. A stitching yarn with a tensile modulus of at least 3
GPa facilitates a preferred level of support in areas where
additional support is required during physical activity without
being too constricting for a wearer's foot which would deteriorate
the wearing comfort.
[0043] At least one stitching yarn may comprise high-tenacity
polyester. High-tenacity polyester is a lightweight and durable
material with a low elasticity that is particularly suitable for
regions of the upper that require additional support.
[0044] At least one stitching yarn may comprise a polyamide
material. Polyamide materials are particularly lightweight and
particularly durable with a low elasticity that is suitable for
regions of the upper that require additional support.
[0045] The stitching yarn may comprise carbon fiber. Carbon fiber
materials are particularly lightweight and durable with a low
elasticity that is suitable for regions of the upper that require
additional support.
[0046] The stitching yarns may provide unique benefits such as
cooling or warming, they may be electrically conductive, for
example for safety purposes, they may provide the upper with
auxetic properties.
[0047] A plurality of stitching yarns may be incorporated at a
density of at least 1 stitching yarn end per cm along the weft
direction. It is found that, in order to locally engineer the
properties of the shoe upper, the density of the stitching yarns
does not need to be high. Preferably this density is at least 1
stitching yarn end per cm along the weft direction. More preferably
this density is at least 2 stitching yarn ends per cm along the
weft direction. At this density, the stiffness of the stretched
woven portion is increased significantly at strains of 20% to 30%.
The stitching yarns may be integrated in large numbers over a great
width or in small numbers over a narrow width.
[0048] The weaving may comprise at least two stitching axes. The
stitching axis is given by the physical direction of the
displacement means that facilitates the lateral displacement of the
stitching yarn. For a single-axis arrangement, the displacement of
the stitching yarn is preferably in a direction substantially
parallel to the weft yarns. However, a stitching axis may be
parallel to the weft or warp direction, or it may not be parallel
to either the weft or warp direction. The second stitching axis may
be parallel to the first stitching axis, or it may not be parallel
to the first stitching axis. Using a second stitching axis allows
for more complex stitching patterns to be incorporated into the
woven portion which improves the extent to which the woven
portions' properties can be engineered.
[0049] The invention further concerns a method of making a woven
portion for a shoe upper, comprising: providing a plurality of warp
yarns and a plurality of weft yarns; interweaving the plurality of
weft yarns and the plurality of warp yarns; providing at least one
stitching yarn, arranged substantially parallel to the warp yarns;
and simultaneously interweaving the stitching yarn during the
weaving process by laterally displacing the stitching yarn
substantially along the weft direction and moving the stitching
yarn in and out of at least one open reed gap in a reed.
[0050] This shoe upper can be generally light-weight and durable.
The upper can be engineered to have desired performance
requirements concerning, for example, stretch, durability, support,
haptic, etc. The properties of specific regions can be engineered
by locally incorporating at least one stitching yarn during the
weaving process without increasing the weight of the upper
significantly.
[0051] The displacement of the stitching yarn is in a direction
substantially parallel to the weft yarns, which effects that two
subsequent interlacing points between the weft yarns and the
stitching yarn may occur diagonally from each other. The stitching
yarns are separate from the warp yarns and are controlled
individually or as a group by needles eyelets. The stitching yarn
feeder is able to move laterally between weaving cycles. The action
of the feeding needles is "non-orthogonal", meaning that the
stitching yarn is able to change direction, i.e. change the angle
it makes with the warp and weft direction. The feeding needles are
controlled electronically or via a mechanical cam or dobby system.
A displacement mechanism provides sufficient lateral displacement
to cover at least a half width of a shoe upper, typically up to 10
cm. Since the stitching yarn is added during the weaving, the
process has a reduced complexity compared to a two-step process
where a stitching yarn is incorporated in a second step either
manually or by a machine. In conventional weaving, the reed is
closed at the top and the yarns are not free to leave the read
through either vertical or horizontal movement. For the present
invention, an open reed is required, wherein the reed has openings
at the top where the stitching yarn can move out of the reed and
re-enter at a different lateral position within the reed.
[0052] It is possible that in some regions of the shoe upper, the
stitching yarns run in a linear, warp-wise direction.
[0053] Compared to the two-step process, the stitching yarn can be
arranged in a more accurate and reproducible manner. Since a needle
is not required for incorporating the stitching yarn, there is also
less risk of damage to the warp or weft yarns which could be
damaged by a needle in a second step comprising an embroidery
process.
[0054] The present invention allows for a full digital design and
customization of an upper at the development stage, allowing for
mechanical properties, design, size, and fit to be determined at
this early creation stage.
[0055] In conventional weaving techniques, incorporating a complex
pattern would result in waste yarns at the back of the woven fabric
and hence an increased average area weight of the fabric. The
reason for this is that with conventional techniques, a localized
pattern can only be created by moving a yarn to the top of the
weave at those positions where it is supposed to show and hiding
said yarn at the back of the weave over the whole length or width
of the weave in those positions where it is not supposed to be
visible. The present method prevents waste yarns at the back of the
fabric as the stitching yarn allows localized patterns to be
incorporated into a textile without the need to hide the yarn at
the back of the textile in portions of the fabric where it is not
supposed to be visible. As a consequence, the average area weight
of the woven fabric may be reduced, thereby improving the
performance of the shoe upper. Note that with the present method,
the area weight of the fabric may also be engineered to vary
locally (the area weight in regions comprising the stitching yarn
may be higher than in regions without the stitching yarn) more
specifically than with conventional methods, thus allowing, for
example, reinforcement regions to be engineered into some portions
of the fabric while keeping other portions more lightweight.
[0056] An additional benefit of the present method is that the
stitching yarn can be used to crimp the edge of the woven sheet to
prevent fraying. Part of the woven sheet is cut after weaving to
form the woven portion, either manually or automatically via
conventional cutting or laser cutting. The shoe is then formed via
a lasting and finishing process. One of the major hurdles in using
woven materials, for example Leno-type woven fabric, for producing
shoe uppers is the unravelling of material during handling. This
method allows for open woven structures without the need for glues
or adhesives, such as melt yarns, to prevent unravelling during
handling.
[0057] The reed may comprise at least two groups of reed gaps,
wherein a reed gap of the first group is at least partially covered
by an insertion bevel, and wherein a reed gap of the second group
is not covered by an insertion bevel. One problem of using an open
reed is that the stitching yarn may get stuck at the top of the
reed gap during insertion into the reed gap. This can be prevented
by using an insertion bevel which guides the stitching yarn into
the intended reed gap and blocks neighboring reed gaps.
[0058] The stitching yarn may comprise a meltable component. The
stitching yarn can be either coated or comprised entirely of low
temperature melt, typically with melting temperatures between
40.degree. and 200.degree. C. By melting the meltable component, it
is possible to locally fix the structure permanently, for example
to prevent unravelling during further processing or when the shoe
is worn. In particular, the use of a yarn comprising a meltable
component enables the additional stiffness that is introduced by
the stitching yarn to be spread over a whole region rather than
just along the stitching yarn. The step of melting the meltable
component can be conducted in a 2-D form, for example with a stent
frame heat setting, or in a 3-D form, or when the upper is arranged
on a last. This has the advantage that the shoe upper obtains a
shape specific to the mold or lasting geometry.
[0059] It is also possible that melt yarns are incorporated into
the woven portion outside of the boundary of a normal 2-D shoe
upper. Therefore, when it 2-D upper is lasted to bring it to a 3-D
form, these excess melt yarns could be used to close the shoe upper
around the last.
[0060] The stitching yarn can have a tensile modulus greater than
the tensile modulus of the warp yarns and/or the weft yarns. By
using an elastic material for the warp and/or weft yarns and a less
elastic material for the stitching yarn, the upper may have a good
and comfortable fit but still provides the required level of
support in regions where increased support is required due to the
presence of the less elastic stitching yarn.
[0061] The stitching yarn may be located in a midfoot region of the
shoe. Typically, the midfoot region requires an increased level of
support, for example for running or playing football. Therefore, a
stitching yarn that is located in the midfoot region of the upper,
may facilitate the required level of support, without adding much
weight to the upper.
[0062] The stitching yarn may be located within 2 cm from at least
one lace eyelet. The region around the lace eyelet is subject to
increased wear and tear in normal everyday use of a shoe.
Therefore, by incorporating the at least one stitching yarn in the
area around the lace eyelets it is possible to add support locally
in this area as required but without increasing the weight of the
upper significantly.
[0063] The stitching yarn may be located around a heel counter. The
region around the heel counter requires additional support in
normal everyday use of a shoe. Therefore, by incorporating the at
least one stitching yarn in the area around the heel counter it is
possible to add support locally in this area as required but
without increasing the weight of the upper significantly.
[0064] The stitching yarn may be located in a sole region of the
shoe upper. When a shoe comprising a midsole and an upper is
formed, a sole region of the shoe upper is at the interface between
the midsole and the upper. Incorporating the at least one stitching
yarn in a sole region of the upper is functional as it increases
the stability in this area and reduces the risk of the upper
detaching from the midsole or tearing at this point.
[0065] In particular, in combination with the use of a meltable
component, the meltable component could be melted, partly or fully,
such as to facilitate a strong bond to be formed between the
midsole and the upper. For example, the midsole could be a football
plate comprising thermoplastic polyurethane and the meltable
component in the stitching yarn could comprise thermoplastic
polyurethane. Therefore, a particularly strong bond would be formed
between the midsole and the upper without the use of any additional
adhesive. Connecting the midsole and the upper may comprise
activating at least one portion of a first connection surface by
providing heat energy without contact, for example by infrared
radiation and connecting the midsole with the upper by joining the
connection surfaces of the midsole and the upper. This process is
sometimes called infrared welding.
[0066] The method may comprise providing at least a first and a
second stitching yarn, wherein the second stitching yarn is
interwoven substantially parallel to the first stitching yarn. The
first or the second stitching yarn or both the first and the second
stitching yarn may have the properties of the "at least one
stitching yarn" described herein. Substantially parallel in this
context means parallel within +/-10 degrees to allow for
manufacturing imperfections. In many cases, it may not be
sufficient to include a single stitching yarn. By incorporating a
second stitching yarn that is substantially parallel to the first
stitching yarn, the effect of incorporating the first stitching
yarn is enhanced by the second stitching yarn and thus a greater
amount of stiffness can be achieved.
[0067] At least one stitching yarn may make an angle of between
30.degree. and 60.degree. with the warp or weft yarns between at
least two different interlacing points. A conventional woven fabric
is most stable along the warp (0.degree.) or weft (90.degree.)
directions. Woven materials are often unstable along a "bias
direction" substantially along +/-45.degree. to the warp direction.
If the stitching yarn is added at an angle of between 30.degree.
and 60.degree. to the warp direction, the mechanical properties in
this angular range reflect the properties of the stitching yarn.
Therefore, for example, by using a strong stitching yarn it is
possible to add support that reduces strains when mechanical
stresses, or forces, are present at an angle of between
approximately 30.degree. and 60.degree. to the warp direction. It
is also possible to engineer a woven portion that is "locked" by
the stitching yarn and has only very little elasticity in a
specific direction or region. Furthermore, by arranging the
stitching yarn at such angles, it is possible for the stitching
yarn to follow the natural contours of a shoe upper to improve the
fit and aesthetic aspects of the upper.
[0068] Said two interlacing points may be located in a midfoot
region of the upper. As disclosed herein, when the stitching yarn
makes an angle of between 30.degree. and 60.degree. with the warp
or weft yarns, it is possible to engineer additional support
against distortions in this direction. The midfoot region of an
upper is frequently subject to the large stresses and forces in a
range of directions during physical activity. Therefore, it is
often preferable that additional support is provided in the midfoot
region of the upper, especially along the frequently weakest
directions of the fabric.
[0069] Said two interlacing points may be located within 2 cm from
at least one lace eyelet. The region around the lace eyelets is
often subject to large stresses and forces in a range of directions
during physical activity. Therefore, it is preferable to engineer
additional support for the region around the lace eyelets by
incorporating the stitching yarn at an angle of between 30.degree.
and 60.degree. with the warp yarns or weft yarns.
[0070] The method may further comprise forming a reinforcement
region comprising: a. stitching at least one stitching yarn along a
first direction; b. changing the direction of the stitching yarn to
a second direction, which is at an angle of at least 30 degrees to
the first direction; c. changing the direction of the stitching
yarn to a third direction which is at an angle of at least 30
degrees to the second direction; and d. changing the direction of
the stitching yarn to a fourth direction which is at an angle of
less than 30 degrees to the first direction. In other words, the
reinforcement region comprises at least one stitching yarn that
starts off along a first direction and follows a zigzag path before
it returns approximately back to the first direction. The
advantageous effect is that specific regions where additional
strength is required can be reinforced without the need to
incorporate a different type of yarn. This type of reinforcement
region is not possible in conventional weaving.
[0071] The method may further comprise configuring at least one
stitching yarn as a lacing yarn, comprising: extending at least one
stitching yarn beyond the edge of the woven portion and configuring
said stitching yarn to be moveable within the woven portion. The
lacing yarn may be a strand and/or a ribbon.
[0072] An advantage of incorporating a stitching yarn that is
configured as a lacing yarn into the woven portion, is that the
speed of production of the upper may be increased significantly as
in conventional shoe manufacturing the step of lacing an upper is
still manual and thus time consuming and expensive. Another
advantage of incorporating a stitching yarn that is a lacing yarn
is that much more elaborate and effective lacing systems can be
developed.
[0073] The lacing yarn can be configured to be moveable within the
woven portion for example by having a relatively small number of
points at which it is interwoven with the warp and weft yarns. The
lacing yarn may be chosen from a stronger material such as
high-tenacity polyester or nylon to prevent tearing. The lacing
yarn can be provided to extend beyond the edge of the woven portion
for example by interweaving the lacing yarn in a sheet from which
the woven portion is later cut but extending the lacing yarn beyond
the edges of the woven portion in the sheet.
[0074] The lacing yarn may be interwoven such that it changes
direction in a ripstop region, which has a similar function as a
lacing eyelet. A ripstop region can be formed using any method
known in the art and may comprise tear-resistant yarn such as high
tenacity polyester or nylon. This way, the lacing yarn may be used
to adjust the fit of the upper without risking tearing the upper in
those regions, where the pulling force on the upper exerted by the
lacing yarn would be greatest.
[0075] There may be two or more lacing yarns instead of just one
lacing yarn. This way, it is easier to design a lacing system as
the two or more lacing yarns may be connected.
[0076] At least one lacing yarn may comprise a meltable component
and the method may further comprise melting the meltable component
so that the lacing yarn can be fixedly attached to the warp and
weft yarns at a desired end point of the lacing yarn. Alternatively
or additionally, two lacing yarns may be fixedly attached to each
other by activating the meltable component at a chosen connection
point.
[0077] Providing a plurality of warp and weft yarns, and at least
one stitching yarn may comprise providing at least one stitching
yarn and/or one weft yarn and/or one warp yarn that is dissolvable
in a solvent and dissolving the dissolvable warp, weft, and/or
stitching yarn in the solvent. This way it is possible to create
gaps, i.e. areas that provide improved ventilation and flexibility,
in the woven portion. It is not feasible to create these gaps in
conventional weaving, as the warp and weft yarns will slide across
each other to close any gaps. Here, the dissolvable yarn keeps a
space clear from non-dissolvable yarns during weaving. After
weaving, the dissolvable yarn is dissolved and a gap is created.
This process may include fixing the woven portion before dissolving
the dissolvable yarns, for example by melting selected melt yarns
in order to improve the stability of the gap. The dissolvable yarn
may be dissolved prior to lasting of the upper or it may be
dissolved after lasting of the upper. Dissolving the dissolvable
yarn may be performed prior to sale or after sale of the shoe, i.e.
it is also possible that the decision whether or not to dissolve
the dissolvable yarns is left up to the customer.
[0078] Dissolving the dissolvable yarn may be done at temperatures
of 70.degree.-100.degree. C. to increase the solubility of the
dissolvable yarn in the solvent.
[0079] The solvent may be water. Water is non-toxic and safe to use
even on a large scale. A water-dissolvable yarn could comprise
poly(vinyl alcohol), which has the advantage that it is not toxic
and has a high solubility in water.
[0080] However, many combinations of dissolvable yarn and solvent
are suitable. It is only important that the dissolvable yarn is
soluble in the solvent. The solvent may be an ionic liquid or an
organic solvent, depending on the material of the dissolvable yarn.
For example, alternatively, the dissolvable yarn may comprise
polycaprolactone for which a suitable solvent would be chloroform
or dichloromethane, or a mixture of both. Alternatively, the
dissolvable yarn could be made from nylon for which a suitable
solvent would be acetic acid.
[0081] The warp yarns and/or the weft yarns may contain a volume
fraction of at least 0.1% of elastane. Preferably, the warp yarns
and/or the weft yarns contain a volume fraction of between 0.1 and
30%, more preferably the warp yarns and/or the weft yarns contain a
volume fraction of between 0.5 and 20%. By incorporating a
significant volume fraction of elastane, the upper conforms well to
a wearer's foot and the upper can be lightweight and comfortable to
wear. In particular, the basic fabric formed by the warp and weft
yarns has an inherent amount of stretch and elasticity, deforming
and recovering from strains of up to 20% in at least one direction.
The person skilled in the art will recognize that this value is
significantly higher than for conventional woven or knitted fabric,
which typically experience irreversible damage at strains of about
4% or higher. However, the basic fabric formed by the warp and weft
yarns may also have no inherent elasticity.
[0082] A base fabric, comprising the warp yarns and the weft yarns,
but excluding the stitching yarn(s), of the woven portion may have
a mass of 15-700 grams per square meter, more preferably between 50
and 350 grams per square meter. A lightweight fabric improves the
performance and wearing comfort of the upper. The mass per unit
area (also known as area weight) of the woven portion comprising
the warp yarns and the weft yarns, but excluding the stitching yarn
may be measured by cutting out a portion of the fabric that does
not comprise a stitching yarn, weighing said portion and
normalizing the measured weight (or mass) by the area of the
cut-out portion. Of course, an analogous procedure allows measuring
the area weight of portions of the fabric that also comprise the
stitching yarn.
[0083] At least one stitching yarn may have a tensile modulus of at
least 3 GPa. A stitching yarn with a tensile modulus of at least 3
GPa facilitates a preferred level of support in areas where
additional support is required during physical activity without
being too constricting for a wearer's foot which would deteriorate
the wearing comfort.
[0084] At least one stitching yarn may comprise high-tenacity
polyester. High-tenacity polyester is a lightweight and durable
material with a low elasticity that is particularly suitable for
regions of the upper that require additional support.
[0085] At least one stitching yarn may comprise a polyamide
material. Polyamide materials are particularly lightweight and
particularly durable with a low elasticity that is suitable for
regions of the upper that require additional support.
[0086] At least one stitching yarn may comprise carbon fiber.
Carbon fiber materials are particularly lightweight and durable
with a low elasticity that is suitable for regions of the upper
that require additional support.
[0087] The stitching yarns may provide unique benefits such as
cooling or warming, they may be electrically conductive, for
example for safety purposes, they may provide the upper with
auxetic properties.
[0088] A plurality of stitching yarns may be incorporated at a
density of at least 1 stitching yarn end per cm along the weft
direction. It is found that, in order to locally engineer the
properties of the shoe upper, the density of the stitching yarns
does not need to be high. Preferably this density is at least 1
stitching yarn end per cm along the weft direction. More preferably
this density is at least 2 stitching yarn ends per cm along the
weft direction. At this density, the stiffness of the stretched
woven portion is increased significantly at strains of 20% to 30%.
The stitching yarns may be integrated in large numbers over a great
width or in small numbers over a narrow width.
[0089] The weaving may comprise at least two stitching axes. The
stitching axis is given by the physical direction of the
displacement means that facilitates the lateral displacement of the
stitching yarn. For a single-axis arrangement, the displacement of
the stitching yarn is preferably in a direction substantially
parallel to the weft yarns. However, a stitching axis may be
parallel to the weft or warp direction, or it may not be parallel
to either the weft or warp direction. The second stitching axis may
be parallel to the first stitching axis, or it may not be parallel
to the first stitching axis. Using a second stitching axis allows
for more complex stitching patterns to be incorporated into the
woven portion which improves the extent to which the woven
portions' properties can be engineered.
BRIEF DESCRIPTION OF THE FIGURES
[0090] The present invention will be described in more detail with
reference to the accompanying figures in the following. These
figures show:
[0091] FIG. 1: Schematic of an exemplary weaving apparatus which
can be used in the context of the present invention;
[0092] FIG. 2: Schematic of an exemplary weaving machine which can
be used in the context of the present invention;
[0093] FIGS. 3A, B: Exemplary reinforced woven portions according
to the present invention;
[0094] FIG. 4: Exemplary woven portion with a reinforcement region
and a dissolvable yarn according to the present invention;
[0095] FIGS. 5A, B: Exemplary woven sheets comprising a stitching
yarn comprising a meltable component for a shoe upper according to
the present invention; and
[0096] FIG. 6A-C: Exemplary woven sheets and woven portions
comprising a lacing yarn according to the invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0097] FIG. 1 shows an exemplary embodiment of a weaving apparatus
10 suitable for producing a woven sheet 20 from which a woven
portion can be cut for a shoe upper according to a method of the
present invention. A first set of warp yarns 11a is raised by a
reed 18. An alignment mechanism 13 containing a needle eyelet 14
allows two stitching yarns 15 to be raised or lowered along a
substantially vertical direction 16. The needle can enter and leave
the open reed gaps 19 in the reed. When a weft (not shown in FIG.
1) is inserted at a weft insertion port the weaving apparatus 10
therefore allows simultaneous weaving of the weft and the warp
yarns and stitching of the stitching yarns. It is evident to the
person skilled in the art, that there could also only be a single
alignment mechanism 13 providing a single stitching yarn 15, or
there could be several alignment mechanisms arranged in a group
containing several stitching yarns 15. The present invention merely
requires that there is at least one stitching yarn 15.
[0098] Since the stitching yarn 15 is added during the weaving, the
process has a reduced complexity compared to a two-step process
where a stitching yarn is incorporated in a second step either
manually or by a machine. In conventional weaving, the reed 18 is
closed at the top and the yarns are not free to leave the read
through either vertical or horizontal movement. For the present
invention, an open reed is required, wherein the reed has openings
19 at the top where the stitching yarn 15 can move out of the reed
and re-enter at a different lateral position within the reed.
[0099] It is possible that in some regions of the shoe upper, the
stitching yarns 15 run in a linear, warp-wise direction.
[0100] Compared to the two-step process, the stitching yarn 15 can
be arranged in a more accurate and reproducible manner. Since a
needle is not required for incorporating the stitching yarn, there
is also less risk of damage to the warp or weft yarns which could
be damaged by a needle in a second step comprising an embroidery
process.
[0101] In conventional weaving techniques, incorporating a complex
pattern would result in waste yarns at the back of the woven fabric
and hence an increased average area weight of the fabric. The
reason for this is that with conventional techniques, a localized
pattern can only be created by moving a yarn to the top of the
weave at those positions where it is supposed to show and hiding
said yarn at the back of the weave over the whole length or width
of the weave in those positions where it is not supposed to be
visible. The present method prevents waste yarns at the back of the
fabric as the stitching yarn allows localized patterns to be
incorporated into a textile without the need to hide the yarn at
the back of the textile in portions of the fabric where it is not
supposed to be visible. As a consequence, the average area weight
of the woven fabric may be reduced, thereby improving the
performance of the shoe upper. Note that with the present method,
the area weight of the fabric may also be engineered to vary
locally (the area weight in regions comprising the stitching yarn
may be higher than in regions without the stitching yarn) more
specifically than with conventional methods, thus allowing
reinforcement regions to be engineered into some portions of the
fabric while keeping other portions more lightweight.
[0102] An additional benefit of the present method is that the
stitching yarn can be used to crimp the edge of the woven sheet to
prevent fraying. Part of the woven sheet is cut after weaving,
either manually or automatically via conventional cutting or laser
cutting. The shoe is then formed via a lasting and finishing
process. One of the major hurdles in using woven materials, for
example Leno-type woven fabric, for producing shoe uppers is the
unravelling of material during handling. This method allows for
open woven structures without the need for glues or adhesives, such
as melt yarns, to prevent unravelling during handling.
[0103] The reed may comprise at least two groups of reed gaps,
wherein a reed gap of the first group is at least partially covered
by an insertion bevel, and wherein a reed gap of the second group
is not covered by an insertion bevel. One problem of using an open
reed is that the stitching yarn may get stuck at the top of the
reed gap during insertion into the reed gap. This can be prevented
by using an insertion bevel which guides the stitching yarn into
the intended reed gap and blocks neighboring reed gaps.
[0104] The stitching yarns 15 can have a tensile modulus greater
than the tensile modulus of the warp yarns 11a and 11b and/or the
weft yarns. By using an elastic material for the warp and/or weft
yarns and a less elastic material for the stitching yarn 15, an
upper comprising the woven portion has a good and comfortable fit
but still provides the required level of support in regions where
increased support is required due to the presence of the less
elastic stitching yarns 15.
[0105] A displacement mechanism (see FIG. 2) allows for the lateral
displacement of the alignment mechanism 13 substantially along the
weft direction 17. Therefore, two subsequent interlacing points
between the weft yarns and the stitching yarn may occur diagonally
from each other. A conventional woven fabric is most stable along
the warp (0.degree.) or weft (90.degree.) directions. Woven
materials are often unstable along a bias direction substantially
along +/-45.degree. to the warp direction. If the stitching yarn is
added at an angle of between 30.degree. and 60.degree. to the warp
direction, the mechanical properties in this angular range reflect
the properties of the stitching yarn. Therefore, for example, by
using a strong stitching yarn it is possible to add support that
reduces strains when mechanical stresses, or forces, are present at
an angle of between approximately 30.degree. and 60.degree. to the
warp direction. The weaving apparatus 10 therefore allows a woven
portion to be produced that is significantly more stable along a
bias direction than a conventional woven fabric. It is also
possible to engineer a woven portion that is "locked" by the
stitching yarn and has only very little elasticity in a specific
direction or region. Furthermore, by arranging the stitching yarn
at such angles, it is possible for the stitching yarn to follow the
natural contours of a shoe upper to improve the fit and aesthetic
aspects of the upper.
[0106] The warp yarns 11a, 11b and/or the weft yarns contain a
volume fraction of at least 0.5% of elastane. By incorporating a
significant volume fraction of elastane, an upper comprising the
woven portion conforms well to a wearer's foot and the upper is
lightweight and comfortable to wear. In particular, the basic
fabric formed by the warp and weft yarns has an inherent amount of
stretch and elasticity, deforming and recovering from strains of up
to 20% in at least one direction. The person skilled in the art
will recognize that this value is significantly higher than for
conventional woven or knitted fabric, which typically experience
irreversible damage at strains of about 4% or higher.
[0107] A base fabric, comprising the warp yarns 11a, 11b and the
weft yarns, but excluding the stitching yarns 15, of the woven
portion has a mass of 15-700 grams per square meter. A lightweight
woven portion improves the performance and wearing comfort of the
upper.
[0108] The stitching yarns 15 have a tensile modulus of at least 3
GPa. A stitching yarn 15 with a tensile modulus of at least 3 GPa
facilitates a preferred level of support in areas where additional
support is required during physical activity without being too
constricting for a wearer's foot which would deteriorate the
wearing comfort.
[0109] The stitching yarns 15 may comprise high-tenacity polyester,
polyamide, and/or carbon fiber. It is possible that some stitching
yarns comprise one of these materials and some other stitching
yarns comprise another one of these materials. It is also possible
that one stitching yarn comprises a composition of two or all of
these materials. These materials are particularly lightweight and
particularly durable with a low elasticity that is suitable for
regions of the woven portion that require additional support.
[0110] The stitching yarns 15 are incorporated at a density of at
least 1 stitching yarn end per cm along the weft direction. It is
found that, in order to locally engineer the properties of the
woven portion, the density of the stitching yarns does not need to
be high. Preferably this density is at least 1 stitching yarn end
per cm along the weft direction. More preferably this density is at
least 2 stitching yarn ends per cm along the weft direction. At
this density, the stiffness of the stretched woven portion is
increased significantly at strains of 20% to 30%. The stitching
yarns may be integrated in large numbers over a great width or in
small numbers over a narrow width.
[0111] Some or all of the stitching yarns 15 may comprise a
meltable component (not shown in the figures). The stitching yarns
can be either coated or comprised entirely of low temperature melt,
typically with melting temperatures between 40.degree. and
200.degree. C. By melting the meltable component, it is possible to
locally fix the structure permanently, for example to prevent
unravelling during further processing or when the shoe is worn.
[0112] FIG. 2 shows an exemplary weaving machine 21 suitable for
producing a woven sheet 20 from which a woven portion can be cut
for a shoe upper according to a method of the present invention.
Yarn packages are stored on spools 22 for the warp yarns, the weft
yarns, and/or the stitching yarns. An alignment mechanism 13
provides the stitching yarns 15. The displacement mechanism 23
facilitates the lateral displacement of the alignment mechanism 13
along a direction substantially parallel to the weft direction 17.
Typically, the displacement mechanism 23 allows for up to 10 cm of
lateral displacement. This range of motion is sufficient to cover
the half width of a shoe upper in order to engineer areas of the
woven portion. It is also possible that the displacement mechanism
23 allows for a greater range of lateral displacement. The
displacement mechanism 23 further allows a dipping motion along a
substantially vertical direction 16 to insert and remove the
alignment mechanism 13 into and out of the open reed gaps 19.
[0113] FIG. 3A shows an exemplary embodiment of a woven sheet 20a
for a woven portion 34 comprising two stitching yarns 15a of a
first type. The stitching yarns 15a are located in a part of the
woven sheet 20a that will be cut to form a woven portion 34 for a
midfoot region of the shoe upper. The woven sheet 20a also
comprises a cut-away region 32 which will not form part of the
woven portion of the shoe upper. Typically, the midfoot region
requires an increased level of support, for example for running or
playing football. Therefore, a stitching yarn that is located in
the midfoot region of the upper, may facilitate the required level
of support, without adding much weight to the upper.
[0114] The stitching yarns 15a make an angle of between 30.degree.
and 60.degree. with the direction 35 of the warp yarns between
several different interlacing points. A conventional woven fabric
is most stable along the warp (0.degree.) or weft (90.degree.)
directions. Woven materials are often unstable along a "bias
direction" substantially along +/-45.degree. to the warp direction.
If the stitching yarn is added at an angle of between 30.degree.
and 60.degree. to the warp direction, the mechanical properties in
this angular range reflect the properties of the stitching yarn.
Therefore, for example, by using a strong stitching yarn it is
possible to add support that reduces strains when mechanical
stresses, or forces, are present at an angle of between
approximately 30.degree. and 60.degree. to the warp direction. It
is also possible to engineer a woven portion that is "locked" by
the stitching yarn and has only very little elasticity in a
specific direction or region. Furthermore, by arranging the
stitching yarn at such angles, it is possible for the stitching
yarn to follow the natural contours of a shoe upper to improve the
fit and aesthetic aspects of the upper.
[0115] These interlacing points are located in an area of the woven
portion 34 that will be located in a midfoot region of the upper.
As disclosed herein, when the stitching yarn makes an angle of
between 30.degree. and 60.degree. with the warp or weft yarns, it
is possible to engineer additional support against distortions in
this direction. The midfoot region of an upper is frequently
subject to the large stresses and forces in a range of directions
during physical activity. Therefore, it is often preferable that
additional support is provided in the midfoot region of the upper,
especially along the frequently weakest directions of the
fabric.
[0116] FIG. 3B shows an exemplary embodiment of a woven sheet 20b
for a woven portion 34 comprising two stitching yarns 15a of a
first type and two stitching yarns 15b of a second type. The
stitching yarns of the first type 15a are located in a part of the
woven portion 34 that will be located in a midfoot area of the shoe
upper. The woven sheet 20b also comprises a cut-away region 32 that
will not form part of the woven portion of the shoe upper.
[0117] The stitching yarns 15b of the second type are located close
to, and within 2 cm from, several lace eyelets 33. The region
around the lace eyelets is subject to increased wear and tear in
normal everyday use of a shoe. Therefore, by incorporating the
stitching yarns 15b of the second type in the area around the lace
eyelets it is possible to add support locally in this area as
required but without increasing the weight of the upper
significantly. The stitching yarns 15a of the first type may have a
different composition and/or tensile modulus than the stitching
yarns 15b of the second type. For example, it is preferable to have
very stiff stitching yarns 15b of a second type with a very high
tensile modulus around the lace eyelets where no elasticity is
required, whereas the stitching yarns 15a of the first type could
be more elastic and have a lower tensile modulus to allow for a
certain degree of flexibility in the midfoot region.
[0118] The stitching yarns 15a and 15b make an angle of between
30.degree. and 60.degree. with the direction 35 of the warp yarns
between several different interlacing points. This is in order to
add support that reduces strains when mechanical stresses, or
forces, are present at an angle of between approximately 30.degree.
and 60.degree. to the warp direction. These stresses are often
present in the midfoot region and the region around the lace
eyelets 33 during physical exercise.
[0119] The woven sheets 20a and 20b comprise a reinforcement region
36, comprising: a. at least one stitching yarn 15 along a first
direction; b. the stitching yarn 15 then changes to a second
direction, which is at an angle of at least 30 degrees to the first
direction; c. the stitching yarn 15 then changes to a third
direction which is at an angle of at least 30 degrees to the second
direction; and d. the stitching yarn 15 then changes to a fourth
direction which is at an angle of less than 30 degrees to the first
direction. In other words, the reinforcement region 36 comprises at
least one stitching yarn 15 that starts off along a first direction
and follows a zigzag path before it returns approximately back to
the first direction. The advantageous effect is that specific
regions where additional strength is required can be reinforced
without the need to incorporate a different type of yarn. This type
of reinforcement region is not possible in conventional
weaving.
[0120] FIG. 4 shows an exemplary embodiment of a woven sheet 20c
for a woven portion 34 comprising several stitching yarns 15a, 15b,
15c, 15d of four different types. The stitching yarns 15a, 15b,
15c, 15d are located in a part of the woven portion 34 that will be
located in a midfoot region of the shoe upper. The woven sheet 20c
also comprises a cut-away region 32 which will not form part of the
woven portion. The stitching yarns of one type may have a different
composition and/or tensile modulus than the stitching yarns of
another type.
[0121] The woven sheet 20c comprises a reinforcement region 36,
comprising: a. at least one stitching yarn 15 along a first
direction; b. the stitching yarn 15 then changes to a second
direction, which is at an angle of at least 30 degrees to the first
direction; c. the stitching yarn 15 then changes to a third
direction which is at an angle of at least 30 degrees to the second
direction; and d. the stitching yarn 15 then changes to a fourth
direction which is at an angle of less than 30 degrees to the first
direction. In other words, the reinforcement region 36 comprises at
least one stitching yarn 15 that starts off along a first direction
and follows a zigzag path before it returns approximately back to
the first direction. The advantageous effect is that specific
regions where additional strength is required can be reinforced
without the need to incorporate a different type of yarn. This type
of reinforcement region is not possible in conventional
weaving.
[0122] The woven sheet 20c comprises two stitching yarns 41 that
are dissolvable in a solvent. This way it is possible to create
gaps, i.e. areas that provide improved ventilation and flexibility,
in the woven portion. It is not feasible to create these gaps in
conventional weaving, as the warp and weft yarns will slide across
each other to close any gaps. Here, the dissolvable yarns 41 keep a
space clear from non-dissolvable yarns during weaving. After
weaving, the dissolvable yarns are dissolved and a gap is created.
This process may include fixing the woven portion before dissolving
the dissolvable yarns, for example by melting selected melt yarns
in order to improve the stability of the gap. The dissolvable yarns
may be dissolved prior to lasting of the upper or they may be
dissolved after lasting of the upper. Dissolving the dissolvable
yarns may be performed prior to sale or after sale of the shoe,
i.e. it is also possible that the decision whether or not to
dissolve the dissolvable yarns is left up to the customer.
[0123] While in this example two stitching yarns are dissolvable in
a solvent, it is to be understood that a stitching yarn, a warp
yarn, and/or a weft yarn may be dissolvable in a solvent. There may
be one or more than one dissolvable yarn.
[0124] Dissolving the dissolvable yarns 41 may be done at
temperatures of 70.degree.-100.degree. C. to increase the
solubility of the dissolvable yarns 41 in the solvent.
[0125] In this example, the solvent is water. Water is non-toxic
and safe to use even on a large scale. The exemplary
water-dissolvable yarn 41 comprises poly(vinyl alcohol), which has
the advantage that it is not toxic and has a high solubility in
water.
[0126] However, many combinations of dissolvable yarn and solvent
are suitable. It is only important that the dissolvable yarn is
soluble in the solvent. The solvent may be an ionic liquid or an
organic solvent, depending on the material of the dissolvable yarn.
For example, alternatively, the dissolvable yarn may comprise
polycaprolactone for which a suitable solvent would be chloroform
or dichloromethane, or a mixture of both. Alternatively, the
dissolvable yarn could be made from nylon for which a suitable
solvent would be acetic acid.
[0127] The woven sheet 20a, 20b, 20c shown in FIGS. 3A, 3B, 4 can
be produced, for example, using the weaving apparatus shown in FIG.
1 or the weaving machine shown in FIG. 2. A shoe upper is then
formed by cutting a woven portion 34 from the woven sheet 20a, 20b,
20c for manual or automated shoe make-up using conventional cutting
or laser cutting. The shoe is then formed via a lasting and
finishing process. A shoe upper according to the present invention
can be manufactured using a reduced number of reinforcements
steps.
[0128] FIG. 5A shows an exemplary embodiment of a woven sheet 20d
comprising stitching yarns 15 which comprise a meltable component.
FIG. 5A shows the woven sheet with the warp direction 17 and the
weft direction 35. The woven sheet 20d shows an exemplary
embodiment of incorporating the stitching yarns in order to
reinforce the midfoot region of an upper.
[0129] FIG. 5B shows an exemplary embodiment of a woven sheet 20e
comprising stitching yarns 15 which comprise a meltable component.
FIG. 5B shows the woven sheet with the warp direction 17 and the
weft direction 35. The woven sheet 20e shows an exemplary
embodiment of incorporating the stitching yarns in order to
reinforce the heel counter region of an upper.
[0130] The woven sheets 20d and 20e comprise at least a first 15
and a second 15 stitching yarn, wherein the second stitching yarn
15 is incorporated substantially parallel to the first stitching
yarn 15. The first 15 or the second 15 stitching yarn or both the
first 15 and the second 15 stitching yarn may have the properties
of the "at least one stitching yarn" 15 described herein.
Substantially parallel in this context means parallel within +/-10
degrees to allow for manufacturing imperfections. In many cases, it
may not be sufficient to include a single stitching yarn. By
incorporating a second stitching yarn that is substantially
parallel to the first stitching yarn, the effect of incorporating
the first stitching yarn is enhanced by the second stitching yarn
and thus a greater amount of stiffness can be achieved.
[0131] The stitching yarns 15 can be either coated or comprised
entirely of low temperature melt, typically with melting
temperatures between 40.degree. and 200.degree. C. By melting the
meltable component, it is possible to locally fix the structure
permanently, for example to prevent unravelling during further
processing or when the shoe is worn. In particular, the use of a
yarn comprising a meltable component enables the additional
stiffness that is introduced by the stitching yarn to be spread
over a whole region rather than just along the stitching yarn 15.
The step of melting the meltable component can be conducted in a
2-D form, for example with a stent frame heat setting, or in a 3-D
form, or when the upper is arranged on a last. This has the
advantage that the shoe upper obtains a shape specific to the mold
or lasting geometry.
[0132] It is also possible that melt yarns 15 are incorporated into
the woven sheet outside of the boundary of a normal 2-D shoe upper,
i.e. outside the woven portion that will become part of the upper.
Therefore, when it 2-D upper is lasted to bring it to a 3-D form,
these excess melt yarns 15 could be used to close the shoe upper
around the last.
[0133] The woven sheets 20d and 20e comprise a reinforcement region
36, comprising: a. at least one stitching yarn 15 along a first
direction; b. the stitching yarn 15 then changes to a second
direction, which is at an angle of at least 30 degrees to the first
direction; c. the stitching yarn 15 then changes to a third
direction which is at an angle of at least 30 degrees to the second
direction; and d. the stitching yarn 15 then changes to a fourth
direction which is at an angle of less than 30 degrees to the first
direction. In other words, the reinforcement region 36 comprises at
least one stitching yarn 15 that starts off along a first direction
and follows a zigzag path before it returns approximately back to
the first direction. The advantageous effect is that specific
regions where additional strength is required can be reinforced
without the need to incorporate a different type of yarn. This type
of reinforcement region is not possible in conventional
weaving.
[0134] The woven sheets 20d and 20e shown in FIGS. 5A and 5B can be
produced, for example, using the weaving apparatus shown in FIG. 1
or the weaving machine shown in FIG. 2. A shoe upper is then formed
by cutting a woven portion from the woven sheet 20d, 20e for manual
or automated shoe make-up using conventional cutting or laser
cutting. The shoe is then formed via a lasting and finishing
process. A shoe upper according to the present invention can be
manufactured using a reduced number of reinforcements steps.
[0135] FIGS. 6A-C show exemplary woven sheets 20f,g and woven
portions 34 for a shoe upper according to the present
invention.
[0136] FIG. 6A shows an exemplary woven sheet 20f comprising a
woven portion 34 with the boundary at which the woven portion is to
be cut indicated by a solid line. The exemplary woven portion
comprises two stitching yarns 61a,b that are lacing yarns, wherein
the lacing yarns 61a,b extend beyond the edge of the woven portion
34 and are configured to be moveable within the woven portion 34.
The lacing yarns 61a and 61b may be a strand and/or a ribbon.
[0137] An advantage of incorporating stitching yarns 61a,b that are
configured as lacing yarns is that the speed of production of the
upper may be increased significantly as in conventional shoe
manufacturing the step of lacing an upper is still manual and thus
time consuming and expensive. Another advantage of incorporating
stitching yarns 61a,b that are lacing yarns is that much more
elaborate and effective lacing systems can be developed.
[0138] The lacing yarns 61a,b are configured to be moveable within
the woven portion by having a relatively small number of points at
which the lacing yarns 61a,b are interwoven with the warp and weft
yarns forming the base fabric 62. The exemplary lacing yarns 61a,b
are chosen from a stronger material such as high-tenacity polyester
or nylon to prevent tearing. The lacing yarns 61a,b are provided to
extend beyond the edge of the woven portion 34 by interweaving the
lacing yarns 61a,b in the sheet 20f from which the woven portion 34
is later cut but extending the lacing yarns 61a,b beyond the edges
of the woven portion 34 in the sheet 20f In this example, the
lacing yarns 61a,b are straight between two subsequent woven
portions. At the exemplary "loose" point 64 the lacing yarns are
not attached to the base fabric 62. At the exemplary fixing point
63 the lacing yarns 61a,b are attached to the base fabric 62. Thus
the lacing yarns 61a,b may be removed from the base fabric 62
easily by disconnecting them only at a single point, for example by
cutting.
[0139] In this example, there are two lacing yarns 61a and 61b. The
advantage of having two lacing yarns is that it is easier to make a
lacing system as the two lacing yarns may be connected. However,
there may be only one lacing yarn, or there may be more than two
lacing yarns.
[0140] In this example, both lacing yarns 61a and 61b comprise a
meltable component and the method further comprises melting the
meltable component so that the lacing yarn can be fixedly attached
to the warp and weft yarns at a desired end point 65 of the lacing
yarns 61a and 61b. Additionally, in this example, the two lacing
yarns 61a and 61b are fixedly attached to each other by activating
the meltable component at a chosen connection point 65. However,
only one lacing yarn may comprise a meltable component or no lacing
yarn may comprise a meltable component and the lacing yarn or
lacing yarns may be attached by any other suitable means to each
other or to the base fabric.
[0141] FIG. 6B shows a similar woven sheet 20g for the production
of a woven portion 34 comprising two lacing yarns 61a and 61b. The
lacing yarns 61a,b are provided to extend beyond the edge of the
woven portion 34 by interweaving the lacing yarns 61a,b in the
sheet 20g from which the woven portion 34 is later cut but
extending the lacing yarns 61a,b beyond the edges of the woven
portion 34 in the sheet 20f In this example, the lacing yarns 61a,b
are not straight between subsequent woven portions that are to be
cut from the woven sheet 20g. This allows the space between
subsequent woven portions to be used more effectively. At the
exemplary "loose" point 64 the lacing yarns are not attached to the
base fabric 62. At the exemplary fixing point 63 the lacing yarns
61a,b are attached to the base fabric 62. Thus the lacing yarns
61a,b may be removed from the base fabric 62 easily by
disconnecting them only at a single point, for example by
cutting.
[0142] In this example, lacing yarn 61a comprise a meltable
component while lacing yarn 61b does not and the method further
comprises melting the meltable component in lacing yarn 61a so that
the lacing yarn 61a can be fixedly attached to the warp and weft
yarns at a desired end point 65 of the lacing yarn 61a. The melting
of the meltable component of lacing yarn 61a at end point 65 also
effects that the two lacing yarns 61a and 61b are fixedly attached
to each other by activating the meltable component at a chosen
connection point 65.
[0143] FIG. 6C shows an example of part of a woven portion 34
comprising two lacing yarns 61a and 61b. In this example, the
lacing yarns 61a and 61b change direction in a ripstop region 66,
which has a similar function as a lacing eyelet. The ripstop region
66 comprises tear-resistant yarn such as high tenacity polyester or
nylon and can be formed using any technique known in the art. This
way, the lacing yarns 61a and 61b may be used to adjust the fit of
the upper without risking tearing the upper in those regions, where
the pulling force on the upper exerted by the lacing yarns 61a and
61b would be greatest.
[0144] The woven sheets 20f and 20g shown in FIGS. 6A and 6B can be
produced, for example, using the weaving apparatus shown in FIG. 1
or the weaving machine shown in FIG. 2. A shoe upper is then formed
by cutting a woven portion 34 as shown in FIGS. 6A-C from the woven
sheet 20f, 20g for manual or automated shoe make-up using
conventional cutting or laser cutting. The shoe is then formed via
a lasting and finishing process.
[0145] The woven portion 34 may be a portion of an upper, such as
for example a tongue or vamp, or it may form substantially all of
the upper.
REFERENCE NUMERALS
[0146] 10: weaving apparatus
[0147] 11a: raised warp yarns
[0148] 11b: lowered warp yarns
[0149] 12: weft insertion point
[0150] 13: alignment mechanism
[0151] 14: needle eyelet
[0152] 15: stitching yarn
[0153] 16: vertical direction
[0154] 17: weft direction
[0155] 18: reed
[0156] 19: open reed gap
[0157] 20: woven sheet
[0158] 21: weaving machine
[0159] 22: spool
[0160] 23: displacement device
[0161] 32: cut-away region
[0162] 33: lace eyelets
[0163] 34: woven portion
[0164] 35: warp direction
[0165] 36: reinforcement region
[0166] 41: dissolvable yarn
[0167] 61: lacing yarn
[0168] 62: base fabric
[0169] 63: fixing point
[0170] 64: loose point
[0171] 65: connection point
[0172] 66: ripstop region
* * * * *