U.S. patent application number 17/464314 was filed with the patent office on 2021-12-23 for articles of footwear, manufacturing systems, and processes for forming footwear using recycled plastics.
This patent application is currently assigned to NIKE, Inc.. The applicant listed for this patent is NIKE, Inc.. Invention is credited to Bryan N. Farris, Noah Murphy-Reinhertz.
Application Number | 20210394475 17/464314 |
Document ID | / |
Family ID | 1000005814764 |
Filed Date | 2021-12-23 |
United States Patent
Application |
20210394475 |
Kind Code |
A1 |
Farris; Bryan N. ; et
al. |
December 23, 2021 |
ARTICLES OF FOOTWEAR, MANUFACTURING SYSTEMS, AND PROCESSES FOR
FORMING FOOTWEAR USING RECYCLED PLASTICS
Abstract
Presented are manufacturing systems, methods, and devices for
forming footwear using scrap or waste plastic materials. A method
for manufacturing an article of footwear, such as an athletic shoe,
begins with receiving a batch of recycled plastic, which may
include thermoplastic elastomers or ethylene-vinyl acetate, and
grinding the batch of recycled plastic material. The ground
recycled material is processed, for example, by adding a foaming
agent that activates at elevated temperatures. The processed
recycled material is placed into the internal cavity of a final
mold that is shaped like a segment of the footwear, such as a
unitary sole structure. To form the footwear segment, the processed
recycled material is heated past the threshold activation
temperature of the foaming agent such that the foaming agent causes
the recycled material to expand and fill the internal cavity of the
final mold. The formed footwear segment is then extracted from the
mold.
Inventors: |
Farris; Bryan N.; (North
Plains, OR) ; Murphy-Reinhertz; Noah; (Portland,
OR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
NIKE, Inc. |
Beaverton |
OR |
US |
|
|
Assignee: |
NIKE, Inc.
Beaverton
OR
|
Family ID: |
1000005814764 |
Appl. No.: |
17/464314 |
Filed: |
September 1, 2021 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
16425299 |
May 29, 2019 |
11135796 |
|
|
17464314 |
|
|
|
|
62678472 |
May 31, 2018 |
|
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|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B29C 2045/1698 20130101;
A43B 1/0027 20130101; Y02P 70/62 20151101; B29C 39/023 20130101;
A43B 1/12 20130101; A43B 13/04 20130101; B29C 44/04 20130101; B29B
17/0042 20130101; C08J 2300/30 20130101; Y02P 20/143 20151101; B29C
45/1679 20130101; C08J 9/103 20130101; B29C 70/64 20130101; B29C
45/1634 20130101; B29D 35/122 20130101; B29D 35/0009 20130101; B29D
35/0054 20130101; C08J 11/06 20130101; A43B 1/0063 20130101; B29C
2037/0039 20130101 |
International
Class: |
B29D 35/12 20060101
B29D035/12; A43B 13/04 20060101 A43B013/04; B29D 35/00 20060101
B29D035/00; A43B 1/00 20060101 A43B001/00; A43B 1/12 20060101
A43B001/12; B29C 45/16 20060101 B29C045/16; B29C 39/02 20060101
B29C039/02; B29C 70/64 20060101 B29C070/64 |
Claims
1. An article of footwear for a foot of a user, the article of
footwear comprising: an upper configured to receive the foot of the
user; and a sole structure attached to the upper and configured to
support thereon the foot of the user, the sole structure having an
outsole section that defines a ground-engaging portion of the
footwear, wherein an outer surface of the sole structure includes a
plurality of distinctly shaped cavities, a plurality of distinctly
shaped protrusions, and a plurality of distinctly shaped plastic
fragments.
2. The article of footwear of claim 1, wherein the outer surface of
the sole structure is substantially covered with the distinctly
shaped cavities, the distinctly shaped protrusions, and the
distinctly shaped fragments.
3. The article of footwear of claim 1, wherein the distinctly
shaped cavities, the distinctly shaped protrusions, and the
distinctly shaped plastic fragments are randomly dispersed on the
outer surface of the sole structure.
4. The article of footwear of claim 1, wherein the plurality of
distinctly shaped cavities includes at least 50 distinctly shaped
cavities, the plurality of distinctly shaped protrusions includes
at least 50 distinctly shaped protrusions, and the plurality of
distinctly shaped plastic fragments includes at least 50 distinctly
shaped plastic fragments.
5. The article of footwear of claim 1, wherein the sole structure
includes recycled plastic material.
6. The article of footwear of claim 5, wherein the sole structure
is fabricated entirely from the recycled plastic material.
7. The article of footwear of claim 5, wherein the recycled plastic
material includes scrap and/or waste material comprising
thermoplastic elastomer (TPE) plastic and/or ethylene-vinyl acetate
(EVA) copolymer plastic.
8. The article of footwear of claim 5, wherein the recycled plastic
material includes a butadiene rubber.
9. The article of footwear of claim 5, wherein the sole structure
is fabricated from a mixture of the recycled plastic material and
virgin polymer material.
10. The article of footwear of claim 9, wherein the recycled
plastic material includes scrap and/or waste ethylene-vinyl acetate
(EVA), and wherein the virgin polymer material includes an EVA
copolymer having 15-60 mole percent vinyl acetate.
11. The article of footwear of claim 9, wherein the sole structure
includes at least 40 parts of the recycled plastic material per 100
parts of the virgin polymer material.
12. The article of footwear of claim 9, wherein the sole structure
includes a chemical crosslinking agent linking a polymer chain of
the recycled plastic material to a polymer chain of the virgin
polymer material.
13. The article of footwear of claim 1, wherein the sole structure
is fabricated from a mixture of a recycled plastic material and a
polyurethane (PU) base material.
14. The article of footwear of claim 1, wherein the sole structure
is fabricated from a mixture of a recycled plastic material and a
virgin synthetic rubber material.
15. The article of footwear of claim 1, wherein the sole structure,
including the distinctly shaped cavities, the distinctly shaped
protrusions, and the distinctly shaped plastic fragments, is
integrally formed as a single-piece structure.
16. The article of footwear of claim 1, wherein the plurality of
distinctly shaped plastic fragments includes multiple distinctly
shaped, sized, and colored plastic fragments.
17. The article of footwear of claim 1, wherein the plurality of
distinctly shaped cavities includes multiple distinctly shaped and
sized cavities with irregular geometries.
18. The article of footwear of claim 1, wherein the plurality of
distinctly shaped protrusions includes multiple distinctly shaped
and sized protrusions with irregular geometries.
Description
CLAIM OF PRIORITY AND CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional of U.S. patent application
Ser. No. 16/425,299, which was filed on May 29, 2019, is now
allowed, and claims priority to U.S. Provisional Patent Application
No. 62/678,472, which was filed on May 31, 2018, and is now lapsed.
Both of the foregoing applications are incorporated herein by
reference in their respective entireties and for all purposes.
TECHNICAL FIELD
[0002] The present disclosure relates generally to methods for
manufacturing articles of footwear. More specifically, aspects of
this disclosure relate to manufacturing systems and processes for
forming footwear sole structures using scrap or waste plastic
materials.
BACKGROUND
[0003] Articles of footwear, such as shoes, boots, slippers,
sandals, and the like, are generally composed of two primary
elements: an upper for securing the footwear to a user's foot; and
a sole for providing subjacent support to the foot. Uppers may be
fabricated from a variety of materials, including textiles, foams,
polymers, natural and synthetic leathers, etc., that are stitched
or bonded together to form a shell or harness for securely
receiving a foot. For sandals and slippers, the upper may have an
open toe or open heel construction, or may be generally limited to
a series of straps extending over the instep and, in some designs,
around the user's ankle. Conversely, boot and shoe applications
typically employ a full upper with a closed toe and heel
construction that encases the foot. An ankle opening through a rear
quarter portion of the upper provides access to the footwear's
interior, facilitating entry and removal of the foot into and from
the upper. A lace or strap may be utilized to secure the foot
within the upper.
[0004] A sole structure is generally attached to the underside of
the upper, positioned between the user's foot and the ground. In
many articles of footwear, including athletic shoes and boots, the
sole structure is a layered construction that generally
incorporates a comfort-enhancing insole, an impact-mitigating
midsole, and a surface-contacting outsole. The insole, which may be
located partially or entirely within the upper, is a thin and
compressible member that provides a contact surface for the
underside "plantar" region of the user's foot. By comparison, the
midsole is mounted underneath the insole, forming a middle layer of
the sole structure. In addition to attenuating ground reaction
forces, the midsole may help to control foot motion and impart
enhanced stability. Secured to the underside of the midsole is an
outsole that forms the ground-contacting portion of the footwear.
The outsole is usually fashioned from a durable, wearproof material
that includes tread patterns engineered to improve traction.
[0005] Some conventional methods of footwear manufacture use
slabstock plastic to die-cut structural segments of the shoe,
including midsoles, insole sock liners, and unitary sole
constructions. Large extruding machines or heat presses are used to
make the polymer slabs, which are then skived, cut, and shaped to
the final parts prior to assembly into the individual shoes.
Historically, a considerable amount of plastic scrap material is
generated during the shoe manufacturing process. For example, scrap
can be generated due to mold flashing, race-tracking, air
entrapment, sink marking, burning or warpage, all of which may
result in unacceptably damaged (C-grade) parts. In the footwear
industry, waste plastic is also generated from outside sources,
such as worn footwear that is discarded by the end user. Much
effort has been expended to collect and recycle scrap materials
produced during manufacture and waste materials from used products.
In many instances, however, waste and scrap plastic cannot simply
be blended with virgin starting materials because the recycled mass
may be inconsistent from batch-to-batch, may be contaminated, or
may have thermoset properties that prevent use in this fashion.
SUMMARY
[0006] Presented herein are manufacturing systems and processes for
forming footwear using scrap or waste materials, methods for
operating such systems, shoe structure segments fabricated from
such materials, and articles of footwear assembled with such
segments. By way of example, there is presented a manufacturing
process workflow for fabricating a single-piece midsole/outsole of
an athletic shoe using scrap and/or waste (collectively "recycled")
plastics, such as thermoplastic elastomers (TPE) or ethylene-vinyl
acetate (EVA) copolymers. In a compression molding application, a
preform is fabricated e.g., via compression molding or injection
molding, from recycled material mixed with a blowing/foaming agent
that activates at high temperatures. The non-foamed preform is
placed into a mold, which is then sealed, pressurized, and heated
to activate the foaming agent. In so doing, the additive
blowing/foaming agent foams and expands the polymer preform to fill
the mold cavity. Comparatively, for an injection molding
application, spent scrap and waste material is ground into granular
form and mixed into a composition containing virgin polymer and
foaming agent. The mixture of recycled, virgin, and foaming
materials is injected, under pressure, into a mold that is smaller
than (e.g., about half the size of) the finished sole structure.
Due to increased temperatures within the mold, the foaming agent
activates and expands the polymer mixture, which becomes entrained
with high-pressure micro bubbles. The mold is then cooled and
unsealed; when the mold is opened, these micro bubbles rapidly
expand to enlarge the polymer mixture to a full-size sole
structure, e.g., causing the sole to eject from the mold.
[0007] It is envisioned that an assortment of different techniques
may be employed to fabricate a segment of an article of footwear
using recycled EVA and/or TPE. For instance, the recycled polymer
material compound may be ground into an injectable polymer (IP)
formulation and processed per corresponding protocol prior to final
formation. Processing may include the addition of foaming agents,
fillers, pigments, processing aids, and/or crosslinking agents.
Optionally, the recycled polymer compound may be ground into a
compression molding polymer (CMP) preform material, processed per
corresponding protocol, and molded into a desired preform
configuration. Processing protocol may include batch mixing,
cooling and dispersion, and calendaring or granulation to make a
final mix compound ready for production. As an alternative to this
concept, the ground recycled material is introduced directly into a
preform mold, virgin CMP material (e.g., Phylon or synthetic rubber
chips) is added to the preform mold, additional processing per
corresponding protocol may be carried out, and the resultant
mixture is molded into a desired preform configuration. As an
extension of this concept, ground recycled material may be
introduced directly into a final mold, a preform of virgin CMP
material is then placed into the final mold, additional recycled
material grind is scattered on the exposed surface of the virgin
preform, corresponding processing is performed, and the final
product is formed.
[0008] Other techniques for fabricating footwear using recycled EVA
and/or rubber may include wetting a preform of virgin material,
e.g., with soap and water, placing the wet preform in a container
with ground recycled material, agitating the container to cover the
preform with grind, placing the preform in a finishing mold,
processing per usual protocol, and forming to final product. The
foregoing process may be modified by using a preform fabricated
with or entirely from the recycled EVA/TPE material. As another
option, an IP preform of recycled polymer material compound may be
fabricated as described above; the IP preform is then introduced
into a compression molding cavity for final processing and
formation. In the same vein, an IP preform of recycled polymer
material may be created, fit into a mold scattered with recycled
material grind, covered with recycled material grind, and
subsequently processed and formed to a final product.
[0009] Continuing with the above discussion of representative
manufacturing processes for fabricating footwear using recycled EVA
and/or TPE, a composition of ground recycled material may be mixed
into a polyurethane (PU) base material, such as poly-isocyanate
polyol. The PU-grind mixture may be dosed into a mixing head with a
dosing attachment (e.g., dosing pump and feeder nozzle with
automated hydraulic non-return valve). Rather than dosing into the
mixing head, ground recyclate may be dosed directly into the mold
prior to introducing PU base material into the mold. For a rubber
outsole compound option, recycled polymer material compound may be
mixed into virgin rubber material or may be added as a "surface"
option, i.e., sprinkled into the mold and onto the preform. Also
similar to the options described above, the rubber may be ground
and lightly coated onto the preform itself prior to placing the
preform in the final mold.
[0010] Aspects of this disclosure are directed to manufacturing
processes for fabricating footwear. In an example, a method is
presented for manufacturing an article of footwear for a foot of a
user. This representative method includes, in any order and in any
combination with any of the above or below disclosed features and
options: receiving a batch of recycled plastic material; grinding
the batch of recycled plastic material; processing the ground
recycled material, the processing including adding at least a
foaming agent to the ground recycled material; placing the
processed recycled material into an internal cavity of a final
mold, which is shaped like a segment of the article of footwear;
forming the footwear segment by heating the processed recycled
material past a threshold activation temperature of the foaming
agent such that the foaming agent causes the recycled material to
expand and fill the internal cavity of the final mold; and,
extracting the formed footwear segment from the mold.
[0011] Further aspects of the present disclosure are directed to
footwear and/or segments of an article of footwear fabricated from
any of the discloses processes and materials. For instance, an
article of footwear, such as an athletic shoe, includes an upper
that receives and attaches to the user's foot. A sole structure,
which is attached to a lower portion of the upper, supports thereon
the user's foot. This sole structure includes an outsole that
defines the ground-engaging portion of the footwear. The sole
structure is formed or machined with multiple distinctly shaped and
sized cavities, multiple distinctly shaped and sized protrusions,
and/or multiple distinctly shaped, sized, and colored plastic
fragments, all of which are erratically dispersed on an outer
surface of the sole structure. For at least some configurations,
the entire outer surface of the sole structure is substantially
covered with the erratically dispersed cavities, protrusions, and
plastic fragments. Optionally, the sole structure is provided with
50 or more distinctly shaped cavities, 50 or more distinctly shaped
protrusions, and 50 or more distinctly shaped/colored plastic
fragments. This sole structure can be formed from any of the
methods disclosed above and below. An attendant advantage to using
a disclosed methodology in this manner is that no two sole
structures will be identical.
[0012] The above summary is not intended to represent every
embodiment or every aspect of the present disclosure. Rather, the
foregoing summary merely provides an exemplification of some of the
novel concepts and features set forth herein. The above features
and advantages, and other features and attendant advantages of this
disclosure, will be readily apparent from the following detailed
description of illustrated examples and representative modes for
carrying out the present disclosure when taken in connection with
the accompanying drawings and the appended claims. Moreover, this
disclosure expressly includes any and all combinations and
subcombinations of the elements and features presented above and
below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a lateral, side-view illustration of a
representative article of footwear with a unitary sole structure
fabricated from recycled scrap or waste plastic material in
accordance with aspects of the present disclosure.
[0014] FIG. 2 is a bottom-view illustration of the representative
unitary sole structure of FIG. 1.
[0015] FIG. 3 is a plan-view illustration of the representative
unitary sole structure of FIG. 1.
[0016] FIG. 4 is a flowchart illustrating a representative workflow
process for manufacturing a segment of an article of footwear,
which may correspond to memory-stored instructions executed by a
manufacturing system controller, control-logic circuitry,
programmable electronic control unit, or other integrated circuit
(IC) device or a network of IC devices in accord with aspects of
the disclosed concepts.
[0017] The present disclosure is amenable to various modifications
and alternative forms, and some representative embodiments have
been shown by way of example in the drawings and will be described
in detail herein. It should be understood, however, that the novel
aspects of this disclosure are not limited to the particular forms
illustrated in the above-enumerated drawing. Rather, the disclosure
is to cover all modifications, equivalents, combinations,
subcombinations, permutations, groupings, and alternatives falling
within the scope of this disclosure as encompassed by the appended
claims.
DETAILED DESCRIPTION
[0018] This disclosure is susceptible of embodiment in many
different forms. There are shown in the drawings and will herein be
described in detail representative embodiments of the disclosure
with the understanding that these illustrated examples are provided
as an exemplification of the disclosed principles, not limitations
of the broad concepts of the disclosure. To that extent, elements
and limitations that are described, for example, in the Abstract,
Technical Field, Background, Summary, and Detailed Description
sections, but not explicitly set forth in the claims, should not be
incorporated into the claims, singly or collectively, by
implication, inference or otherwise.
[0019] For purposes of the present detailed description, unless
specifically disclaimed: the singular includes the plural and vice
versa; the words "and" and "or" shall be both conjunctive and
disjunctive; the words "any" and "all" shall both mean "any and
all"; and the words "including" and "comprising" and "having" shall
each mean "including without limitation." Moreover, words of
approximation, such as "about," "almost," "substantially,"
"generally," "approximately," and the like, may be used herein in
the sense of "at, near, or nearly at," or "within 0-5% of," or
"within acceptable manufacturing tolerances," or any logical
combination thereof, for example. Lastly, directional adjectives
and adverbs, such as fore, aft, medial, lateral, proximal, distal,
vertical, horizontal, front, back, left, right, etc., may be with
respect to an article of footwear when worn on a user's foot and
operatively oriented with the base of the sole structure seated on
a flat surface, for example.
[0020] Referring now to the drawings, wherein like reference
numbers refer to like features throughout the several views, there
is shown in FIG. 1 a representative article of footwear, which is
designated generally at 10 and portrayed herein for purposes of
discussion as an athletic shoe or "sneaker." The illustrated
footwear 10--also referred to herein as "shoe" for brevity--is
merely an exemplary application with which novel aspects and
features of this disclosure may be practiced. In the same vein,
implementation of the present concepts to manufacture a unitary
sole structure of an athletic shoe should also be appreciated as a
representative application of the concepts disclosed herein. It
should therefore be understood that aspects and features of this
disclosure may be implemented to manufacture other segments of a
shoe, and may be implemented to construct any logically relevant
type of footwear. As used herein, the terms "shoe" and "footwear,"
including permutations thereof, may be used interchangeably and
synonymously to reference any relevant type of garment worn on a
human foot. Lastly, the features presented in the drawings are not
necessarily to scale and are provided purely for instructional
purposes. Thus, the specific and relative dimensions shown in the
drawings are not to be construed as limiting.
[0021] The representative article of footwear 10 is generally
depicted in FIGS. 1 and 2 as a bipartite construction that is
primarily composed of a foot-receiving upper 12 mounted on top of a
subjacent sole structure 14. For ease of reference, the footwear 10
may be divided into three anatomical regions: a forefoot region
R.sub.FF, a midfoot region R.sub.MF, and a hindfoot (heel) region
R.sub.HF, as shown in FIG. 2. Footwear 10 may also be divided along
a vertical plane into a lateral side S.sub.LA--a distal half of the
shoe 10 farthest from the sagittal plane of the human body--and a
medial side S.sub.ME a proximal half of the shoe 10 closest to the
sagittal plane of the human body--opposite the lateral side
S.sub.LA. In accordance with recognized anatomical classifications,
the forefoot region R.sub.FF is located at the front of the
footwear 10 and generally corresponds with the phalanges (toes),
metatarsals, and any interconnecting joints thereof. Interposed
between the forefoot and hindfoot regions R.sub.FF and R.sub.HF is
the midfoot region R.sub.MF, which generally corresponds with the
cuneiform, navicular, and cuboid bones (i.e., the arch area of the
foot). Hindfoot region R.sub.HF, in contrast, is located at the
rear of the footwear 10 and generally corresponds with the talus
(ankle) and calcaneus (heel) bones. Both lateral and medial sides
S.sub.LA and S.sub.ME of the footwear 10 extend through all three
anatomical regions R.sub.FF, R.sub.MF, R.sub.HF, and each
corresponds with a respective transverse side of the footwear 10.
While only a single shoe 10 for a left foot of a user is shown in
FIGS. 1 and 2, a mirrored, substantially identical counterpart for
a right foot of a user may be provided. Recognizably, the shape,
size, material composition, and method of manufacture of the shoe
10 may be varied, singly or collectively, to accommodate
practically any conventional and nonconventional application.
[0022] With continuing reference to FIG. 1, the upper 12 is
depicted as having a shell-like closed toe and heel configuration
for encasing a human foot. Upper 12 of FIG. 1 is generally defined
by three adjoining sections, namely a toe box 12A, a vamp 12B, and
a heel counter 12C. Toe box 12A is located in the forefoot region
R.sub.FF to cover and protect the user's toes. Vamp 12B, by
comparison, is located in the forefoot and midfoot regions R.sub.FF
and R.sub.MF, aft of the toe box 12A, to extend around and cover
the user's instep. As shown, the vamp 12B also provides a tongue
cover 16 and a shoe tongue 18. Heel counter 12C is aft of the vamp
12B and includes the rear and rear sides of the upper 12 to cover
the foot from the ankle to the heel. While portrayed in the
drawings as comprising three primary segments--the toe box 12A,
vamp 12B, and heel counter 12C--the upper 12 may be fabricated as a
single-piece construction or may be composed of any number of
segments, including a toe cap, heel cap, ankle cuff, interior
liner, etc. For sandal and slipper applications, the upper 12 may
take on an open toe or open heel configuration, or may be replaced
with a single strap or multiple interconnected straps.
[0023] The upper 12 portion of the footwear 10 may be fabricated
from any one or combination of a variety of materials, such as
textiles, engineered foams, polymers, natural and synthetic
leathers, etc. Individual segments of the upper 12, once cut to
shape and size, are stitched, adhesively bonded, welded, or
otherwise joined together to form an interior void for comfortably
receiving a foot. The individual material elements of the upper 12
may be selected and located with respect to the footwear 10 in
order to impart properties of durability, air-permeability,
wear-resistance, flexibility, and comfort, for example. An ankle
opening 11 in the rear quarter of the upper 12 provides access to
the interior of the assembled shoe 10. A shoe strap 20, lace,
bungee, buckle, or other conventional mechanism may be utilized to
modify the girth of the upper 12 to more securely retain the foot
within the interior of the shoe 10 as well as to facilitate entry
and removal of the foot into/from the upper 12. Strap 20 may be
threaded through a series of eyelets in the upper 12; a tongue 18
may extend between the strap 20 and the interior void of the upper
12.
[0024] Sole structure 14 is rigidly secured to the upper 12 such
that the sole structure 14 extends between the upper 12 and a
support surface upon which a user stands, for example. In effect,
the sole structure 14 functions as an intermediate support platform
that separates the user's foot from the ground. In addition to
attenuating ground reaction forces and providing cushioning for the
foot, sole structure 14 of FIGS. 1-3 may provide traction, impart
stability, and help to limit various foot motions, such as
inadvertent foot inversion and eversion. In accordance with the
illustrated example, the sole structure 14 is fabricated as a
single-piece, unitary structure with integrally formed insole,
midsole, and outsole sections. Alternative sole configurations may
be fabricated as a sandwich structure with a top-most insole, a
bottom-most outsole, and an intermediate midsole sandwiched between
and adjoining the insole and outsole. Sole structure 14 may
incorporate one or more materials or embedded elements that enhance
the comfort, performance, and/or ground-reaction-force attenuation
properties of footwear 10. These elements and materials may
include, individually or in any combination, a polymer foam
material, such as polyurethane or ethylene-vinyl acetate, filler
materials, moderators, air-filled bladders, plates, lasting
elements, or motion control members. Sole structure 14 may
incorporate a rubber material that provides a durable and
wear-resistant surface for engaging the ground. In addition, sole
structure 14 may also be textured to enhance the traction (i.e.,
friction) properties between footwear 10 and the underlying support
surface.
[0025] With collective reference to FIGS. 1-3, the sole structure
14 may be fabricated with an atypical and, in some applications,
one of a kind surface topology that may be typified by a distinct
pattern of craters and bumps that is further differentiated by a
unique color scheme. For instance, the outer surface of the
illustrated sole structure 14 is fabricated using a manufacturing
process 100 (described below with respect to FIG. 4) that is
engineered to generate a randomly interspersed mixture of
distinctly shaped and sized cavities, a representative sample of
which is designated at 30 in the inset view of FIG. 2. Footwear 10
of FIG. 2 is also fabricated with a randomly interspersed mixture
of distinctly shaped and sized protrusions, a representative sample
of which is designated at 32, that project in multiple directions
from the outer peripheral surface and ground-engaging surface of
the sole structure 14. As a further option, an assortment of
distinctly shaped, sized, and colored plastic fragments, a
representative sample of which are designated at 34 in the inset
view of FIG. 2, may be erratically dispersed across and embedded in
the outer surface of the sole structure 14. Generally speaking, the
surface topology of the sole structure 14 may be characterized by a
lack of two structurally identical, equisized sections of surface
area as viewed by the naked eye. Cratering and bulging of the sole
structure 14 surface may result from recycled polymers "sweating"
entrained oils during the foaming and forming operations described
below.
[0026] Continuing with the above discussion, the outer surface of
the sole structure 14 is shown covered in its entirety with the
erratically dispersed cavities 30, protrusions 32, and colored
fragments 34. Alternative shoe configurations may be formed or
machined with specific segments of the sole structure 14 that lack
the cavities 30, the protrusions 32, and/or the colored fragments
34. Producing the sole structure 14 using the manufacturing process
100 described below may result in any number of craters, bumps, and
colors; the sole structure 14 of FIG. 2, for example, includes
fifty (50) or more distinctly shaped cavities 30, fifty (50) or
more distinctly shaped protrusions 32, and fifty (50) or more
distinctly shaped and colored plastic fragments 34. While not per
se required, the number of cavities 30, number of protrusions 32
and number of colored fragments 34 may be distinct from one
another. It is further envisioned that these cavities 30,
protrusions 32, and colored fragments 34 may take on an
indeterminate combination of shapes, including regular and
irregular geometric forms, and sizes, as restricted by the total
surface area of the sole structure 14.
[0027] A variety of techniques, elective processes, and system
architectures may be utilized to manufacture the athletic shoe 10
of FIGS. 1-3. By way of non-limiting example, FIG. 4 presents an
improved footwear manufacturing method, designated generally at
100, for forming a footwear sole structure, such as sole structure
14, in accordance with aspects of the present disclosure. Some or
all of the operations illustrated in FIG. 4 and described in
further detail below may be representative of an algorithm that
corresponds to processor-executable instructions that may be
stored, for example, in main or auxiliary or remote memory, and
executed, for example, by a local or remote controller, processing
unit, control logic circuit, or other module or device, to perform
any or all of the above or below described functions associated
with the disclosed concepts. One or more of the illustrated
operations may be carried out or assisted manually by an onsite
technician. It should be recognized that the order of execution of
the illustrated operation blocks may be changed, additional blocks
may be added, and some of the blocks described may be modified,
combined, or eliminated.
[0028] Method 100 of FIG. 4 is initialized at terminal block 101,
e.g., responsive to receipt of an activation command signal
received from a human machine interface (HMI) of a central control
terminal. Initial stages of the manufacturing process may comprise
supplying, accessing, and/or utilizing (collectively "providing")
the various materials, tools and machines needed to manufacture the
athletic shoe 10. At process block 103, for example, a batch of
recycled plastic material is accessed from an available store of
polymer recyclate. As used herein, the term "recycled plastic" may
encompass used or excess or scrapped plastic that is put into a
recycling stream, including wholesale recycling of entire products,
disassembly of products and recycling only selected parts,
recycling of manufacturing byproduct, all of which may require
sorting and cleaning of collected materials. For at least some
embodiments, scrap and waste polyolefin foams are recovered and
incorporated into foamed articles produced with at least some
virgin polyolefin materials. It may be desirable, depending on an
intended application, that at least 40 parts of recycled EVA foam
per 100 parts virgin EVA be incorporated into newly foamed EVA
articles by the methods described herein. The batch of recycled
plastic material may include thermoplastic elastomer (TPE)
plastics, such as a synthetic rubber, or ethylene-vinyl acetate
(EVA) copolymer plastics, such as Phylon. Phylon is conventionally
made of EVA pellets that are compressed, heat expanded, and then
cooled in a mold.
[0029] Once the batch of recycled plastic is received and any
attendant sorting, cleaning or other pre-processing is complete at
process block 103, the method 100 shreds, chops, cuts or otherwise
grinds the batch of recycled plastic at process block 105. A
dedicated recycling station may be responsible for grinding
recycled Phylon or rubber into pelletized form; ground recycled
material may be produced in real-time or stored in inventory and
reused when desired. Alternatively, "grinding" may comprise feeding
a hot compound of recyclate into an extruder fitted with a
perforated die; a cutter immediately in front of the die slices
extruded strings of compound into granulized pellets. Cut pellets
are then cooled as they are transported to a sieve grader to
separate out irregularly sized pellets. Unlike some conventional
techniques for recycling polyolefin polymers, the method 100 may
grind and reuse excess Phylon that was previously heated above the
threshold temperature at which the foaming agent is activated. In
addition, the method 100 may minimize or otherwise eliminate the
use of hydrocarbon resin compatibilzers to modify the physical
properties of the recycled and virgin materials during production
of the molded articles.
[0030] At process block 107, the ground recycled material is mixed
with a composition of virgin polymer material. A recycled material
may be contrasted with a virgin material in that a raw material has
neither been expanded through activation of an intermixed foaming
agent nor been formed into an end product. The virgin polymer may
be the same general polymer composition as or may be a
distinguishable polymer composition from the recyclate. For
instance, a batch of recycled EVA may be mixed with virgin EVA or
virgin synthetic rubber. The virgin resin may comprise EVA
copolymer having 15-60 mole percent vinyl acetate. As another
option, at this stage of the manufacturing workflow process 100,
ground recycled material may also be mixed with a polyurethane (PU)
base material. Pelletized virgin polymer may be stowed as inventory
in a storage bay, and retrieved from inventory, e.g., utilizing a
first-in-first-out (FIFO) scheme according to the known shelf-life
of the inventoried polymer.
[0031] For some applications, the virgin and recycled materials are
not pre-mixed prior to forming. Rather, one or more of the
individual constituent parts of the recycled and virgin polymer
composition may be shaped into a preform prior to placing the
polymer composition into a final mold for forming a desired segment
of an article of footwear, as indicated at optional process block
109. In an example, the ground recyclate may be melted, extruded,
skived, cut and then die cut to a desired length. These die-cut
planks may each be shaped in a preform mold to an intermediate
preform size and shape. Preforming the recycled EVA/TPE material
may be achieved via compression molding, injection molding, or any
other suitable molding technique using a preform mold. For some
optional applications, a metered amount of virgin polymer material
may be added into the preform mold during fabrication of the
recyclate preform. It is also envisioned that the virgin polymer
material be processed as described above into a virgin polymer
preform. The final mold may comprise a discrete complementary
recess for each of the foregoing preforms. A release agent may be
applied to an exposed surface of each preform and/or an exposed
surface of each complementary recess to facilitate separation of
the final product from the mold assembly after its formation.
[0032] With continuing reference to FIG. 4, method 100 continues to
process block 111 with instructions to treat the mixture of
recycled material, e.g., with the addition of blowing/foaming
agents, fillers, pigments, processing aids, and/or crosslinking
agents. In at least some implementations, a foaming agent is
incorporated as a separate ingredient into the mixture of recycled
and virgin polymer material for invoking the expansion of the
mixture during molding. This foaming agent may be thermally
decomposable, and may be selected from organic and inorganic
chemical foaming agents. The foaming agent may comprise any
substance which, alone or in combination with other substances, is
capable of producing a cellular structure in a plastic. Foaming
agents may include compressed gases that expand when pressure is
released, soluble solids that leave pores when leached out, liquids
that develop cells when they change to gases, and chemical agents
that decompose or react under the influence of heat to form a gas.
By way of example, the chemical foaming agent may range from a
simple salt, such as ammonium or sodium bicarbonate, to a complex
nitrogen releasing agent. For at least some applications, the
foaming agent includes azohexahydrobenzonitrile, diazocarbamide,
azodicarbonamide, diazodiaminobenzene, benzenesulfonylhydrazide,
terephthalazide, sulfonylhydrazide compounds, sodium bicarbonate,
ammonium bicarbonate, or any combination thereof. In operation,
once the forming apparatus arrives at the activation temperature of
the foaming agent, a polymer chain of the EVA mixture begins to
break down causing the EVA to attain elastomeric properties. The
decomposition temperature of the foaming agent may be from about
120.degree. C. to about 200.degree. C.
[0033] Numerous other additives may be incorporated into the
recyclate batch prior to introduction into the final mold for
forming the footwear sole structure. As an example, a chemical
foaming auxiliary agent may be added to lower the decomposition
temperature of the foaming agent. Conversely, a chemical foaming
inhibitor may be added in measure to raise the decomposition
temperature of the thermally decomposable foaming agent. Another
option may include adding a metered amount of a chemical
crosslinking agent to link the polymer chain of the recyclate
material to the polymer chain of the virgin material. Under the
temperature conditions of the reaction, a peroxide-based agent may
be activated to initiate the process of crosslinking by removing a
hydrogen atom from a polymer backbone to thereby provide sites for
crosslinking. The nature and level of the crosslinking agent may be
selected to provide suitable foaming and crosslinking in
conjunction with the foaming agent.
[0034] Other components can be added to the polymer compositions,
including fillers, activators, homogenizing agents, pigments, fire
retardants, lubricants, and other suitable additives. Non-limiting
examples of filler materials include talcum powder, mica silicate,
bearing sulfate, magnesium hydroxide, magnesium carbonate,
magnesium silicate, calcium carbonate, and other commercially
available fillers. The polymer compositions can also contain rubber
fillers, such as ethylene propylene rubber (EPR), styrene isoprene
styrene (SIS) copolymer rubber, styrene butadiene rubber, as well
as other polyolefin resins, in addition to EVA or TPE base
materials. In other examples, polyethylene wax may be used as a
processing agent, stearic acid may be used as a lubricant, dicumyl
peroxide may be used as a polymerization initiator, zinc oxide may
be used as an activator for the foaming agent, while titanium
dioxide may be used as a white pigment.
[0035] Once the polymer composition is complete and ready for
molding, the processed recycled material is placed into the
internal cavity of a final mold that is shaped like a segment of an
article of footwear, as indicated at process block 113. This
footwear segment may be formed via compression molding, injection
molding, two-shot molding, insert molding, co-injection molding or
any other technique for forming the desired footwear segment. In a
representative example, the recycled EVA and/or TPE materials are
batch mixed, e.g., in a kneader or continuous mixing extruder
(process block 107), treated and processed (process block 111),
cooled and dispersed on an open mill, and calendared or granulated
to produce a final mix compound ready for production foam. Large
steam heat presses may be used to make slabs of polymer foam; the
slab stock foam is then skived and cut into preforms, then finally
molded (process block 113) into unitary sole structures, midsoles,
outsoles, insoles or sock liners, or other desired segment or
segments of a shoe. For a Phylon application, raw material compound
may be pressed into sheet form, which is then foamed and
post-processed, e.g., to remove an unwanted skin, thereafter die
cut into preforms, and the individual preforms pressed in the final
mold. For injection molded Phylon, the recyclate and virgin
material compound may be injected directly into the final mold.
Conversely, for compression molded Phylon, the polymer material
compound may be blown into a semi-finalized shape, which is then
buffed and finished into the final state.
[0036] For applications in which the virgin polymer composition is
first shaped into a preform, a metered portion of the processed
recycled material may first be scattered around the internal cavity
of the final mold. The virgin polymer preform is then placed into
the internal cavity and, after proper placement of the preform,
another metered portion of the recycled material is scattered on an
exposed surface of the virgin polymer preform. It is also
envisioned that only select segments of the preform be covered with
the recycled material. As an additional or alternative option, the
virgin polymer preform may be fashioned with a predetermined amount
of the recycled polymer material. Another option may include
wetting the virgin polymer preform prior to placement in the final
mold. The wet preform is then placed inside a sealable container.
This container may be partially pre-filled with polymer recyclate;
once the wet preform is inside the container, processed recycled
material may be dosed into the container. The container is shaken,
vibrated or otherwise agitated to coat the preform with recycled
material. After being coated with recyclate, the virgin polymer
preform may be placed inside the internal cavity of the final mold.
The formed footwear segment is extracted from the final mold at
process block 115; at this juncture, the method 100 may terminate
or may loop back to terminal block 101 and run in a repeatable or
continuous loop.
[0037] Aspects of this disclosure may be implemented, in some
embodiments, through a computer-executable program of instructions,
such as program modules, generally referred to as software
applications or application programs executed by any of a
controller or the controller variations described herein. Software
may include, in non-limiting examples, routines, programs, objects,
components, and data structures that perform particular tasks or
implement particular data types. The software may form an interface
to allow a computer to react according to a source of input. The
software may also cooperate with other code segments to initiate a
variety of tasks in response to data received in conjunction with
the source of the received data. The software may be stored on any
of a variety of memory media, such as CD-ROM, magnetic disk, bubble
memory, and semiconductor memory (e.g., various types of RAM or
ROM).
[0038] Moreover, aspects of the present disclosure may be practiced
with a variety of computer-system and computer-network
configurations, including multiprocessor systems,
microprocessor-based or programmable-consumer electronics,
minicomputers, mainframe computers, and the like. In addition,
aspects of the present disclosure may be practiced in
distributed-computing environments where tasks are performed by
resident and remote-processing devices that are linked through a
communications network. In a distributed-computing environment,
program modules may be located in both local and remote
computer-storage media including memory storage devices. Aspects of
the present disclosure may therefore be implemented in connection
with various hardware, software or a combination thereof, in a
computer system or other processing system.
[0039] Any of the methods described herein may include machine
readable instructions for execution by: (a) a processor, (b) a
controller, and/or (c) any other suitable processing device. Any
algorithm, software, control logic, protocol or method disclosed
herein may be embodied as software stored on a tangible medium such
as, for example, a flash memory, a CD-ROM, a floppy disk, a hard
drive, a digital versatile disk (DVD), or other memory devices. The
entire algorithm, control logic, protocol, or method, and/or parts
thereof, may alternatively be executed by a device other than a
controller and/or embodied in firmware or dedicated hardware in an
available manner (e.g., implemented by an application specific
integrated circuit (ASIC), a programmable logic device (PLD), a
field programmable logic device (FPLD), discrete logic, etc.).
Further, although specific algorithms are described with reference
to flowcharts depicted herein, many other methods for implementing
the example machine-readable instructions may alternatively be
used.
[0040] Aspects of the present disclosure have been described in
detail with reference to the illustrated embodiments; those skilled
in the art will recognize, however, that many modifications may be
made thereto without departing from the scope of the present
disclosure. The present disclosure is not limited to the precise
construction and compositions disclosed herein; any and all
modifications, changes, and variations apparent from the foregoing
descriptions are within the scope of the disclosure as defined by
the appended claims. Moreover, the present concepts expressly
include any and all combinations and subcombinations of the
preceding elements and features.
* * * * *