SOLE ASSEMBLY AND RELATED METHOD OF MANUFACTURE
A method of forming a sole assembly for footwear construction comprises providing a first polymeric composition having a first density and a second polymeric composition having a second density in a mold to form a pre-expanded midsole. The pre-expanded midsole is expanded using a supercritical fluid to form a midsole. The midsole includes an exterior portion having a third density and an interior portion having a fourth density, which is different than the third density. The midsole defines a first surface and a second surface opposite the first surface. An outsole is joined with the second surface of the midsole.
1 . A footwear construction comprising:
a midsole comprising a cured product of a pre-expanded midsole comprising a first polymeric composition comprising ethylene vinyl acetate and titanium dioxide and having a first density, and a second polymeric composition comprising ethylene vinyl acetate and a colorant and having a second density, the pre-expanded midsole having been expanded in the presence of a supercritical fluid, the midsole further comprising:
an exterior portion comprising a cured, expanded reaction product of the first polymeric composition;
an interior portion comprising a cured, expanded reaction product of the second polymeric composition; and
a first surface at least partially defined by the interior portion and bounded at least partially by a midsole wall comprising the exterior portion;
a second surface opposite the first surface and defined by the exterior portion, the midsole wall defining a perimeter surface that extends around a perimeter of the midsole, the perimeter surface of the midsole wall defining a plurality of medial notches and a plurality of corresponding lateral notches; and
a plurality of medial stanchions disposed between the plurality of medial notches and a plurality of corresponding lateral stanchions disposed between the plurality of corresponding of lateral notches; and
an outsole defining an upper surface and a ground-contacting surface with the upper surface of the outsole adjacent the second surface of the midsole, the outsole including a plurality of segments at least partially separated from one another by a plurality of channels defined by the exterior portion;
wherein each of the plurality of channels extend in a lateral direction between respective ones of each of the plurality of medial notches and each of the plurality of corresponding lateral notches; and
wherein each of the plurality of segments extends in a lateral direction between each of the plurality of medial stanchions and each of the plurality of corresponding lateral stanchions.
2 . The footwear construction of claim 1 ,
wherein the exterior portion has a third density and comprises a cured, expanded reaction product of the first polymeric composition,
wherein the interior portion has a fourth density and comprises a cured, expanded reaction product of the second polymeric composition; and
wherein the third and fourth densities are different as a result of expanding the first and second polymeric compositions in the presence of the supercritical fluid.
3 . A footwear construction comprising:
a midsole comprising a cured product of a pre-expanded midsole comprising a first polymeric composition comprising ethylene vinyl acetate and titanium dioxide and having a first density and a second polymeric composition comprising ethylene vinyl acetate and a colorant and having a second density, the pre-expanded midsole having been expanded in the presence of a supercritical fluid, the midsole comprising:
an exterior portion comprising a cured, expanded reaction product of the first polymeric composition and having a third density, whereby the exterior portion is configured to provide structural rigidity and energy return;
an interior portion comprising a cured, expanded reaction product of the second polymeric composition and having a fourth density, whereby the interior portion is configured to provide cushion;
a first surface at least partially defined by the interior portion and bounded at least partially by a midsole wall comprising the exterior portion extending around a perimeter of the first surface, the first surface defining a foot-receiving cavity; and
a second surface opposite the first surface and defined by the exterior portion; and
an outsole comprising a plurality of segments and defining an upper surface and a ground-contacting surface, the upper surface of the outsole adjacent the second surface of the midsole and the ground-contacting surface, whereby the ground contacting surface is configured to provide traction on a plurality of terrains,
wherein at least two of the plurality of segments are at least partially separated from each other with a respective portion of the midsole therebetween, whereby the footwear construction is configured to provide energy return and cushion on a plurality of terrains.
4 . The footwear construction of claim 3 ,
wherein the plurality of segments extends in a lateral direction between a medial periphery of the footwear construction and a lateral periphery of the footwear construction and wherein the plurality of segments are at least partially separated from one another with a plurality of channels defined by the exterior portion.
5 . The footwear construction of claim 4 ,
wherein the exterior portion is translucent, and the interior portion is colored, and at least a portion of the plurality of channels exhibit a color gradient extending from the medial periphery towards the lateral periphery of the footwear construction, the color gradient resulting from a varying thickness of the exterior portion and the interior portion adjacent thereto.
6 . The footwear construction of claim 4 ,
wherein at least a portion of the plurality channels increases in depth as the plurality of channels extend between a medial periphery of the footwear construction and a lateral periphery of the footwear construction.
7 . The footwear construction of claim 3 ,
wherein the exterior portion is translucent, and the interior portion has a color, wherein visible portions of the midsole wall and the second surface exhibit the color to varying degrees depending on a thickness of the exterior portion with the interior portion adjacent thereto.
8 . The footwear construction of claim 3 ,
wherein the midsole wall comprising the exterior portion defines a perimeter surface that extends around a perimeter of the footwear construction and defines a plurality of medial notches on a medial periphery and a plurality of corresponding lateral notches on a lateral periphery;
wherein each of the plurality of segments of the outsole are at least partially separated from one another with a plurality of channels defined by the second surface,
wherein respective ones of the plurality of channels at least partially extend between respective ones of the plurality of medial notches and respective ones of the plurality of corresponding lateral notches.
9 . The footwear construction of claim 8 ,
wherein a plurality of medial stanchions are interposed among the plurality of medial notches and a plurality of corresponding lateral stanchions are interposed among the plurality of corresponding lateral notches.
10 . The footwear construction of claim 9 ,
wherein each of the plurality of medial stanchions have a first width and each of the plurality of corresponding lateral stanchions have a second width,
wherein the first width of each of the plurality of medial stanchions is greater than the second width of each of the plurality of the corresponding lateral stanchions in a midfoot region of the footwear construction.
11 . The footwear construction of claim 10 ,
wherein the first polymeric composition consists essentially of ethylene vinyl acetate and titanium dioxide, and the second polymeric composition consists essentially of ethylene vinyl acetate and a second colorant, which is different than titanium dioxide.
12 . The footwear construction of claim 11 ,
wherein the third and fourth densities are different as a result of expanding the first and second polymeric compositions in the presence of a supercritical fluid.
13 . A footwear construction comprising:
a midsole comprising a cured product of a pre-expanded midsole comprising a first polymeric composition comprising ethylene vinyl acetate and titanium dioxide and having a first density, and a second polymeric composition comprising ethylene vinyl acetate and a colorant and having a second density, the pre-expanded midsole having been expanded in the presence of a supercritical fluid, the midsole comprising:
an exterior portion comprising a cured, expanded reaction product of the first polymeric composition;
an interior portion comprising a cured, expanded reaction product of the second polymeric composition; and
a first surface at least partially defined by the interior portion and bounded at least partially by a midsole wall comprising the exterior portion;
a second surface opposite the first surface and defined by the exterior portion; and
the midsole wall defining a perimeter surface that extends around a perimeter of the midsole;
wherein the exterior portion is translucent and the interior portion includes a color,
wherein visible portions of the midsole wall and the second surface exhibit the color through the midsole wall to a plurality of varying degrees depending on a thickness of the exterior portion with the interior portion adjacent thereto.
14 . The footwear construction of claim 13 ,
wherein the exterior portion has a third density and comprises a cured, expanded reaction product of the first polymeric composition,
wherein the interior portion has a fourth density and comprises a cured, expanded reaction product of the second polymeric composition; and
wherein the third and fourth densities are different as a result of expanding the first and second polymeric compositions in the presence of the supercritical fluid.
15 . The footwear construction of claim 14 ,
wherein the midsole defines a plurality of medial notches and a plurality of corresponding lateral notches,
wherein a plurality of medial stanchions are disposed among respective ones of the plurality of medial notches,
wherein a plurality of corresponding lateral stanchions are disposed among respective ones of the plurality of corresponding lateral notches.
16 . The footwear construction of claim 15 , comprising:
an outsole defining an upper surface and a ground-contacting surface,
wherein the upper surface of the outsole is adjacent the second surface of the midsole,
wherein the outsole includes a plurality of segments at least partially separated from one another by respective ones of a plurality of channels defined by the exterior portion.
17 . The footwear construction of claim 16 ,
wherein each of the plurality of channels extend in a lateral direction between each of the plurality of medial notches and each of the plurality of corresponding lateral notches,
wherein each of the plurality of segments extends in a lateral direction between each of the plurality of medial stanchions and each of the plurality of corresponding lateral stanchions.
18 . The footwear construction of claim 17 ,
wherein the plurality of segments extends in a lateral direction between a medial periphery of the midsole and a lateral periphery of the midsole,
wherein the plurality of segments are at least partially separated from one another.
19 . The footwear construction of claim 18 ,
wherein the exterior portion is translucent,
wherein the interior portion is colored,
wherein at least a portion of the plurality of channels exhibit a color gradient extending from the medial periphery toward the lateral periphery,
wherein the color gradient is produced via a varying thickness of the exterior portion and the interior portion adjacent thereto.
20 . The footwear construction of claim 13 ,
wherein the second polymeric composition comprises at least one of an olefin block copolymer and a polyolefin elastomer.