Molded footwear with woven appearance and ventilation features
View Patent ↗According to embodiments of the invention, a precursor sheet is formed by injecting an EVA-based material into a mold cavity. The mold cavity is configured to create a series of indentations through a first portion of the precursor sheet and into a second portion of the precursor sheet. The precursor sheet is removed from the mold cavity and the second portion of the precursor sheet is removed from the first portion of the precursor sheet to create an isolated sheet with a series of through-holes. The isolated sheet is then formed into a portion of a shoe.
1. A method of making a molded material sheet having a three-dimensional structure, comprising:
injecting a material into a mold cavity to create a molded material comprising:
a first surface; and
a second surface opposite the first surface;
wherein:
the mold cavity is configured to create a series of indentations into the first surface of the molded material; and
the series of indentations terminate in closed ends in the interior of the molded material sheet;
removing the molded material from the mold cavity; and
isolating a first portion of the molded material sheet that comprises at least a portion of the first surface from a second portion of the molded material sheet that comprises at least a portion of the second surface.
2. The method of claim 1 , wherein the isolating the first portion of the molded material sheet from the second portion of the molded material sheet includes removing at least a portion of the closed ends of the series of indentations from the remaining portions of the intendations, to form an isolated first portion having a series of through holes.
3. The method of claim 1 , wherein the thickness of the first isolated portion is less than the depth of at least a portion of the series of indentations, to form an isolated first portion having a series of through holes.
4. The method of claim 1 , wherein the isolating the first portion of the molded material sheet from the second portion of the molded material sheet cuts away the closed ends from the first isolated portion of the molded material sheet, to form an isolated first portion having a series of through holes.
5. The method of claim 1 , wherein the material expands to shrink at least one dimension of the series of indentations after injection due to expansion of the material around a perimeter of at least a portion of the series of indentations.
6. The method of claim 1 , wherein the material is an EVA-based material.
7. The method of claim 1 , wherein the isolating the first portion of the molded material sheet from the second portion of the molded material sheet comprises cutting the molded material sheet along a plane that does not intersect the first surface of the molded material sheet.
8. The method of claim 7 , wherein the step of isolating the first portion of the molded material sheet from the second portion of the molded material sheet further comprises cutting the molded material sheet along a plane that does not intersect the first surface of the molded material sheet at a surface of the precursor sheet that intersects the first surface.
9. The method of claim 7 , wherein the step of isolating the first portion of the molded material sheet from the second portion of the molded material sheet further comprises cutting the molded material sheet along a second plane that intersects the first surface along a line located outside of the series of indentations.
10. The method of claim 1 , wherein the indentations are circular or square.
11. The method of claim 1 , further comprising forming the isolated first portion into at least a portion of an article of footwear.
12. The method of claim 11 , wherein forming the isolated first portion into at least a portion of the article of footwear comprises the following steps: heating the isolated first portion and compressing the isolated first portion about a last.
13. The method of claim 1 , wherein the material has an expansion coefficient approximately equal to or lower than 1.7.
14. The method of claim 13 , wherein the material has an expansion coefficient of 1.43.
15. The method of claim 1 , wherein the mold cavity is further configured to create a second series of indentations into the second surface of the molded material sheet, wherein each indentation in the second series of indentations includes a closed end in the interior of the molded material sheet.
16. The method of claim 15 , further comprising isolating the second portion of the molded material sheet from a third portion of the molded material sheet, including removing at least a portion of the closed ends of the second series of indentations from the remaining portions of the indentations, to form an isolated second portion having a series of through holes.
17. The method of claim 15 , further comprising isolating the second portion of the molded material sheet from a third portion of the molded material sheet, wherein the thickness of the second isolated portion is less than the depth of at least a portion of the second series of indentations, to form an isolated second portion having a series of through holes.
18. The method of claim 15 , further comprising isolating the second portion of the molded material sheet from a third portion of the molded material sheet, such that the closed ends of the second series of indentations are cut away from the second isolated portion of the molded material sheet, to form an isolated second portion having a series of through holes.