Method of manufacturing a bladder element with an etched feature and article having a bladder element with an etched feature

1. A method of manufacturing an article of footwear having a sole assembly with a midsole and an outsole, and having an upper, the method comprising:

etching an etched feature on a surface of a first polymeric sheet;

disposing the first polymeric sheet in a mold assembly;

forming a fluid-filled bladder element at least partially from the first polymeric sheet; wherein the bladder element has a sealable internal cavity that retains fluid;

wherein said forming the fluid-filled bladder element includes conforming the first polymeric sheet to a mold surface of the mold assembly to at least partially form the fluid-filled bladder element;

wherein said etching the etched feature in the surface of the first polymeric sheet is prior to conforming the first polymeric sheet to the mold surface or after the fluid-filled bladder element is formed; and

assembling the bladder element in the midsole so that a first portion of the fluid-filled bladder element having the etched feature is exposed to view through an opening in one of the midsole, the outsole, and the upper, and a second portion of the fluid-filled bladder element is blocked from view by said one of the midsole, the outsole, and the upper.

2. The method of claim 1 , wherein:

said assembling the fluid-filled bladder element includes aligning the etched feature with the opening so that the etched feature is exposed to view through the opening.

3. The method of claim 2 , wherein:

said assembling includes securing the fluid-filled bladder element to the sole assembly.

4. The method of claim 3 , wherein:

the opening is in the midsole or the outsole.

5. The method of claim 1 , wherein:

at least a portion of the outsole is substantially transparent; and

said assembling comprises securing the outsole to the fluid-filled bladder element so that the etched feature is exposed to view through the portion of the outsole that is substantially transparent.

6. The method of claim 1 , wherein:

the fluid-filled bladder element further includes a second polymeric sheet; and

said forming the fluid-filled bladder element includes:

bonding the first polymeric sheet to the second polymeric sheet at a peripheral seam so that the first polymeric sheet and the second polymeric sheet together define the internal cavity sealed at the peripheral seam; and wherein the peripheral seam is spaced apart from the etched feature.

7. The method of claim 1 , wherein said etching the etched feature on the surface of the first polymeric sheet is by at least one of laser etching or mechanical etching.

8. The method of claim 1 wherein the etched feature comprises at least one of a protrusion from or a recess in the surface of the fluid-filled bladder element.

9. The method of claim 1 , wherein:

the mold surface has a curved portion;

the fluid-filled bladder element has a curved portion corresponding with the curved portion of the mold surface; and

said disposing the first polymeric sheet in the mold assembly is so that the etched feature is on the curved portion of the fluid-filled bladder element.

10. The method of claim 1 , wherein:

the first polymeric sheet has a first thickness; and

the etched feature has a maximum depth into the first polymeric sheet of not more than about one-half of the first thickness.

11. The method of claim 1 , wherein:

the first polymeric sheet comprises a gas barrier polymer; and

the gas barrier polymer is not compromised by said etching the etched feature.

12. The method of claim 1 , further comprising:

prior to said assembling the fluid-filled bladder element in the midsole, filling the sealable internal cavity with fluid; and

sealing the sealable internal cavity so that the fluid is retained in the sealable internal cavity; wherein the fluid is a gas at or above ambient pressure.

13. The method of claim 1 , wherein:

the first polymeric sheet comprises a thermoplastic polymeric material;

the thermoplastic polymeric material comprises a thermoplastic polymeric polyurethane (TPU); and

the TPU is present on at least an outer surface of the first polymeric sheet.

14. The method of claim 13 , wherein the first polymeric sheet comprises a multi-layer polymeric sheet that is a laminate membrane having:

at least a first layer comprising the TPU; and

at least a second layer comprising a gas barrier polymer.

15. The method of claim 14 , wherein the gas barrier polymer is an ethylene-vinyl alcohol copolymer.

16. The method of claim 1 , further comprising:

securing a topcoat to the fluid-filled bladder element over the etched feature; and wherein the topcoat is substantially transparent so that the etched feature is exposed to view through the topcoat.

17. The method of claim 1 , wherein:

the mold surface has an etched area; and

said conforming the first polymeric sheet to the mold surface comprises imparting an impression of the etched area onto the surface of the fluid-filled bladder element.

18. The method of claim 17 , further comprising:

at least partially aligning the etched feature with the etched area of the mold assembly during said disposing the first polymeric sheet in the mold assembly so that the impression of the etched area is at least partially on the etched feature.

19. A method of manufacturing an article, the method comprising:

etching an etched feature on a surface of a first polymeric sheet;

disposing the first polymeric sheet in a mold assembly;

forming a fluid-filled bladder element at least partially from the first polymeric sheet wherein the bladder element has a sealable internal cavity that retains fluid;

wherein said forming the fluid-filled bladder element includes conforming the first polymeric sheet to a mold surface of the mold assembly to at least partially form the fluid-filled bladder element;

wherein said etching the etched feature in the surface of the first polymeric sheet is prior to conforming the first polymeric sheet to the mold surface or after the fluid-filled bladder element is formed; and

after said conforming the first polymeric sheet to the mold surface to at least partially form the fluid-filled bladder element, treating the surface of the fluid-filled bladder element to achieve at least one of a predetermined level of opacity, transparency, or luster of the fluid-filled bladder element.

20. The method of claim 19 , wherein said treating is by at least one of heating the surface of the fluid-filled bladder element or applying a softening agent to the surface of the fluid-filled bladder element.

21. The method of claim 19 , wherein said treating comprises:

treating a first area of the surface of the fluid-filled bladder element to achieve a first predetermined level of opacity, transparency, or luster;

wherein:

a second area of the surface of the fluid-filled bladder element has a second predetermined level of opacity, transparency, or luster that is at least ten percent greater than or at least ten percent less than that of the first predetermined level of opacity, transparency, or luster; and

the etched feature is on at least one of the first area or the second area of the fluid-filled bladder element.

22. A method of manufacturing an article, the method comprising:

etching an etched feature on a surface of a first polymeric sheet;

disposing the first polymeric sheet in a mold assembly;

forming a fluid-filled bladder element at least partially from the first polymeric sheet wherein the bladder element has a sealable internal cavity that retains fluid;

wherein said forming the fluid-filled bladder element includes conforming the first polymeric sheet to a mold surface of the mold assembly to at least partially form the fluid-filled bladder element;

wherein said etching the etched feature in the surface of the first polymeric sheet is prior to conforming the first polymeric sheet to the mold surface or after the fluid-filled bladder element is formed; and

wherein said conforming the first polymeric sheet comprises at least one of compression forming the first polymeric sheet, vacuum forming the first polymeric sheet, or thermoforming the first polymeric sheet.