Method of manufacturing a bladder element with an impression of etched area of mold assembly and article having bladder element with impression

A method of manufacturing an article includes disposing polymeric material in a mold assembly that has a mold surface that has an etched area. The method further comprises forming a fluid-filled bladder element at least partially by conforming the polymeric material to the mold surface, thereby imparting an impression of the etched area on a surface of the bladder element. The method includes assembling the bladder element in the article so that a first portion of the bladder element with the impression of the etched area is exposed to view, and a second portion of the bladder element is blocked from view by the article. An article comprises the bladder element with the etched area.

TECHNICAL FIELD

The present teachings generally include an article that comprises a bladder element having a surface with an impression, and a method of manufacturing the bladder element from a mold assembly with an etched area.

BACKGROUND

Clothing, an accessory, and/or athletic wear are often a source of expression for the wearer. The clothing, accessory, and/or athletic wear may provide an association with a team, coordinate with another item, or provide the owner or user with an attractive or customized item.

Footwear typically includes a sole configured to be located under a wearer's foot to space the foot away from the ground or floor surface. Footwear sometimes utilizes polyurethane foam or other resilient materials in the sole to provide cushioning

DESCRIPTION

A method of manufacturing an article includes disposing polymeric material in a mold assembly that has a mold surface. The mold surface has an etched area. The method further comprises forming a fluid-filled bladder element at least partially by conforming the polymeric material to the mold surface. The conforming imparts an impression of the etched area on a surface of the fluid-filled bladder element. The method includes assembling the fluid-filled bladder element in the article so that a first portion of the fluid-filled bladder element with the impression of the etched area is exposed to view, and a second portion of the fluid-filled bladder element is blocked from view by the article. The fluid-filled bladder element has a sealable internal cavity that retains fluid.

The article may have an opening, and the impression may be aligned with the opening, and exposed to view through the opening. For example, the article may be an article of footwear having a sole assembly and an upper, with the opening in one of the sole assembly and the upper. Assembling the fluid-filled bladder element in the article may comprise securing the fluid-filled bladder element to the sole assembly so that the impression is aligned with the opening and exposed to view through the opening. For example, the opening may be in a midsole or an outsole of the sole assembly. In an embodiment, the method may comprise securing an outsole, at least one portion of which is substantially transparent, to the fluid-filled bladder element so that the at least one portion of the outsole that is substantially transparent is aligned with the impression, and the impression is exposed to view through the at least one portion of the outsole that is substantially transparent.

The method may comprise etching the etched area in the mold surface by at least one of laser etching, mechanical etching, or chemical etching prior to conforming the polymeric material to the mold surface and imparting the impression. In some embodiments, the method may include applying a colored medium to the first polymeric sheet prior to imparting the impression, and disposing the polymeric material in the mold assembly may comprise positioning the first polymeric sheet in the mold assembly so that the impression of the etched area is adjacent to or on the colored medium on the first polymeric sheet. In other embodiments, a colored medium may be applied to the bladder element after it is formed. The impression may comprise at least one of a protrusion from or a recess in the surface of the bladder element. In one embodiment, a substantially transparent topcoat may be secured to the fluid-filled bladder element over the impression to protect the impression from damage and abrasion.

Etching of the etched area may be controlled in various ways to enable fluid retention in the internal cavity of the fluid-filled bladder element. For example, etching the etched area may be controlled so that the impression has a maximum depth into the first polymeric sheet of not more than about one-half of a first thickness of the first polymeric sheet. For example, if chemical etching is used, a depth of etching in the mold surface may be controlled at increments of 0.008 to 0.015 inches. In some embodiments, the first polymeric sheet comprises a gas barrier polymer. Etching the etched area may be controlled so that the gas barrier polymer is not compromised by the impression. As used herein, the gas barrier polymer is not compromised by the impression if the fluid retention ability of the fluid-filled bladder element is not decreased due to the etching. In other words, the gas transmission rate of the fluid-filled bladder element does not decrease due to the impression.

The method may further comprise polishing a first region of the mold surface to a first average surface roughness, wherein a second region of the mold surface has a second average surface roughness. The etched area is at least partially in at least one of the first region or the second region. The first average surface roughness may be at least ten percent greater than or at least ten percent less than the second average surface roughness. The surface of the fluid-filled bladder element has a first area corresponding with the first region of the mold surface and a second area corresponding with the second region of the mold surface.

The method may further comprise 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. Treating the surface of the fluid-filled bladder element may be 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.

Conforming the polymeric material to the mold surface may be by any or all of blow-molding, compression forming, vacuum forming, or thermoforming. Additionally, the etched area may be at least partially on a curved portion of the mold surface so that the at least a portion of the surface of the fluid-filled bladder element with the impression of the etched area is a corresponding curved portion of the fluid-filled bladder element.

The method may further comprise inflating the bladder element by filling the sealable internal cavity with a fluid, and then sealing the sealable internal cavity so that the fluid is retained in the sealable internal cavity. In one embodiment, the fluid is a gas at or above ambient pressure. The fluid-filled bladder element may have a gas transmission rate for nitrogen of less than 10 cubic centimeters per square meter per atmosphere per day, or of less than 1 cubic centimeter per square meter per atmosphere per day.

The fluid-filled bladder element may be formed from various polymeric materials enabling fluid retention and the gas transmission rate as described. For example, the polymeric material may comprise at least a first polymeric sheet that comprises a thermoplastic polymeric material. In one embodiment, the thermoplastic polymeric material may be a thermoplastic polyurethane (TPU). In one embodiment, the TPU is present on at least an outer surface of the first polymeric sheet. The first polymeric sheet may comprise a multi-layer polymeric sheet. The multi-layer polymeric sheet may be a laminate membrane that comprises at least a first layer comprising the TPU, and at least a second layer comprising a gas barrier polymer. The gas barrier polymer may comprise an ethylene-vinyl alcohol copolymer. In one embodiment, the at least a first layer consists essentially of the TPU, and the at least a second layer consists essentially of the ethylene-vinyl alcohol copolymer.

The method may include forming a peripheral seam in the bladder element by bonding in the mold assembly. The peripheral seam at least partially seals the sealable internal cavity in the bladder element. The peripheral seam is spaced apart from the impression. The method may include assembling the peripheral bladder element in the article so that the impression is at least partially aligned with the opening in the article. Furthermore, the peripheral seam may be covered by the article.

Optionally, in addition to the impression on the first polymeric sheet, the method may include etching an etched feature on the first polymeric sheet prior to disposing the polymeric material on the mold assembly or after the bladder element is formed. Etching of the etched feature is controlled so that a gas barrier layer of the first polymeric sheet is not compromised by the etching. Furthermore, the etched feature may be at least partially aligned with the etched area of the mold assembly during disposing of the first polymeric sheet in the mold assembly so that the impression of the etched area is at least partially on the etched feature. The surface of the bladder element having the impression may be an outer surface. The etched feature may be on one of the outer surface or an inner surface of the bladder element. The method may further comprise applying a colored medium to the first polymeric sheet before or after the bladder element is formed, in which case at least one of the etched feature and the impression may be adjacent to or on the colored medium on the first polymeric sheet.

Within the scope of the present teachings, an article comprises a fluid-filled bladder element including a polymeric material that has a surface with an impression thereon. The fluid-filled bladder element has a sealable internal cavity that retains fluid. A first portion of the fluid-filled bladder element with the impression is exposed to view, and a second portion of the fluid-filled bladder element is blocked from view by the article. Stated differently, the impression is at least partially aligned with the opening and exposed to view through the opening.

The fluid-filled bladder element may be manufactured by disposing the polymeric material in a mold assembly, and then conforming the polymeric material to a mold surface of the mold assembly to at least partially form the fluid-filled bladder element, thereby imparting the impression of the etched area onto the surface of the fluid-filled bladder element. The etched area of the mold surface may be etched on the mold surface by at least one of laser etching, mechanical etching, or chemical etching.

The surface of the fluid-filled bladder element may have a first area corresponding with a first region of the mold surface and a second area corresponding with a second region of the mold surface. The impression is in at least one of the first area and the second area. The first region of the mold surface has a first average surface roughness and the second region of the mold surface has a second average surface roughness. The first average surface roughness is at least ten percent greater than or at least ten percent less than the second average surface roughness.

The polymeric material may be conformed to the mold surface by at least one of blow-molding, compression forming, vacuum forming, or thermoforming the polymeric material. The polymeric material may include a first polymeric sheet, and the article may further comprise a colored medium applied to the first polymeric sheet. The impression of the etched area may be adjacent to or on the colored medium on the first polymeric sheet. In one embodiment, the portion of the surface of the fluid-filled bladder element with the impression of the etched area is a curved portion of the fluid-filled bladder element that corresponds with the curved portion of the mold surface.

In one embodiment of the article, the fluid-filled bladder element has a seam that at least partially seals the sealable internal cavity. The impression is spaced apart from the peripheral seam. The peripheral seam may be covered by and blocked from view by the article.

As described with respect to the method, the polymeric material used to form the fluid-filled bladder element of the article may comprise a thermoplastic polymeric material. In one embodiment, the thermoplastic polymeric material may be a thermoplastic polyurethane (TPU). In one embodiment, the polymeric material includes a first polymeric sheet, and the TPU is present on at least an outer surface of the first polymeric sheet. The first polymeric sheet may comprise a multi-layer polymeric sheet. The multi-layer polymeric sheet may be a laminate membrane that comprises at least a first layer comprising the TPU, and at least a second layer comprising a gas barrier polymer. The gas barrier polymer may comprise an ethylene-vinyl alcohol copolymer. In one embodiment, the at least a first layer consists essentially of the TPU, and the at least a second layer consists essentially of the ethylene-vinyl alcohol copolymer. Additionally, in one embodiment, the fluid-filled bladder element may have a gas transmission rate for nitrogen of less than 10 cubic centimeters per square meter per atmosphere per day, or of less than 1 cubic centimeter per square meter per atmosphere per day. The sealable internal cavity may be filled with a gas at or above ambient pressure.

In various embodiments, the impression may comprise at least one of a protrusion from or a recess in the surface of the fluid-filled bladder element. For example, the polymeric material may comprise a first polymeric sheet that has a first thickness. The impression may have a maximum depth into the first polymeric sheet of not more than about one-half of the first thickness. For example, when the first polymeric sheet comprises a gas barrier layer, the maximum depth of the impression does not compromise the gas barrier layer. A substantially transparent topcoat may be secured to the fluid-filled bladder element over the impression.

In one embodiment, the surface of the fluid-filled bladder element has a treated area with at least one of a predetermined level of opacity, transparency, or luster. The polymeric material may comprise at least a first polymeric sheet, and a feature may be etched on the first polymeric sheet. The feature may be at least partially aligned with the impression. The surface of the fluid-filled bladder element having the impression may be an outer surface, and the feature may be on one of the outer surface or an inner surface of the bladder element. A colored medium may be applied to the first polymeric sheet, and at least one of the feature or the impression may be adjacent to or on the colored medium on the first polymeric sheet.

The above features and advantages and other features and advantages of the present teachings are readily apparent from the following detailed description of the modes for carrying out the present teachings when taken in connection with the accompanying drawings.

Those having ordinary skill in the art will recognize that terms such as “above,” “below,” “upward,” “downward,” “top,” “bottom,” etc., are used descriptively relative to the figures, and do not represent limitations on the scope of the invention, as defined by the claims.

Referring to the drawings, wherein like reference numbers refer to like components throughout the several views,FIGS. 1 and 2show a fluid-filled bladder element10that has impressions12B,12C,12D imparted thereon. As further explained herein, the impressions12B,12C,12D are imparted from etched features of a mold assembly32A,32B, and because at least a portion of the fluid-filled bladder element10is substantially transparent, the impressions12B,12C,12D can be viewed from an exterior of the fluid-filled bladder element10when the fluid-filled bladder element10is assembled in an article, such as the article of footwear18ofFIG. 9. In the embodiment shown, the entire bladder element10is a substantially transparent polymeric material, and is formed from a first polymeric sheet20and a second polymeric sheet22.

As used herein, a “fluid” includes a gas, including air, an inert gas such as nitrogen, or another gas. Accordingly, “fluid-filled” includes “gas-filled”. As used herein, a component is “substantially transparent” if it has a luminous transmittance (i.e., a percentage of incident light that is transmitted) of at least 80 percent and haze (i.e., percentage of transmitted light that is scattered) of not more than 56 percent. The various materials used for the bladder element10, and other embodiments of bladder elements discussed herein, may be substantially transparent. Those skilled in the art will readily understand a variety of methods to determine luminous transmittance and haze of an object, such as the bladder element10. For example, the luminous transmittance and haze of the bladder element10can be determined according to American Society for Testing and Materials (ASTM) Standard D1003-00, Standard Test Method for Haze and Luminous Transmittance of Transparent Plastics. Additionally, in some embodiments, the bladder element10may have a tinted color.

Optionally, as further described herein, a colored medium46is aligned with and is adjacent to or on the impressions12B and12C. The colored medium46can be ink or paint, and may include reflective particles48, as shown in the close-up view ofFIG. 2. As indicated in the close-up view inFIG. 2, the colored medium46is an ink as a base and has reflective particles48. The reflective particles48allow for light to be cast back towards its source. The reflective particles48may also allow light to be scattered. In such embodiments, this provides a safety feature for low-light or full-light environments. The reflective particles48can be metal flakes or may include a phosphorescent material so that the reflective particles are a “glow-in-the-dark” material. In embodiments with reflective particles48, a curved portion60of the inflated bladder element10, discussed with respect toFIG. 9, facilitates reflecting of the light by the reflective particles48. For example, during a normal gait, a foot on which the article of footwear18is worn is repeatedly lifted and planted. The motion of the normal gait creates an additional “flash” of reflected light from the reflective particles48and makes the article of footwear18more noticeable.

Optionally, an etched feature12A can be etched on the bladder element10. Etched feature12A, shown inFIG. 1, is etched on the first polymeric sheet20, impressions12C and12D are imparted on the first polymeric sheet20, and the impression12B is imparted on the second polymeric sheet22, as shown inFIG. 3. In an embodiment in which the colored medium46is an ink, applying the colored medium46to the bladder element10may be by printing the ink on the first polymeric sheet20prior to or after imparting the impressions12C and12D and etching the etched feature12A, and printing the ink on the second polymeric sheet22prior to or after imparting the impression12B. Exemplary printing techniques include direct and indirect printing techniques.

The first polymeric sheet20and the second polymeric sheet22are secured to one another so that the bladder element10defines a sealable internal cavity23. As explained herein, the materials of the first polymeric sheet20and the second polymeric sheet22, as well as the construction of the bladder element10are configured so that the bladder element10is capable of retaining fluid in the sealable internal cavity23when the sealable internal cavity23is sealed. For example, the sealable internal cavity23may be filled with a gas at or above ambient pressure.

The etched feature12A is aligned with and adjacent to colored medium46applied to the first polymeric sheet20. The impression12C is also shown aligned with and on the colored medium46applied to the first polymeric sheet20. The impression12B is aligned with the colored medium applied to the second polymeric sheet22. As best shown inFIG. 1, a portion of the impression12B is on the colored medium46, and a portion of the impression12B is adjacent to the colored medium46applied to the second polymeric sheet22.FIG. 12shows an embodiment in which the colored medium46is applied on an outer surface41of the second polymeric sheet22as a star-shaped image in the embodiment shown prior to formation of the bladder element10.FIG. 13shows an embodiment in which the colored medium46is applied on an outer surface40of the first polymeric sheet20as an image of the number one and a number sign in the embodiment shown prior to formation of the bladder element10.

The bladder element10with etched feature12A and impressions12B,12C,12D is included in a sole assembly16of an article of footwear18. As shown inFIG. 14, the article of footwear18is an athletic shoe, and the bladder element10is a cushioning element. In other embodiments, the sole assembly16could be for an article of footwear that is a dress shoe, a work shoe, a sandal, a slipper, a boot, or any other category of footwear. Alternatively, the fluid-filled bladder element10could be used as a cushioning element in another article, such as but not limited to a shoulder strap, a backpack, a shoulder pad, a glove, an elbow pad, a knee pad, a shin guard, or other apparel, or a sports ball.

FIG. 4shows that the impression12B is a protrusion in the outer surface41of the second polymeric sheet22in the shape of a star. Impressions12C and12D are imparted on the outer surface40of the first polymeric sheet20. When the bladder element10is formed, the impression12C is on a bottom surface53, which is part of the outer surface40. In the embodiment shown, the impression12B is a star shape. In the embodiment shown, the impression12C includes the number one and the number sign. For example, the impression12C may be a player number. The impression12C is a recess in the outer surface40of the first polymeric sheet20. The impression12D is a series of protrusions in the form of elongated stripes on the outer surface40. In the embodiment shown inFIG. 1, the etched feature12A is a diamond pattern.

As shown inFIG. 3, even though the impression12B is on the second polymeric sheet22, it can be viewed from an exterior of the bladder element10through the first polymeric sheet20(i.e., is exposed to view through the first polymeric sheet20) due to the substantially transparent nature of the first and second polymeric sheets20,22. In another embodiment, the bladder element10may be formed from a single polymeric sheet or may be formed from substantially transparent polymeric material not in sheet form.

The fluid-filled bladder element10can be formed from a variety of polymeric materials. In an embodiment shown and described at least with respect toFIGS. 1-3, the bladder element10can be formed from any of various polymeric materials that can retain a fluid at a predetermined pressure, including a fluid that is a gas, such as air, nitrogen, or another gas. For example, the bladder element10can be thermoplastic polymeric material. The bladder element10can be a urethane, polyurethane, polyester, polyester polyurethane, and/or polyether polyurethane. Moreover, the bladder element10can be formed of layers of different materials.FIG. 9, which is a close-up fragmentary cross-sectional portion of the bladder element10in an article of footwear18taken at lines9-9inFIG. 14, shows that the first polymeric sheet20is a laminate membrane formed from thin films having one or more first layers24that comprise thermoplastic polyurethane layers24and that alternate with one or more second layers26, also referred to herein as barrier layers, gas barrier polymers, or gas barrier layers, that comprise a copolymer of ethylene and vinyl alcohol (EVOH) that is impermeable to the pressurized fluid contained therein as disclosed in U.S. Pat. No. 6,082,025 to Bonk et al., which is incorporated by reference in its entirety. The second polymeric sheet22may be formed from the same materials shown and described inFIG. 9with respect to the first polymeric sheet20. The first layer24may be arranged to form an outer surface of the first polymeric sheet20. That is, the outermost first layer24shown inFIG. 9may be a portion of the outer surface40of the bladder element10. The bladder element10may also be formed from a material that includes alternating layers of thermoplastic polyurethane and ethylene-vinyl alcohol copolymer, as disclosed in U.S. Pat. Nos. 5,713,141 and 5,952,065 to Mitchell et al. which are incorporated by reference in their entireties. Alternatively, the layers may include ethylene-vinyl alcohol copolymer, thermoplastic polyurethane, and a regrind material of the ethylene-vinyl alcohol copolymer and thermoplastic polyurethane. The bladder element10may also be a flexible microlayer membrane that includes alternating layers of a gas barrier polymer material such as second layers26and an elastomeric material such as first layers24, as disclosed in U.S. Pat. Nos. 6,082,025 and 6,127,026 to Bonk et al. which are incorporated by reference in their entireties. Additional suitable materials for the bladder element10are disclosed in U.S. Pat. Nos. 4,183,156 and 4,219,945 to Rudy which are incorporated by reference in their entireties. Further suitable materials for the bladder element10include thermoplastic films containing a crystalline material, as disclosed in U.S. Pat. Nos. 4,936,029 and 5,042,176 to Rudy, and polyurethane including a polyester polyol, as disclosed in U.S. Pat. Nos. 6,013,340, 6,203,868, and 6,321,465 to Bonk et al. which are incorporated by reference in their entireties. In selecting materials for the bladder element10, engineering properties such as tensile strength, stretch properties, fatigue characteristics, dynamic modulus, and loss tangent can be considered. The thicknesses of the first and second polymeric sheets20,22of materials used to form the bladder element10can be selected to provide these characteristics. For example, in various embodiments, the bladder element10may have a Shore A hardness of about 20 to about 100 when inflated.

As further explained herein, the first and second polymeric sheets20,22used to form the bladder element10may be treated or processed, and/or have properties specifically selected to enable the etched feature12A and the impressions12B,12C and12D to be lasting and aesthetically pleasing while protecting the ability of the bladder element10to sealingly retain the fluid.

In various embodiments, the etched feature12A may comprise at least one of a protrusion from or a recess in the surface of the bladder element10. For example,FIG. 10shows a series of recesses33A arranged to form the diamond pattern of the etched feature12A. The recesses33A are generally triangular grooves in cross section, as shown inFIG. 10, and may be made by removing some of the material of the outermost layer24of first polymeric sheet20during the etching process.FIG. 10also shows the protruding impression12D on the etched feature12A.FIG. 11shows an alternative etching pattern to create an alternative etched feature12AA that can be used in place of etched feature12A. The etched feature12AA forms the diamond pattern by a series of protrusions33B that are arranged by displacing some of the material of the outermost layer26from recesses33C to protrusions33B during the etching process.FIG. 11shows the protruding impression12D on the etched feature12AA.

As shown inFIG. 9, the first polymeric sheet20has a first thickness T1. In an embodiment in which the first polymeric sheet20comprises a gas barrier polymer, such as in an embodiment in which the second layers26are a gas barrier polymer, a maximum depth of the etched feature12A in the first polymeric sheet20is controlled so that the gas barrier polymer of layers26is not compromised. A maximum depth D into the first polymeric sheet20of the etched feature12A is much less than a thickness T1of the first polymeric sheet20and is less than the thickness of the outermost one of the first layers24. The maximum depth D could range up to about one-half of the thickness T1of the first polymeric sheet20, as the innermost layer26A of the gas barrier layers26would still be intact, enabling a desired maximum gas transmission rate. For example, the bladder element10may have a gas transmission rate for nitrogen of less than 10 cubic centimeters per square meter per atmosphere per day, or of less than 1 cubic centimeter per square meter per atmosphere per day. In various embodiments, by way of non-limiting example, the depth of the etched feature12A may be from 73 micrometers to 270 micrometers.

In certain embodiments, a protective coating layer15, also referred to as a topcoat or barrier and shown inFIGS. 1 and 4with respect to impression12B, can be placed on and secured to the bladder element10over one or more of the impressions12B,12C,12D or etched feature12A to protect the impressions12B,12C,12D or etched feature12A. Exemplary materials for a coating layer include polymers or prepolymers such as polyurethane, polytetrafluorethylene, polypropylene, polycarbonate, and the like, as non-limiting examples.

The bladder element10may be manufactured using a mold assembly32A,32B that includes a first mold half32A ofFIGS. 7 and 8, and a second mold half32B ofFIGS. 5 and 6. The first mold half32A has a cavity portion36A with a mold surface34A. Referring toFIGS. 7 and 8, the mold surface34A has an etched area37, which in the embodiment shown is a protrusion in the shape of a reverse (i.e., mirror image) of the number one and the number sign that are imparted as the impression12C. When the first polymeric sheet20is conformed to the mold surface34A during forming of the bladder element10as discussed herein, the impression12C of the etched area37is imparted on the outer surface40of the bladder element10. The material of the first polymeric sheet20is displaced by the protruding etched area37so that the impression12C is a recess in the first polymeric sheet20.

Referring toFIG. 4, a maximum depth D1of the impression12C in the first polymeric sheet20is controlled so that the gas barrier polymer of layers26shown inFIG. 9are not compromised. For example, referring toFIG. 7, the etching of the mold surface34A is controlled to provide a maximum height H1of the protrusion of the etched area37, with the maximum height H1equaling the maximum depth D1. In one embodiment, if chemical etching is used, a depth of etching in the mold surface34A may be controlled at increments of 0.008 to 0.015 inches. Referring toFIG. 4, the maximum depth D1into the first polymeric sheet20of the impression12C is much less than a thickness T1of the first polymeric sheet20. The maximum depth D1could range up to about one-half of the thickness T1of the first polymeric sheet20, as the innermost layer26A of the gas barrier layers26(shown inFIG. 9) would still be intact, enabling a desired maximum gas transmission rate.

The mold surface34A also has an etched area31A, which in the embodiment shown is a series of diagonal, etched grooves39A. The etched grooves39A are recessed in the mold surface34A. When the first polymeric sheet20is conformed to the mold surface34A during forming of the bladder element10, the impression12D of the etched area31A is imparted onto the outer surface40of the bladder element10. The material of the first polymeric sheet20fills the etched grooves39A of the mold half32A during forming of the bladder element10, creating the impression12D. The impression12D this is a protrusion from the first polymeric sheet20. The etched feature12A on the first polymeric sheet20at least partially aligns with the impression12D, as shown inFIGS. 1 and 14.

The mold surface34B also has an etched area31B, which in the embodiment shown is an outline of a star shape. The etched area31B is recessed in the mold surface34B. When the second polymeric sheet22is conformed to the mold surface34B during forming of the bladder element10, the impression12B of the etched area31B is imparted onto the outer surface41of the bladder element10. The material of the second polymeric sheet22fills the etched area31B of the mold half32B during forming of the bladder element10, creating the impression12B. The colored medium46on the second polymeric sheet22at least partially aligns with the impression12B, as shown inFIGS. 1 and 15.

Although the etched feature12A is shown on the outer surface40, the etched feature12A may instead be on an inner surface of the bladder element10by etching the etched feature12A on an opposite side of the first polymeric sheet20.FIG. 14also illustrates that the etched feature12A and/or the impression12D can be configured in one embodiment to be adjacent to or on the colored medium46on the first polymeric sheet20.

The bladder element10may be manufactured by first disposing the first polymeric sheet20in a mold assembly32A,32B that includes a first mold half32A ofFIGS. 7 and 8, and a second mold half32B ofFIGS. 5 and 6. The second polymeric sheet22is placed on the first polymeric sheet20. The polymeric sheets20,22are shown for purposes of illustration on the first mold half32A, although not shown in the plan view ofFIG. 8for purposes of clarity. The polymeric sheets20,22lay over the mold cavity36A ofFIG. 8when placed on the first mold half32A as shown inFIG. 7. The mold assembly32A,32B is then closed by placing the mold halves32A,32B together, with the second mold half32B on first mold half32A and the first and second polymeric sheets20,22between the mold halves32A,32B.

The first polymeric sheet20is then conformed to the mold surface34A and the second polymeric sheet22is conformed to the mold surface34B to at least partially form the bladder element10with the sealable internal cavity23. Conforming the first and second polymeric sheets20,22to the mold surfaces34A,34B may be, for example, by vacuum forming with a vacuum applied through the openings, also referred to as vacuum ports35(only some of which are indicated with the reference number) and/or by thermoforming. The first and second polymeric sheets20,22conform to the etched area37,31A, respectively, imparting impression12B onto the outer surface41of the second polymeric sheet22, and the impressions12C and12D of the etched areas37,31A onto the outer surface40of the first polymeric sheet20. The etched feature12A and impressions12C,12D are on the outer surface40of the bladder element10.

The etched feature12A may be etched on the outer surface40of the first polymeric sheet20by at least one of laser etching or mechanical etching. Laser etching can be carried out with a laser etching machine that uses a computer controlled laser. The laser moves according to a predetermined pattern and at predetermined depths pursuant to a stored software algorithm to create the etched feature12A. Mechanical etching can be accomplished using a tool head that contacts the surface40of the first polymeric sheet20to etch the etched feature12A. A mechanical etching machine can be used so that the tool head is also computer controlled to move according to a predetermined pattern and at predetermined depths pursuant to a stored software algorithm to create the etched feature12A.

With reference toFIG. 1, the first polymeric sheet20is bonded to the second polymeric sheet22to form a peripheral seam28around a periphery of the bladder element10. The peripheral seam28partially seals the internal cavity23of the bladder element10, and the internal cavity23is completely sealed once a fill tube or other filling mechanism formed with the bladder element10is plugged. The fill tube is formed at mating recesses38A,38B of the mold assembly32A,32B as described with respect toFIGS. 5-8, and is subsequently trimmed from the bladder element10after being used to inflate the internal cavity23and after being plugged. The peripheral seam28may also help the bladder element10retain its shape. The first and second polymeric sheets20,22can be bonded to one another with or without the use of an adhesive and by thermal bonding during thermoforming, compression forming, radio frequency (RF) welding in the mold assembly32A,32B as shown inFIGS. 6 and 7.

Referring toFIG. 8, to form the bladder element10in the mold assembly32A,32B, either before or after the etched feature12A is etched on the first polymeric sheet20, the first polymeric sheet20is laid on the first mold half32A, across the mold cavity portion36A so that the colored medium46shown inFIG. 13is aligned with the etched area37. The second polymeric sheet22is then placed on the first polymeric sheet20so that the colored medium46shown inFIG. 12is aligned with the impression12B. Alternatively, colored medium46could be applied after the bladder element10is formed. Both the first and the second polymeric sheets20,22are in their original, generally flat form when initially placed on the first mold half32A. After the first and second polymeric sheets20,22are placed on the first mold half32A, the mold assembly32A,32B is closed. Alternatively, if polymeric material not in the form of sheets is used, the material could be placed in the mold cavity portion36A prior to closing the mold assembly32A,32B.

A forming process is then used to shape the first and second polymeric sheets20,22to the mold halves32A,32B, such as by the use of temperature and pressure control. For example, the forming process may include any or all of thermoforming, vacuum forming, compression forming, or radio frequency (RF) welding. Vacuum ports35are shown extending through the mold halves32A,32B, and a vacuum may be applied through the ports35to pull the first and second polymeric sheets20,22against the mold surfaces34A,34B in the mold halves32A,32B. Only some of the many like vacuum ports35are numbered inFIGS. 5 and 8. The first and second polymeric sheets20,22may be heated by the mold assembly32A,32B during the forming process. Additionally, a fill tube may be formed by the first and second polymeric sheets20,22at the recesses38A,38B in the mold halves32A,32B. The recesses38A,38B mate when the mold assembly32A,32B is closed. The portion of the first and second polymeric sheets20,22surrounding the mold cavity portions36A,36B are bonded to one another by any or all of thermal bonding during thermoforming, radio frequency welding, or compression forming through pressure applied by the mold halves32A,32B or by a separate machine after removal from the mold halves32A,32B.

After the first and second polymeric sheets20,22are formed to the contours of the mold assembly32A,32B in the mold cavity portions36A,36B and, if heated, sufficiently cooled, the mold halves32A,32B are then separated, and excess material of the first and second polymeric sheets20,22around the periphery of the seam28is trimmed. The fill tube formed at the recesses38A,38B may be used to inflate the bladder element10with gas at or above ambient pressure, and then the fill tube may be plugged and trimmed so that the bladder element10is in its final, formed state.

As best shown inFIGS. 1, 9 and 14, at least the etched feature12A and a portion of the impression12D are on a curved portion60of the outer surface40of the bladder element10. The etched feature12A and the impressions12B,12C and12D are each spaced apart from the peripheral seam28on the formed bladder element10due to the initial placement of the etched areas37,31A,31B in the mold assembly32A,32B away from a perimeter66A,66B of the mold cavity portions36A,36B. The etched feature12A is etched on the first polymeric sheet20so that it is also spaced apart from the peripheral seam28.

The surface40of the bladder element10may have at least one of a predetermined level of opacity, transparency or luster achieved by treating the surface40of the bladder element10by at least one of heating or applying a softening agent. For example, with reference toFIG. 3, a first area61of the outer surface40of the bladder element10is the area both including the number one of the impression12C and within the number one. The impression12C is on the first area61. The first area61has a first predetermined level of opacity, transparency or luster. A second area63of the surface40of the bladder element10is the area surrounding and not within the impression12C, and has a second predetermined level of opacity, transparency or luster that is different than the first predetermined level, such as at least ten percent greater than or at least ten percent less than the first predetermined level of opacity, transparency or luster.

The second area63may achieve a predetermined level of opacity, transparency, or luster by heating the entire bladder element10, such as after formation and/or while in the mold assembly32A,32B. The first area61may be made more lustrous than the second area63such as by applying a softening agent only to the first area61.

The surface roughness of the mold surfaces34A,34B can also affect the opacity, transparency, and luster of the bladder element10. Alternatively, or in addition to treating the bladder element10, a region of either or both of the mold surfaces34A,34B can be polished to a predetermined surface roughness to help achieve the predetermined level of opacity, transparency or luster of the bladder element10. For example, with reference toFIG. 8, a first region84of the mold surface34A can be polished to a first average surface roughness. The first region84has a perimeter86shown in phantom. A second region88of the mold surface34A is the region outside of the perimeter86, surrounding the first region84. The second region88has a second average surface roughness that can be obtained by polishing, or can be obtained simply by the casting or machining of the mold half32A. Polishing can be by sandblasting, such as at 0.001 inch increments. The etched area37is shown with the first region84. The etched area31A is partially in the first region84and partially in the second region88. The polishing of the first region84results in a first average surface roughness of the mold surface34A in the first region84which is at least ten percent greater than or at least ten percent less than the second average surface roughness in the second region88, as may be accomplished by the material selected and used to polish the surface34A. The surface40of the bladder element10has a first area90with a perimeter92as shown inFIG. 3. The first area90corresponds with the first region84of the mold surface34A. The surface40of the bladder element10also has a second area94that corresponds with the second region88of the mold surface34A. The first area90and the second area94may differ in opacity, transparency, or luster as a result of the difference in polishing between the regions84,88. For example, the level of transparency and the level of haze may be measured as described herein, such as by using the American Society for Testing and Materials (ASTM) Standard D1003-00, Standard Test Method for Haze and Luminous Transmittance of Transparent Plastics.

With reference toFIG. 14, the bladder element10can be secured in the sole assembly16such as by bonding to a midsole70of the sole assembly16. For example, the bladder element10can be bonded with adhesive to the formed midsole70. Alternatively, the bladder element10can be placed in a midsole mold assembly (not shown), and the midsole70may be formed around the bladder element10, such as by injecting foam into the midsole mold assembly. In still other embodiments, the bladder element10is secured to the sole assembly16by an interference fit. In some embodiments, the bladder element10serves as at least a portion of a midsole, an outsole, or both. In all such embodiments, because the etched feature12A and the impressions12B,12C, and12D are spaced apart from the peripheral seam28, the bladder element10can be assembled in the article of footwear18so that the etched feature12A and the impressions12B,12C, and12D are aligned with and exposed to view through the openings in the sole assembly16and/or in a footwear upper extending over the sole assembly16, such as represented by an insole or sockliner73as described herein, while the seam28can be covered by and block from view by the article of footwear18. For example, as shown inFIG. 14, the midsole70is formed with an opening72A. The etched feature12A is positioned at the opening72A so that it is exposed at the exterior of the article of footwear18, while the seam28is covered by the midsole70and is not exposed at the opening72A. Stated differently, a first portion of the bladder element10including the etched feature12A is aligned with the opening72A and exposed to view through the opening72A (i.e., such as from a viewpoint of a side view as inFIG. 14). A second portion of the bladder element (i.e., the portion indicated with hidden lines inFIG. 14) is covered by and blocked from view by the midsole70.

In another example, as shown inFIG. 15, the sockliner73also has an opening72B and the bladder element10is secured to the sole assembly16so that the sole assembly16and the sockliner73do not cover the impression12B, and a first portion of the bladder element10with the impression12B is exposed to view through the opening72B, with the impression12B aligned with the opening72B. A second portion of the bladder element10, including the peripheral seam28, is not exposed at the opening72B, but is covered by and blocked from view at least by the sockliner73(i.e., from the viewpoint ofFIG. 15).

As is apparent inFIG. 16, the sole assembly16does not cover at least the impression12C. The sole assembly16includes an outsole76A secured to a lower surface75of the midsole70as also shown inFIG. 14. In one embodiment, the outsole76A has an opening72C that is aligned with the impression12C so that the impression12C is exposed at the exterior of the article of footwear18and may be viewed from a viewpoint looking at a bottom of the footwear18, such as when a wearer of the article of footwear18lifts a heel portion74of the article of footwear18. A second portion of the bladder element10, represented by hidden lines inFIG. 16, is covered by the outsole76A and blocked from view by the outsole76A.

The outsole76A is shown with tread elements78A having bottom surfaces that form a ground contact surface of the article of footwear18. The tread elements78A can have various alternative shapes and can be arranged in various alternative arrangements. The outsole76A shows grooves81formed in the outsole76A.

FIG. 17shows an alternative embodiment of an outsole76B secured to the midsole70ofFIG. 14and to the bladder element10. The outsole76B has at least a portion80, bounded by phantom lines, that is substantially transparent. The substantially transparent portion80is aligned with the impression12C so that the impression12C is exposed to view at an exterior of an article of footwear18A, and may be viewed, such as when a wearer lifts the heel portion74of the article of footwear18A. A remaining portion82of the outsole76B, not bounded by the phantom lines, can also be substantially transparent. In the embodiment shown, the entire outsole76B is substantially transparent. Alternatively, the remaining portion82could be opaque or not substantially transparent. The outsole76B shows grooves81formed in the outsole76B and a different arrangement of tread elements78B. The article of footwear18A has a different outsole76B than the article of footwear18, but is otherwise the same as the article of footwear18.

Referring toFIG. 18, a method100of manufacturing an article, such as the article of footwear18, is described with respect to the bladder element10ofFIGS. 1-4, the mold assembly32A,32B ofFIGS. 5-8, and the article of footwear18ofFIG. 14. The method100may begin with step102, etching any or all of the etched areas37,31A in the mold surface34A by at least one of laser etching, mechanical etching, or chemical etching. Step102may also include etching the etched area31B in the mold surface36B. Etching of the etched area37,31A, and/or31B in step102may be controlled in various ways to enable fluid retention in the internal cavity23of bladder element10. For example, step102may include sub-step104, controlling the etching of the etched area37so that the impression12C has a maximum depth D1into the first polymeric sheet20of not more than about one-half of a first thickness T1of the first polymeric sheet20, as discussed with respect toFIG. 4. In some embodiments, the first polymeric sheet20comprises a gas barrier polymer. Etching the etched area37may be controlled in sub-step104so that the gas barrier polymer is not compromised by the impression12C.

The method100may further comprise step106, polishing the first region84of the mold surface34A to a first average surface roughness, wherein the second region88of the mold surface34A has a second average surface roughness. The etched area37and/or the etched area31A is at least partially in at least one of the first region84or the second region88, as shown inFIG. 8. The first average surface roughness may be at least ten percent greater than or at least ten percent less than the second average surface roughness. The surface40of the bladder element10includes the first area90corresponding with the first region84of the mold surface34A and the second area94corresponding with the second region88of the mold surface34A, as discussed with respect toFIG. 3. Step106may occur prior to or after step102. The mold surface34B may also be polished in a similar manner.

In some embodiments, the method100may include step108, applying a colored medium46to the first polymeric sheet20, such as to create the shape of the number one and the number sign, as shown inFIG. 13, that will be aligned with the etched feature12C. The colored medium46may also be applied to the first polymeric sheet20to create a diamond pattern as shown inFIG. 13, and the etched feature12A may be etched to be adjacent to or on the colored medium46on the first polymeric sheet20. The colored medium46may also be applied to the second polymeric sheet22to create a star pattern that will be aligned with the impression12B. It is to be understood that the colored medium46could be of different colors or materials at the different areas of application on the first and second polymeric sheets20,22.

In some embodiments, the method100may include step110, etching the etched feature12A on the surface40of the first polymeric sheet20by at least one of laser etching or mechanical etching. The etched feature12A may be etched to be adjacent to or on the colored medium46on the first polymeric sheet20. Step102, including sub-step104, step106, step108, and step110can be performed in any order. In some embodiments of the method100, the first and second polymeric sheets20,22may be obtained with the colored medium46already applied thereon, or with the etched feature12A already etched thereon, in which case steps108and110are not performed. In still other embodiments, steps108and/or110may be performed after the bladder element10is formed, i.e., after step132.

The method100further comprises step112, disposing a first polymeric sheet20in a mold assembly32A,32B. The first polymeric sheet20may be disposed in the mold assembly32A,32B so that the surface40of the first polymeric sheet20with the etched feature12A will be on one of an inner surface or an outer surface of the bladder element10. In the embodiment shown, the surface40is an outer surface of the bladder element10. In an embodiment in which a colored medium46is applied to the first polymeric sheet in step108, disposing the first polymeric sheet20in step112may include sub-step114, aligning the colored medium46with the etched area31A so that the impression12C will be on or adjacent to the colored medium46. Similarly, the colored medium46on the second polymeric sheet22can be aligned with the etched area31B so that the impression12B will be on or adjacent to the colored medium46.

In an embodiment in which the mold assembly32A,32B includes a mold surface34A with an etched area31A, the method100also includes step116, aligning the etched feature12A with the etched area31A so that the impression12D of the etched area31A will be adjacent to or on the etched feature12A, as shown inFIGS. 1, 2 and 14.

After disposing the polymeric material in the mold assembly32A,32B, the method100further comprises step118, conforming the polymeric material to the mold surfaces34A and34B to form a bladder element10with a sealable internal cavity23. Conforming the polymeric material, such as the first polymeric sheet20, to the mold surface34A imparts the impression12C of the etched area37and the impression12D of the etched area31A onto the surface40of the bladder element10. Conforming the polymeric material, such as the second polymeric sheet22, to the mold surface34B imparts the impression12B of the etched area31B onto the surface41of the second polymeric sheet22. Conforming the polymeric material, such as the first and second polymeric sheets20,22to the mold surface34A and the mold surface34B may be by any or all of blow molding in sub-step120, compression forming in sub-step122, vacuum forming in sub-step124, or thermoforming in sub-step126. In other words some or all of the sub-steps120,122,124, and126may be performed. For example, if the polymeric material is in other than sheet form, blow molding may be used.

The method100may further comprise step128, forming a peripheral seam28in the bladder element10that at least partially seals the internal cavity23. Forming the peripheral seam28in step128may be by compression forming the first polymeric sheet20to the second polymeric sheet22, such as during step122while the sheet20is conformed to the mold surface34A, by radio frequency (RF) welding, and/or by the use of adhesives. Forming the bladder element10in step128is accomplished so that the first and second polymeric sheets20,22are bonded at the peripheral seam28, at least a portion of the etched feature12A and the impressions12B,12C and12D are spaced apart from the peripheral seam28. Additionally, disposing the first polymeric sheet20in the mold assembly32A,32B may be so that the etched feature12A and a portion of the impression12D is at least partially on a curved portion60of the bladder element10corresponding to a curved portion45of the mold surface34A indicated inFIG. 8. In other words, in step108, the first polymeric sheet20is disposed on the first mold surface34A, so that the etched feature12A and a portion of the impression12D will be on the curved portion60of the bladder element10when the bladder element10is formed.

The method100may further comprise step130, inflating the bladder element10by filling the sealable internal cavity23with a fluid, and then sealing the sealable internal cavity23in step132so that the fluid is retained in the sealable internal cavity23. In one embodiment, the fluid is a gas at or above ambient pressure. The bladder element10may have a gas transmission rate for nitrogen of less than 10 cubic centimeters per square meter per atmosphere per day, or of less than 1 cubic centimeter per square meter per atmosphere per day.

In one embodiment, a substantially transparent topcoat15may be secured over the impression12B in step134, such as to protect the impression12B from abrasion. Although described with respect to the impression12B, the topcoat15may be secured over any or all of the impressions12B,12C, or12D and/or over the etched feature12A.

The method100may further comprise step136, treating the surface40and/or41of the bladder element10to achieve at least one of a predetermined level of opacity, transparency, or luster of the bladder element10. This treatment may occur after conforming the first polymeric sheet20to the mold surface34A and the second polymeric sheet22to the mold surface34B to at least partially form the bladder element10. For example, treating the surface40,41of the bladder element10may be by at least one of heating the surface40,41of the bladder element10, such as while the bladder element is in the mold assembly32A,32B, or by applying a softening agent to the surface40,41of the bladder element10. As previously discussed, in some embodiments, the first area61of the surface40of the bladder element10may be treated to achieve a first predetermined level of opacity, transparency, or luster. The second area63of the surface40of the bladder element10may have 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. The impression12C is on the first area61of the surface40of the bladder element10, and the impression12D is on both the first area61and the second area63of the surface40of the bladder element10. The surface41of the second polymeric sheet22of the bladder element10could be treated in a similar manner to achieve at least one of a predetermined level of opacity, transparency, or luster of a first area90of the surface41that is different than a second predetermined level of opacity, transparency of luster of a second area94of the surface41, with the impression12B in one of the first area90or the second area94of the surface41.

After any cooling period that may be provided, the mold assembly32A,32B is opened, and the bladder element10is removed from the mold assembly32A,32B. The bladder element10with the etched feature12A and the impressions12B,12C, and12D is now complete. Optionally, if the same entity carrying out steps102-136also assembles the bladder element10in an article such as the article of footwear18, then the method100can proceed with steps138,140and142. In step138, the fluid-filled bladder element10is assembled in the sole assembly16of the article of footwear18. Assembling the bladder element10in the article of footwear18may include sub-step140, securing the bladder element10to the midsole70. In various embodiments, securing the bladder element10to the midsole70can be accomplished with adhesive or by forming the midsole70around the bladder element10in a midsole mold assembly (not shown). In all such embodiments, the bladder element10may be assembled in the article of footwear18so that the peripheral seam28and the second portion of the bladder element10are covered by and blocked from view by the article of footwear18, and the impressions12B,12C, and12D, as well as etched feature12A, if included, are exposed to view through openings such as opening72A in the midsole70and opening72B in the sockliner73, as described with respect to the embodiment ofFIGS. 9 and 14. In other words, the etched feature12A and a portion of the impression12D are aligned with the opening72A so that the etched feature12A and impression12D are exposed to view and can be viewed through the opening72A from an exterior of the article of footwear18. Similarly, the impression12B is aligned with the opening72B so that the impression12B is exposed to view and can be viewed through the opening72B from an exterior of the article of footwear18.

Next, in step142, an outsole can be secured to the midsole70. If outsole76A ofFIG. 16is used, the opening72C is aligned with the impression12C and with a portion of impression12D. The impression12B can also be viewed through the substantially transparent bladder element10at the opening72C. If outsole76B ofFIG. 17is used, the substantially transparent portion80of the outsole76B is aligned with the impression12C and with a portion of the impression12D so that the impressions12C,12D are exposed to view through the substantially transparent portion of the outsole76B. As discussed above, the entire outsole76B may be substantially transparent.

While several modes for carrying out the many aspects of the present teachings have been described in detail, those familiar with the art to which these teachings relate will recognize various alternative aspects for practicing the present teachings that are within the scope of the appended claims. It is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative only and not as limiting.