A sole structure for an article of footwear comprises a midsole system with a plurality of cushioning units, each having multiple cushioning layers configured to work together as a system to absorb a compressive load, such as a dynamic compressive load due to impact with the ground, in stages of progressive cushioning according to the relative stiffness values of the layers. Various midsole systems disclosed include isolated cushioning units, linked cushioning units, sole layers having stanchions interfacing with the midsole system, midsole systems with sole layers having keyed and unkeyed portions overlying a bladder, and midsole systems with vertically-stacked cushioning units disposed in inverted relationship to one another.

Expandable thermoplastic polyurethane comprising blowing agent, wherein the Shore hardness of the thermoplastic polyurethane is from A 44 to A 84.

Expandable thermoplastic polyurethane comprising blowing agent, wherein the Shore hardness of the thermoplastic polyurethane is from A 44 to A 84.

Expandable thermoplastic polyurethane comprising blowing agent, wherein the Shore hardness of the thermoplastic polyurethane is from A 44 to A 84.

Expandable thermoplastic polyurethane comprising blowing agent, wherein the Shore hardness of the thermoplastic polyurethane is from A 44 to A 84.

Expandable thermoplastic polyurethane comprising blowing agent, wherein the Shore hardness of the thermoplastic polyurethane is from A 44 to A 84.

Presented are footwear sole structures with foot-cushioning insoles movably mounted onto impact-attenuating midsoles, methods for making/using such sole structures, and footwear fabricated with such sole structures. A multilayered sole structure assembly includes an insole movably mounted on a midsole. The midsole is formed with a first compressible material and includes opposing upper and lower midsole surfaces, multiple protrusions projecting from the upper midsole surface, and multiple pockets recessed into the upper midsole surface and interleaved with the midsole protrusions. The insole, which is formed with a second compressible material distinct from the first compressible material, includes opposing upper and lower insole surfaces, multiple protrusions projecting from the lower insole surface and interleaved with the midsole protrusions, and multiple pockets recessed into the lower insole surface and interleaved with the insole protrusions. Each midsole protrusion nests within a respective insole pocket, while each insole protrusion nests within a respective midsole pocket.

A method of forming a fluid-filled chamber for an article of footwear is provided and includes positioning a first sheet of material and a second sheet of material in a pressure chamber, increasing a fluid pressure within the pressure chamber to a first value, and coupling the first sheet of material to the second sheet of material within the pressure chamber to define a fluid-filled chamber defined by the first sheet of material and the second sheet of material and having a fluid pressure equal to the first value. The method also includes decreasing the fluid pressure within the pressure chamber to a second value.

An injection-molding process for injecting a shoe soling including at least two adjacent injection-molding layers onto a shoe upper drawn over a shoe last, uses a mold cavity including a frame, the cavity being covered at the top by the upper also serving as a mold cover, with plastic material being injected into the cavity below the upper. To produce two adjacent injection-molding layers of plastic materials having different properties and reaction times in one operation, i.e. without needing an interim mold opening, before covering the cavity a film is clamped over it by a clamp mounted on the frame. When filling the cavity, the space below the film is first filled with plastic material to produce the first injection-molding layer and then, to produce the adjacent second injection-molding layer, the space above the film is filled with plastic material. Plastic materials are used that inseparably attach to the film.