Fluid-Filled Bladder Tessellation for Footwear Midsole
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional polymer foam midsoles in athletic footwear lose compressibility and force attenuation characteristics over time due to cell structure deterioration from repeated compressions, leading to decreased performance.
Innovation Solution
A fluid-filled bladder with a tessellation configuration is integrated into the midsole, formed by bonding thermoplastic polymer sheets in a mold, minimizing waste and energy consumption, and featuring a sealed, impermeable structure with a pressurized fluid to maintain cushioning effectiveness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If polymer foam midsole is used to provide force attenuation, then initial cushioning performance is achieved, but compressibility and force attenuation characteristics deteriorate over time due to cell structure deterioration
Solution Approach 1:
The patent replaces the solid polymer foam material with a fluid-filled bladder system. The bladder is filled with fluid (such as water or other suitable fluids) that provides force attenuation through hydraulic compression. This fluid-filled structure maintains consistent cushioning performance over time because the fluid does not undergo the same cellular deterioration that occurs in foam materials, thereby resolving the contradiction between initial performance and long-term durability
Solution Approach 2:
The invention changes the physical state of the cushioning medium from solid foam to fluid. By transitioning from a compressible solid structure with cells to an incompressible or nearly incompressible fluid, the system maintains stable mechanical properties over time. The fluid's inability to undergo structural collapse or cell deterioration ensures consistent force attenuation characteristics throughout the product's service life
2Ease of manufacture
If conventional two-film bonding technique is used to manufacture bladder, then bladder structure is formed, but significant material waste and energy consumption occur
Solution Approach 1:
The patent employs a single sheet of flexible material that is thermally formed into the three-dimensional bladder shape. This thermal forming process creates the complete bladder structure from one continuous piece of material, eliminating the need for cutting, bonding, or assembling multiple separate films. The process minimizes material waste by utilizing nearly 100% of the original sheet and reduces energy consumption by eliminating multiple heating and bonding cycles required in conventional two-film techniques
3Ease of manufacture
If conventional two-film bonding technique is used to manufacture bladder, then bladder structure is formed, but multiple heating and bonding cycles increase energy consumption
Solution Approach 1:
The invention performs the entire bladder formation process in a single thermal forming operation rather than through multiple sequential steps. The single sheet of material is heated once and molded into the final three-dimensional shape in one continuous process. This preliminary action approach eliminates the need for subsequent heating and bonding cycles, significantly reducing total energy consumption while maintaining manufacturing efficiency
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The fluid-filled bladder maintains consistent cushioning and force attenuation, reducing material waste and energy usage in manufacturing, while extending the lifespan of footwear by preserving midsole performance.
Implementation Method 1
a fluid-filled bladder with a tessellation configuration integrated into a midsole of footwear. The bladder is devoid of internal connections and is filled with a pressurized fluid
Implementation Method 2
formed by bonding thermoplastic polymer sheets in a mold
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A fluid-filled structure, such as a bladder (40) , is disclosed. The bladder has a first surface (41) and an opposite second surface (42) that are peripherally joined (43) to define various edges (51-56) . The bladder encloses a fluid between the first surface and the second surface. A portion of the edges may have a concave configuration, or the edges may have both concave and convex configurations . A shape, of the bladder may be a tessellation pattern such as a hexagon so that a plurality of the bladder may be efficiently manufactured.