Foamed Sole Components With Uniform SCF Expansion and Bonding
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Solution Overview
Problem
Existing methods using supercritical fluid (SCF) expansion for three-dimensional foaming materials result in varying degrees of hardness, density, and resilience, leading to non-uniform expansion and bonding issues in sole components, which are not adequately addressed in prior art.
Innovation Solution
A method involving pre-expanded polymer materials with or without apertures, subjected to three-dimensional SCF expansion, followed by fusion with other components through post-compression molding to achieve uniform expansion and improved bonding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If traditional blowing agents are used in foaming processes, then foam production is achieved, but environmental harm and ozone depletion occur
Solution Approach 1:
The patent replaces traditional harmful blowing agents with supercritical carbon dioxide, an inert gas that does not deplete ozone or harm the environment. The process uses CO2 in its supercritical state to achieve foaming while eliminating the environmental damage associated with conventional blowing agents like CFCs and HCFCs.
Solution Approach 2:
The patent changes the physical state and parameters of carbon dioxide to supercritical conditions (temperature and pressure above critical point) to enable it to function as an effective blowing agent. This parameter change allows CO2 to achieve the necessary density and solubility for foam formation while maintaining environmental benefits.
2Weight of moving object
If SCF expansion is used for three-dimensional foaming, then weight reduction and material savings are achieved, but non-uniform expansion and varying hardness/density/resilience occur
Solution Approach 1:
The patent applies a preliminary expansion step before the final SCF expansion. The pre-expanded polymer material serves as a foundation that ensures more uniform subsequent expansion. This two-stage approach prevents the non-uniform expansion problems that occur with direct three-dimensional SCF foaming.
Solution Approach 2:
The patent introduces apertures at specific locations within the polymer material to control and uniformize the expansion process. These apertures act as nucleation sites that ensure consistent cell formation and expansion throughout the material, creating uniform hardness, density, and resilience properties in different regions.
3Manufacturing precision
If apertures are added to pre-expanded polymer material, then uniform SCF expansion is achieved, but additional processing steps are required
Solution Approach 1:
The apertures are created during the preliminary expansion step rather than as a separate operation. The pre-expansion process itself generates the aperture structure that will guide uniform SCF expansion, combining what would otherwise be separate steps into one integrated operation.
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 method ensures consistent hardness, density, and resilience in sole components, enhancing bonding and producing composite soles with optimized properties for specific footwear types.
Implementation Method 1
subjected to three-dimensional SCF expansion
Implementation Method 2
three-dimensional foaming materials
Implementation Method 3
fusion with other components through post-compression molding
Data Source
AI summary
A sole structure for articles of footwear and a method of manufacturing them comprising at least one polymeric foamed component expanded through supercritical fluid (SCF) expansion of a shaped pre-expanded polymeric material. The polymeric foamed component may include apertures situated and fashioned in the formation of the pre-expanded polymeric material to promote uniform expansion and optimal curing conditions during the SCF expansion process. At least one polymeric foamed component having one set of physical properties that may be bound to or assembled in conjunction with one or more sole components having the same or another set of physical properties.