Co-molded Flex Modifier Footwear Sole Structure

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Solution Overview

Problem

Current footwear sole structures lack customization and efficiency in providing tailored rigidity and flex characteristics for different athletic and non-athletic applications, leading to suboptimal performance and comfort.

Innovation Solution

Incorporating a co-molded flex modifier component made of fiber material and mold-compatible polymer within the outer sole component, allowing for selective modification of flex characteristics at specific locations, such as an elongated shank extending through the midfoot region, to enhance performance and customization.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a uniform sole structure is used throughout the footwear, then manufacturing is simple and cost-effective, but the footwear cannot provide customized rigidity and flex characteristics for different athletic applications

Engineering Contradiction:
Improvecustomization of rigidity and flex characteristicsVSAvoidsole structure complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The sole structure is divided into multiple components: an outer sole component and a separate flex modifier component. This segmentation allows each component to have specialized functions - the outer sole provides structural support while the flex modifier component selectively modifies rigidity and flex characteristics in specific regions, enabling customization without requiring complete redesign of the entire sole structure.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The flex modifier component is designed to provide localized modification of sole properties. By positioning this component at specific locations (such as the midfoot region), the footwear can have different rigidity and flex characteristics in different areas, allowing customization for specific athletic applications while maintaining simplicity in other regions.

Inventive Principle:
Principle #3Local quality

2Adaptability or versatility

If multiple separate components are added to customize sole characteristics, then performance customization is achieved, but manufacturing complexity and cost increase

Engineering Contradiction:
Improveperformance customizationVSAvoidmanufacturing efficiency
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The flex modifier component is co-molded with the outer sole component in a single integrated manufacturing process. This combining of components that would traditionally require separate assembly steps allows performance customization through design variations in the mold rather than through complex assembly operations, maintaining manufacturing efficiency while achieving customization.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The co-molding process serves multiple functions simultaneously: it creates the outer sole structure, integrates the flex modifier component, and establishes the mechanical bond between them in a single operation. This multi-functionality in the manufacturing process achieves performance customization without proportionally increasing manufacturing complexity or cost.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Strength

If traditional bonding methods are used to attach sole components, then assembly is straightforward, but the bond strength and durability are insufficient for high-performance athletic footwear

Engineering Contradiction:
Improvebond strength between sole componentsVSAvoidbonding process complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The bonding function is extracted from the assembly process and integrated into the molding process itself. Rather than attaching components through separate bonding operations, the flex modifier component is co-molded with the outer sole, creating an integral structure where the bond strength is inherent to the molded joint rather than dependent on external bonding agents or processes.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

Traditional mechanical or chemical bonding systems are replaced with a molded joint system. The co-molding process creates a mechanically integrated connection between the outer sole and flex modifier component, where the bond strength derives from the molded material flow and interlocking geometry rather than from adhesives, stitches, or other external bonding mechanisms.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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

This solution provides improved rigidity and flex characteristics, enabling smooth motion and reduced buckling, while facilitating efficient and cost-effective manufacturing of footwear with player- or position-specific performance enhancements.

Implementation Method 1

a fiber-reinforced cover layer is fusion bonded with the inner surface of the sole body

Methodology Applied
Scientific EffectFusion bonding:

Data Source

PatentEP3402359B1Sole structure for an article of footwear, comprising an outer sole component with a co-molded flex modifier component, and method of making said sole structure
Publication Date: 2021.05.12 NIKE INNOVATE CV
  • EP3402359B1 patent drawingFigure 1
  • EP3402359B1 patent drawingFigure 2
  • EP3402359B1 patent drawingFigure 3~5

AI summary

A sole structure (103) for an article of footwear (100) includes an outer sole component (106) with a co-molded flex modifier component (208). The outer sole component is formed of a first mold material, such as a rubber mold material. The flex modifier component includes a fiber material and a second mold material. The second mold material may be mold compatible with the first mold material. The sole structure may be formed by co-molding an outer sole component blank or pre-form (620, 621) (e.g., rubber mold material), and a flex modifier component, e.g., in a hot press molding process using a molding system having a mold cavity (606, 607) configured to form the outer sole component. The flex modifier component may be formed (e.g., cut or stamped) from a sheet of flex modifier material (301), such as a thermoplastic extruded hot melt film sandwiched between fusion bonded non-woven fiber fabric material impregnated with a styrene-coated polymer.