Electromagnetic Mold Heating for Homogeneous Shoe Sole Molding

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Solution Overview

Problem

Conventional molds for steam chest molding shoe soles require high energy for heating, have slow cooling processes, and struggle with uniform steam distribution, leading to inefficient manufacturing of shoe soles from expanded thermoplastic polyurethane particles.

Innovation Solution

A mold comprising a mixture of polymer material and filler material, adapted for heating via an electromagnetic field, which enhances thermal conductivity and permittivity, allowing for homogeneous energy distribution and faster heating/cooling processes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If conventional molds with high mass are used for steam chest molding, then heating is achieved, but energy consumption increases and cooling becomes slow

Engineering Contradiction:
Improvemold heating capabilityVSAvoidenergy consumption
Core Design Contradiction:
TemperatureVSUse of energy by moving object

Solution Approach 1:

The patent replaces the conventional steam-based thermal conduction heating system with an electromagnetic field-based heating system. The mold contains electromagnetic field-generating elements (such as coils or capacitors) that directly generate electromagnetic fields to heat the shoe sole particles, eliminating the need for external steam supply and reducing the mold's thermal mass requirements.

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

Solution Approach 2:

The patent changes the heating mechanism from thermal conduction (steam) to electromagnetic induction or dielectric heating. This parameter change allows for faster heating rates and better energy efficiency, as electromagnetic fields can penetrate and heat the material volumetrically rather than through surface conduction, thereby reducing the energy required and accelerating the heating process.

Inventive Principle:
Principle #35Parameter changes

2Stability of the object's composition

If conventional molds with high mass are used, then structural stability is maintained, but cooling process becomes slow extending cycle times

Engineering Contradiction:
Improvemold structural stabilityVSAvoidcooling cycle time
Core Design Contradiction:
Stability of the object's compositionVSLoss of time

Solution Approach 1:

The patent divides the mold into multiple sections or zones, each equipped with independent electromagnetic field-generating elements. This segmentation allows different regions of the mold to be cooled or heated independently and at different rates, enabling faster overall cycle times while maintaining structural integrity through the modular design.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent employs dynamically controllable electromagnetic field generation, where the heating and cooling processes can be adjusted in real-time based on the material's state and process requirements. This dynamic control allows for optimized heating rates during molding and rapid cooling rates during demolding, reducing cycle times while maintaining mold stability.

Inventive Principle:
Principle #15Dynamics

3Strength

If pressurized steam is used for heating, then particle fusion is achieved, but uniform energy distribution is difficult to accomplish

Engineering Contradiction:
Improveparticle interconnectionVSAvoidhomogeneity of molding
Core Design Contradiction:
StrengthVSManufacturing precision

Solution Approach 1:

The patent replaces the mechanical steam injection system with an electromagnetic field system that distributes energy uniformly throughout the material volume. The electromagnetic fields penetrate the particles evenly, ensuring consistent heating and fusion across the entire shoe sole, thereby improving manufacturing precision and homogeneity.

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

Solution Approach 2:

The patent changes the energy delivery mechanism from localized steam contact to volumetric electromagnetic field penetration. This parameter change ensures that energy is distributed uniformly throughout the particle mass, achieving homogeneous heating and fusion without the hot spots or cold zones that occur with steam chest molding.

Inventive Principle:
Principle #35Parameter changes

4Productivity

If the mold material is adapted for electromagnetic field heating, then heating efficiency improves, but traditional steam chest molding capability is lost

Engineering Contradiction:
Improveheating efficiencyVSAvoidmolding process flexibility
Core Design Contradiction:
ProductivityVSAdaptability or versatility

Solution Approach 1:

The patent designs the mold with multi-functional capabilities by integrating both electromagnetic field-generating elements and retaining the basic steam chest structure. This allows the mold to operate in multiple modes: electromagnetic field heating for high-efficiency applications, traditional steam chest molding for compatibility with existing processes, or a combination of both, thereby maintaining versatility while improving productivity.

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

Solution Approach 2:

The patent employs composite mold construction that combines materials optimized for electromagnetic field generation (such as conductive or dielectric materials) with traditional mold materials. This composite structure enables the mold to function effectively with electromagnetic heating while maintaining the structural properties and adaptability needed for various molding applications.

Inventive Principle:
Principle #40Composite materials

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 mold achieves efficient, homogeneous molding with reduced cycle times and improved quality of shoe soles, particularly midsoles, by optimizing energy distribution and thermal management.

Implementation Method 1

the filler material is adapted to allow a heating of the component inside the mold by means of an electromagnetic field

Methodology Applied
Scientific EffectElectromagnetic field heating: Dielectric Heating

Implementation Method 2

The electromagnetic radiation may be chosen such that it permeates the mold loaded with the material for the piece of sports apparel essentially homogeneously and supplies an essentially constant amount of energy to all portions of the piece of sports apparel

Methodology Applied
Scientific EffectElectromagnetic radiation energy supply: Electromagnetic Induction

Data Source

PatentEP4631706A1Mold and method for manufacturing a shoe sole by molding
Publication Date: 2025.10.15 ADIDAS AG
  • EP4631706A1 patent drawingFigure 1
  • EP4631706A1 patent drawingFigure 2a~2b
  • EP4631706A1 patent drawingFigure 2c~2d

AI summary

The present invention relates to a mold for molding a component, in particular a piece of sports apparel, a method for manufacturing the component using such a mold and a shoe with such a component. In one embodiment, a mold (100) for molding a component (120), in particular a piece of sports apparel (120), comprises: (a.) a mixture of a polymer material and a filler material, (b.) wherein the polymer material comprises a foamed material, and (c.) wherein the filler material is adapted to allow a heating of the component inside the mold (100) by means of an electromagnetic field.