Tire Casing Conductive Wire Joule Heating Retreading

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Solution Overview

Problem

The existing retreading methods face challenges in efficiently heating and pressurizing the hot-melt bonding layer during tire retreading, which can lead to inadequate adhesion and increased processing time.

Innovation Solution

Incorporating an electrically conductive wire inside the tire casing to heat the bonding layer through the Joule effect, combined with a reinforcing ply and inflation to apply pressure, facilitating the adhesion process while minimizing overheating and ensuring robust mechanical reinforcement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If conventional heating methods (infrared, forced convection, contact conduction) are used to heat the bonding layer, then the bonding layer can be heated to the required temperature, but the heating process is time-consuming and requires complex heating equipment that may harm the conduction or convection of heat flow

Engineering Contradiction:

Improvebonding layer temperatureVSAvoidheating time

Core Design Contradiction:

TemperatureVSLoss of time

Solution Approach 1:

The patent replaces conventional mechanical heating systems (infrared heaters, forced convection equipment, contact conduction devices) with an electrical heating system using resistive heating elements embedded in or near the bonding layer. This substitution eliminates the need for complex external heating equipment and significantly reduces heating time by directly generating heat within the bonding layer itself through electrical resistance.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Strength

If pressure is applied to the tread during heating to press the bonding layer between the tread and carcass, then adhesion is improved, but the pressure equipment must be compatible with the heating means and cannot harm heat conduction or convection

Engineering Contradiction:

Improveadhesion strengthVSAvoidpressure equipment compatibility

Core Design Contradiction:

StrengthVSDevice complexity

Solution Approach 1:

The patent merges the heating function and pressure application function into a single integrated process. The electrical heating elements are positioned to work in conjunction with the pressure application system, allowing simultaneous heating and pressing without requiring separate, incompatible equipment. The electrical heating system does not interfere with pressure application, eliminating the compatibility constraints of conventional heating methods.

Inventive Principle:

Principle #5Merging (Combining)

3Temperature

If the bonding layer is heated to high temperatures for extended periods, then the thermofusible material softens adequately for bonding, but this may cause overcooking or unwanted annealing of the rubber in the envelope

Engineering Contradiction:

Improvebonding layer temperatureVSAvoidrubber degradation

Core Design Contradiction:

TemperatureVSObject-affected harmful factors

Solution Approach 1:

The patent applies local quality by positioning heating elements specifically within or adjacent to the bonding layer, concentrating thermal energy exactly where needed for thermofusible material softening. This localized heating approach allows the bonding layer to reach required temperatures while the surrounding rubber envelope remains at lower temperatures, preventing overcooking and unwanted annealing of the rubber components.

Inventive Principle:

Principle #3Local quality

4Strength

If a reinforcing ply is added to the casing to prevent failure during rolling, then mechanical strength is improved, but the device complexity and manufacturing cost increase

Engineering Contradiction:

Improvecasing mechanical strengthVSAvoidcasing structure

Core Design Contradiction:

StrengthVSDevice complexity

Solution Approach 1:

The patent applies multi-functionality by designing the bonding layer to serve dual purposes: (1) providing thermal activation for adhesion through thermofusible material softening, and (2) providing mechanical reinforcement during rolling and operation. This eliminates the need for a separate reinforcing ply, as the bonding layer itself becomes structurally integral to the tire casing, reducing overall device complexity while maintaining strength.

Inventive Principle:

Principle #6Universality (Multi-functionality)

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 method enables efficient heating and pressurization of the bonding layer, reducing processing time and ensuring strong adhesion between the tread and carcass, while also providing mechanical reinforcement during rolling.

Implementation Method 1

the wire allows heating by Joule effect of the bonding layer with a view to retreading the casing

Methodology Applied

Scientific EffectJoule effect: Joule Heating

Implementation Method 2

the carcass is inflated. Thus, the inflation of the carcass leads to an increase in its volume. The carcass and the tread firmly press the binding layer together

Methodology Applied

Scientific EffectPressure application through inflation: Pressure Increase

Data Source

PatentEP3086931B1Methods for manufacturing and retreading tire and tire casings.

Publication Date: 2019.05.01 MICHELIN & CO (CIE GEN DES ESTAB MICHELIN)

Figure 1~3
Figure 4

AI summary

In a method for manufacturing a tyre casing (2), at least one electrically conducting wire (12), forming turns centred on a main axis (8) of the casing, and a connecting layer (10) are incorporated into the casing.