Tyre-Curing Membrane With Variable-Depth Air Drainage Channels

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Solution Overview

Problem

Current tire baking membranes face issues with air pocket formation due to trapped air between the membrane and the tire blank, leading to defects, reduced performance, and shortened membrane lifespan due to deep channels needed for effective drainage.

Innovation Solution

A baking membrane with a network of channels on its external surface, where channel depth increases towards the evacuation zone, allowing for efficient air drainage and reducing saturation, while maintaining membrane strength by placing deeper channels near the evacuation zone, and incorporating undercuts to facilitate demolding and reduce rubber penetration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If deep channels are used for air drainage, then air evacuation efficiency is improved, but membrane strength and lifespan are reduced

Engineering Contradiction:
Improveair evacuation efficiencyVSAvoidmembrane strength
Core Design Contradiction:
ProductivityVSStrength

Solution Approach 1:

The channel depth varies locally along the drainage path, being shallower near the tire blank contact area and progressively deeper toward the evacuation zone. This local variation in channel depth allows effective air evacuation while preserving membrane strength in critical areas, resolving the contradiction between drainage efficiency and structural integrity.

Inventive Principle:
Principle #3Local quality

2Productivity

If deep channels are used for air drainage, then air evacuation efficiency is improved, but membrane lifespan is reduced

Engineering Contradiction:
Improveair evacuation efficiencyVSAvoidmembrane lifespan
Core Design Contradiction:
ProductivityVSDuration of action of stationary object

Solution Approach 1:

The progressive depth variation of channels along the drainage path reduces overall membrane weakening while maintaining effective air evacuation. The shallower channels in high-stress areas preserve membrane lifespan, while the deeper channels toward the evacuation zone ensure complete air removal, thus resolving the contradiction between productivity and duration of action.

Inventive Principle:
Principle #3Local quality

3Use of energy by moving object

If the membrane thickness is reduced to improve heat transmission, then heat transfer efficiency is improved, but membrane strength is reduced

Engineering Contradiction:
Improveheat transfer efficiencyVSAvoidmembrane strength
Core Design Contradiction:
Use of energy by moving objectVSStrength

Solution Approach 1:

The variable channel depth design allows the membrane to maintain uniform thin thickness for optimal heat transmission while compensating for strength losses through strategic channel depth variation. The shallower channels in load-bearing areas preserve structural integrity, enabling thin-membrane design without sacrificing strength.

Inventive Principle:
Principle #3Local quality

4Productivity

If channels are arranged densely to improve air drainage coverage, then air evacuation effectiveness is improved, but membrane structure is weakened

Engineering Contradiction:
Improveair drainage coverageVSAvoidmembrane structural integrity
Core Design Contradiction:
ProductivityVSStrength

Solution Approach 1:

The channel network density and depth are optimized locally, with shallower channels providing adequate drainage coverage in high-stress regions and deeper channels providing enhanced evacuation capacity in lower-stress regions. This local optimization achieves comprehensive air drainage without excessive structural weakening.

Inventive Principle:
Principle #3Local quality

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 membrane effectively evacuates air pockets, improving tire quality and extending its lifespan by maintaining membrane strength and preventing clogging, ensuring faster and more efficient air drainage without weakening the membrane.

Implementation Method 1

The fluid under pressure is also a heat transfer, so that the blank is cooked by the calories transmitted by the fluid through the membrane

Methodology Applied
Scientific EffectHeat transfer: Conduction (thermal)

Implementation Method 2

the flexible wall of the membrane is deployed against the blank, by inflation using a pressurized fluid

Methodology Applied
Scientific EffectPressure: Pressure Increase

Data Source

PatentEP4058279B1Tyre-curing membrane equipped with a drainage structure
Publication Date: 2023.09.06 MICHELIN & CO (CIE GEN DES ESTAB MICHELIN)
  • EP4058279B1 patent drawingFigure 1~2
  • EP4058279B1 patent drawingFigure 3~5
  • EP4058279B1 patent drawingFigure 6

AI summary

Tyre curing membrane (7) having a shape exhibiting symmetry of revolution with a central axis and comprising a flexible wall made of crosslinked rubber, the external surface (20) of said wall comprising an air drainage zone (21), and an air removal zone (22) adjacent to said drainage zone, the membrane (7) being equipped with an air drainage structure comprising elements recessed into said external surface, said recessed elements forming a network of channels (30) extending in the air drainage zone (21) and as far as the air removal zone (22). According to the invention, the depth of a channel (30) of said network, defining the shortest path (31) connecting any arbitrary point of said network of channels, which point is situated in the air drainage zone (21) and the air removal zone (22), increases along the length of said path.