Tyre Tread Composition for Low Heat and Crown Endurance

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Solution Overview

Problem

Current heavy-duty tires face challenges in maintaining endurance and wear resistance, especially under high-speed and long-distance conditions, due to temperature-related issues and shear constraints, which lead to premature degradation and reduced lifespan.

Innovation Solution

A tire design with a radial carcass reinforcement featuring a summit frame with a circumferential reinforcement layer made of polymerian mixture having low thermal conductivity and a styrene-butadiene copolymer matrix with a glass transition temperature between -65°C and -30°C, combined with a high proportion of inorganic reinforcing load, such as silica, to enhance wear resistance and rolling performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of substance

If conventional heavy-duty tires are used for high-speed and long-distance travel, then the tread wear decreases, but the endurance of the crown reinforcement deteriorates due to temperature rise and shear constraints

Engineering Contradiction:
Improvetread wearVSAvoidendurance of crown reinforcement
Core Design Contradiction:
Loss of substanceVSReliability

Solution Approach 1:

The patent applies local quality by implementing a triangulation ply specifically in the crown area where shear constraints and temperature rise are most severe. This additional reinforcement layer is strategically positioned to provide localized structural support and heat management where needed most, rather than uniformly reinforcing the entire tire structure.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent employs composite materials by combining the triangulation ply made of metal wires or cables with the existing crown reinforcement layers and rubber compounds. This multi-material approach creates a composite structure that leverages the high strength and thermal stability of metal elements alongside the elastic properties of rubber, thereby improving overall endurance while managing thermal and mechanical stresses.

Inventive Principle:
Principle #40Composite materials

2Reliability

If the crown reinforcement is strengthened to improve endurance, then the reliability increases, but the rolling resistance increases

Engineering Contradiction:
Improveendurance of crown reinforcementVSAvoidrolling resistance
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The patent applies parameter changes by carefully selecting the orientation angles of the triangulation ply wires (between 45° and 90° with the circumferential direction) and controlling the density and distribution of reinforcing elements. These parameter optimizations allow the structure to provide necessary strength while minimizing deformation under load, thereby reducing rolling resistance despite the enhanced reinforcement.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If additional reinforcement layers are added to improve endurance, then the reliability increases, but the device complexity increases

Engineering Contradiction:
Improveendurance of crown reinforcementVSAvoidstructure of crown reinforcement
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies segmentation by dividing the crown reinforcement into distinct functional layers: the existing working plies for primary structural support, and the additional triangulation ply specifically targeted at managing shear constraints and thermal effects. This segmented approach allows each layer to perform its specialized function efficiently, improving endurance while maintaining a manageable structural organization.

Inventive Principle:
Principle #1Segmentation

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 tire exhibits improved wear resistance, endurance, and rolling resistance performance, allowing for increased driving distance before needing replacement, while maintaining satisfactory thermal management and reducing the risk of premature degradation.

Implementation Method 1

the thermal conductivity of said layer of polymeric mixture forming the tread surface being strictly less than 0.270 W/(m.K)

Methodology Applied
Scientific EffectThermal conductivity: Conduction (thermal)

Implementation Method 2

a copolymer based on styrene and butadiene having a glass transition temperature Tg strictly greater than -65°C and less than or equal to -30°C

Methodology Applied
Scientific EffectGlass transition:

Implementation Method 3

Cables are said to be elastic when said cables exhibit, under a tensile force equal to the breaking load, a relative elongation at least equal to 3% with a maximum tangent modulus less than 150 GPa

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 4

at least one reinforcing filler comprising, in the majority, a reinforcing inorganic filler

Methodology Applied
Scientific EffectReinforcement:

Data Source

PatentEP4178810B1Tyre having improved properties of endurance and rolling resistance
Publication Date: 2025.01.29 MICHELIN & CO (CIE GEN DES ESTAB MICHELIN)
  • EP4178810B1 patent drawingFigure 1

AI summary

The invention relates to a tyre comprising a crown reinforcement formed from at least one layer of circumferential reinforcing elements. According to the invention, the thermal conductivity of the layer of polymer mixture forming the tyre tread is strictly less than 0.270 W/(m.K)) and said layer of polymer mixture forming the tyre tread is formed from a rubber composition based on at least one elastomer matrix mainly comprising a styrene-butadiene-based copolymer having a glass transition temperature Tg strictly higher than -65°C and lower than or equal to -30°C, and at least one reinforcing filler mainly consisting of an inorganic filler.