Multi-Layer Elastomer Tread for Heavy-Duty Tire Wear and Heat
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Solution Overview
Problem
Current heavy-duty tires face issues with endurance and resistance to wear, temperature rises, and punctures, leading to premature degradation and reduced lifespan, especially under high-speed and long-distance conditions.
Innovation Solution
A tire design featuring a crown reinforcement with multiple layers of elastomeric mixtures, including a radially outer layer with low hysteresis and inner layers with higher rigidity, optimized for reduced hysteresis and enhanced resistance to punctures, featuring specific elastomeric mixtures with controlled modulus and loss factor properties to manage stress and deformation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of moving object
If a single elastomeric material is used for the tread, then the structure is simple and manufacturing is easier, but the tire shows premature degradation and reduced lifespan under high-speed and long-distance conditions
Solution Approach 1:
The tread is segmented into multiple layers (first radially outer layer and second radially inner layer) with different elastomeric compositions. The first layer uses a harder elastomer for wear resistance, while the second layer uses a softer elastomer for flexibility and crack prevention, allowing each layer to perform its specific function optimally
Solution Approach 2:
Different regions of the tread are assigned different local qualities through the use of distinct elastomeric materials in each layer. The radially outer layer has higher hardness for contact patch durability, while the radially inner layer has lower hardness to accommodate deformations and reduce stress concentration at the tread-crown reinforcement interface
2Strength
If elastomeric materials with improved wear resistance are chosen for the tread, then wear resistance is improved, but hysteretic properties are penalized leading to excessive temperature rises
Solution Approach 1:
The tread structure applies local quality by positioning harder, more wear-resistant elastomer in the radially outer layer that contacts the road, while placing softer, more hysteretic elastomer in the radially inner layer that does not contact the road. This allows the outer layer to provide wear resistance while the inner layer absorbs hysteretic energy and reduces temperature rises
Solution Approach 2:
The tread is divided into functional segments where the first layer handles wear resistance and the second layer handles heat management through controlled hysteresis, allowing the tire to simultaneously achieve both wear resistance and acceptable temperature levels
3Ease of manufacture
If the tread structure is simplified, then manufacturing is easier, but resistance to punctures and attacks is reduced
Solution Approach 1:
The tread is segmented into two distinct layers with different elastomeric properties, where the first layer provides a protective barrier against punctures and attacks while the second layer provides structural support. This layered segmentation enhances reliability without significantly complicating the manufacturing process
Solution Approach 2:
The tread uses composite elastomeric materials with different properties in each layer. The first layer uses a harder elastomer for puncture resistance, while the second layer uses a softer elastomer for flexibility, creating a composite structure that enhances overall reliability and protection
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 achieves improved wear resistance, reduced temperature rises, and enhanced resistance to punctures and attacks, extending the rolling distance before retreading and maintaining performance under severe conditions.
Implementation Method 1
a first elastomeric mixture having a modulus of elasticity under tension at 10% elongation less than or equal to 10 MPa... the second elastomeric mixture having a maximum value of tan(δ), denoted tan(δ)max, less than or equal to 0.30
Implementation Method 2
the second elastomeric mixture having a maximum value of tan(δ), denoted tan(δ)max, less than or equal to 0.30... the third elastomeric mixture having a maximum value of tan(δ), denoted tan(δ)max, less than 0.10
Data Source
Figure 1
AI summary
The invention relates to a tyre of which the tread comprises at least two layers of elastomer blends (61, 62). According to the invention, the first layer (61) forming the radially exterior portion of the tread extends radially inside the grooves over a thickness of at least 1 mm and is formed by a first elastomer blend of which the elastic modulus in tensile stress at 10% elongation is less than or equal to 10 MPa, and the second layer (62) is formed by a central portion (621) and two axially exterior portions (622), said central portion, at least 1 mm thick, being formed by a second elastomer blend having an elastic modulus in tensile stress at 10% elongation greater than or equal to 20 MPa and a maximum tan(δ) value referred to as tan(δ) max, less than or equal to 0.30, the axially exterior portions being formed by a third elastomer blend having a maximum tan(δ) value, referred to as tan(δ) max, less than 0.10.