Thermally Adaptive Tyre Underlayer for Winter Grip and Wear Balance
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Solution Overview
Problem
Traditional winter tires face challenges such as reduced durability, increased rolling resistance, and excessive road wear due to softer tread layers, which are not optimally suited for varying weather conditions, especially during seasonal transitions when temperatures fluctuate around the freezing point.
Innovation Solution
A pneumatic tire design featuring a thermally adaptive underlayer with a polymer system comprising elastomers that exhibit low miscibility and distinct glass transition temperatures, allowing the tire to self-adjust its performance characteristics based on temperature, thereby improving grip and durability across different conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a softer tread layer rubber composition is used to improve winter grip properties, then grip on cold surfaces is enhanced, but tread wear resistance deteriorates and rolling resistance increases
Solution Approach 1:
The tyre is divided into functionally distinct layers: a tread layer optimized for wear resistance and a separate underlayer optimized for cold-temperature grip. This segmentation allows each layer to perform its specific function without compromising the other, resolving the contradiction between grip and durability.
Solution Approach 2:
Different rubber compositions are assigned to different locations within the tyre structure. The underlayer uses a softer composition with lower glass transition temperature for cold surface adhesion, while the tread layer uses a harder, more durable composition. This local differentiation enables simultaneous optimization of grip and wear resistance.
2Reliability
If a softer tread layer is used to enhance winter grip, then adhesion to cold surfaces improves, but rolling resistance increases leading to higher fuel consumption
Solution Approach 1:
The tyre structure separates the grip function (underlayer) from the structural support function (tread layer). The softer underlayer provides cold-temperature adhesion while the harder tread layer maintains structural integrity and reduces rolling resistance, thus improving energy efficiency without sacrificing winter grip.
Solution Approach 2:
The tyre uses a composite structure with two distinct rubber compositions having different glass transition temperatures. The underlayer uses elastomers with lower Tg for cold flexibility and grip, while the tread layer uses elastomers with higher Tg for structural stability and lower rolling resistance, achieving both winter performance and energy efficiency.
3Reliability
If studded pneumatic tyres are used to increase grip on ice and snow, then winter grip properties improve, but road wear increases rapidly
Solution Approach 1:
The tyre separates the stud support function from the road contact function. The underlayer provides a compliant base that supports stud penetration into ice and snow for enhanced grip, while the harder tread layer minimizes direct road wear during normal operation. This segmentation allows stud effectiveness without excessive pavement damage.
4Device complexity
If a single tyre composition is used throughout the year, then tyre simplicity is maintained, but performance adaptability to varying seasonal conditions deteriorates
Solution Approach 1:
The tyre employs a composite structure with two rubber compositions having distinctly different glass transition temperatures. The underlayer uses elastomers with lower Tg (e.g., -50°C to -80°C) for cold-temperature flexibility and grip, while the tread layer uses elastomers with higher Tg (e.g., -20°C to -40°C) for warm-temperature stability and wear resistance. This composite approach enables seasonal performance adaptability while maintaining a relatively simple two-layer structure.
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 thermally adaptive underlayer maintains stable dynamic stiffness at warmer temperatures and increases stiffness at colder temperatures, enhancing winter grip and reducing road wear, while maintaining rolling resistance similar to conventional tires.
Implementation Method 1
a first elastomer having a first glass transition temperature and a second elastomer having a second glass transition temperature, wherein a difference of at least 20° K exists between the first glass transition temperature and the second glass transition temperature
Data Source
AI summary
A pneumatic tyre contains a structure wherein a thermally adaptive underlayer is positioned beneath a tread layer and an intermediate layer. The thermally adaptive underlayer is based on a polymer system that containing elastomers with distinct glass transition temperatures sufficiently far apart which exhibit low miscibility towards each other. Due to the tyre construction and the thermally adaptive underlayer, while driving a vehicle, the performance characteristics of the pneumatic tyre adapt to the driving conditions on the road based on the temperature experienced by the thermally adaptive underlayer. This is of particular relevance for a winter tyre, wherein the thermally adaptive underlayer may be used to design an improved tread layer and for a studded pneumatic tyre, wherein the composition and thickness of the thermally adaptive underlayer may control dynamic impact of the stud on a driving surface, when the tyre is in motion.