Pneumatic Tire Cap Tread Modulus and Earthing Tread Resistivity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Studless tires face challenges in maintaining performance on ice and snow while ensuring electrostatic suppression and preventing separation at the boundary face between the earthing tread and cap tread due to increased silica content, which affects electrical resistance and ground contact pressure.
Innovation Solution
A pneumatic tire design featuring a cap tread with a modulus of 3.0-7.0 Mpa, an undertread with a modulus of 10.0-20.0 Mpa, and an earthing tread made from the same rubber material as the undertread, with a volume resistivity of 1×10^7 Ω·cm or less, forming an integral structure to improve ice performance and separation resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the silica content of the cap tread is increased to improve ice and snow performance, then the performance on ice is improved, but the electrical resistance value increases and electrostatic suppression performance decreases
Solution Approach 1:
The tread is divided into two functional layers: the cap tread containing silica for ice performance, and the earthing tread containing conductive carbon black for electrostatic suppression. This segmentation allows each layer to independently perform its specific function without interfering with the other.
Solution Approach 2:
Different regions of the tread are assigned different material compositions tailored to their specific functions. The cap tread uses silica-rich compound for ice traction, while the earthing tread uses carbon black-rich compound for electrical conductivity, creating local optimization of properties.
2Reliability
If the silica content of the cap tread is increased to improve ice performance, then the performance on ice is improved, but the difference in modulus between the earthing tread and cap tread increases, causing separation at the boundary face
Solution Approach 1:
The modulus of the cap tread is controlled within a specific range (3.0-7.0 MPa) by adjusting silica content and compound formulation, while the earthing tread modulus is maintained at a higher level (10.0-20.0 MPa) through carbon black reinforcement. This parameter optimization ensures both ice performance and structural stability.
Solution Approach 2:
The tread employs composite rubber compounds in each layer: the cap tread combines silica with rubber base materials for ice traction, while the earthing tread combines carbon black with rubber for conductivity and strength. The composite structure allows simultaneous achievement of different functional requirements.
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 design enhances braking performance on ice, electrostatic suppression, and separation resistance by maintaining uniform ground contact pressure and reducing step wear, while ensuring effective electrostatic discharge through the earthing tread.
Implementation Method 1
the earthing tread being made from a rubber material with a volume resistivity of 1×10^7 Ω·cm or less
Data Source
AI summary
In a pneumatic tire, a modulus at 300% elongation of a cap tread ranges from 3.0 Mpa to 7.0 Mpa, and the modulus at 300% elongation of an undertread ranges from 10.0 Mpa to 20.0 Mpa. Additionally, an earthing tread is made from a rubber material with a volume resistivity of 1×10{circumflex over ( )}7 Ω·cm or less. The earthing tread is made from the same rubber material as the undertread and has an integral structure with the undertread.