Semi-Aromatic Polyamide Tyre Reinforcement
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Solution Overview
Problem
High-performance tyres face challenges in maintaining mechanical properties and adhesion under extreme driving conditions due to limitations in existing reinforcing materials, such as aliphatic and aromatic polyamides, which suffer from fatigue, thermal stability, and cost issues.
Innovation Solution
The development of semi-aromatic polyamide reinforcing elements with a glass transition temperature greater than 90°C, characterized by a bimodal tensile modulus trend, improved adhesion, and thermal stability, which are incorporated into the tyre's carcass and belt structures to enhance tensile strength and fatigue resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If aliphatic polyamides are used for reinforcing elements, then fatigue strength is improved, but thermal stability deteriorates at high operating temperatures
Solution Approach 1:
The patent employs semi-aromatic polyamides as a composite material that combines the fatigue resistance characteristics of aliphatic polyamides with the thermal stability of aromatic polyamides. This composite material approach resolves the contradiction by integrating beneficial properties from both material classes into a single reinforcing element material that performs reliably under both cyclic loading and high temperature conditions.
2Temperature
If aromatic polyamides are used for reinforcing elements, then thermal stability is improved, but adhesion to rubber deteriorates
Solution Approach 1:
The semi-aromatic polyamide material exhibits local quality characteristics where different segments of the polymer chain contribute different properties: the aromatic segments provide thermal stability while the aliphatic segments maintain adhesion to rubber. This local differentiation within the material structure allows simultaneous achievement of both thermal stability and good adhesion properties.
3Reliability
If inflation pressure is reduced to increase footprint area, then adherence is improved, but dynamic rigidity deteriorates
Solution Approach 1:
The patent changes the material parameter of the reinforcing elements from conventional aliphatic or aromatic polyamides to semi-aromatic polyamides with specific glass transition temperatures and mechanical properties. This parameter change allows the tyre to maintain optimal dynamic rigidity even at reduced inflation pressures, thereby preserving both adherence and responsiveness without requiring pressure compromise.
4Weight of moving object
If tyre structure is made lighter to reduce weight, then fuel efficiency is improved, but structural rigidity deteriorates
Solution Approach 1:
The patent utilizes parameter changes in the reinforcing element material properties, specifically employing semi-aromatic polyamides with optimized glass transition temperatures and tensile moduli. These parameter changes enable the use of lighter tyre structures that nonetheless maintain or improve structural rigidity and dynamic response characteristics, resolving the contradiction between weight reduction and rigidity maintenance.
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
These semi-aromatic polyamide reinforcing elements provide optimal mechanical properties, maintaining tyre performance and adhesion even at high temperatures, thus ensuring better handling and durability in extreme driving conditions.
Implementation Method 1
The elongated reinforcing element shows in the diagram tenacity - elongation % a bimodal trend of tenacity, characterized by an incremental ratio R between the chord modulus E1 and the chord modulus E2 greater than 1
Implementation Method 2
said at least one elongated reinforcing element is characterised in that it shows in the diagram tenacity - elongation % a bimodal trend of tenacity... wherein said at least one elongated reinforcing element comprises one or more polymeric threads comprising at least one semi-aromatic polyamide having a glass transition temperature (Tg) greater than 90°C
Data Source
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AI summary
The present invention refers to reinforcing elements for tyres, to tyre components and to tyres for vehicle wheels which comprise them, in particular to high performance tyres subjected to severe operating conditions, such as for example racing tyres, wherein said reinforcing elements comprise semi-aromatic polyamides.