Coextruded Tire Tread With Microchimneys for Static Dissipation
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Solution Overview
Problem
Tire manufacturers face complexity and inefficiency in producing tire treads with multiple rubber compounds and conductive chimneys, as existing methods require multiple application stations and are prone to inconsistencies that can break the conductive path, leading to inadequate static charge dissipation.
Innovation Solution
A method of forming a composite tread with microchimneys using a coextruded strip of a non-conductive and conductive rubber compound, wound spirally onto a tire building drum, allowing for independent flow of compounds from a single application head, reducing the need for multiple stations and ensuring multiple conductive paths for effective static discharge.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple application stations are used to apply different rubber compounds, then the tire tread can be formed with multiple compounds including conductive material, but the device complexity and manufacturing process complexity increase significantly
Solution Approach 1:
The patent combines multiple compound application capabilities into a single application head by using a coextrusion system. The coextrusion die integrates multiple extrusion channels that deliver different rubber compounds (conductive and non-conductive) simultaneously through one nozzle, eliminating the need for multiple separate application stations and reducing device complexity while maintaining the ability to form treads with multiple compounds
Solution Approach 2:
The single application head is designed with multi-functionality to apply different rubber compounds. The coextrusion system allows one application head to perform the functions of multiple heads by incorporating separate extrusion channels for conductive and non-conductive compounds, enabling versatile compound application without increasing the number of stations
2Reliability
If extrusion method is used to form conductive chimneys, then the conductive path can be created, but any inconsistencies in extrusion can break the conductive path and fail to dissipate static charge
Solution Approach 1:
The coextrusion system merges the application of conductive and non-conductive compounds in a controlled manner, with the conductive compound being extruded through a dedicated channel adjacent to the non-conductive compound channel. This integrated approach ensures consistent positioning and thickness of the conductive layer, preventing extrusion inconsistencies that could break the conductive path
Solution Approach 2:
The patent controls the extrusion parameters of the coextrusion system to ensure consistent delivery of the conductive compound. By maintaining precise control over extrusion pressure, temperature, and flow rates of both compounds, the system ensures uniform conductive path formation without breaks or inconsistencies
3Productivity
If a single application head with coextrusion is used, then the number of application stations is reduced, but the complexity of splice bar design and die work increases
Solution Approach 1:
The coextrusion die is segmented into multiple independent extrusion channels, each dedicated to a specific rubber compound. This segmentation allows for simplified design of each individual channel while maintaining the ability to deliver multiple compounds simultaneously, reducing the overall complexity compared to coordinating multiple separate application stations with intricate splice bar designs
Data Source
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AI summary
A method for forming a composite tread with microchimneys is disclosed. The method comprises: providing a coextruded strip (210) formed of a first compound and a second compound, wherein the first compound is a tread compound and the second compound is electrically conductive and different from the first compound, and then winding the coextruded strip (210) onto a tire building drum (18) to form a tread (300). Also, a tire having a tread (200) is disclosed, the tread (200) being formed from a spirally wound coextruded strip (210) of rubber compound, wherein the coextruded strip (210) of rubber compound is a dual layer of a first layer (210) of a first rubber compound and of a second layer (212) of a second rubber compound, and wherein the second rubber compound is electrically conductive and different from the first rubber compound.