Fluororubber Vulcanizing Bladder for High-Sulfur Tire Curing
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Solution Overview
Problem
The vulcanization bladder in tire production tends to deteriorate due to sulfur migration from the unvulcanized tire's high sulfur concentration rubber member, leading to uneven sulfur distribution and reduced durability, which affects the physical properties of the vulcanized tire.
Innovation Solution
A tire production method using a vulcanizing bladder made of a rubber composition containing 50-100% fluororubber, specifically vinylidene fluoride-based, with a crosslinking agent, and additional components like carbon black and fatty oil to inhibit sulfur migration, ensuring the bladder's durability and maintaining intended tire properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional vulcanizing bladder is used for vulcanizing tires with high sulfur concentration rubber members, then the vulcanization process can be completed, but sulfur migrates from the tire to the bladder causing deterioration and reduced durability
Solution Approach 1:
The patent applies the intermediary principle by introducing a fluororubber material as a barrier between the high sulfur concentration rubber member and the vulcanizing bladder. The fluororubber composition acts as a mediator that prevents sulfur migration while allowing the vulcanization process to proceed. Specifically, the bladder is constructed with a fluororubber layer that serves as a protective intermediary, blocking sulfur from reaching the bladder structure and causing deterioration.
Solution Approach 2:
The patent employs composite materials by creating a vulcanizing bladder with a multi-layer structure consisting of fluororubber and other rubber materials. The fluororubber component (containing vinylidene fluoride, hexafluoropropylene, and perfluoro(alkylvinyl ether) units) is combined with crosslinking agents and other additives to form a composite material that possesses both sulfur resistance and adequate mechanical properties for vulcanization.
2Duration of action of stationary object
If sulfur migrates from the high sulfur concentration rubber member to the vulcanizing bladder, then the bladder deteriorates and its life is shortened, but the sulfur distribution in the tire becomes uneven affecting physical properties
Solution Approach 1:
The fluororubber bladder acts as an intermediary barrier that prevents sulfur migration in both directions. It protects the bladder from sulfur attack while simultaneously preventing sulfur from leaching out of the tire's rubber member, thereby maintaining uniform sulfur distribution within the tire and preserving the intended physical properties.
Solution Approach 2:
The patent converts the potentially harmful interaction between sulfur and the bladder into a beneficial situation by using fluororubber's inherent sulfur resistance. Instead of sulfur causing damage, the fluororubber material utilizes its chemical stability to create a protective interface, turning the presence of high sulfur concentration into an opportunity to demonstrate the material's superior resistance properties.
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
Effectively inhibits sulfur migration to the vulcanizing bladder, maintaining the tire's sulfur content and intended physical properties during vulcanization, thereby prolonging the bladder's life and ensuring consistent tire performance.
Implementation Method 1
a rubber composition for a bladder, which rubber composition contains fluororubber by 50 mass % to 100 mass %... It is possible to effectively inhibit by the aforementioned features the migration of sulfur from a high sulfur concentration rubber member to a vulcanizing bladder
Implementation Method 2
a crosslinking agent selected from the group consisting of a polyol-based crosslinking agent, a polyamine-based crosslinking agent, an oxazole-based crosslinking agent, a thiazole-based crosslinking agent, an imidazole-based crosslinking agent, and a triazine-based crosslinking agent
Implementation Method 3
a vulcanization process of vulcanizing an unvulcanized tire... wherein the vulcanization process employs a vulcanizing bladder
Data Source
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AI summary
An object of the present disclosure is to provide a tire production method which effectively inhibits the migration of sulfur to a vulcanizing bladder in a process of vulcanizing an unvulcanized tire provided at an inner surface thereof with a member having a high concentration of sulfur. Specifically, a tire production method includes a vulcanization process of vulcanizing an unvulcanized tire which is provided, in at least a portion of the innermost surface thereof, with a high sulfur concentration rubber member made of a rubber composition containing sulfur by ≥ 1.0 parts by mass with respect to 100 parts by mass of a rubber component, wherein the vulcanization process employs a vulcanizing bladder made of a rubber composition for a bladder, which rubber composition contains fluororubber by 50 mass % to 100 mass %.