Fluororubber Tire Vulcanizing Bladder With Air-Release Grooves

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Solution Overview

Problem

The use of fluororubber tire vulcanizing bladders results in a large volume of air remaining between the bladder and the raw tire during shaping, leading to insufficient contact and potential bareness on the vulcanized tire surface.

Innovation Solution

A tire vulcanizing bladder made of fluororubber with a configuration of grooves and recesses on its outer surface, and bladder ridges and protrusions on the inner surface, designed to enhance contact and prevent air retention, with specific dimensions and patterns to improve surface quality and reduce bareness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If fluororubber is used for the tire vulcanizing bladder, then painting with release agent is not required, but air remains between the bladder and raw tire during shaping causing insufficient contact

Engineering Contradiction:
Improveelimination of painting processVSAvoidcontact quality between bladder and raw tire
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The invention introduces grooves (depth: 0.3-0.5mm) and recesses (depth: 0.1-0.25mm) on the outer surface of the fluororubber bladder, creating a porous-like structure that allows air to escape during shaping. This enables the bladder to maintain close contact with the raw tire inner surface while using fluororubber material that eliminates the need for painting with release agents.

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The bladder surface is segmented into multiple grooves and recesses distributed across the outer surface. These segmented features create multiple air escape paths, ensuring that air can be effectively evacuated from between the bladder and raw tire during the shaping process, thereby improving contact quality.

Inventive Principle:
Principle #1Segmentation

2Loss of energy

If fluororubber bladder is used, then operation energy and materials are saved, but bareness is generated on vulcanized tire inner surface

Engineering Contradiction:
Improveoperation energy of painting machineVSAvoidbareness on vulcanized tire surface
Core Design Contradiction:
Loss of energyVSObject-affected harmful factors

Solution Approach 1:

The grooves and recesses create a controlled porous structure on the bladder surface that facilitates air escape during shaping. This prevents air entrapment that would otherwise cause bareness on the vulcanized tire inner surface, while maintaining the energy-saving benefits of using unpainted fluororubber bladder.

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The invention converts the potential harm of air entrapment (which causes bareness) into a beneficial design feature by intentionally creating grooves and recesses that guide air escape. The air that would otherwise be trapped and cause defects is now channeled through predetermined paths, transforming a manufacturing challenge into a solution.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

3Quantity of substance

If fluororubber bladder is used, then material cost is reduced, but air retention causes insufficient contact and potential defects

Engineering Contradiction:
Improvematerial consumptionVSAvoidcontact reliability during shaping
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The grooves (0.3-0.5mm depth) and recesses (0.1-0.25mm depth) create a porous-like structure that enables air to escape during shaping. This maintains reliable contact between the fluororubber bladder and raw tire inner surface throughout the vulcanization process, ensuring consistent product quality while using cost-effective fluororubber material.

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The segmented groove and recess pattern distributes air escape paths across the entire bladder surface, ensuring that air can be effectively evacuated from all regions during shaping. This segmentation approach maintains uniform contact reliability across the entire tire inner surface.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP3730267B1Bladder for tire vulcanization and pneumatic tire
Publication Date: 2024.05.29 BRIDGESTONE CORP
  • EP3730267B1 patent drawingFigure 1~2
  • EP3730267B1 patent drawingFigure 3~4
  • EP3730267B1 patent drawingFigure 5~6

AI summary

Provided is a tire vulcanizing bladder comprising fluororubber, wherein a plurality of grooves extending in a width direction are formed on a circumference of an outer surface of the tire vulcanizing bladder, and a plurality of recesses connecting the grooves to each other are formed between the grooves. Also provided is a pneumatic tire comprising one or more fluorine-containing particles having a maximum diameter of 1.0 µm or more per area of 100 µm2 of a tire inner surface, wherein a plurality of bladder ridges extending in a tire width direction are formed on a circumference of the tire inner surface, and a plurality of protrusions connecting the bladder ridges to each other are formed between the bladder ridges.