Inclined Partial Tie Rubber Layer Prevents Vulcanization Defects
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Solution Overview
Problem
Pneumatic tires with partial tie rubber layers face vulcanization defects, such as air pockets and separation issues, which hinder weight reduction and rolling resistance improvement efforts.
Innovation Solution
A partial tie rubber layer is disposed between the carcass and innerliner layers, with inclined end surfaces forming an acute angle of 20° to 60°, and a specific thickness and hardness to prevent air-pocket formation and ensure proper bonding during the tire manufacturing process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If a partial tie rubber layer is used to reduce tire weight and rolling resistance, then weight and rolling resistance are reduced, but vulcanization defects such as air pockets and separation occur at the end portions
Solution Approach 1:
The end surfaces of the partial tie rubber layer are designed as inclined surfaces rather than flat surfaces. This curvature change allows air to escape more easily during vulcanization, preventing air pocket formation. The inclined surface geometry transforms the flat termination into a sloped configuration that facilitates air removal while maintaining the weight reduction benefits of the partial tie rubber layer.
Solution Approach 2:
The inclination angle of the end surfaces is optimized within a specific range (15° to 45°) to balance air removal efficiency with structural integrity. By adjusting this geometric parameter, the patent achieves optimal vulcanization quality while maintaining reduced tire weight and rolling resistance, resolving the contradiction between weight reduction and vulcanization reliability.
2Quantity of substance
If the width of the tie rubber layer is narrowed to reduce the used amount of tie rubber, then tire weight is reduced, but end portions fail to bond together properly
Solution Approach 1:
By transforming the flat end surfaces into inclined surfaces, the patent enables proper bonding and air removal even with reduced tie rubber quantity. The inclined geometry compensates for the reduced width by providing an angle that facilitates both bonding and air escape, allowing the use of less material without sacrificing manufacturing precision.
3Loss of energy
If a partial tie rubber layer is disposed at shoulder regions to reduce rolling resistance, then rolling resistance is reduced, but separation occurs at the end portions
Solution Approach 1:
The inclined end surfaces prevent separation by providing a geometry that facilitates air removal and improves bonding. This curvature modification maintains layer bonding stability in the shoulder regions where partial tie rubber layers are used to reduce rolling resistance, resolving the contradiction between energy loss reduction and compositional stability.
Data Source
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Figure 3A~3B
AI summary
A pneumatic tire and a method of manufacturing the same that can prevent vulcanization defects, which are a concern when employing a partial tie rubber layer and can sufficiently achieve reduced tire weight and rolling resistance due to employing a partial tie rubber layer. A partial tie rubber layer (40) is disposed between a carcass layer (4) and an innerliner layer (9) in a limited manner across an entire region excluding end portions near a pair of bead portions (3); end surfaces on both sides in a tire lateral direction of the partial tie rubber layer (40) are inclined surfaces that form an acute angle with respect to a surface of the partial tie rubber layer (40) on the carcass layer (4) side; and an inclination angle θ of the inclined surfaces with respect to the surface of the partial tie rubber layer (40) on the carcass layer (4) side is from 20° to 60°.