Flat Aramid Reinforcement Tape for Pneumatic Tyres
Solution Overview
Problem
The height of reinforcement layers in pneumatic vehicle tires and drive belts significantly influences rolling resistance, and reducing the height using conventional round cross-section reinforcements is limited by material properties, making it difficult to achieve improved rolling resistance while maintaining strength.
Innovation Solution
A reinforcement layer using a tape with a large number of aramid filaments arranged parallel to each other, held together by an adhesion promoter, providing a very flat cross-section that reduces the height of the reinforcement layer and the encasing elastomer layer, thereby lowering hysteresis and weight.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If conventional round cross-section reinforcements are used, then the structural strength is maintained, but the height of the reinforcement layer cannot be reduced sufficiently
Solution Approach 1:
The patent applies asymmetry by transitioning from the conventional symmetric round cross-section reinforcement to an asymmetric flat tape cross-section. This asymmetric shape allows the reinforcement to achieve the required structural strength while minimizing the height dimension, directly resolving the contradiction between maintaining strength and reducing layer height.
Solution Approach 2:
The patent employs dimensionality change by spreading the reinforcement cross-section from a round shape (isotropic in cross-section) to a flat tape shape (anisotropic in cross-section). This dimensional transformation redistributes the material primarily in the width dimension rather than the height dimension, enabling height reduction while preserving strength through the flattened geometry.
2Loss of energy
If the height of the reinforcement layer is reduced, then the rolling resistance improves, but the material properties and strength requirements become harder to meet
Solution Approach 1:
The asymmetric flat tape cross-section allows the reinforcement to concentrate its material distribution in a way that maximizes strength efficiency. By eliminating the redundant height dimension and redistributing material in the width and length dimensions, the design achieves lower rolling resistance while maintaining the necessary strength properties through optimized material placement.
Solution Approach 2:
The patent changes the geometric parameters of the reinforcement from a round cross-section with diameter d to a flat tape cross-section with height a and width b, where a << d. This parameter transformation directly reduces the reinforcement layer height, lowering hysteresis and rolling resistance, while the adjusted width and length parameters compensate to maintain the required strength characteristics.
3Weight of moving object
If the thickness of the encasing elastomer layer is reduced, then the weight and rolling resistance improve, but the minimum layer thickness required for proper encasement is approached
Solution Approach 1:
The asymmetric flat tape reinforcement creates a more efficient encasement geometry where the elastomer layer thickness can be minimized. The flat profile allows the elastomer to encase the reinforcement more tightly with less material, reducing overall tire weight and rolling resistance while still providing adequate protection and adhesion.
Solution Approach 2:
By changing the reinforcement cross-section from round to flat, the patent enables the elastomer layer to distribute its thickness more efficiently. The reduced height dimension of the tape allows the elastomer to achieve proper encasement with reduced thickness, as the material can be distributed more effectively in the width and length dimensions rather than requiring excessive height coverage.
Data Source
Figure 1
Figure 2~4
AI summary
Reinforcement layer (13) comprises at least one reinforcing element, which is embedded in elastomeric material. The reinforcing element comprises non-metallic materials, and the cross-sectional height of the reinforcement is less than the cross-sectional width of the reinforcement. The reinforcing element is arranged in the reinforcement layer such that the extending direction of cross-sectional width is approximately parallel to the planar extent of the reinforcement layer. The reinforcing element is a band (9), which contains aramid and number of filaments made of a non-metallic material. Reinforcement layer (13) comprises at least one reinforcing element, which is embedded in elastomeric material. The reinforcing element comprises non-metallic materials, and the cross-sectional height of the reinforcement is less than the cross-sectional width of the reinforcement. The reinforcing element is arranged in the reinforcement layer such that the extending direction of cross-sectional width is approximately parallel to the planar extent of the reinforcement layer. The reinforcing element is a band (9), which contains aramid and number of filaments arranged parallel to the longitudinal extension direction of the band. The filaments are held together within the band by an adhesion promoter. An independent claim is also included for a pneumatic vehicle tire comprising at least one reinforcement layer.