Closed-Cell Polyolefin Noise Reduction in Self-Sealing Tyres
Solution Overview
Problem
Conventional self-sealing and soundproof tires fail to achieve effective sealing performance due to interference from noise-reducing materials, which are often crushed by puncture forces, creating micro-channels that compromise air retention.
Innovation Solution
Incorporating a closed-cell polyolefin material with closed macrocells as the noise-reducing element, which maintains structural integrity and enhances both sealing and soundproofing capabilities, while withstanding thermal and mechanical stresses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If conventional noise-reducing materials (open-cell polyurethane) are used in self-sealing tyres, then soundproofing performance is improved, but sealing performance deteriorates due to material crushing and micro-channel formation
Solution Approach 1:
The patent changes the cell structure parameter of the noise-reducing material from open-cell to closed-cell configuration. This parameter change prevents the material from being crushed into micro-channels during puncture events, as the closed cells maintain structural integrity while still providing acoustic damping. The closed-cell structure fundamentally alters how the material responds to mechanical stress during sealing operations.
Solution Approach 2:
The patent employs composite material design by combining closed-cell polyolefin foam with specific elastomeric sealing compositions. The closed-cell polyolefin provides both noise reduction and puncture resistance, while the elastomeric composition delivers sealing functionality. This composite approach allows the noise-reducing element to work synergistically with the sealing layer rather than interfering with it.
2Object-generated harmful factors
If noise-reducing elements are added to the tyre inner cavity, then soundproofing performance is improved, but device complexity increases
Solution Approach 1:
The closed-cell polyolefin noise-reducing element serves multiple functions simultaneously: it provides acoustic damping for cavity noise reduction, maintains structural integrity during puncture events, and works synergistically with the elastomeric sealing composition. This multi-functionality reduces the need for separate components and simplifies the overall tyre structure despite adding noise reduction capabilities.
3Object-generated harmful factors
If open-cell polyurethane foam is used for noise reduction, then acoustic performance is improved, but thermal and mechanical stability deteriorates under tyre operating conditions
Solution Approach 1:
The patent changes the material composition parameter from polyurethane to polyolefin, and the cell structure from open-cell to closed-cell. The closed-cell configuration provides superior thermal and mechanical stability under tyre operating conditions, as the enclosed cells prevent material degradation and maintain structural integrity during cyclic loading and heating. The polyolefin base material also offers enhanced resistance to oxidation and environmental degradation compared to polyurethane.
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
The use of closed-cell polyolefin materials ensures excellent soundproofing and sealing performance, resisting humidity and mechanical stress, and maintains physical integrity and noise reduction over time without interfering with the sealing action.
Implementation Method 1
a noise reducing element (16), comprising a closed-cell polyolefin material, preferably with closed macrocells
Implementation Method 2
a layer of sealing elastomeric composition (10) applied on at least a portion of the radially inner surface of the layer of airtight elastomeric material
Data Source
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AI summary
The present invention relates to soundproof self-sealing tyres for vehicles wheels and to processes for the manufacture thereof. In particular, the soundproof self- sealing tyres of the invention comprise closed-cell foamed polyolefin materials, preferably with closed macrocells, optionally perforated. These noise-reducing materials surprisingly allow maintaining the sealing performance of traditional self-sealing systems, which are instead compromised in the case of conventional noise-reducing materials based on open-cell foamed polyurethanes.