Fire-Retardant Textile Covering for Air Spring Bellows
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current polymer articles used for vehicle suspension and vibration damping, such as air spring bellows and metal-rubber elements, face challenges in meeting stringent fire protection standards due to high heat release rates and toxic smoke production, and existing fire-retardant solutions compromise physical properties or increase manufacturing complexity.
Innovation Solution
A base body made of polymeric material with an elastic article surface partially or completely covered by a textile fabric or three-dimensional structure, which provides fire-retardant properties without direct adhesion, allowing for double protection against heat and flames, and can be equipped with fire-retardant substances applied via water-based solutions or cold-vulcanization processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If fire-retardant substances are directly mixed into rubber compounds, then fire behavior is improved, but physical properties such as springing, setting and vibration properties deteriorate significantly
Solution Approach 1:
The patent divides the fire protection function into a separate outer layer that is vulcanized onto the base body. This outer layer contains the fire-retardant substances (such as expandable graphite, aluminum hydroxide, or magnesium hydroxide), while the base body maintains its original elastomeric composition with optimized physical properties. The segmentation allows each layer to be independently optimized for its specific function without compromise.
Solution Approach 2:
The outer layer acts as an intermediary between the fire hazard and the base body. It provides fire protection while being vulcanized onto the base body through a controlled process that prevents reversion. The outer layer mediates the conflict by containing fire-retardant substances without allowing them to interfere with the physical properties of the underlying elastomeric mixture.
2Object-affected harmful factors
If a separate outer layer with fire-retardant substances is vulcanized onto the base body, then fire behavior is improved, but manufacturing complexity and production costs increase due to double vulcanization
Solution Approach 1:
The outer layer is prepared in advance with the appropriate composition including fire-retardant substances, fillers, and vulcanization agents. This pre-prepared layer can then be applied to the base body and vulcanized in a controlled manner. The preliminary preparation allows for optimized formulation without complicating the overall manufacturing process.
Solution Approach 2:
The patent employs a two-stage vulcanization process with different temperature parameters. The base body is vulcanized at standard temperatures first, then the outer layer is vulcanized at comparatively low temperatures (below 100°C) that prevent reversion of the base body while still achieving proper bonding and fire protection. This parameter optimization reduces manufacturing complexity.
3Strength
If the outer layer is vulcanized at high temperatures to ensure proper bonding, then adhesion is improved, but reversion processes occur in the underlying polymer mixture
Solution Approach 1:
The patent changes the vulcanization temperature parameter for the outer layer to comparatively low temperatures (below 100°C). This temperature optimization allows sufficient adhesion and bonding between the outer layer and base body while preventing the reversion of the underlying elastomeric mixture, particularly important for NR and IR-based compounds.
Solution Approach 2:
The vulcanization process is made dynamic and staged: first the base body is vulcanized at standard temperatures to achieve its final structure, then the outer layer is vulcanized at lower temperatures to bond to the base body without causing reversion. This dynamic temperature control optimizes both adhesion and structural stability.
4Object-affected harmful factors
If expandable graphite is used as flame-retardant substance in coating, then fire protection is improved, but abrasion resistance and elasticity of the coating deteriorate
Solution Approach 1:
The patent segments the functional requirements by placing expandable graphite exclusively in the outer layer, which is vulcanized onto the base body. The base body maintains its full elastomeric properties including abrasion resistance, while the outer layer provides fire protection. The segmentation isolates the compromise to only the outer layer where abrasion resistance is less critical.
Solution Approach 2:
The outer layer is given local quality with high fire-retardant substance content (particularly expandable graphite) to provide fire protection where it is most needed on the surface. The base body maintains its original high-quality elastomeric composition with optimized abrasion resistance and mechanical properties. Each region has the quality it needs for its specific function.
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 solution enhances fire protection while maintaining the necessary physical properties and reducing manufacturing complexity, providing effective fire resistance without compromising the elasticity and elongation of the polymer base body, and avoids health hazards associated with organic solvents.
Implementation Method 1
dual function both as a cover and as a fire-retardant finish
Implementation Method 2
cold-vulcanization processes
Data Source
Figure 1~2
AI summary
The invention relates to an article comprising a main body (6, 7, 8) that consists of a polymer material having elastic properties, particularly an air spring bellows (2), a metal-rubber element or a vibration damper. In order for fire-retardant properties to be improved, the article is provided, partially or fully, with a cover (9) formed from at least one flat textile structure and/or at least one three-dimensional textile structure and/or at least one shrink film. The cover can be fire-retardant itself or can be equipped to be fire-retardant.