Flame-Retardant Rubber Composition for Air Spring Bellows
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Articles with elastomeric mixtures used for vehicle suspension and vibration damping fail to meet stringent fire protection requirements due to high heat release rates and toxic smoke production, and traditional flame retardants compromise physical properties.
Innovation Solution
A single-layer or multi-layer base body with a rubber mixture containing carbon black and different particle sizes of aluminum trihydrate, along with additional flame retardants, to optimize fire protection without deteriorating hardness and dynamic properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If halogen-free flame retardants are added in large amounts (30-130 phr) to improve fire behavior, then fire protection is improved, but hardness and dynamic properties deteriorate
Solution Approach 1:
The invention changes the particle size parameter of aluminum trihydrate from conventional single-size to a specific size range (0.5-2.0 μm), and optimizes the carbon black structure parameter (surface area 10-30 m²/g). This parameter optimization allows achieving fire protection requirements without excessive flame retardant addition, thereby maintaining hardness and dynamic properties.
Solution Approach 2:
The invention creates a composite filler system combining aluminum trihydrate with specific carbon black types (N339, N550, N660) in optimized ratios. This composite approach synergistically improves fire protection while maintaining physical properties, avoiding the need for large amounts of single flame retardant additives that would compromise hardness.
2Strength
If conventional elastomeric mixtures (NR/IR/CR) are used to achieve good elastic and dynamic properties, then vibration damping and springing are improved, but fire protection behavior deteriorates due to high heat release rate and toxic smoke
Solution Approach 1:
The invention introduces a specifically formulated filler system (aluminum trihydrate with carbon black) as an intermediary that modifies the fire behavior of conventional elastomeric mixtures without compromising their elastic properties. The optimized filler acts as a mediator between the rubber matrix and fire protection requirements.
Solution Approach 2:
The invention optimizes the particle size parameter of aluminum trihydrate (0.5-2.0 μm) and carbon black surface area (10-30 m²/g) to achieve effective fire protection with minimal impact on the elastomeric matrix, thereby maintaining good elastic properties while improving fire behavior.
3Duration of action of stationary object
If flame-retardant elastomeric mixtures based on CR are used to improve weather and heat resistance, then durability is improved, but smoke toxicity increases making them non-compliant with fire standards
Solution Approach 1:
The invention changes the particle size parameter of aluminum trihydrate to a specific range (0.5-2.0 μm) and optimizes carbon black properties, which effectively reduces smoke toxicity during combustion while maintaining the durability and weather resistance characteristics of CR-based elastomeric mixtures.
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 significantly improves fire protection behavior while maintaining the necessary physical properties, enabling compliance with EN45545 standards without adverse effects on hardness or dynamic performance.
Implementation Method 1
at least one other aluminum trihydrate (ATH 2), wherein the first aluminum trihydrate (ATH1) and the other aluminum trihydrate (ATH 2) each have a different particle size
Implementation Method 2
at least one carbon black with a BET surface area according to DIN-ISO 9277 between 35 and 140 m2/g and an oil absorption number (OAN) according to ISO 4656 between 70 and 140 ml/100g
Data Source
AI summary
The invention relates to an article comprising a single or multi-layer main body having elastic properties, in particular air spring bellows, a metal-rubber element or a vibration damper. In order to improve the flame-retarding properties, the main body of the article consists of or contains at least one layer D formed of a rubber mixture that is free from halogen-containing flame retardant means and contains at least one carbon black with a BET surface area of between 35 and 140 m2/g (according to DIN-ISO 9277) and with an oil absorption number (OAN) of between 70 and 140 ml /100g (according to ISO 4656), and a first aluminium trihydrate (ATH_1) and at least one further aluminium trihydrate (ATH_2), wherein the first aluminium trihydrate (ATH_1) and the further aluminium trihydrate (ATH_2) each have a different particle size.