Aromatic Polyamide Fuel Line Hoses with Impact Modifiers
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Solution Overview
Problem
Current polymeric hollow bodies, such as tubing for motor vehicle fuel lines, face challenges in high-temperature applications due to limitations in barrier properties, permeation, and long-term heat aging, particularly with aliphatic polyamide PA12, which suffers from fuel permeation and mechanical degradation, and multilayer constructions are prone to delamination.
Innovation Solution
A hollow body comprising at least one layer of aromatic polyamide with an impact modifier, optionally combined with an aliphatic polyamide layer, providing improved thermal and mechanical properties without the need for fluoropolymer layers, and allowing for various layer configurations to enhance barrier resistance and flexibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If aliphatic polyamide (PA12) is used for fuel line tubing, then flexibility and ease of manufacture are improved, but fuel permeation and long-term heat aging resistance deteriorate
Solution Approach 1:
The patent uses a composite material system consisting of an aromatic polyamide matrix combined with specific elastomers (EPDM, SEBS, or POE) as impact modifiers. This composite structure provides both the flexibility needed for ease of manufacture and the fuel permeation resistance required for reliability, resolving the contradiction between these two properties.
2Reliability
If multilayer constructions are used to improve barrier properties, then fuel permeation resistance is improved, but delamination and construction complexity worsen
Solution Approach 1:
The patent changes the chemical composition parameters of the polyamide material by incorporating aromatic polyamides with specific chemical structures (polyphthalamides, aramid copolymers) and adding controlled amounts of elastomers (5-40 parts per 100 parts polyamide). This compositional parameter change achieves superior barrier properties without requiring complex multilayer constructions, thus reducing construction complexity while maintaining reliability.
3Temperature
If fluoropolymer layers are added to improve heat resistance, then temperature resistance is improved, but manufacturing complexity and cost increase
Solution Approach 1:
The patent achieves heat resistance by changing the chemical parameters of the base polyamide material itself - using aromatic polyamides with high thermal stability and controlled elastomer content. This material parameter change provides inherent heat resistance without requiring additional fluoropolymer layers, thereby reducing layer complexity and manufacturing complexity while maintaining temperature resistance.
4Strength
If aromatic polyamide with impact modifier is used, then impact strength and thermal properties are improved, but material complexity increases
Solution Approach 1:
The patent optimizes the material composition by controlling the elastomer content within specific ranges (5-40 parts per 100 parts polyamide) and selecting from a limited set of proven elastomer types (EPDM, SEBS, POE). This controlled parameter change achieves the desired impact strength while limiting material complexity through standardized formulations rather than uncontrolled material variations.
Data Source
AI summary
Hollow bodies made from impact-modified polyamide. Fuel line hoses for both liquid fuel delivery and fuel vapor recovery.