Polyamide 6 Hydrogen Tank Liner for Cryogenic Impact Resistance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Hydrogen tank liners face challenges in maintaining excellent gas barrier properties and impact resistance, especially at cryogenic temperatures below −40° C, with existing materials either failing to provide adequate protection against brittle fracture or gas leakage.
Innovation Solution
A hydrogen tank liner material composed of polyamide 6 combined with a copolyamide and an impact-resistant material, such as ethylene/α-olefin-based copolymers, which enhances both gas barrier properties and impact resistance while allowing for laser welding and monolayer injection molding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If polyamide resins are used to improve gas barrier properties, then gas barrier property is improved, but impact resistance at cryogenic temperatures deteriorates
Solution Approach 1:
The patent uses a composite material system consisting of polyamide 6 as the base resin, copolyamide as a modifier, and impact-resistant material (such as polyolefin or elastomer) dispersed throughout. This composite structure allows the polyamide 6 to provide excellent gas barrier properties while the copolyamide and impact-resistant material work together to maintain impact resistance at cryogenic temperatures below −40°C, resolving the contradiction between gas barrier performance and low-temperature toughness.
2Strength
If impact-resistant materials are added to polyamide resins to improve impact resistance, then impact resistance is improved, but gas barrier property deteriorates
Solution Approach 1:
The patent applies local quality by creating a multi-phase composite where polyamide 6 domains provide gas barrier functionality in regions where gas permeation resistance is critical, while copolyamide and impact-resistant material domains provide toughness and impact resistance. This spatial differentiation of material functions allows the composite to simultaneously achieve both excellent gas barrier properties and high impact resistance at cryogenic temperatures.
3Productivity
If high pressure of 70 MPa is used to increase travel distance, then travel distance is improved, but temperature during high-speed travel decreases to cryogenic levels
Solution Approach 1:
The patent employs beforehand cushioning by incorporating impact-resistant materials and copolyamide into the polyamide 6 resin matrix in advance, creating a composite structure pre-designed to withstand cryogenic temperatures. This preventive measure ensures that when the hydrogen tank operates at high pressure (70 MPa) during high-speed travel, the liner material is already prepared to maintain its mechanical properties and prevent brittle fracture at the resulting low temperatures, thus enabling extended travel distance without compromising safety.
Data Source
AI summary
A hydrogen tank liner material comprises a polyamide resin composition which comprises (A) a polyamide resin at 85-40 wt %, (B) a copolyamide at 5-30 wt % and (C) an impact-resistant material at 10-30 wt % with respect to the total weight of the polyamide resin composition. Preferably, the (B) copolyamide is PA6/66 and the (C) impact-resistant material is an acid-modified ethylene/α-olefin-based copolymer. A hydrogen tank liner material with excellent gas barrier properties and superior impact resistance even at low temperatures is obtained.