Fluoropolymer Hose Barrier Layer for Fuel Stability and Crack Resistance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Hoses used for transporting aggressive media like acids, fuels, or oils face challenges in achieving dynamic capability and crack resistance while maintaining media stability and electrical conductivity, as the addition of conductive carbon blacks can lead to material degradation and loss of thermoplastic properties.
Innovation Solution
A hose design featuring a barrier layer composed of a mixture of thermoplastic fluoropolymers, fluororubber, and carbon fillers such as conductivity carbon black, graphene, or carbon nanotubes, or irradiated polytetrafluoroethylene (PTFE), which is extruded and vulcanized to provide enhanced stability and reduced permeability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conductive carbon blacks are added to achieve electrical conductivity and media stability, then electrical conductivity and media stability are improved, but dynamic capability and crack resistance deteriorate due to material degradation
Solution Approach 1:
The patent changes the processing parameters by using lower extrusion temperatures (200-250°C) and specific shear rate ranges (10-100 s⁻¹) to minimize thermal and mechanical degradation of the carbon-black-reinforced polymer, thereby maintaining crack resistance while achieving electrical conductivity
Solution Approach 2:
The patent uses composite materials by combining polymer matrices with conductive carbon blacks and reinforcing fillers in specific ratios, creating a multi-phase composite that simultaneously provides electrical conductivity, media stability, and mechanical strength
2Reliability
If conductive carbon blacks are added to achieve electrical conductivity, then electrical conductivity is improved, but thermoplastic properties are lost due to material degradation
Solution Approach 1:
The patent modifies processing parameters including extrusion temperature (200-250°C), residence time, and cooling rate to preserve the thermoplastic nature of the base polymer while incorporating conductive carbon blacks, allowing the material to maintain its ability to be reprocessed
Solution Approach 2:
The patent applies local quality by creating heterogeneous distributions of carbon black within the polymer matrix, with conductive aggregates formed in specific regions while leaving other areas with sufficient thermoplastic character for easy manufacturing
3Strength
If dynamic capability is improved by reducing carbon filler content, then crack resistance and elasticity are improved, but electrical conductivity and media stability deteriorate
Solution Approach 1:
The patent optimizes the concentration of conductive carbon black within narrow ranges (0.1-5 wt%) and controls the aspect ratio and morphology of filler particles to achieve percolation thresholds that provide electrical conductivity with minimal filler loading, thereby preserving dynamic capability
Solution Approach 2:
The patent employs composite material design by combining conductive carbon blacks with non-conductive but mechanically reinforcing fillers, creating a synergistic composite where the conductive phase provides electrical properties and the reinforcing phase maintains mechanical performance
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 achieves good dynamic capability, crack resistance, and high media stability, preventing material degradation and maintaining thermoplastic properties, with the addition of carbon fillers or irradiated PTFE reducing permeation and shear forces during processing.
Implementation Method 1
If plastics are to have an electrical conductivity, electrically conductive fillers, such as conductivity carbon blacks, are often used.
Implementation Method 2
These so-called FKM mixtures, also known as FPM mixtures, may be crosslinked with polyols and quaternary ammonium salts
Implementation Method 3
c) irradiated polytetrafluoroethylene (PTFE)
Data Source
AI summary
The invention relates to a hose having at least one barrier layer inner layer and an outer layer, wherein the barrier layer is obtainable by extrusion of a mixture comprising a) at least one thermoplastic fluoropolymer, b) at least one fluororubber and a crosslinking agent and/or at least one fluororubber elastomer and c) at least one carbon filler selected from carbon black, in particular conductivity carbon black, graphene, carbon nanofillers, in particular carbon nanotubes, carbon nanohorns, or a combination thereof in an amount of 0.05% by weight to 20% by weight of the carbon filler(s), or irradiated PTFE, and vulcanization. The hose exhibits a high fuel, diesel and oil stability and dynamic capability.