Fluorinated Plastomer Pipe Layer for Low-Permeability Refrigerant Lines
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Solution Overview
Problem
Current polymer pipes used in motor vehicle air conditioning systems and other applications fail to achieve low enough permeability and high enough mechanical resistance to refrigerants like R-134 and CO2, especially under high pressures and over the vehicle's life cycle, while also meeting stringent testing requirements.
Innovation Solution
A pipe with a layer comprising a mixture of a fluorinated plastomer and an elastomeric material, where the fluorinated plastomer is present in greater amounts than the elastomeric material, along with additional layers such as reinforcing spun fibers and a coating layer, to enhance mechanical resistance and impermeability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of substance
If conventional polymer pipes are used in air conditioning systems, then they provide ease of manufacture and weight reduction, but they exhibit high permeability to refrigerants like R-134 and CO2
Solution Approach 1:
The patent employs a composite material structure consisting of an inner layer made from fluorinated plastomer and elastomeric material mixture, combined with an outer protective layer. This composite structure achieves low refrigerant permeability while maintaining ease of manufacture, as the layers can be applied through conventional coating and extrusion processes.
Solution Approach 2:
The patent modifies the chemical composition parameters by incorporating fluorinated plastomer (20-80 parts by weight per 100 parts elastomeric material) and specific elastomeric materials with controlled molecular structures. This parameter optimization reduces refrigerant permeability while keeping the manufacturing process compatible with existing production methods.
2Strength
If polymer pipes are used to replace aluminum piping, then production costs and weight are reduced, but mechanical resistance to high pressures is insufficient
Solution Approach 1:
The patent creates a composite pipe structure with an inner pressure-resistant layer (fluorinated plastomer + elastomeric material) and an outer protective layer. This composite design provides aluminum-level mechanical strength while maintaining the weight and manufacturing advantages of plastic materials.
Solution Approach 2:
The pipe is segmented into functional layers: an inner layer for pressure resistance and chemical resistance, and an outer layer for mechanical protection. This segmentation allows each layer to be optimized for its specific function, achieving high strength-to-weight ratio.
3Duration of action of stationary object
If conventional polymer pipes are used, then they provide ease of manufacture, but they fail to maintain functionality over the vehicle's entire life cycle under high pressure conditions
Solution Approach 1:
The patent uses a composite structure with an inner functional layer (fluorinated plastomer + elastomeric material) and an outer protective layer, providing long-term durability against pressure, chemical etching, and environmental factors while maintaining a relatively simple manufacturing process.
Solution Approach 2:
The pipe structure applies local quality optimization by using fluorinated plastomer (which provides excellent chemical resistance and low permeability) specifically in the inner layer that contacts the refrigerant, while the outer layer provides general mechanical protection. This localized material selection extends service life without requiring complex multi-material construction throughout the entire pipe.
Data Source
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AI summary
The invention relates to a low permeability pipe resistant to high pressures for adducting a fluid in a motor vehicle comprising at least one layer comprising a fluorinated plastomer and an elastomeric material, in which the fluorinated plastomer is in a greater amount with respect to the elastomeric material. The pipe may further comprise a reinforcing spun fibre and a coating layer made of elastomeric material and/or other layers.