Rubber-Polyamide Refrigerant Hose Without Adhesive Layer
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Solution Overview
Problem
Existing automotive refrigerant hoses face issues with temperature stability, permeation, and adhesion, particularly due to the use of adhesives in bonding rubber and plastic layers, which can lead to spotty adhesion and increased permeability to refrigerants.
Innovation Solution
A hose design featuring a rubber backing layer directly bonded to a polyamide layer without an intervening adhesive, utilizing a composition of ethylene propylene diene monomer (EPDM), phenylenedimaleimide, and maleated compounds, allowing for improved adhesion and reduced permeation across a wide temperature range.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If an adhesive layer is used to bond the rubber backing layer to the plastic layer, then the bonding process is simplified, but the adhesion becomes spotty and permeation increases
Solution Approach 1:
The patent removes the adhesive layer from the hose structure, eliminating the source of spotty adhesion and permeation issues. The rubber backing layer is directly bonded to the plastic layer through surface treatment and chemical bonding mechanisms, rather than relying on an intermediate adhesive layer that creates weak points in the structure.
Solution Approach 2:
The patent employs composite material strategies by treating the surfaces of the rubber and plastic layers to enhance direct bonding. This includes using silane crosslinking agents and surface plasma treatment to create chemically active surfaces that form strong bonds without requiring an adhesive intermediary.
2Ease of manufacture
If standard rubber and plastic materials are used, then the hose is easy to manufacture, but temperature stability and permeation resistance are insufficient
Solution Approach 1:
The patent modifies the chemical and physical parameters of the rubber and plastic materials to achieve superior temperature stability and permeation resistance. This includes selecting specific polymer compositions, crosslinking densities, and crystalline structures that maintain structural integrity across extreme temperature ranges while resisting refrigerant permeation.
Solution Approach 2:
The patent uses composite material constructions with specifically engineered rubber and plastic layers that provide both ease of manufacture and superior temperature stability. The multi-layer structure incorporates materials with complementary properties that collectively achieve the desired performance characteristics.
3Device complexity
If an adhesive layer is used for bonding, then the manufacturing process is simpler, but the hose becomes more permeable to refrigerants
Solution Approach 1:
The patent eliminates the adhesive layer that acts as a permeation pathway for refrigerants. By achieving direct bonding between the rubber and plastic layers through surface treatment and chemical bonding, the structure removes the weak link that allows refrigerant migration, thereby reducing substance loss.
Solution Approach 2:
The patent employs thin film structures with optimized thickness and composition in the rubber and plastic layers to prevent refrigerant permeation. The direct bond between layers creates a continuous, impermeable barrier that blocks refrigerant migration paths.
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 provides enhanced low and high-temperature stability, decreased permeation, and improved adhesion between the rubber and polyamide layers, outperforming standard automotive refrigerant hoses in terms of refrigerant retention and durability.
Implementation Method 1
the rubber backing layer is directly covalently bonded directly to the polyamide layer without adhesive
Implementation Method 2
a maleated compound is present in the rubber backing composition
Data Source
AI summary
A hose is provided comprising a rubber backing layer directly bonded to a continuous polyamide layer without an intervening adhesive layer, wherein the hose exhibits increased low and high temperature capability and decreased permeation compared to standard automotive refrigerant hoses.