Cable Termination Adhesion via Surface Treatment
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Solution Overview
Problem
Current cable termination methods face challenges in achieving a tight and sealed connection, especially with non-polyvinyl chloride (PVC) materials, due to poor adhesion between insulation materials and sealants, leading to difficulties in ensuring water tightness and electromagnetic shielding.
Innovation Solution
A method involving preparation of the cable end's outer jacket to promote adhesion with a sealant, using polyurethane material and techniques like overmolding, application of adhesive tapes, plasma treatment, and heat-shrinkable sleeves to create a watertight seal without an additional housing, utilizing materials like PVC, rubber, and silicone for improved adhesion and sealing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If solid gaskets or liquid gaskets based on silicone adhesives are used to seal between the cable and housing, then sealing is achieved, but adhesion is poor when the insulation material is non-PVC (e.g., XLPE, polyolefins, silicone)
Solution Approach 1:
The cable insulation surface is prepared in advance (mechanically roughened, chemically treated, or plasma treated) before applying the polyurethane sealant. This preliminary surface preparation creates a surface that promotes adhesion, allowing the sealant to bond effectively to non-PVC insulation materials like XLPE and polyolefins.
Solution Approach 2:
An intermediate layer or surface treatment is introduced between the non-PVC cable insulation and the polyurethane sealant. This intermediate surface layer (created through roughening, chemical treatment, or plasma treatment) acts as a mediator that enables adhesion between materials that would otherwise be incompatible.
2Ease of manufacture
If polyurethane material is used as sealant, then good adhesion to PVC is achieved, but adhesion to non-PVC materials (XLPE, polyolefins) is very poor
Solution Approach 1:
The surface parameters of the non-PVC insulation material are changed through mechanical roughening, chemical treatment, or plasma treatment. These parameter changes modify the surface energy and texture of the insulation, making it compatible with polyurethane sealant and enabling effective adhesion.
Solution Approach 2:
Chemical treatments involving oxidants or plasma treatment are applied to the non-PVC insulation surface to create a more reactive surface. This accelerated oxidation or chemical modification of the surface creates bonding sites that enable polyurethane adhesion to materials like XLPE and polyolefins.
3Reliability
If additional housing is used to ensure water tightness, then sealing is improved, but device complexity and manufacturing cost increase
Solution Approach 1:
The sealing function is merged with the housing structure itself. The polyurethane sealant is integrated directly into the housing, forming a unified sealing system that eliminates the need for separate additional housing components while maintaining water tightness.
Solution Approach 2:
The polyurethane sealant performs multiple functions: it provides sealing against water, ensures electrical insulation, and offers electromagnetic shielding. This multi-functionality eliminates the need for additional specialized housing components, reducing overall device complexity.
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 method achieves a 100% tight insulation against water, oils, acids, and chemicals, with resistance to temperature and vibrations, and allows for low-pressure injection molding, eliminating the need for a separate housing and enabling effective sealing in high-voltage applications.
Implementation Method 1
preparation of the protective outer jacket of the cable end such as to promote adhesion with a sealant
Implementation Method 2
This allows the use of low-pressure injection molding technology wherein the overmold of sealant may be molded to form a watertight and sealed outer enclosure
Implementation Method 3
positioning a sleeve made of heat shrinkable material over the sealing ring, heat shrinking the sleeve to exert a compressive force onto the sealing ring
Implementation Method 4
an elastic sealing ring positioned over a cable end... exert a compressive force onto the sealing ring
Data Source
AI summary
A cable termination includes a cable end of a cable having a protective outer jacket and an overmolded sealant. The cable termination is manufactured using a method having the steps of providing a cable end of a cable having a protective outer jacket, preparing the protective outer jacket of the cable end such as to promote adhesion with a sealant, and overmolding the cable end with a sealant.