Semi-Conductive Composite Resin Shielding Material for Stable Cable Resistance
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Solution Overview
Problem
Traditional semi-conductive shielding materials for high-voltage cables exhibit a high positive temperature coefficient (PTC) that causes resistance variations under high-voltage conditions, affecting the stability of high-voltage cables.
Innovation Solution
A composite resin-based semi-conductive shielding material is developed using a blend of low-density polyethylene resin and ethylene-acrylic acid resin, with specific ratios and additives, which stabilizes the electrically conductive network by suppressing thermal expansion and enhancing filler contact, thereby reducing the PTC effect.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional semi-conductive shielding materials are used for high-voltage cables, then the cable structure is simple and easy to manufacture, but the positive temperature coefficient (PTC) is high causing wide resistance variations under high-voltage conditions
Solution Approach 1:
The patent employs a composite resin system comprising low-density polyethylene resin and ethylene-acrylic acid resin in specific proportions (mass ratio 1:4 to 1:1). This composite material combines the low PTC characteristics of ethylene-acrylic acid resin with the structural stability of polyethylene, achieving resistance stability under high-voltage conditions while managing the complexity through defined composition ranges.
Solution Approach 2:
The patent optimizes multiple parameters including the mass ratio of resin components (1:4 to 1:1), melt flow index of polyethylene (0.25-2g/10min), and cross-linking agent content (0.9-2 parts by mass). These parameter adjustments create a balanced formulation that reduces PTC effect while maintaining manufacturability and structural integrity for high-voltage cable applications.
2Reliability
If the PTC is reduced to stabilize resistance, then the bonding strength with insulating layer improves, but the manufacturing process becomes more complex
Solution Approach 1:
The patent specifies precise parameter ranges for manufacturing: mass ratios of resin components (1:4 to 1:1), controlled melt flow index (0.25-2g/10min), and cross-linking agent dosage (0.9-2 parts by mass). These defined parameters standardize the manufacturing process, making the complex composite system reproducible and manageable in production while achieving the desired low PTC and improved bonding strength.
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 composite resin-based material maintains stable conductivity and improves bonding strength with the insulating layer, increasing the lifespan of high-voltage cables by minimizing resistance fluctuations.
Implementation Method 1
the melting expansion of the ethylene-acrylic acid resin with the increase of temperature during the use of the cable is suppressed by the low-density polyethylene resin
Implementation Method 2
mixing the granulated material with the cross-linking agent to obtain a preform; and heating the preform
Data Source
Figure 1
AI summary
The present application relates to a composite resin-based semi-conductive shielding material, prepared from raw materials including following components: 55 to 65 parts by mass of a composite resin, 20 to 30 parts by mass of electrically conductive fillers, and 0.9 to 2 parts by mass of a cross-linking agent, wherein the composite resin is a composite of a low-density polyethylene resin and an ethylene-acrylic acid resin, and the ethylene-acrylic acid resin is at least one of an ethylene-ethyl acrylate resin or an ethylene-butyl acrylate resin.