Non-crosslinked Polyethylene Power Cable Insulator
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Solution Overview
Problem
Crosslinked polyethylene resins used in power cables are not recyclable, leading to environmental pollution, and non-crosslinked polyethylene resins lack sufficient heat resistance and processability, resulting in poor performance as insulators, especially in outdoor and harsh environments.
Innovation Solution
A non-crosslinked polyethylene composition for power cables is developed, comprising middle-density and linear low-density polyethylene resins, metal hydroxides, red phosphorus, and carbon black, which enhances tracking resistance, mechanical properties, and environmental durability while reducing density and manufacturing costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If crosslinked polyethylene resin is used as insulating material, then heat resistance and chemical resistance are improved, but recyclability deteriorates and environmental pollution increases
Solution Approach 1:
The invention changes the fundamental parameter of polyethylene structure from crosslinked (thermosetting) to non-crosslinked (thermoplastic) form. By using non-crosslinked polyethylene resin with specific density ranges (0.915-0.935 g/cm³) and incorporating flame retardants and stabilizers, the material achieves both environmental friendliness and sufficient heat resistance for cable applications.
Solution Approach 2:
The invention creates a composite material system by combining non-crosslinked polyethylene resin with flame retardants (metal hydroxides, red phosphorus), stabilizers (antioxidants, UV stabilizers), and other additives. This composite approach enables the thermoplastic polyethylene to achieve properties comparable to crosslinked polyethylene, including flame resistance and long-term heat stability, while maintaining recyclability.
2Object-generated harmful factors
If non-crosslinked thermoplastic polyethylene resin is used, then recyclability and environmental friendliness are improved, but heat resistance deteriorates
Solution Approach 1:
The invention modifies the parameters of non-crosslinked polyethylene by selecting specific resin types (MDPE, LLDPE) with controlled density and molecular weight, and by optimizing the formulation with flame retardants and stabilizers. These parameter changes enable the thermoplastic material to withstand cable operating temperatures and resist thermal degradation over time.
Solution Approach 2:
The invention introduces stabilizers (antioxidants like Irganox 1010 and 168, UV stabilizers) as intermediaries that protect the non-crosslinked polyethylene from thermal and environmental degradation. These additives act as mediators between the thermoplastic resin and harsh operating conditions, preventing chain scission and maintaining mechanical properties at elevated temperatures.
3Temperature
If cross-linkage process using organic peroxide is applied, then heat resistance is improved, but productivity deteriorates due to high pressure and temperature requirements
Solution Approach 1:
The invention extracts and eliminates the cross-linkage process entirely from the manufacturing workflow. By using non-crosslinked polyethylene resin that inherently provides sufficient performance when properly formulated, the complex cross-linking steps involving organic peroxide, high pressure, and high temperature are removed, dramatically simplifying production and improving productivity.
Solution Approach 2:
Instead of starting with crosslinked polyethylene and seeking alternatives, the invention inverts the approach by starting with non-crosslinked polyethylene and enhancing it through formulation. This reversal eliminates the need for post-processing cross-linkage steps and enables direct extrusion and installation.
4Reliability
If metal hydroxide is added to improve tracking resistance, then flame retardancy is improved, but mechanical properties deteriorate due to poor compatibility with polyethylene
Solution Approach 1:
The invention introduces coupling agents (silane-based or titanate-based) as intermediaries between metal hydroxide particles and polyethylene resin. These coupling agents improve interfacial adhesion, ensure uniform stress distribution, and prevent particle aggregation, thereby maintaining tensile strength and elongation even with 5-15 parts by weight of metal hydroxide incorporated.
Solution Approach 2:
The invention optimizes the particle size, surface treatment, and distribution of metal hydroxide fillers to minimize their negative impact on mechanical properties. By controlling these parameters and using appropriate coupling agents, the formulation achieves both flame retardancy and acceptable mechanical performance.
5Manufacturing precision
If high pressure is applied to remove bubbles during cross-linkage, then insulator quality is improved, but productivity deteriorates and equipment complexity increases
Solution Approach 1:
The invention extracts and eliminates the bubble removal step entirely by preventing bubble formation in the first place. Since the non-crosslinked polyethylene processing does not involve high-temperature decomposition reactions that generate gases, no high-pressure debubbling equipment or processes are needed, simplifying the manufacturing line and improving productivity.
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 composition provides excellent tracking resistance, mechanical properties, and long-term reliability, enabling the use of non-crosslinked polyethylene as a reusable and environmentally friendly insulator for power cables, with improved processability and reduced environmental impact.
Implementation Method 1
an organic peroxide is decomposited by high temperature heat to produce radicals, thereby completing the cross-linkage reaction
Implementation Method 2
an organic peroxide is decomposited by high temperature heat to produce radicals
Data Source
AI summary
Provided is a polymer composition usable as a covering material of a power cable for outdoors, and more particularly, a non-crosslinked polyethylene composition for a power cable using a non-crosslinked type polyethylene resin instead of using a crosslinked polyethylene which is widely used around the world as the existing power cable insulator. The power cable using a covering material made of the polymer composition according to the present invention may have excellent tracking resistance to be appropriately used in costal areas containing large salts, industrial complexes containing large pollutants, and the like.