Polyolefin Cable Insulation Composition Without Crosslinking
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing polyolefin-based insulation materials for electric cables face challenges with low-temperature impact resistance, rigidity, and flexibility, leading to issues during installation and operation, and are not recyclable due to crosslinking, which also generates environmental contamination.
Innovation Solution
A polyolefin resin composition comprising 70-95% ethylene-propylene block copolymer and 5-30% ethylene-propylene rubber copolymer, with specific glass transition and melting temperatures, melt index, and additives, allowing for improved flexibility, low-temperature impact resistance, and recyclability without crosslinking.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If polyethylene or EPR/EPDM is crosslinked to maintain mechanical and electrical characteristics at operating temperature, then thermal resistance is improved, but recyclability is lost and environmental contamination occurs
Solution Approach 1:
The patent changes the chemical structure parameter by using polypropylene homopolymer or copolymer instead of crosslinked polyethylene, achieving high-temperature resistance (110-130°C operating temperature) without crosslinking, thus eliminating environmental contamination from crosslinking by-products while maintaining thermal stability
Solution Approach 2:
The patent extracts the crosslinking step from the material processing sequence, using non-crosslinked polypropylene that inherently provides high-temperature resistance, thereby removing the source of environmental contamination while preserving the required thermal performance
2Temperature
If polypropylene is used to raise operating temperature to 110-130°C, then thermal resistance is improved, but low-temperature impact resistance deteriorates and cables may break during installation
Solution Approach 1:
The patent creates a composite material system by blending polypropylene homopolymer or copolymer with specific elastomers (ethylene-propylene rubber, butadiene rubber, or isoprene rubber) in controlled ratios, where the elastomer components provide low-temperature flexibility and impact resistance while the polypropylene matrix maintains high-temperature stability, enabling the cable to withstand both high operating temperatures and low-temperature installation conditions
3Ease of operation
If rubber phase content is increased to improve softness and flexibility, then ease of installation is improved, but mechanical properties and heat deformation resistance are compromised
Solution Approach 1:
The patent optimizes the compositional parameters by precisely controlling the rubber phase content within 5-30 wt% and selecting specific glass transition temperatures (-60 to -40°C) for the rubber component, achieving the optimal balance where sufficient flexibility for installation is obtained while maintaining mechanical strength and heat deformation resistance through the controlled interaction between rubber and polypropylene phases
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 flexibility, low-temperature impact resistance, and thermal stability, enabling the use as an insulation layer for electric cables with improved dielectric breakdown strength and volume resistance, suitable for high-voltage operations.
Implementation Method 1
the glass transition temperature of the rubber component in the ethylene-propylene block copolymer appears at -60 to -40°C as measured by a dynamic mechanical analyzer
Implementation Method 2
the melting temperature (Tm) thereof is 145 to 170°C, whereby it is excellent in thermal resistance
Implementation Method 3
excellent flexibility, low-temperature impact resistance, and thermal stability, enabling the use as an insulation layer for electric cables with improved dielectric breakdown strength and volume resistance
Data Source
AI summary
The present invention relates to a polyolefin resin composition having improved softness suitable for electric cables for power transmission and distribution. In particular, the present invention relates to a polyolefin resin composition having excellent resistance to low temperatures, mechanical, and insulation characteristics, as well as improved softness. Since it can be used as an insulation material for electric cables without being crosslinked, it is recyclable.