Multimodal Olefin Copolymer Cable Jacket Composition
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current cable jacket compositions, such as Borstar®HE6067, face challenges in achieving low shrinkage while maintaining reasonable hardness and environmental stress cracking resistance (ESCR), with a need for improved abrasion resistance and processability, especially in high-density fiber optic cables.
Innovation Solution
A cable jacket composition comprising a multimodal olefin copolymer with a density of 0.935-0.960 g/cm3 and MFR2 of 1.5-10.0 g/10 min, featuring a bimodal polymer mixture of low and high molecular weight components, which follows a specific correlation for wear index and MFR2, and includes a MgCl2 supported catalyst for polymerization, enhancing ESCR and abrasion resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the MFR2 of the composition is increased to improve shrinkage, then shrinkage is reduced, but ESCR deteriorates
Solution Approach 1:
The patent applies parameter changes by precisely controlling the MFR2 value within the range of 1.5-10.0 g/10 min and density within 0.935-0.960 g/cm3 to achieve optimal balance between shrinkage reduction and ESCR maintenance. This quantitative parameter optimization resolves the contradiction by finding the sweet spot where both requirements are satisfied simultaneously.
Solution Approach 2:
The patent uses composite materials by formulating a multimodal olefin copolymer that combines different molecular weight distributions and comonomer compositions. This composite polymer structure integrates the low-shrinkage characteristics of higher MFR2 materials with the high ESCR properties of specific copolymer compositions, thereby resolving the contradiction between shrinkage reduction and ESCR maintenance.
2Strength
If the hardness of the jacket is increased to improve mechanical strength, then mechanical strength is improved, but ESCR deteriorates
Solution Approach 1:
The patent resolves this contradiction by changing the compositional parameters of the olefin copolymer, specifically controlling the comonomer content and molecular weight distribution. By adjusting these parameters within specific ranges, the jacket achieves both high mechanical strength and high ESCR, breaking the traditional trade-off between hardness and crack resistance.
Solution Approach 2:
The multimodal olefin copolymer acts as a composite material that combines polymer chains with different characteristics. The mixture of different molecular weight fractions and comonomer types creates a synergistic effect where the material exhibits both high mechanical strength and high environmental stress cracking resistance simultaneously.
3Strength
If the abrasion resistance is improved by increasing MFR2, then abrasion resistance is improved, but processability deteriorates
Solution Approach 1:
The patent applies parameter changes by optimizing the MFR2 value within a specific range (1.5-10.0 g/10 min) rather than simply maximizing it. This controlled parameter adjustment achieves improved abrasion resistance while maintaining adequate processability, resolving the contradiction by finding the optimal balance point rather than extreme values.
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 achieves reduced shrinkage, improved abrasion resistance, and excellent processability, maintaining mechanical properties and ESCR, making it suitable for high-density fiber optic cables and other communication cables.
Implementation Method 1
the polymerization of the multimodal olefin copolymer comprises two main polymerization stages in the presence of a MgCl2 supported catalyst
Data Source
AI summary
The present invention relates to a cable jacket composition comprising a multimodal olefin copolymer, wherein said olefin copolymer has a density of 0.935-0.960 g/cm3 and MFR2 of 1.5-10.0 g/10 min and comprises a bimodal polymer mixture of a low molecular weight homo- or copolymer and a high molecular weight copolymer wherein the composition has ESCR of at least 2000 hours and wherein the numerical values of cable wear index and composition MFR2 (g/10 min) follow the correlation: Wear index<15.500+0.900*composition MFR2. The invention further relates to the process for preparing said composition and its use as outer jacket layer for a cable, preferably a communication cable, most preferably a fiber optic cable.