Cable Jackets With Aligned Microcapillaries

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Solution Overview

Problem

Conventional methods for reducing the weight of power and telecommunications cable coatings through foaming deteriorate mechanical properties due to random void-space distribution, leading to rapid failure under deformation.

Innovation Solution

A coated conductor with an elongated polymeric coating comprising a polymeric matrix material and microcapillaries filled with elastomeric material, where the microcapillaries are aligned in the direction of elongation, providing discrete void spaces surrounded by the matrix material, and containing adhesion modifiers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Weight of moving object

If foaming processes are used to reduce polymer density and jacket weight, then weight is reduced, but mechanical properties deteriorate due to random void-space distribution

Engineering Contradiction:
Improvejacket weightVSAvoidmechanical properties
Core Design Contradiction:
Weight of moving objectVSStrength

Solution Approach 1:

The invention divides the void space into discrete, segmented microcapillaries with controlled dimensions and spacing, rather than having random continuous voids. This segmentation allows each microcapillary to be surrounded by sufficient polymeric matrix material, preventing the formation of weak spots while maintaining weight reduction benefits.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention creates local quality variations by introducing microcapillaries with specific spacing and size distributions throughout the polymeric matrix. This allows different regions of the jacket to have optimized properties - the microcapillaries provide weight reduction locally while the surrounding matrix material maintains mechanical strength locally.

Inventive Principle:
Principle #3Local quality

2Weight of moving object

If microcapillaries are introduced to reduce density and weight, then weight is reduced, but mechanical integrity may be compromised without proper alignment

Engineering Contradiction:
Improvejacket weightVSAvoidmechanical integrity
Core Design Contradiction:
Weight of moving objectVSReliability

Solution Approach 1:

The invention introduces directional asymmetry by aligning microcapillaries in the extrusion direction rather than having random orientation. This asymmetric arrangement optimizes mechanical performance by ensuring that the majority of microcapillary walls are oriented perpendicular to the primary stress direction during deformation, preventing rapid failure.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The invention changes critical parameters including microcapillary spacing (at least 0.5 mm between adjacent microcapillaries), dimensions, and orientation to optimize the balance between weight reduction and mechanical integrity. These parameter changes ensure sufficient matrix material surrounds each microcapillary while maintaining overall jacket strength.

Inventive Principle:
Principle #35Parameter changes

3Strength

If adhesion modifiers are added to improve bonding between matrix and microcapillary materials, then interfacial strength is improved, but formulation complexity increases

Engineering Contradiction:
Improveinterfacial adhesionVSAvoidformulation complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The invention uses adhesion modifiers as intermediary substances at the interface between the polymeric matrix material and microcapillary material. These modifiers act as mediators that improve interfacial bonding and adhesion strength, preventing delamination and enhancing overall mechanical performance.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The invention creates a composite material system combining polymeric matrix material, microcapillary material, and adhesion modifiers. This composite approach leverages the complementary properties of each component - the matrix provides structural continuity, the microcapillaries provide weight reduction, and the adhesion modifiers ensure strong interfacial bonding.

Inventive Principle:
Principle #40Composite materials

Data Source

PatentEP3234956B1Cable jackets having designed microstructures
Publication Date: 2020.05.20 DOW GLOBAL TECHNOLOGIES LLC
  • EP3234956B1 patent drawingFigure 1
  • EP3234956B1 patent drawingFigure 2A~2E
  • EP3234956B1 patent drawingFigure 2C~2D

AI summary

Coated conductors comprising a conductor and elongated polymeric coatings at least partially surrounding the conductor, where the elongated polymeric coatings comprise a polymeric matrix material and a plurality of microcapillaries defining individual, discrete void spaces. Such coated conductors are lighter in weight relative to coated conductors having polymeric coatings without microcapillaries. Also disclosed are dies and methods for making such coated conductors.