Segmented Water-Swellable Cable Barrier Design

Solution Overview

Problem

Existing electric cables with water-swellable materials for water penetration barriers are costly, complex, and can impair thermal insulation and current transfer due to excessive use of water-swellable tape, which is not effectively localized in case of damage.

Innovation Solution

The use of at least two longitudinal elements of water-swellable material wound helically around the metal shielding at intervals, allowing uncovered areas to absorb water and reducing the amount of tape required, with the metal shielding acting as a primary barrier, and the water-swellable strips being loosely applied to minimize production costs and enhance heat dissipation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If water-swellable tape is applied around the metallic shielding to completely cover the cable, then water penetration barrier is improved, but manufacturing cost increases and heat dissipation deteriorates

Engineering Contradiction:

Improvewater penetration barrierVSAvoidcable structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The continuous water-swellable tape is segmented into discrete sections spaced at intervals along the cable length. Each section acts as an independent water barrier segment, allowing water to be contained in localized zones rather than providing continuous coverage. This segmentation reduces material usage while maintaining effective water protection through the swelling action at each interval.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Instead of applying water-swellable material excessively over the entire cable length, the invention uses partial action by positioning discrete sections at strategic intervals. The metallic shielding provides baseline protection, and the water-swellable sections provide enhanced barrier function only where needed, achieving sufficient protection without excessive material application.

Inventive Principle:

Principle #16Partial or excessive action

2Reliability

If water-swellable tape is applied around the metallic shielding, then water penetration barrier is improved, but manufacturing cost increases due to high material quantity

Engineering Contradiction:

Improvewater penetration barrierVSAvoidmanufacturing cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The continuous water-swellable tape is segmented into discrete sections spaced at intervals along the cable length. Each section acts as an independent water barrier segment, allowing water to be contained in localized zones rather than providing continuous coverage. This segmentation reduces material usage while maintaining effective water protection through the swelling action at each interval.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The invention uses discrete sections of water-swellable material that can be simpler and less expensive than continuous tape. These sections are positioned at intervals where water barrier function is most critical, using material more economically while achieving the same protective effect through strategic placement rather than continuous application.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

3Reliability

If water-swellable tape is applied around the metallic shielding, then water penetration barrier is improved, but heat dissipation deteriorates due to thermal insulation

Engineering Contradiction:

Improvewater penetration barrierVSAvoidheat dissipation

Core Design Contradiction:

ReliabilityVSTemperature

Solution Approach 1:

The continuous water-swellable tape is segmented into discrete sections spaced at intervals along the cable length. Each section acts as an independent water barrier segment, allowing water to be contained in localized zones rather than providing continuous coverage. This segmentation reduces material usage while maintaining effective water protection through the swelling action at each interval.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Instead of applying water-swellable material excessively over the entire cable length, the invention uses partial action by positioning discrete sections at strategic intervals. The metallic shielding provides baseline protection, and the water-swellable sections provide enhanced barrier function only where needed, achieving sufficient protection without excessive material application that would impede heat dissipation.

Inventive Principle:

Principle #16Partial or excessive action

4Reliability

If swelling fleece is applied by strips or cross-coils to form separate chambers, then water barrier is improved, but water can still contact conductor strands directly if sheath is torn

Engineering Contradiction:

Improvewater barrierVSAvoidwater contact with conductors

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The invention introduces water-swellable material positioned between the metallic shielding and the outer sheath as an intermediary water barrier. This intermediate layer provides an additional protective function that activates upon water ingress, swelling to block water pathways and prevent water from reaching the conductors even when the outer sheath is damaged.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The water-swellable material is positioned in advance between the metallic shielding and outer sheath to provide preemptive protection. In the event of sheath damage, this pre-positioned material swells upon water contact to create an emergency barrier, cushioning against water ingress before water can reach the conductors.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

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

This solution creates a cost-effective, efficient water barrier that prevents water damage from spreading along the cable while maintaining heat dissipation and reducing production costs by minimizing the amount of water-swellable material used.

Implementation Method 1

an internal barrier against water penetration made of a ribbon-shaped, water-swellable material

Methodology Applied

Scientific EffectWater swelling: Absorption (physical)

Implementation Method 2

the water-swellable material inside the cable forms a barrier in the event of external cable damage and the resulting water ingress

Methodology Applied

Scientific EffectWater swelling: Hydrogel

Data Source

PatentEP2874157B1Electric cable

Publication Date: 2021.02.17 LEONI STUDER

Figure 1~2
Figure 3~5

AI summary

The invention relates to an electrical cable with a barrier against water penetration (9) made of a ribbon-shaped, water-swellable material, which is inserted between a metal shield (7) and an outer sheath 8 made of plastic material surrounding it. The barrier (9) consists of two ribbons (10, 11) of water-swellable material, which are wound helically around the metal shield (7) at specific intervals along the cable, overlapping each other. This creates sections (13) along the cable that are not covered by the ribbons (10, 11). In this way, the amount of ribbon required for manufacturing the barrier is reduced, and the manufacturing costs of the cable are lowered without significantly impairing the protective function of the barrier.