Cable Structural Elongation Control via Adhesive-Coated Steel Filaments

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Solution Overview

Problem

Existing cables exhibit unpredictable structural elongation due to factors like filament structure and voids, leading to instability in tension-elongation curves, particularly in high-precision applications like timing belts, resulting in manufacturing challenges and scrap during production.

Innovation Solution

A cable with a steel cord coated in an adhesive before polymer penetration, achieving a structural elongation of less than 0.025% and an increased E modulus by more than 4%, with a polymer filling rate of over 70% and a polymer coating thickness of less than 10µm, which enhances the anchorage of steel filaments and limits elongation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a cable is made with traditional steel cord and polymer material without adhesive coating, then the manufacturing process is simple, but the structural elongation is unstable and unpredictable

Engineering Contradiction:
Improvepredictability of tension-elongation curveVSAvoidcabling process complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The steel filaments are pre-coated with adhesive before the polymer penetration process. This preliminary action ensures that when polymer material penetrates the cable, it adheres properly to the steel filaments, eliminating the unpredictable structural elongation without requiring complex post-processing or lengthy fine-tune procedures

Inventive Principle:
Principle #10Preliminary action

2Manufacturing precision

If polymer material penetrates deeply into the steel cord to reduce structural elongation, then the structural elongation decreases, but the extrusion process requires high pressure and has limited penetration rate

Engineering Contradiction:
Improvestructural elongation controlVSAvoidextrusion pressure
Core Design Contradiction:
Manufacturing precisionVSStress or pressure

Solution Approach 1:

The adhesive coating is applied to steel filaments before polymer penetration, creating a bonding interface that allows effective polymer penetration at lower pressures. The adhesive acts as a mediator that enables the polymer to anchor to the steel filaments without requiring extreme extrusion pressures

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The adhesive coating serves as an intermediary substance between the polymer material and the steel filaments. It facilitates the bonding process by providing a surface that both materials can adhere to, enabling effective stress transfer without requiring the polymer to penetrate deeply under high pressure

Inventive Principle:
Principle #24Intermediary (Mediator)

3Strength

If the cable uses bare steel cord without adhesive coating, then the E module is lower, but the manufacturing process is simpler

Engineering Contradiction:
ImproveE moduleVSAvoidcoating process complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The adhesive is pre-applied to the steel filaments in a thin layer before polymer penetration. This preliminary coating step is integrated into the manufacturing process and enables the polymer to effectively bond with the steel, increasing the E module by more than 4% without requiring complex multi-step coating procedures

Inventive Principle:
Principle #10Preliminary action

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 significantly reduces the total elongation of the cable at certain loads by 52%, improves the E modulus, and maintains the cable's tensile strength, facilitating more predictable performance and manufacturing efficiency.

Implementation Method 1

The steel filaments of the steel cord are coated with an adhesive before the penetration of the polymer material

Methodology Applied
Scientific EffectAdhesion: Adhesive

Implementation Method 2

The polymer filling rate is more than 70%

Methodology Applied
Scientific EffectPenetration: Permeation

Implementation Method 3

the elongation of the cable is almost linear to the tension of the cable as illustrated by line 120 in FIGURE1. The elongation of the cable increases steadily with the increase of the tension of the cable, i.e. Δε=Δδ/E

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP2104764B1Cable with low structural elongation
Publication Date: 2012.06.27 NV BEKAERT SA
  • EP2104764B1 patent drawingFigure 1~2
  • EP2104764B1 patent drawingFigure 3

AI summary

A cable (211) is provided comprising a steel cord (212) and a polymer material (215). The steel filaments (213) of the steel cord (212) are coated with an adhesive before the penetration of the polymer material (215). The cable (211) has a structural elongation less than 0.025% and an E module 4% greater than the E module of the steel cord (212). These two improvements further decrease the total elongation of the cable at certain load.