Thermoplastic Matrix Coating for Strand Strength and Breakage Resistance

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Solution Overview

Problem

High-strength plastic fibers used in ropes and strands exhibit weakness in the transverse direction, leading to a significant risk of breakage under load, limiting their load-bearing capacity and service life.

Innovation Solution

A method where fibers or wires are surrounded by a matrix material, filling the spaces between them and embedding them completely, creating a composite rope with improved mechanical properties, including enhanced strength and resistance to breakage, by using a thermoplastic matrix material like polypropylene, polycarbonate, or PEEK, which protects and connects the fibers, reducing perpendicular loading and allowing for embedding during the stranding process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If high-strength plastic fibers are used to reduce weight and improve strength-to-weight ratio, then the rope becomes lighter and stronger in longitudinal direction, but the fibers become very weak in transverse direction leading to considerable risk of breakage

Engineering Contradiction:
Improvestrength-to-weight ratioVSAvoidrisk of breakage
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The patent applies composite materials by combining high-strength plastic fibers with a thermoplastic matrix material. The fibers provide longitudinal strength while the matrix material provides transverse support and protection. This composite structure allows the rope to maintain high strength-to-weight ratio while significantly reducing the risk of fiber breakage, as the matrix material surrounds and protects the vulnerable fiber surfaces.

Inventive Principle:
Principle #40Composite materials

2Reliability

If a sheath is added to protect the plastic fibers from damage, then the fibers are protected and held together, but the complexity of the rope structure increases

Engineering Contradiction:
Improveprotection of fibersVSAvoidstructure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the protective sheath function with the matrix material that already surrounds the fibers. Instead of adding a separate sheath layer, the thermoplastic matrix material serves both as the binding medium holding fibers together and as the protective outer layer. This integration reduces structural complexity while maintaining fiber protection and coherence.

Inventive Principle:
Principle #5Merging (Combining)

3Reliability

If the fibers are completely embedded in matrix material, then the mechanical properties and resistance to breakage are improved, but the manufacturing process becomes more complex

Engineering Contradiction:
Improveresistance to breakageVSAvoidmanufacturing process complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent utilizes phase transitions of the thermoplastic matrix material to simplify the embedding process. The matrix material is heated to a molten state during stranding, allowing it to flow around and completely embed the fibers. After stranding, the material is cooled and solidifies, automatically achieving complete fiber embedding without complex additional manufacturing steps. This phase transition approach converts a potentially complex embedding process into a straightforward heating-cooling cycle.

Inventive Principle:
Principle #36Phase transitions

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 method produces ropes and strands with enhanced mechanical properties, increased strength, and longer service life by completely surrounding the fibers with matrix material, reducing the risk of breakage and allowing for easier production of core-sheath structures in a single process step, while maintaining the fibers in a stretched state for improved load absorption.

Implementation Method 1

the individual elements of the cable or strand are heated before or during stranding at least to the point where they are close to the plasticization state

Methodology Applied
Scientific EffectMelting: Melting

Implementation Method 2

cooled to a solidification temperature of the plastic before leaving a stranding device

Methodology Applied
Scientific EffectSolidification: Freezing

Data Source

PatentEP2673415B1Method for producing a strand or cable comprising a thermoplastic coating, strand or cable obtained with said method and laying device comprising a coating means
Publication Date: 2017.07.19 CASAR DRAHTSEILWERK SAAR GMBH
  • EP2673415B1 patent drawingFigure 1~2
  • EP2673415B1 patent drawingFigure 3~4
  • EP2673415B1 patent drawingFigure 5~11

AI summary

The invention relates to a method for producing a strand or cable (20), in which fibres (2) and/or wires are twisted on a twisting point (3) to form the strand or cable (20). According to the invention the fibres (2) and/or wires are coated with a liquefied matrix material (4) in front of and/or at the twisting point (3) and are embedded in the matrix material (4) during twisting. The fibres (2) and/or wires are immersed in the matrix material in front of and/or at the twisting point (3) and the formed strand or the formed cable (20) are cooled after the twisting in order for the matrix material (4) to solidify, preferably by air or in a cooling liquid, for example water. The invention further relates to a device for carrying out the method and to a cable which can be produced by means of the method.