TPU PVB Cable Jacket Blend Abrasion Fire Resistance

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Solution Overview

Problem

Heavy industry cables, such as mining cables, face challenges with abrasion and fire resistance due to stringent safety standards, with existing materials like thermoplastic polyurethane (TPU) being expensive and halogenated alternatives like chlorinated polyethylene (CPE) and polychloroprene rubber producing toxic smoke, requiring additional processing steps and increasing production costs.

Innovation Solution

A polymer blend comprising thermoplastic polyurethane (TPU) and Polyvinylbutyral (PVB) with a ratio of less than 50% PVB by weight, combined with fire retardants and plasticizers, is used to create a cable jacket that maintains mechanical strength and abrasion resistance while reducing costs and toxic smoke production.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If thermoplastic polyurethane (TPU) is used for cable jackets, then abrasion and tear resistance are improved, but production cost increases

Engineering Contradiction:
Improveabrasion and tear resistanceVSAvoidproduction cost
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

The patent uses a composite material system combining TPU base polymer with specific additives including abrasion resistance agents (such as silica or alumina trihydrate), fire retardants (such as magnesium hydroxide or aluminum diethyl phosphinate), and processing aids. This composite approach allows the cable jacket to achieve enhanced abrasion and fire resistance properties while maintaining cost-effectiveness by optimizing the formulation and ratios of components rather than using pure TPU throughout.

Inventive Principle:
Principle #40Composite materials

2Reliability

If halogenated polymers like CPE or CR are used for cable jackets, then fire resistance is improved, but toxic smoke production increases

Engineering Contradiction:
Improvefire resistanceVSAvoidtoxic smoke
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent employs halogen-free fire retardant additives such as magnesium hydroxide (MGH) or aluminum diethyl phosphinate (DEPAL) that decompose endothermically to release water vapor and form protective char layers, effectively suppressing flame propagation and toxic smoke generation. These additives are incorporated into the TPU-based polymer blend, replacing halogenated polymers like CPE or CR, thereby achieving fire resistance without the harmful toxic smoke emissions associated with halogenated materials.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Reliability

If elastomer solutions like CPE or CR are used for cable jackets, then fire resistance is improved, but additional crosslinking processing steps are required

Engineering Contradiction:
Improvefire resistanceVSAvoidprocessing steps
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent substitutes the chemical crosslinking process (required for elastomers like CPE or CR) with a thermoplastic processing system. The TPU-based polymer blend can be extruded and formed into cable jackets using standard thermoplastic extrusion equipment without requiring subsequent crosslinking steps. The fire resistance is achieved through incorporated halogen-free additives rather than through crosslinking chemistry, thereby simplifying the manufacturing process and eliminating additional processing steps.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

4Ease of manufacture

If TPU-based polymer blend with reduced TPU content is used, then production cost is reduced, but mechanical strength may be compromised

Engineering Contradiction:
Improveproduction costVSAvoidmechanical strength
Core Design Contradiction:
Ease of manufactureVSStrength

Solution Approach 1:

The patent optimizes the formulation parameters of the TPU-based polymer blend by carefully selecting and balancing the types and ratios of additives. Abrasion resistance agents (such as silica or alumina trihydrate at controlled loadings), fire retardants (such as magnesium hydroxide or aluminum diethyl phosphinate), and processing aids are incorporated at optimized concentrations to maintain mechanical strength properties while reducing the overall cost by limiting the amount of expensive TPU base polymer required. The synergistic interactions between components are leveraged to achieve cost-effective performance.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3447775B1Polymer blend for cable jackets
Publication Date: 2020.07.08 NEXANS SA
  • EP3447775B1 patent drawingFigure 1
  • EP3447775B1 patent drawingFigure 2
  • EP3447775B1 patent drawingFigure 3~4

AI summary

The invention relates to a cable comprising one or more conductors; and a jacket, wherein said jacket is made from a composition including a polymer blend of thermoplastic polyurethane (TPU), and Polyvinylbutyral (PVB), with the ratio of PVB to TPU being less than 50% PVB by weight of the total weight of the polymer blend, the remainder of the polymer blend being TPU.