Melt-Spun TPU Fiber Composition for Heat-Resistant Disperse Dyeing

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Solution Overview

Problem

Existing thermoplastic polyurethane (TPU) fibers face challenges in melt-spinning due to lack of heat resistance, making them unsuitable for dyeing with other fibers and limiting their use in fabrics, while also posing environmental concerns from solvent-based dry spinning processes.

Innovation Solution

A melt-spun TPU fiber composition comprising a polyol component derived from caprolactone monomer and poly(tetramethylene ether glycol), a chain extender, and an isocyanate cross-linking agent, allowing for high heat resistance and elasticity, enabling dyeing at elevated temperatures with other fibers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If dry spinning process is used to make TPU fibers, then heat resistance is improved, but manufacturing cost increases and environmental concerns arise due to solvent use

Engineering Contradiction:
Improveheat resistanceVSAvoidmanufacturing cost and environmental impact
Core Design Contradiction:
TemperatureVSEase of manufacture

Solution Approach 1:

The patent changes the fundamental parameter of the spinning process from solvent-based dry spinning to solvent-free melt spinning. This is achieved by formulating TPU compositions with specific polyol components (copolymer diols from caprolactone and PTMEG) and chain extenders that enable the material to be processed in melt state without solvents, eliminating environmental concerns while maintaining heat resistance through proper polymer structure design

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention extracts and eliminates the harmful solvent component from the dry spinning process. By developing TPU formulations that can be directly melted and spun without requiring dissolving agents, the patent removes the environmental burden of volatile solvent handling while preserving the essential heat-resistant properties of TPU fibers

Inventive Principle:
Principle #2Taking out (Extraction)

2Productivity

If melt-spinning process is used to make TPU fibers, then manufacturing efficiency is improved, but heat resistance deteriorates making fibers unsuitable for dyeing conditions

Engineering Contradiction:
Improvemanufacturing efficiencyVSAvoidheat resistance
Core Design Contradiction:
ProductivityVSTemperature

Solution Approach 1:

The patent creates a composite TPU formulation combining specific polyol components (copolymer diol from caprolactone and PTMEG) with carefully selected chain extenders and crosslinking agents. This composite structure enables the material to withstand high temperatures during melt-spinning and subsequent dyeing processes (up to 130-135°C) while maintaining the elasticity and stretch recovery properties characteristic of melt-spun fibers

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The invention modifies the chemical composition parameters of TPU to achieve a balance between processability and heat resistance. By adjusting the ratio and type of polyol components, chain extenders, and crosslinking agents, the patent creates a formulation that maintains structural integrity at dyeing temperatures while remaining suitable for melt-spinning processing

Inventive Principle:
Principle #35Parameter changes

3Ease of manufacture

If TPU fibers are exposed to dyeing conditions, then fabric coloration is achieved, but stretch and recovery properties are lost

Engineering Contradiction:
Improvedyeing capabilityVSAvoidstretch and recovery properties
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent incorporates crosslinking agents into the TPU formulation before fiber formation. These crosslinking agents create a preliminary network structure within the fiber that stabilizes the polymer chains, preventing degradation of elastic properties during subsequent dyeing exposure. The crosslinked structure is formed during or before dyeing, ensuring property retention

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

The TPU fibers exhibit high heat resistance, maintaining elasticity and stretch properties during dyeing, and can be combined with other fibers to form fabrics that retain shape and fit, with the option for recycling.

Implementation Method 1

the thermoplastic polyurethane composition used in the fiber comprises the reaction product of (i) a polyol component which comprises or consists of a copolymer diol derived from caprolactone monomer and poly(tetramethylene ether glycol), (ii) a hydroxyl terminated chain extender component, and (iii) a first diisocyanate component

Methodology Applied
Scientific EffectPolymerization: Chemical Bonding

Implementation Method 2

The isocyanate prepolymer crosslinking agent comprises or consists of the reaction product of (i) poly(tetramethylene ether glycol) and a second diisocyanate component or (ii) neopentyl glycol adipate and a second diisocyanate component

Methodology Applied
Scientific EffectCrosslinking: Chemical Bonding

Implementation Method 3

melting the reactive thermoplastic polyurethane composition in an extruder

Methodology Applied
Scientific EffectMelting: Melting

Implementation Method 4

cooling the melt-spun fiber

Methodology Applied
Scientific EffectFreezing: Freezing

Data Source

PatentEP4237605B1Melt-spun thermoplastic polyurethane fiber
Publication Date: 2026.04.01 LUBRIZOL ADVANCED MATERIALS INC

AI summary

The invention relates to a melt-spun thermoplastic polyurethane fiber which comprises a copolymer diol derived from caprolactone and polyether polyol and fabrics made therefrom, both of which are capable of being dyed under disperse dyeing conditions.