Polyurethane Elastic Fiber Recycling via Solvent Extraction

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing methods for recycling polyurethane elastic fibers from fabrics face challenges such as low recovery rates and deterioration of properties, particularly when recovering polyurethane from fabrics containing other fibers like nylon and polyester.

Innovation Solution

A solvent-extraction separation method is used to separate polyurethane from other fibers in a recovered fabric without pulverization, followed by centrifugation, utilizing solvents like dimethylacetamide and centrifugal separation to achieve high recovery rates and maintain fiber properties.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of substance

If conventional pulverization methods are used to recover polyurethane from fabric, then polyurethane can be recovered, but the recovery rate and properties of the polyurethane elastic fibers deteriorate

Engineering Contradiction:

Improvepolyurethane recovery rateVSAvoidpolyurethane fiber properties

Core Design Contradiction:

Loss of substanceVSReliability

Solution Approach 1:

The patent applies solvent extraction to selectively dissolve and separate polyurethane from mixed fabrics without mechanical pulverization. The solvent extracts polyurethane molecules directly from the fabric structure, enabling high recovery rates while preserving fiber properties.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces conventional mechanical pulverization with a chemical extraction process using solvents. This substitution eliminates the mechanical damage that deteriorates fiber properties while maintaining effective polyurethane recovery from mixed fabrics.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Ease of manufacture

If polyurethane is recovered from fabric containing other fibers (nylon, polyester), then polyurethane can be separated, but the separation process becomes complex and recovery efficiency decreases

Engineering Contradiction:

Improvepolyurethane separation processVSAvoidpolyurethane recovery efficiency

Core Design Contradiction:

Ease of manufactureVSProductivity

Solution Approach 1:

The patent uses a solvent as an intermediary substance to selectively interact with polyurethane in mixed fabrics. The solvent acts as a mediator that dissolves polyurethane while leaving other fibers intact, simplifying the separation process and improving recovery efficiency.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the chemical parameters of the separation process by using specific solvents with appropriate solubility characteristics. This allows selective extraction of polyurethane from mixed fabrics based on chemical property differences, simplifying separation and enhancing productivity.

Inventive Principle:

Principle #35Parameter changes

3Loss of substance

If chemical recycling methods are used on recovered fabric, then polyurethane can be recovered, but the process requires complex chemical treatment and reduces fiber quality

Engineering Contradiction:

Improvepolyurethane recovery amountVSAvoidfiber quality

Core Design Contradiction:

Loss of substanceVSManufacturing precision

Solution Approach 1:

The patent uses selective solvent extraction to remove polyurethane from recovered fabric without harsh chemical treatment. This extraction method recovers polyurethane in high amounts while preserving the quality of both the recovered polyurethane and remaining fibers.

Inventive Principle:

Principle #2Taking out (Extraction)

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 enables high recovery rates of polyurethane with preserved functional properties, allowing for the production of recycled polyurethane elastic fibers suitable for applications like clothing, particularly undergarments, with improved breaking strength and elongation.

Implementation Method 1

by using a solvent-extraction separation method, fibers other than polyurethane can be easily separated from polyurethane, and polyurethane can be obtained at a high recovery rate

Methodology Applied

Scientific EffectSolvent-extraction separation: Solvation

Implementation Method 2

They also found that by blending highly accurately recovered polyurethane with virgin polymer, it is possible to obtain a polyurethane elastic fiber containing recycled polyurethane

Methodology Applied

Scientific EffectCentrifugal separation: Centrifugal Separation

Data Source

PatentUS20250205932A1Polyurethane elastic fiber and method for producing such

Publication Date: 2025.06.26 TORAY OPELONTEX CO LTD

AI summary

To provide a recycled-material polyurethane elastic fiber using recovered fabric containing a polyurethane fiber and a final product as raw materials, and a method for producing such. A recycled-material polyurethane elastic fiber wherein a recovered fabric containing a polyurethane fiber is used as at least a portion of raw materials, and a component separated by solvent-extraction separation of the fabric is used as at least a portion of raw materials.