Fiber Structure Heat Retention via Hygroscopic Conversion

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Solution Overview

Problem

Conventional garments for heat retention, such as those with a three-layer structure, are not suitable for innerwear due to thickness issues, and existing heat retention fiber products have low heat retention rates, necessitating a fiber structure with improved heat retention and comfort.

Innovation Solution

A fiber structure comprising viscose rayon fibers (15-40% by mass), cation dyeable polyester filament yarns (10-45% by mass), polyacrylic synthetic fibers (25-60% by mass), and spandex fibers (3-15% by mass), formed into a knitted two-layer fabric with a nap on the surface, enhancing heat retention and comfort through hygroscopic heat generation and air pocket insulation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If a three-layer structure is used for heat retention, then heat retention is improved, but fabric thickness increases making it unsuitable for innerwear

Engineering Contradiction:
Improveheat retentionVSAvoidfabric thickness
Core Design Contradiction:
TemperatureVSLength of stationary object

Solution Approach 1:

The invention merges multiple functions into a single fabric layer by blending viscose rayon fibers (for hygroscopic heat generation), polyacrylic synthetic fibers (for heat retention), and spandex fibers (for elasticity). This combination allows the fabric to achieve both heat retention and innerwear suitability without requiring a three-layer structure.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The invention uses composite fiber materials with specific composition ratios (viscose rayon 15-40%, polyacrylic synthetic fiber 25-60%, spandex fiber 3-15%) to create a multi-functional fabric that simultaneously provides heat retention, moisture management, and comfort properties in a single layer.

Inventive Principle:
Principle #40Composite materials

2Temperature

If conventional heat retention fiber products are used, then heat retention is provided, but the heat retention rate is low

Engineering Contradiction:
Improveheat retention rateVSAvoidheat retention performance
Core Design Contradiction:
TemperatureVSReliability

Solution Approach 1:

The invention changes the physical and chemical parameters of the fiber composition, specifically optimizing the ratios of viscose rayon fibers (15-40%), polyacrylic synthetic fibers (25-60%), and spandex fibers (3-15%), to achieve a heat retention rate of 25% or more, significantly improving heat retention performance compared to conventional products.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention utilizes the phase transition properties of viscose rayon fibers through hygroscopic heat generation, where the absorption and desorption of moisture by the fibers directly converts to heat energy, achieving a hygroscopic heat generation of 2.2°C or more and enhancing heat retention without adding fabric thickness.

Inventive Principle:
Principle #36Phase transitions

3Temperature

If a raising process is performed to form nap, then heat retention is improved, but fluff adhesion may increase

Engineering Contradiction:
Improveheat retentionVSAvoidfluff adhesion
Core Design Contradiction:
TemperatureVSObject-generated harmful factors

Solution Approach 1:

The invention applies local quality by forming a nap structure specifically on the fabric surface through selective raising process, while maintaining the underlying fiber composition and structure that prevents excessive fluff generation. The nap provides heat retention through air trapping, while the controlled fiber blend minimizes fluff adhesion.

Inventive Principle:
Principle #3Local quality

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 fiber structure achieves excellent heat retention and comfort by converting body moisture into heat energy, maintaining warmth through polyacrylic insulation and air pockets, while preventing wrinkles and fluff generation, with a heat retention rate of 25% or more and hygroscopic heat generation of 2.2°C or more.

Implementation Method 1

the viscose rayon fiber adsorbs a water vapor generated from a human body and a kinetic energy of a water molecule is converted into heat energy

Methodology Applied
Scientific EffectHygroscopic heat generation: Absorption (physical)

Implementation Method 2

heat insulation effects of the polyacrylic synthetic fiber

Methodology Applied
Scientific EffectHeat insulation: Thermal Insulation

Implementation Method 3

air pocket formed between fibers of a raised surface

Methodology Applied
Scientific EffectThermal insulation: Thermal Insulation

Data Source

PatentEP3616540B1Fiber structure
Publication Date: 2022.11.16 TORAY INDUSTRIES INC

AI summary

In order to provide a fiber structure having excellent heat retention and wearing comfort and a garment obtained by using the same, there is provided a fiber structure containing: a viscose rayon fiber in an amount of more than 15% by mass and less than 40% by mass; a cation dyeable polyester filament yarn in an amount of more than 10% by mass and less than 45% by mass; a polyacrylic synthetic fiber in an amount of more than 25% by mass and less than 60% by mass; and a spandex fiber in an amount of more than 3% by mass and less than 15% by mass, wherein the fiber structure has a nap formed on a front surface or a back surface thereof.