Grooved Multifilament Woven Fabric for Buoyancy and Water Repellency

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Solution Overview

Problem

Existing water-repellent fabrics for swimming wear struggle to balance properties such as stretchability, water repellency, low water retention rate, and buoyancy, with structures either compromising on porosity for low water retention or increasing underwater weight due to water retention in voids.

Innovation Solution

A woven fabric using synthetic fiber multifilament yarns with grooves along the fiber length, combined with elastic fibers, and a water repellent film, achieving a porosity of 75% or less, and specific cross-sectional grooves to trap air for buoyancy while maintaining water repellency and reducing water retention.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If the fabric structure is made dense to reduce porosity, then water retention rate is reduced, but buoyancy is compromised

Engineering Contradiction:
Improvewater retention rateVSAvoidunderwater weight
Core Design Contradiction:
Quantity of substanceVSWeight of moving object

Solution Approach 1:

The invention applies local quality by creating specific groove structures on the fiber surfaces that locally trap air, while the overall fabric maintains a dense weave structure. The grooves are strategically positioned to capture and retain air pockets that provide buoyancy without requiring the entire fabric to have high porosity.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The invention uses nested doll by incorporating grooves within the fiber structure itself, creating a hierarchical structure where air pockets are trapped within the groove channels of the fibers. This nested air-trapping mechanism allows buoyancy to be achieved without increasing overall fabric porosity.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Weight of moving object

If the fabric has high porosity to improve buoyancy, then air can be contained, but water retention rate increases

Engineering Contradiction:
ImprovebuoyancyVSAvoidwater retention rate
Core Design Contradiction:
Weight of moving objectVSQuantity of substance

Solution Approach 1:

The invention applies local quality by creating specific groove structures on the fiber surfaces that locally trap air, while the overall fabric maintains a dense weave structure. The grooves are strategically positioned to capture and retain air pockets that provide buoyancy without requiring the entire fabric to have high porosity.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The invention uses porous materials by creating controlled grooves and channels within the fiber structure that can trap and retain air pockets. These controlled porous structures within the grooves provide buoyancy while the overall fabric density maintains low water retention.

Inventive Principle:
Principle #31Porous materials

3Ease of operation

If float yarns are used to reduce flowing water resistance, then water flow is improved, but inter-structure voids increase causing water retention

Engineering Contradiction:
Improveflowing water resistanceVSAvoidwater retention rate
Core Design Contradiction:
Ease of operationVSQuantity of substance

Solution Approach 1:

The invention applies segmentation by dividing the fiber surface into multiple grooves and channels that segment the water flow path. This segmentation allows water to flow more easily around the fiber structure while the grooves themselves trap air pockets that prevent water penetration and maintain buoyancy.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention uses another dimension by creating three-dimensional groove structures on the fiber surfaces that extend along the fiber length. This adds a vertical dimension to the fiber structure, creating air-trapping channels that reduce water flow resistance while preventing water penetration into the fabric.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 fabric achieves high water repellency, low water retention, and buoyancy, maintaining these properties even after wear and washing, suitable for competitive swimming suits.

Implementation Method 1

a water repellent film is provided on a front surface, inside of the woven fabric, and a back surface

Methodology Applied
Scientific EffectHydrophobe: Hydrophobe

Implementation Method 2

the grooves of the single fiber have a depth of 1.0 to 10.0 μm, and an inlet width of 0.5 to 10.0 μm

Methodology Applied
Scientific EffectSurface tension: Surface Tension

Data Source

PatentEP4640933A1textile
Publication Date: 2025.10.29 TORAY INDUSTRIES INC
  • EP4640933A1 patent drawingFigure 1~2
  • EP4640933A1 patent drawingFigure 3~4
  • EP4640933A1 patent drawingFigure 5

AI summary

To provide a water-repellent woven fabric having excellent water repellency, low water retention rate, and buoyancy, and capable of maintaining these properties, a woven fabric of the present invention is a woven fabric including a synthetic fiber multifilament yarn and an elastic fiber, wherein at least a part of the synthetic fiber multifilament used in the woven fabric includes a synthetic fiber including a single fiber having, on a surface of the single fiber, a plurality of grooves continuous in a fiber length direction, the grooves of the single fiber have a wide part wider than an inlet in a cross section, a depth of 1.0 to 10.0 µm, and an inlet width of 0.5 to 10.0 µm, a width of a top of a protrusion is 10.0 µm or less, a porosity of the woven fabric is 75% or less, a porosity resulting from a fiber cross-section shape of the single fiber having the plurality of grooves on the surface is 3 to 30%, and a water repellent film is provided on a front surface, inside of the woven fabric, and a back surface.