Brushed Circular Knit Structure for Resilient Stretch Outerwear

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Solution Overview

Problem

Existing brushed fabrics for coats and jackets lack a balance of resiliency feeling, stretchability, pilling resistance, and durability, with wool-based materials being expensive and prone to insect infestation, while synthetic alternatives are too soft or lack stretchability.

Innovation Solution

A brushed circular knitted fabric with double loops formed by layers of synthetic fiber multifilaments, where one layer has a boiling water shrinkage of 12 to 30% and the other less than 12%, and a FT index of 2.1 or greater, enhancing resiliency and stretchability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If wool spun yarn is used to create melton fabric with water repellency and heat retention, then durability and warmth are improved, but price increases and handling becomes difficult due to insect attachment and damage

Engineering Contradiction:
ImprovedurabilityVSAvoidhandling
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent replaces expensive wool with synthetic fibers (polyester, polyamide, acrylic) that are more economical and resistant to insect damage. The synthetic fiber composition eliminates the handling problems associated with wool while maintaining durability through the knitted structure and brushing treatment.

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

Solution Approach 2:

The patent uses composite synthetic fiber structures with different shrinkage rates (first synthetic fiber: 10-30% shrinkage, second synthetic fiber: less than 10% shrinkage) to create a blended fabric that combines the benefits of warmth, durability, and insect resistance without the handling issues of pure wool.

Inventive Principle:
Principle #40Composite materials

2Ease of operation

If synthetic fiber brushed materials are used to solve handling problems, then ease of operation is improved and pilling resistance is enhanced, but the fabric becomes too soft with excessive stretchability making it unsuitable for coats and jackets

Engineering Contradiction:
ImprovehandlingVSAvoidstructural integrity
Core Design Contradiction:
Ease of operationVSStrength

Solution Approach 1:

The patent controls the shrinkage parameters of the synthetic fibers to achieve the desired balance. The first synthetic fiber has a shrinkage rate of 10-30% while the second has less than 10%, creating a structured fabric with appropriate firmness. The stitch length ratio (first thread: second thread = 2:3 to 4:5) further controls the structural integrity to prevent excessive softness while maintaining ease of handling.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent applies brushing treatment to only one surface of the fabric, creating local softness and warmth on the brushed side while maintaining the structural integrity of the reverse side. This selective treatment provides the desired hand feel without compromising the overall fabric strength and shape retention needed for outerwear.

Inventive Principle:
Principle #3Local quality

3Strength

If woven fabric with high-shrinkage yarn is used to provide resiliency feeling, then resiliency is improved, but stretchability is lost

Engineering Contradiction:
Improveresiliency feelingVSAvoidstretchability
Core Design Contradiction:
StrengthVSAdaptability or versatility

Solution Approach 1:

The patent divides the fabric structure into two distinct functional components: first synthetic fiber threads providing resiliency through higher shrinkage (10-30%), and second synthetic fiber threads providing stretchability through lower shrinkage (less than 10%). This segmentation allows each fiber type to perform its specialized function while working together in the knitted structure.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent creates a dynamic fabric structure where the differential shrinkage between the two synthetic fiber types enables the fabric to adapt to body movement. The knitted construction with specific stitch length ratios allows the fabric to stretch and recover dynamically, providing both resiliency feeling and necessary stretchability for comfortable wear.

Inventive Principle:
Principle #15Dynamics

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 moderate resiliency feeling, stretchability, and excellent pilling resistance, making it suitable for outer garments like coats and jackets.

Implementation Method 1

the inside of the double loops is obtainable with the synthetic fiber multifilament A having a boiling water shrinkage of 12 to 30%

Methodology Applied
Scientific EffectBoiling water shrinkage: Thermal Contraction

Implementation Method 2

at least one surface of the circular knitted fabric has undergone brush processing to fuzz threads of the fabric

Methodology Applied
Scientific EffectBrush processing: Abrasion

Data Source

PatentEP3330419B1Brushed circular knitted fabric
Publication Date: 2025.11.26 MITSUKAWA
  • EP3330419B1 patent drawingFigure 1
  • EP3330419B1 patent drawingFigure 2
  • EP3330419B1 patent drawingFigure 3~5

AI summary

Provided is a brushed circular knitted fabric that has double loops stacked with at least two kinds of synthetic fiber multifilaments, wherein at least one surface of the circular knitted fabric has undergone brush processing, and the FT index represented by the equation (T2/T1) [T1: thickness (of one layer) according to a method prescribed by JIS, T2: thickness according to the same method prescribed by JIS at a state where the fabric is folded in two] is 2.1 or greater. It is possible to provide a brushed circular knitted fabric that has resiliency feeling and stretchability suitable for use in a coat or jacket, and is excellent in physical properties such as pilling resistance and changes in dimensions with washing.