Stretch Fabric Motion Followability via Knitting Angles

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Solution Overview

Problem

Existing stretch fabrics fail to maintain snap back performance under high-speed and abrupt-acceleration conditions, leading to increased wearing pressure and delayed recovery, which affects comfort and durability.

Innovation Solution

A warp knitted fabric composed of hard yarns and elastic yarns with specific included angles between sinker loops and the knitting direction, utilizing polyurethane fibers with a specific molar ratio of ethylenediamine to branched aliphatic diamine compounds, optimized for maximum snap back performance and strength balance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If conventional polyurethane fiber stretch fabric is used, then the fabric has good snap back performance under low speed and constant speed conditions, but it fails to recover in time after stretching under high speed and abrupt-acceleration conditions

Engineering Contradiction:
Improvemotion speedVSAvoidsnap back performance
Core Design Contradiction:
SpeedVSReliability

Solution Approach 1:

The patent modifies the chemical composition parameters of the polyurethane fiber by specifying a particular ratio of ethylenediamine (98-82 wt%) to branched aliphatic diamine compounds (2-18 wt%), which changes the molecular structure and elastic properties of the fiber to enable rapid recovery under high-speed conditions

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite yarn structure by combining elastic yarns (polyurethane fiber) with hard yarns (non-elastic support yarn) in a specific configuration, where the elastic component provides rapid recovery and the hard component provides structural support, achieving both high-speed snap back performance and durability

Inventive Principle:
Principle #40Composite materials

2Stability of the object's composition

If different knitting stitches are used to increase binding force, then the fabric structure stability is improved, but the expansion and contraction performance is reduced, affecting snap back performance

Engineering Contradiction:
Improvefabric structure stabilityVSAvoidsnap back performance
Core Design Contradiction:
Stability of the object's compositionVSReliability

Solution Approach 1:

The patent applies different knitting patterns to different regions of the fabric: the elastic yarns are knitted with tricot stitches in certain areas to maintain elasticity, while hard yarns are knitted with 5-needle warp sateen stitches in other areas to provide structural support, creating local variations in binding force that balance stability and snap back performance

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent designs the knitting pattern to be dynamic in nature, with the elastic yarns forming loops that can expand and contract freely, while the hard yarns provide a stable framework that allows controlled movement, enabling the fabric to adapt its structure during expansion and contraction cycles without compromising overall stability

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 effectively prevents pressure increase and delayed recovery under high-speed conditions, maintaining comfort and preventing issues like busting and tearing, while ensuring long-lasting elasticity and improved motion followability.

Implementation Method 1

An elastic stretch fabric formed by polyurethane fibers has relatively good snap back performance under low speed and constant speed conditions, but it will not recover in time after stretching under high speed and abrupt-acceleration conditions

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3508630B1Shell fabric with motion followability
Publication Date: 2021.07.14 TORAY INDUSTRIES INC
  • EP3508630B1 patent drawingFigure 1~2
  • EP3508630B1 patent drawingFigure 3~4

AI summary

Provided is a stretch fabric with an excellent snap back performance. The stretch fabric is a warp knitted fabric formed from hard yams and elastic yams, wherein the included angle (α) between a sinker loop (2) of the elastic yam and the knitting direction of a needle loop is 0-10°, and the included angle (β) between a sinker loop (4) of the hard yam and the knitting direction of a loop is 5-85°. Particularly under high-speed stretching and recovery motion conditions, a wearing pressure increase caused by an elongation stress and a wearing pressure decrease caused by a delayed recovery can be effectively inhibited; moreover, the wearing comfort can be maintained and muscle vibration can be prevented.