Knit-by-Design Fabric Hydro-Setting to Reduce Shrinkage

Solution Overview

Problem

Traditional methods for producing circular-knit elastic fabrics require dry heat setting, which increases costs and can damage sensitive yarns, and result in permanent creases and reduced fabric yield due to the need for high-temperature heat setting.

Innovation Solution

A method that limits the draft of elastomeric material during knitting and uses a hydro-setting treatment instead of dry heat setting, allowing the elastomeric material to be set without the need for high-temperature heat setting, thereby maintaining desired fabric parameters and reducing fabric creases.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If dry heat setting is used to set spandex in circular-knit elastic fabrics, then fabric recovery performance is improved, but manufacturing cost increases and fabric yield decreases due to permanent creases

Engineering Contradiction:

Improvefabric recovery performanceVSAvoidfabric yield

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The patent changes the temperature parameter from high-temperature dry heat setting (typically 150-200°C) to low-temperature hydro-setting (below 100°C). This parameter change allows the spandex to be set effectively without the harmful effects of high heat, thereby maintaining fabric recovery performance while eliminating permanent creases and improving fabric yield

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent replaces the mechanical dry heat setting process with a chemical hydro-setting process using aqueous solutions. This substitution eliminates the need for high-temperature thermal treatment, avoiding yarn damage and permanent creases while achieving the same spandex setting effect, thus improving both fabric quality and yield

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If dry heat setting is used to set spandex, then fabric recovery performance is improved, but manufacturing cost increases

Engineering Contradiction:

Improvefabric recovery performanceVSAvoidmanufacturing cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent changes the temperature parameter from high-temperature dry heat setting (typically 150-200°C) to low-temperature hydro-setting (below 100°C). This parameter change allows the spandex to be set effectively without the harmful effects of high heat, thereby maintaining fabric recovery performance while eliminating permanent creases and improving fabric yield

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent replaces the mechanical dry heat setting process with a chemical hydro-setting process using aqueous solutions. This substitution eliminates the need for high-temperature thermal treatment, avoiding yarn damage and permanent creases while achieving the same spandex setting effect, thus improving both fabric quality and yield

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Reliability

If high-temperature heat setting is used to set spandex, then spandex recovery is improved, but sensitive companion yarns are damaged

Engineering Contradiction:

Improvespandex recoveryVSAvoidyarn damage

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent changes the temperature parameter from high-temperature dry heat setting (typically 150-200°C) to low-temperature hydro-setting (below 100°C). This parameter change allows the spandex to be set effectively without the harmful effects of high heat, thereby maintaining fabric recovery performance while eliminating permanent creases and improving fabric yield

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent replaces the mechanical dry heat setting process with a chemical hydro-setting process using aqueous solutions. This substitution eliminates the need for high-temperature thermal treatment, avoiding yarn damage and permanent creases while achieving the same spandex setting effect, thus improving both fabric quality and yield

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 produces circular knit, single jersey elastic fabrics with improved elongation, reduced shrinkage, and increased fabric yield, while avoiding the costs and yarn damage associated with traditional heat setting processes.

Implementation Method 1

the circular knit, single jersey elastic fabric may be contacted with a continuous phase aqueous solution under conditions of temperature and pressure for a period of time sufficient to substantially set the bare elastomeric material

Methodology Applied

Scientific EffectHydro-setting:

Data Source

PatentUS7779655B2Knit-by-design method and fabric

Publication Date: 2010.08.24 THE LYCRA CO LLC

AI summary

The invention provides a method for knitting fabric with bare spandex comprising: providing bare spandex yarn; providing hard yarn; drafting the bare spandex; knitting fabric from the hard yarn and the drafted bare spandex with the hard yarn and the drafted bare spandex plated in every course; and contacting the knit fabric with a continuous phase aqueous solution under conditions of temperature and pressure for a time sufficient to set the bare spandex without heating the knit fabric on a tenter frame above 160° C. in air having a relative humidity of less than 50%. The invention further provides a bare spandex-containing knit fabric containing spandex in every knit course that has been exposed to manufacturing process temperature no higher than 160° C. as shown by molecular weight analysis of the spandex and that exhibits wash shrinkage of less than about 14%.