Pre-Dyed Polyester Heather Yarn to Prevent Screen Print Sublimation

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Solution Overview

Problem

Conventional polyester heather fabrics are limited to producing two-tone effects with shades of the same color due to the absorption properties of cationic and normal polyester fibers, and they suffer from dye sublimation issues during screen printing, leading to undesirable color bleeding.

Innovation Solution

The production of spun heather yarns using pre-colored staple fibers dyed with cationic dyestuffs, which are then spun together to create fabrics that can achieve multiple color hues and tones without sublimation, allowing for the creation of 100% polyester heather fabrics with a bleed-free colorfast effect.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If fabric double-dye procedure is used to produce polyester heather fabrics, then two-tone color effect can be achieved, but color combinations are limited to shades of the same color and dye sublimation occurs during screen printing

Engineering Contradiction:

Improvetwo-tone color effect productionVSAvoidcolor combination variety

Core Design Contradiction:

Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The patent applies preliminary action by pre-dyeing polyester fibers with cationic dyestuffs before spinning them into yarns. This allows the fibers to be pre-colored in various hues (not just shades of one color) while maintaining colorfastness. The pre-dyed fibers are then blended and spun together to create heather yarns with diverse color combinations, eliminating the need for fabric double-dyeing and preventing dye sublimation during screen printing.

Inventive Principle:

Principle #10Preliminary action

2Ease of manufacture

If fabric double-dye procedure is used, then heather effect can be achieved, but dye sublimation and bleeding occur during screen printing

Engineering Contradiction:

Improveheather fabric productionVSAvoidcolorfastness during screen printing

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The patent changes the chemical parameter of the dyestuff from disperse dye to cationic dyestuff. Cationic dyestuffs form strong ionic bonds with polyester fibers, creating a chemically stable colorfastness that prevents dye sublimation during high-temperature screen printing. This parameter change transforms the unreliable disperse dye system into a reliable cationic dye system that maintains color integrity under thermal stress.

Inventive Principle:

Principle #35Parameter changes

3Ease of manufacture

If cationic dyeable polyester fibers are used in fabric double-dye, then first dyeing can be achieved, but second dyeing stains the first dye and alters original hue

Engineering Contradiction:

Improvesequential dyeing processVSAvoidcolor hue accuracy

Core Design Contradiction:

Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent applies preliminary action by completing all dyeing operations on individual fibers before they are spun into yarns and woven into fabrics. Each fiber is pre-dyed with a cationic dyestuff to its final desired color. This eliminates the sequential fabric double-dyeing process where the second dye bath would stain previously dyed areas, thereby preserving the accuracy and purity of each color hue in the final heather fabric.

Inventive Principle:

Principle #10Preliminary action

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

This method enables the production of fabrics with diverse color combinations that are resistant to dye sublimation, reducing water usage in dyeing processes, and achieving high colorfastness ratings, making them suitable for screen printing applications.

Implementation Method 1

the first and second pre-colored staple fibers are both dyed with a cationic dyestuff

Methodology Applied

Scientific EffectIonic bonding: Chemical Bonding

Implementation Method 2

the disperse dye on the normal polyester fibers is subject to dye sublimation when exposed to high temperatures

Methodology Applied

Scientific EffectSublimation: Sublimation

Data Source

PatentUS12258686B1Heather spun yarns and fabrics, and methods for producing the same

Publication Date: 2025.03.25 WINDS ENTERPRISES LIMITED

AI summary

A spun heather yarn includes first pre-colored staple fibers comprising first polyester fibers dyed with a first cationic dyestuff, and second pre-colored staple fibers comprising second polyester fibers dyed with a second cationic dyestuff. A knitted heather fabric includes a plurality of the spun heather yarns knitted together to form the knitted heather fabric. The first and/or second pre-colored staple fibers may have contrasting colors. A method of manufacturing a spun heather yarn includes preparing a plurality of first pre-colored staple fibers by dyeing first uncolored staple fibers using a first cationic dyestuff, preparing a plurality of second pre-colored staple fibers by separately dyeing second uncolored staple fibers using a second cationic dyestuff, and spinning the first and second pre-colored staple fibers together to form the spun heather yarn. The spun heather yarns may then be knitted together to form a heather fabric.