Low-Shrinkage PTT Fiber Commingling for Soft, Stable Fabrics

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing polytrimethylene terephthalate fibers do not fully exhibit properties such as low shrinkage and soft hand when made into cloth, and high-speed spinning methods lead to yarn breakage and poor winding shape.

Innovation Solution

Control the boiling water shrinkage rate and modulus of polytrimethylene terephthalate fibers within specific ranges, and produce them using controlled drawing and shrinking processes, followed by air-jet commingling with polyester fibers to create a core-sheath type yarn.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If high-speed spinning is used to produce polytrimethylene terephthalate fiber, then productivity is improved, but yarn breakage increases and winding shape deteriorates

Engineering Contradiction:
Improvespinning speedVSAvoidyarn breakage
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent applies parameter changes by optimizing the drawing ratio (1.05-1.15 times) and drawing temperature (glass transition point ±20°C) to achieve a balance between productivity and yarn strength. This controlled parameter adjustment allows high-speed spinning while preventing yarn breakage through proper fiber orientation and structural integrity.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent implements preliminary action by performing a preliminary drawing process before final winding. The fiber is drawn to the specified ratio and temperature range before being wound onto the bobbin, which pre-orients the molecular chains and strengthens the yarn structure, preventing breakage during subsequent high-speed winding operations.

Inventive Principle:
Principle #10Preliminary action

2Productivity

If high-speed spinning is used to produce polytrimethylene terephthalate fiber, then productivity is improved, but winding shape deteriorates

Engineering Contradiction:
Improvespinning speedVSAvoidwinding shape
Core Design Contradiction:
ProductivityVSShape

Solution Approach 1:

The patent uses parameter changes by controlling the drawing ratio (1.05-1.15 times) and drawing temperature (glass transition point ±20°C) to optimize fiber morphology. This controlled parameter adjustment ensures that fibers maintain proper circular cross-section and surface smoothness even during high-speed winding, preventing deformation of the winding shape.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent implements preliminary action by performing a preliminary drawing process before final winding. The fiber is drawn to the specified ratio and temperature range before being wound onto the bobbin, which pre-orients the molecular chains and strengthens the yarn structure, preventing breakage during subsequent high-speed winding operations.

Inventive Principle:
Principle #10Preliminary action

3Strength

If conventional polytrimethylene terephthalate fiber is used, then low Young's modulus is achieved, but cloth softness is insufficient

Engineering Contradiction:
ImproveYoung's modulusVSAvoidcloth softness
Core Design Contradiction:
StrengthVSEase of operation

Solution Approach 1:

The patent applies parameter changes by controlling the drawing ratio (1.05-1.15 times) and drawing temperature (glass transition point ±20°C) to optimize fiber morphology. This controlled parameter adjustment ensures that fibers maintain proper circular cross-section and surface smoothness even during high-speed winding, preventing deformation of the winding shape.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent implements preliminary action by performing a preliminary drawing process before final winding. The fiber is drawn to the specified ratio and temperature range before being wound onto the bobbin, which pre-orients the molecular chains and strengthens the yarn structure, preventing breakage during subsequent high-speed winding operations.

Inventive Principle:
Principle #10Preliminary action

4Strength

If undrawn yarn is hot drawn at high temperature, then fiber strength is improved, but shrinkage rate increases

Engineering Contradiction:
Improvefiber strengthVSAvoidshrinkage rate
Core Design Contradiction:
StrengthVSLength of moving object

Solution Approach 1:

The patent applies parameter changes by controlling the drawing ratio (1.05-1.15 times) and drawing temperature (glass transition point ±20°C) to optimize fiber morphology. This controlled parameter adjustment ensures that fibers maintain proper circular cross-section and surface smoothness even during high-speed winding, preventing deformation of the winding shape.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent implements preliminary action by performing a preliminary drawing process before final winding. The fiber is drawn to the specified ratio and temperature range before being wound onto the bobbin, which pre-orients the molecular chains and strengthens the yarn structure, preventing breakage during subsequent high-speed winding operations.

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

Results in a low-shrinkage fiber with a soft hand, suitable for producing cloth with enhanced drapability and stability, minimizing yarn breakage and maintaining form under thermal stress.

Implementation Method 1

shrinking the fiber at a ratio of 0.5 times to 0.9 times while heating

Methodology Applied
Scientific EffectThermal shrinking: Thermal Contraction

Implementation Method 2

drawing the polytrimethylene terephthalate to 1.1 times or more at a temperature equal to or lower than a glass transition point

Methodology Applied
Scientific EffectThermal drawing: Deformation

Implementation Method 3

melting and solidifying polytrimethylene terephthalate composed of 90 mol% or more of a trimethylene terephthalate repeating unit

Methodology Applied
Scientific EffectMelting and solidification: Melting

Data Source

PatentEP4696823A1Polytrimethylene terephthalate fiber, method for producing same, air-mixed filament yarn containing said polytrimethylene terephthalate fiber, and fabric composed thereof
Publication Date: 2026.02.18 TEIJIN FRONTIER CO LTD
  • EP4696823A1 patent drawingFigure 1
  • EP4696823A1 patent drawingFigure 2
  • EP4696823A1 patent drawing

AI summary

An object of the present invention is to provide a low-shrinkage fiber substantially composed of polytrimethylene terephthalate, which can be used to produce a raw yarn for cloth having a small shrinkage rate on heating and a soft hand, and a method for producing the same, an air-jet commingled yarn containing the polytrimethylene terephthalate fiber, and cloth composed thereof. In the present invention, there is provided a polytrimethylene terephthalate fiber composed of 90 mol% or more of a trimethylene terephthalate repeating unit. The polytrimethylene terephthalate fiber has a boiling water shrinkage rate of 5% or less and a modulus at an elongation of 20% of 5 cN/dtex or less.