PEF Yarn Drawing for Tire Uniformity

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Solution Overview

Problem

The existing PEF raw yarns lack sufficient strength, particularly in terms of modulus of elasticity, making them inadequate for high-strength applications such as tires, and require improvements for enhanced durability and uniformity.

Innovation Solution

A PEF raw yarn production method involving a single-stage spinning/drawing process where the undrawn yarn is continuously drawn with a draw ratio greater than 6.0 times, and a take-up ratio of 700 to 2,000, resulting in a PEF raw yarn with a high storage modulus, increased crystallinity, and improved birefringence, which enhances the tire's uniformity and high-speed durability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If conventional PEF fiber production methods are used, then environmental burden is reduced through natural origin materials, but strength and modulus of elasticity are insufficient for high-strength applications

Engineering Contradiction:
Improvemodulus of elasticityVSAvoidmanufacturing process complexity
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

The patent applies parameter changes by optimizing the draw ratio to greater than 6.0 times and controlling the take-up rate to extrusion rate ratio (T/E) within 700 to 2,000. These parameter adjustments transform the molecular orientation and crystalline structure of PEF, achieving a storage modulus of 1,500 MPa or more while maintaining the environmental benefits of natural origin materials.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs preliminary action through the single-stage spinning/drawing process where the undrawn yarn is continuously drawn without being recovered. This preliminary drawing action during the spinning process itself prepares the fiber structure for high strength applications, eliminating the need for separate drawing steps and achieving the required modulus of elasticity in one continuous operation.

Inventive Principle:
Principle #10Preliminary action

2Strength

If higher draw ratio is applied to improve storage modulus, then fiber strength increases, but production efficiency may be reduced

Engineering Contradiction:
Improvestorage modulusVSAvoidproduction efficiency
Core Design Contradiction:
StrengthVSProductivity

Solution Approach 1:

The patent merges the spinning and drawing operations into a single continuous process. The undrawn yarn obtained by melt-spinning is immediately drawn without being recovered or handled separately. This combination of spinning and drawing in one continuous flow achieves the high draw ratio needed for 1,500 MPa storage modulus while maintaining production efficiency through uninterrupted processing.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent ensures continuity of useful action by continuously drawing the undrawn yarn without interruption or recovery steps. The single-stage process maintains continuous material flow from extrusion through drawing to take-up, eliminating idle time and handling losses, thereby achieving both high storage modulus and sustained productivity.

Inventive Principle:
Principle #20Continuity of useful action

3Strength

If single-stage spinning/drawing process is used to improve storage modulus, then fiber uniformity increases, but process control difficulty increases

Engineering Contradiction:
Improvestorage modulusVSAvoidprocess control complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The patent simplifies process control by establishing specific parameter ranges: draw ratio greater than 6.0 times and T/E ratio between 700 to 2,000. These defined parameter changes provide clear control targets for the single-stage spinning/drawing process, achieving uniform fiber structure with 1,500 MPa storage modulus while making process control more straightforward through quantified guidelines.

Inventive Principle:
Principle #35Parameter changes

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 a PEF raw yarn with a storage modulus of 1,500 MPa or more, significantly improving the tire's uniformity and high-speed durability, addressing the limitations of existing PEF yarns.

Implementation Method 1

a spinning step wherein the PEF-containing resin composition which has been melted is extruded into filaments and bundled into the undrawn yarn

Methodology Applied
Scientific EffectMelt-spinning: Melting

Implementation Method 2

a drawing step wherein an undrawn yarn, obtained by melt-spinning of a PEF-containing resin composition, is drawn into a PEF raw yarn, wherein a draw ratio in the drawing step is greater than 6.0 times

Methodology Applied
Scientific EffectDrawing: Deformation

Implementation Method 3

The disclosed PEF raw yarn preferably has a degree of crystallinity of 10% or more

Methodology Applied
Scientific EffectCrystallization: Crystallisation

Implementation Method 4

The disclosed PEF raw yarn preferably has a birefringence of 0.05 or more

Methodology Applied
Scientific EffectBirefringence: Birefringence

Data Source

PatentEP3348679B1Method for producing PEF yarn, PEF yarn, and tire
Publication Date: 2019.11.06 BRIDGESTONE CORP
  • EP3348679B1 patent drawingFigure 1
  • EP3348679B1 patent drawingFigure 2
  • EP3348679B1 patent drawingFigure 3

AI summary

Disclosed is a method for producing a polyethylene-2,5-furandicarboxylate (PEF) raw yarn which includes a drawing step wherein an undrawn yarn, obtained by melt-spinning of a PEF-containing resin composition, is drawn into a PEF raw yarn, wherein a draw ratio in the drawing step is greater than 6.0 times.