Polyester Tire Cord Reinforcement for High-Tenacity Lightweight Carcasses

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Solution Overview

Problem

Current tire carcass reinforcement materials lack the necessary high tenacity and Modulus Enhancement Potential (MEP) to reduce tire weight while maintaining dimensional stability and durability, especially under high-speed driving conditions.

Innovation Solution

A process for manufacturing a high-tenacity polyester tire cord reinforcement using polyethylene terephthalate yarn with specific properties, including a minimum tenacity of 8.8 g/d and 110% MEP, achieved through solid phase polymerization, controlled extrusion, and a multi-stage drawing and quenching process to optimize crystalline and amorphous orientation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If conventional polyester yarns are used for tire carcass reinforcement, then the tire maintains dimensional stability, but the tire weight cannot be reduced and load capacity is insufficient

Engineering Contradiction:
ImprovetenacityVSAvoidtire weight
Core Design Contradiction:
StrengthVSWeight of moving object

Solution Approach 1:

The patent applies parameter changes by precisely controlling the intrinsic viscosity of PET chips (0.80-1.05 dL/g) and the drawing temperature (80-120°C) to achieve optimal molecular orientation and crystalline structure. This results in yarn with tenacity ≥8.8 g/d and MEP ≥110%, enabling lighter tire construction with equivalent or superior strength performance

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention creates a composite structure through the multi-stage drawing process that develops both crystalline and amorphous orientation in the polyester yarn. This dual-phase orientation structure provides synergistic enhancement of tenacity and modulus, achieving high strength-to-weight ratio necessary for reducing tire weight while maintaining load capacity

Inventive Principle:
Principle #40Composite materials

2Weight of moving object

If lower denier yarns are used to reduce tire weight, then tire weight decreases, but dimensional stability and durability are compromised

Engineering Contradiction:
Improvetire weightVSAvoiddimensional stability
Core Design Contradiction:
Weight of moving objectVSReliability

Solution Approach 1:

The patent controls the heat set temperature (240-260°C) and heat set time (20-40 seconds) to optimize the crystalline structure development in the yarn. This parameter optimization ensures that even lower denier yarns maintain exceptional dimensional stability with shrink force ≤0.20 g/dtex at 180°C, enabling weight reduction without sacrificing reliability

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The multi-stage drawing process is performed preliminarily before tire manufacturing to pre-establish the optimal molecular orientation and crystalline structure in the yarn. This preliminary structuring ensures that the yarn maintains its dimensional stability and strength properties under subsequent tire processing and service conditions

Inventive Principle:
Principle #10Preliminary action

3Strength

If high tenacity yarns are used to improve load capacity, then load capacity increases, but the Modulus Enhancement Potential is insufficient for high-speed driving conditions

Engineering Contradiction:
Improveload capacityVSAvoidModulus Enhancement Potential
Core Design Contradiction:
StrengthVSStress or pressure

Solution Approach 1:

The patent employs a dynamic, multi-stage drawing process with progressively increasing draw ratios and temperatures. This dynamic approach allows the molecular chains to progressively align and crystallize, achieving superior amorphous orientation that provides high MEP (≥110%) for enhanced stress response under high-speed driving conditions while maintaining high load capacity

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The invention optimizes the drawing temperature range (80-120°C) to maximize amorphous orientation development without excessive crystallization. This parameter control ensures the yarn achieves both high tenacity for load capacity and high MEP for dynamic stress response, meeting both static and dynamic performance requirements

Inventive Principle:
Principle #35Parameter changes

4Reliability

If more reinforcement material is used to improve durability, then durability increases, but tire weight and rubber content increase

Engineering Contradiction:
ImprovedurabilityVSAvoidtire weight
Core Design Contradiction:
ReliabilityVSWeight of moving object

Solution Approach 1:

The patent optimizes the intrinsic viscosity of PET chips to a specific range (0.80-1.05 dL/g) to achieve the highest possible strength and durability per unit weight of yarn. This parameter optimization allows using less reinforcement material while maintaining or improving durability, thereby reducing overall tire weight and rubber content

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 resulting tire cord reinforcement enables a lighter tire with improved load capacity, reduced rubber content, and enhanced durability and dimensional stability, with tenacity and MEP values exceeding those of control samples, leading to reduced rolling resistance and increased fatigue resistance.

Implementation Method 1

A process for manufacturing a high-tenacity polyester tire cord reinforcement using polyethylene terephthalate yarn with specific properties, including a minimum tenacity of 8.8 g/d and 110% MEP, achieved through solid phase polymerization

Methodology Applied
Scientific EffectSolid phase polymerization:

Implementation Method 2

controlled extrusion, and a multi-stage drawing and quenching process to optimize crystalline and amorphous orientation

Methodology Applied
Scientific EffectExtrusion: Extrusion

Implementation Method 3

a multi-stage drawing and quenching process to optimize crystalline and amorphous orientation

Methodology Applied
Scientific EffectQuenching: Cooling

Data Source

PatentUS20240286437A1Polyester carcass reinforcement
Publication Date: 2024.08.29 KORDSA TEKNIK TEKSTIL AS

AI summary

A process for manufacturing a polyester carcass reinforcement has high tenacity improved tensile properties and high Modulus Enhancement Potential (MEP).