Polyester Fiber for Airbag Fabric with Controlled Modulus
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Solution Overview
Problem
Conventional airbag fabrics face challenges in maintaining dimensional stability, flexibility, and mechanical properties, especially under severe conditions of high temperature and high humidity, due to the limitations of existing polyester fibers which have high modulus and stiffness, leading to poor folding and packing properties.
Innovation Solution
A polyester fiber with specific characteristics, including an initial modulus of 40 to 100 g/d, elongation of 0.5% or more at 1.0 g/d, and high intrinsic viscosity, is developed through a melt-spinning and drawing process, optimizing the molecular structure to reduce stiffness and enhance toughness, while minimizing carboxyl end groups that degrade under humid conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If conventional polyester fiber with high modulus is used for airbag fabric, then mechanical strength is improved, but folding and packing properties deteriorate
Solution Approach 1:
The patent applies parameter changes by precisely controlling the initial modulus of polyester fiber within 40-100 g/d and elongation at specific stress points (0.5% at 1.0 g/d, 4.3% at 4.0 g/d, 7.5% at 7.0 g/d). This optimization balances mechanical strength with flexibility, enabling the fabric to maintain strength while improving folding and packing properties for airbag applications.
2Strength
If polyester fiber with high modulus is used for airbag fabric, then mechanical strength is improved, but dimensional stability under high temperature and humidity deteriorates
Solution Approach 1:
The patent optimizes the intrinsic viscosity of polyester polymer within 0.85-1.20 dl/g and controls the initial modulus to 40-100 g/d. These parameter changes ensure the fiber maintains its mechanical strength while achieving superior dimensional stability under high temperature and humidity conditions, preventing excessive shrinkage or deformation.
3Ease of manufacture
If conventional polyester fiber is used for airbag fabric, then manufacturing cost is reduced, but gas barrier effect and air-tightness deteriorate
Solution Approach 1:
The patent achieves the balance between cost and performance by optimizing the intrinsic viscosity of polyester polymer to 0.85-1.20 dl/g and controlling fiber structure parameters. This enables conventional polyester material to be used (maintaining cost advantage) while achieving superior gas barrier effect and air-tightness through optimized fiber characteristics and fabric structure.
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 optimized polyester fiber provides a fabric for airbags with superior mechanical properties, dimensional stability, and gas barrier effects, ensuring effective air-tightness and impact resistance even in severe conditions, while maintaining flexibility and improved folding and packing properties.
Implementation Method 1
melt-spinning a polyester polymer having intrinsic viscosity of 0.85 dl/g or more at 270 to 300° C. so as to prepare an undrawn polyester fiber
Implementation Method 2
drawing the undrawn polyester fiber
Data Source
AI summary
The present invention relates to a polyester fiber that can be applied to a fabric for an airbag, and particularly, to a polyester fiber having elongation of 0.5% or more at a stress of 1.0 g/d, elongation of 4.3% or more at a stress of 4.0 g/d, and elongation of 7.5% or more at a stress of 7.0 g/d, and an initial modulus of 40 to 100 g/d, a method of preparing the same, and a fabric for an airbag prepared therefrom. Since the polyester fiber of the present invention remarkably decreases stiffness and secures superior mechanical properties, it is possible to provide superior packing properties, dimensional stability, and gas barrier effect, and to protect occupants safely by minimizing the impact applied to the occupants, when it is used for the fabric for an airbag.