Polyamide Airbag Fabric for Low-Leakage High-Speed Deployment
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Solution Overview
Problem
Existing airbag modules face challenges in achieving high-speed deployment and maintaining gas utilization efficiency, especially under high-temperature and high-humidity conditions, due to issues with gas leakage and burst resistance, particularly in large-volume airbags designed for pedestrian protection.
Innovation Solution
The development of an airbag fabric using polyamide 6·6 fibers with specific thermal stress management, copper, iodine, and bromine content, along with a cyclic unimer, to enhance heat resistance, reduce air permeability, and maintain deployment speed and burst resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If a non-coated airbag fabric is used to reduce weight, then weight is reduced, but gas utilization efficiency deteriorates due to insufficient deployment gas utilization and leakage
Solution Approach 1:
The patent changes the physical and chemical parameters of the fabric by incorporating specific additives (cyclic unimer, copper, iodine, bromine) into the polyamide 6·6 fiber structure. These parameter changes modify the fabric's thermal stress characteristics and air permeability properties, enabling it to maintain low gas permeability under high-temperature deployment conditions while remaining non-coated and lightweight.
Solution Approach 2:
The patent creates a composite material system by combining polyamide 6·6 base polymer with cyclic unimer and metal elements (copper, iodine, bromine). This composite structure provides both the lightweight characteristic of non-coated fabric and the gas retention properties typically associated with coated materials, resolving the contradiction between weight reduction and gas utilization efficiency.
2Weight of moving object
If polyester fabric is used to reduce weight, then weight is reduced, but burst resistance deteriorates due to melted holes from propellant burning residue
Solution Approach 1:
The patent changes the material composition from polyester to polyamide 6·6 with specific additives, fundamentally altering the thermal resistance parameter. Polyamide 6·6 has a higher melting point than polyester, and the added cyclic unimer and metal elements further enhance heat resistance, preventing melted holes from propellant residue while maintaining the lightweight non-coated structure.
3Temperature
If polyamide 6·6 fabric is used to improve heat resistance, then heat resistance is improved, but air permeability under high pressure increases causing gas leakage
Solution Approach 1:
The patent introduces cyclic unimer and metal elements (copper, iodine, bromine) as additives to the polyamide 6·6 fabric, changing its thermal stress characteristics. These parameter changes enable the fabric to maintain dimensional stability and low air permeability under high-temperature, high-pressure deployment conditions, preventing gas leakage while preserving heat resistance.
4Loss of energy
If inflator volume is increased to prevent gas leakage, then gas utilization efficiency is improved, but device size and weight increase
Solution Approach 1:
The patent makes the fabric itself gas-retentive through the incorporation of cyclic unimer and metal elements, which provide thermal stress resistance and low air permeability properties. This self-service approach eliminates the need for an oversized inflator, as the fabric structure itself prevents gas leakage during deployment, thereby maintaining gas utilization efficiency without increasing inflator volume.
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 airbag fabric ensures efficient gas utilization, high-speed deployment, and reliability under harsh conditions, reducing the need for excessive inflator volume and weight, while maintaining mechanical properties and preventing gas leakage.
Implementation Method 1
the air permeability of the fabric under a pressure of 200 kPa is from 10 to 200 cm3/(100 cm2·min) even after a heat treatment, thanks to the weaving yarn having a specific thermal stress
Implementation Method 2
the air permeability of the fabric under a pressure of 200 kPa is from 10 to 200 cm3/(100 cm2·min)
Data Source
AI summary
An object of the present invention is to provide an airbag module ensuring that when an airbag fabricated using a fabric composed of a polyamide yarn excellent in heat resistance is deployed by an inflator gas, the deployment occurs without loss of the gas and an excessive amount of generated gas is not necessary, as a result, the inflator is reduced in weight, and the airbag module of the present invention comprises an airbag fabric composed of a polyamide yarn, wherein the air permeability of the fabric under a pressure of 200 kPa is from 10 to 200 cc/cm2/sec and in the thermal stress of the constituent yarn as measured under the conditions of an initial load of 0.02 cN/dtex, a yarn length of 25 cm and a temperature rise rate of 80°C/min, the summed thermal stress of the total of the warp yarn and the weft yarn at 230°C is from 0.33 to 1.20 cN/dtex.