What is the main gas used in automotive airbags?
2 Answers
Automotive airbags primarily use nitrogen gas, which inflates within 0.1 seconds. The airbag contains solid sodium azide, which rapidly generates a large amount of nitrogen gas upon impact. The use of airbags can effectively protect the safety of passengers inside the vehicle. Function of airbags: When a collision occurs, the vehicle stops moving first, while the passengers continue to move forward at their original speed due to inertia. If an airbag installed in the steering wheel or dashboard inflates and deploys at this moment, it can protect the passengers by reducing the likelihood of contact with interior objects, more evenly distributing the impact force on the head and chest, and absorbing the passengers' kinetic energy, thereby supplementing the effectiveness of seat belts. Principle of airbags: During vehicle operation, the sensor system continuously sends speed change information to the control unit, which analyzes and evaluates this data. If the measured acceleration, speed change, or other indicators exceed predetermined thresholds (indicating an actual collision), the control unit sends an ignition command to the gas generator, or the sensor directly controls ignition. Upon ignition, an explosive reaction occurs, producing N2 or releasing compressed nitrogen from a gas storage tank to fill the collision airbag.
The primary gas used in automotive airbags is nitrogen, as it is safe, inert, non-combustible, and can rapidly inflate the airbag during a collision to protect occupants. Specifically, a chemical reaction inside the airbag, typically triggered by sodium azide, decomposes under thermal stimulation to produce a large volume of nitrogen gas. The entire process takes just milliseconds, ensuring the airbag inflates before the driver or passenger impacts the steering wheel or windshield. It's not just about the gas itself—the entire system, including sensors, ignition devices, and pressure-release designs, ensures that nitrogen inflation does not cause suffocation or other risks. Modern vehicles may use alternative chemicals, but nitrogen remains the mainstream choice. Combined with the airbag's folded material and control software, it effectively cushions impact forces, reducing severe head and chest injuries. Remember, regularly check the airbag indicator light to prevent system malfunctions from affecting performance in critical moments.
