Most people consider the main part of the airbag to be the fabric airbag cushion that comes out during the crash. Although some call it a “pillow”, they are anything except that: they often deploy at speeds of more than 200 mph, and can cause serious personal injuries or even kill you.
Driver airbags are generally pancake-shaped. Their diameter is usually slightly larger than the steering wheel. Passenger airbags are irregularly shaped, and are designed to fit in the area between the instrument panel (dash), windshield, and the passenger. Thus, passenger airbags are much larger than driver airbag, sometimes up to four times as large.
Airbags are generally constructed of a tightly woven fabric, usually nylon or polyester. The fabrics themselves are characterized by various engineering parameters, including weave, weave count, denier and others. These specify the thickness or density of the material, and the tightness of the weave.
One extremely important characteristic of frontal airbags is whether they include tethers to maximize their safety. Tethers are internal straps inside the airbag that help prevent high speed bag slap injuries to a person’s face. Such bag slap injuries often include eye injury and blindness. Some manufacturers failed to include tethers in their airbags, saving themselves millions of dollars, but putting their customers at risk of serious and permanent injuries. Tethers will be explored in detail in another post.
Sometimes the fabric is coated on the inside to reduce the amount of gas that leaks out through the permeable fabric and the seams. This is often true of driver airbags that deploy from the steering wheel and rollover airbags that deploy from the roof. A rollover airbag must stay inflated longer because rollover crashes last much longer than typical head-on collisions, and using a coated airbag helps the airbag stay inflated.
Side airbags come in a variety of sizes. Some side impact airbags are mounted to the seat and deploy between a passenger and the door to protect the chest and pelvis. Better side impact airbags also protect the passenger’s head. This can be accomplished by a combination torso/head bag deploying from the seat or door, or by using a side curtain airbag that deploys downward from the roof and extends along the side of a vehicle. The best curtain airbags are also triggered during rollover crashes, as well as side impacts. Such rollover airbags have been installed in vehicles sold in the United States since the 2002 model year. However, some manufacturers failed to install them until much later, unnecessarily exposing their customers to the risk of significant injuries during a rollover crash.
