The Chemistry of Airbags


Uploaded by GinoDelG on 12.10.2011

Transcript:
Richie Olsen, I'm the manager of the pyrotechnic development group
for Autoliv. We develop pyrotechnics for the automotive industry. If you think of an accident
it's happening in milliseconds. So when you have an accident, the car is designed to sense a deceleration
It will convert that to an electrical signal. That electrical signal is turned into heat, into thermal energy
which in turn ignites a small pyrotechnic charge. So you're converting
from an electrical, to a thermal to a chemical energy because then you're igniting the pyrotechnic.
When the pyrotechnic ignites, it combusts gas and it fills up the airbag.
You want that event to take place in anywhere from 10 to 30 milliseconds.
You want the whole reaction done, completed, the person is caught by the airbag.
The person never realizes they've actually hit the airbag. They're just sitting there.
Most of us who work here in the airbag industry where involved in the rocket industry.
at some point in time, because airbags did spin off from the rocket motor companies.
In our world, kinetics simply means combustion rate.
That combustion has to occur within a very finite time frame.
in order to adequately protect the occupant of the car.
And so we worry about things like ignition. It has to light rapidly and uniformly.
And then we want that to burn out at the appropriate rate.
We will take what we call different fuels and oxidizers.
Different additives in order to give us the properties we're looking for.
As far as burn rate, how fast it's going to combust.
And our fuel of choice at this time is guanadine nitrate, which is pretty widespread throughout the industry.
Then we'll convert it to a powder.
Then we use different oxidizers in which to ignite, which is an oxygen source to ignite the fuel.
And then there are various oxidizers that are used with that fuel.
Different metallic oxidizers are the main things of choice. Iron oxide, malignium disulfide, cooper oxide.
Like I said, the burning rate. We'll press that into a slug.
And then we'll press it.
The fuse wire goes across the slug.
There you have your burn rate slug.
Then you put a little bit of igniter, DYX igniter to start the burn rate burning.
I hit on.
So this is what the data looks like. This is just the time versus the pressure.
And you can see this point is where it starts to burn at. So you have a start time and an end time.
So between the start time and the end time, we know the time it took to burn the slug.
And with the length of the slug and the burn time we can calculate the burning rate.
of that formulation.
If feels good, you know, that you can provide protection for someone.
You're providing a product that protects people. And that's our whole goal, to protect the public.
To provide that protection for them.