| Answer: There are two basic types
of safety glass. Plastic laminated glass is used for the windshields on
all vehicles while tempered glass is used in side and rear windows of most
vehicles. Plastic laminated glass either has a thin film of plastic sandwiched
between two panes of glass, or a layer of plastic on the inside of a single
pane of glass. The plastic keeps the glass from flying in all directions
when it is shattered, and it acts like a barrier to keep the occupants inside
the vehicle from going through the glass in a collision. Caution: On cars
that have the plastic inner coating on the inside of the windshield, care
must be used when cleaning or wiping the glass to prevent scratching the
relatively soft plastic. Tempered glass, on the other hand, has no plastic
in or on it. The glass is heat treated in such a way that makes it stronger,
but also causes it to crumble into small rounded pieces when it breaks.
This prevents long, jagged shards of glass from cutting you to ribbons.
But it also means the glass can be easily shattered when struck with a hard
object (which makes it easier for thieves to break into cars by smashing
out a side window). So why don't the auto makers use laminated safety glass
on all the windows? Because it costs more. |
