Retroreflective materials return light back to the light source. For example, the headlights of a vehicle will bounce back from the retroreflective striping of a jacket, vest, harness, trousers, etc. to the driver, allowing better visibility of the worker — retroreflectives can return light over a greater distance than regular reflectives. Therefore, the driver’s ability to see the public safety professional is increased, meaning greater safety!
There are two kinds of retroreflection:
spherical and cube corner. Manufacturer’s will use either
and both work equally well. They both reflect light back to
the light source … how they do it is where they differ.
Just cruise through our simple lesson in physics to find out
how they differ.
Spherical Retroreflection
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| The retroreflective material
is covered with hundreds of tiny glass beads. |
A driver’s headlight hits
the reflective sheeting. |
It passes through the front of
the bead and hits the mirrored surface behind it. When the light
bounces off the mirrored surface and back through the glass
bead, it reflects towards the light source, in this case a car’s
headlights. |
Cube Corner Retroreflection
Say the same driver continues down the road and the lights from
the headlight hit another retroreflective vest. They encounter
another reflective surface. However, this time, instead of being
spherical, it’s cube corner, looking much like a pyramid.
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| Rather than shooting through
the round retroreflective element, this beam of light is going
to hit three corners. Imagine playing pool. You bank a shot
off the long side … it doesn’t just stop. The laws
of physics says it still has to keep going, geometry puts its
two cents in and tells the ball to go perpendicularly. So it
continues on its way and hits the short wall. Light obeys these
same laws. |
Our driver’s headlight light beam is going to hit the outside wall of the cube and pass through.
It will continue on and hit another wall.
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After that, it will bank off
the mirrored surface and then continue on through a wall of
the pyramid, returning to the driver’s eyes. |
Both spherical and cube corner’s
retroreflective elements have a smooth top layer that protects
it.
All ANSI compliant apparel has retroreflective striping that
works on either of these two principles. One is not better than
the other. Both styles do the same job, and that is to reflect
light for greater visibility and increase safety.
Learn even more about ANSI Compliant Apparel. Continue on or click any of the links below to go directly to that topic.
