"Comes the total comfort of total stainless steel shaving"
Steel is 50 times harder than human hair.
Yet if you’re a frequent shaver, your razors
probably don’t last more than a few weeks
before they need to be sharpened
or tossed in the trash.
"Men report each gives ten, fifteen or even
more comfortable shaves. Watch."
For a long time, researchers suspected this
failure stemmed from the sharp tip gradually
wearing down and becoming rounder
after each use.
But a new study points to a more complex interaction
between hair and steel involving chipping.
They started with an unusual first step:
growing a beard.
The researcher grew a beard for three days,
shaved it, then looked at the razor under
an electron microscope.
After each shave, they didn’t notice metal
slowly and evenly coming off the blade.
Instead, they noticed something baffling --
the formation of tiny cracks, then chips,
along the sharp edge of the blade.
To better understand how these cracks formed,
researchers rigged a razor and hair under
a microscope to watch the cutting in action.
When the hair was cut exactly perpendicular to the blade, no cracks formed.
But when the blade was tilted at an angle,
conditions more realistic for shaving,
they saw those same mysterious chips.
Changing the angle increased the stress
exerted on the razor.
After analyzing the blades further,
they found the roughness of the edge of the razor
played a role in the formation of these chips.
Despite how smooth a razor may look to the
human eye, the surface is speckled with bumps
even before cutting anything.
Steel is hard overall, but there are some
regions that are softer than others.
These variations lead to the bumps that render
razor blades less effective.
Researchers found that the cracks were more
likely to form where softer regions and harder
regions met. When the hair pushed down the
softer area at an angle, it stressed the boundary,
leading to the formation of a crack.
Now that researchers understand why the blade
is failing, they’re working to create longer-lasting razors.
Traditionally, razors are made by honing steel,
using a hard, rotating wheel to remove
material and form a sharp tip.
But this process results in an uneven surface.
To create a smoother tip, researchers have
experimented with using extreme pressure to
mold the material into a sharp wedge shape.
Soon, they hope to test these blades to see
if they are more durable.
Increasing the lifetime of razors could have
positive environmental impacts--
in 1990, the Environmental Protection Agency estimated
that over 2 billion razors were thrown away annually.
With new blades, we can cut that waste off
at the source.
