Human hair is 50 times softer than steel, but can still cut through the sharpest razor edge. why ?
Whether you shave beard on your face, armpit hair or legs, you have definitely found that the blades get dull quickly and need changing after just a few uses. However, human hair is 50 times softer than steel blades. Why does steel dull so quickly when cutting something as soft as hair?
The question aroused the interest of famous researchers Massachusetts Institute of Technology (MIT) in Boston, a university that specializes in engineering. Until now, the assumption has always been that every shave sharpens the blade evenly until it loses its edge. Some also believe that the corrosion was due to oxidation of the metal.
More Study MIT He reveals that this is not what is happening at all. Alternatively, your bristles can break stainless steel under certain conditions. By photographing the razor blades while working under a scanning electron microscope, they were able to see that a haircut could generate a micro-crack on the blade, perpendicular to its edge. This crack then widens and the steel breaks into small “chips”.
So instead of being damaged evenly, the razor blade loses its sharpness through uneven separation of chips here and there. But how can one hair make the first incision? The researchers found that three conditions can promote the appearance of fissures. First, if the blade attacks the hair at an angle rather than perpendicular (which is usually the case).
Then, if the composition of the steel is not homogeneous, the hardest and softest areas are on the micrometer scale, which is always the case with razors due to their manufacturing process. Cracks always appear on the boundary between a firmer and a softer area. The third condition: the bristles should meet the blade in this place where the steel is softer.
This discovery should make it possible to improve the blade manufacturing process so that it is more uniform and lasts longer. Since only two billion ciphers are dumped each year in the United States, the environmental impact of such a discovery could be enormous.
