Tuesday, June 22, 2010

Multiple Blades, Multiple Functions

Razors with multiple blades have been shown to give a smoother, closer shave and result in fewer missed hairs than do razors without multiple blades. Here’s why:

  • Hairs undergo hysteresis, a process by which the first blade extends the hair so that subsequent blades can further cut the hair shorter down the hair shaft.
  • With more blades, the razor has more contact points onto the skin. The pressure of the razor is therefore distributed in smaller amounts to a larger area of skin. Conversely, with razors with fewer or single blades, there can be more pressure applied to a smaller area of contact. Less pressure can ultimately lead to less skin irritation and fewer cuts. (Also note that other factors influence the pressure on the skin, including the overall size of the razor head as well as the pressure applied by the user himself.)
  • Multiple blades can impact the drag of a razor on the skin. As a razor is stroked, small bulges of skin are pushed up between the blades, leading to resistance. Razors on the market may have anywhere between a single blade to five blades. With multiple blades close together, there is less bulging between blades and reduced friction across the skin.
  • Some razors have independent, spring-mounted blades. This technology allows the razor to maintain close contact with the hair while following the contours of the skin.