A safety razor is a device used to remove hair from areas of the body where it is undesirable such as the face for men and the legs and underarm regions for women. The modern blade razor consists of a specially designed blade mounted in a metal or plastic shell that is attached to a handle. This kind of razor can be designed as a refillable cartridge which can accept new blades or as a disposable unit which is intended to be thrown away after the blade becomes dull.
Since primitive times, shaving has been an important cultural grooming practice. Cave painting show that even the prehistoric men practiced shaving by scraping hair off with crude implements such as stones, flint, clam shells, and other sharpened natural objects. With the advent of the Bronze Age, humans developed the ability forge simple metals and began to make razors from iron, bronze, and even gold. The ancient Egyptians began the custom of shaving their beards and heads, which was eventually adopted by the Greeks and Romans around 330 B.C. This practice was advantageous for soldiers because it prevented enemies from grasping their hair in hand-to-hand combat. The unshaven, unkempt tribes they fought became known as barbarians, meaning the unbarbered.
Until the nineteenth century, the most common razor was still a long handled open blade called a "cut-throat" razor which was difficult to use, required repeated sharpening, and was usually wielded by professional barbers. Credit for the first safety razor is generally given to a Frenchman, Jean-Jacques Perret, who modeled his design after a joiner's plane. He even wrote a book on the subject entitled Pogonotomy or the Art of Learning to Shave Oneself. As with the razors of today, Perret's design covered the blade on three sides to protect the user from nicks and cuts. However, it still required periodic sharpening to give a good shave. Similar inventions were introduced throughout the 1800s. Nonetheless, even as late as the early 1900s most men were still shaved periodically at the barber.
Shaving practices began to change dramatically around the turn of the century. In 1895, an American named King Camp Gillette had the idea of marketing a disposable blade that didn't require sharpening. Gillette designed a razor that had a separate handle and clamp unit that allowed the user to easily replace the blade when it became dull. However, metal working technology took another two years before it was able to make the paper thin steel blades required by Gillette's design. Even though he filed patents in 1901, Gillette could not market his disposable blades until 1903 when he produced a total of 51 razors and 168 blades. By 1905, sales rose to 90,000 razors and 2.5 million blades. Sales continued to grow over the next several years, reaching 0.3 million razors and 14 million blades in 1908. After Gillette's initial success, other manufacturers soon followed suit with their own designs, and an entire industry was born. Over the last 90 years, a variety of products have been introduced including tiny safety razors for women, long-life stainless steel blades, twin-blade safety razors, the completely disposable, one-piece plastic razor introduced by Bic, and the state of the art Sensor and Mach 3 shaving systems by Gillette.
Razor designs vary depending on the style. Some razors, such as the single piece disposables, are relatively simple. They consist of a hollow plastic handle, a blade, and a head assembly to keep the blade in place. They are primarily designed to be simple, economical, and disposable. The refillable cartridge style is more complicated. They are designed to give a more premium shaving experience with options like multiple blades, pivoting heads, and lubricating strips. For example, Gillette's Mach 3 razor, which was introduced in 1998, features a skin guard comprised of flexible microfins, a soft grip handle, water-activated moisturizers, a flow-through cartridge, optimal blade positioning, and other innovative features. The engineering behind some of these advancements is quite impressive. Gillette employs 500 design engineers, who are constantly developing new shaving systems. Preliminary designs are developed into working prototypes that are tested by over 300 company employees, who take part in Gillette's shave-at-work program. The company has 20 booths set up where employees use unmarked razors on different sides of their faces. They then rate performance attributes of each razor with the aid of a computer program. Engineers use this feedback to adjust their designs and create improved prototypes for further evaluation.
Razor blades are periodically exposed to high levels of moisture and therefore must be made from a special corrosion resistant steel alloy. Furthermore, the grade of steel must be hard enough to allow the blade to hold its shape, yet malleable enough to allow it to be processed. The preferred type of steel is called carbide steel because it is made using a tungsten-carbon compound. One patented combination of elements used in stainless steel blade construction includes carbon (0.45-0.55%), silicon (0.4-1%); manganese (0.5-1.0%); chromium (12-14%) and molybdenum (1.0-1.6%); with the remainder being iron.
The plastic portions of a safety razor include the handle and blade cartridge, or portions thereof, depending on the razor design. These parts are typically molded from a number of different plastic resins including polystyrene, polypropylene, and phenyleneoxide based resins as well as elastomeric compounds. These resins are taken in pellet form and are melted and molded into the razor components through a combination of extrusion and injection molding techniques. For example, in making the handle for their advanced shaving systems, Gillette uses a coextrusion process which simultaneously molds an elastomer molded over polypropylene to create a surface that is easy to grip.
Razors may contain a variety of miscellaneous parts which help hold the blade in place, guards which cover the blade during shipping, or springs or other release mechanisms which facilitate changing of the blades. These pieces are molded by similar processes. The more sophisticated brands include a lubricating strip made of polyurethane, or other similar materials, that is impregnated with acrylic polymers. These strips are mounted on the head of the razor, in front of the blades. The polymer film absorbs water and becomes very slippery, thus creating a lubricating surface that helps the blade glide across the surface of the face without snagging or cutting the skin.
All finished razor components must conform to tight specifications before they are released. For example, blades must meet a designated hardness rating and contain a certain amount of steel. Gillette blades must meet a standard knows as Vickers hardness of at least 620 and a carbide density of 10-45 particles per 100 square microns to avoid rejection. The equipment itself operates so precisely that Gillette measures its reject rate in parts per million. Similarly, molded plastic parts are closely inspected by operators with lighted magnifying glasses to check for loose flashing or rough edges; they alert technicians when problems are discovered. In addition, razor components are checked by a computerized vision system which compares a critical dimension to a reference.
Razor manufacturers like Gillette are constantly designing new and improved shaving systems. Their commitment to improved materials science continues to produce blades of increased hardness that are capable of sustaining sharp edge for more shaves. Advanced head design allows the blades to contact the face without cuts or nicks. They are also constantly updating their manufacturing equipment. The future manufacturing techniques also improve efficiency in molding and stamping operations. Gillette claims they are twice as fast as they were 10 years ago and have fewer defects.
Panati, Charles. Extraordinary Origins of Everyday Things. New York: Perennial Library, 1987.
Gillette Company. 1999. http://www.gillette.com/ (April 5,1999).
— Randy Schueller