A Cut Above The Rest
Shaving
Some of us do it daily. Others, weekly or a few times a month. But everyone trims their facial or body hair at one point or another. And humankind has been shaving for millennia. From tweezing with shells or rocks in prehistoric caves to technology that makes hair removal permanent, we’ve come a long way.
We’re usually so focused on avoiding cuts and skin irritation that we forget to stop and appreciate the sophisticated engineering packed into these everyday objects. Even the simplest disposable razor is the product of thousands of years of shaving history. Our industrial CT scanner allows us to understand just how this evolution plays out. Let’s take a closer look.
Cartridge razor
Gillette Venus
Toward the end of the 1800s, the hoe-shaped safety razor marked a giant leap forward for shaving. The safety razor not only left the dangerous and difficult-to-use straight blade in the dust, it also proved perfect for mass production in the dawning age of industry. The aptly named King Camp Gillette led the way, pioneering the automated manufacturing of double-edged carbon steel replaceable blades at the turn of the 20th century. Today, multi-blade cartridge razors have become the most widely used shaving implements, and Gillette remains at the front of the pack.
This Venus Gillette women’s razor features 5 blades, making for a close shave as each blade following the first cuts the hair progressively nearer to the skin. Though too many blades can lead to clogging, multi-blade cartridges evenly distribute pressure and prevent skin from bulging up between the blades, which leads to irritation. With CT, we see how the super-thin corrosion-resistant steel alloy blades are actually welded onto L-shaped supports.
The moisture strip on the front, pivot mechanism in the back, and rounded head shape are all hallmarks of women’s razors. Women’s razors may more accurately be called body razors, since they’re designed for removing finer hair in longer strokes while navigating physical contours and sensitive areas. Gillette has cited these and other “differences in technology, materials, manufacturing, and promotional factors” to account for the on average 13% higher price of personal care products marketed toward women, a phenomenon known as the “pink tax.” Whether or not this is justified, an individual’s specific needs may be a better guide than a razor’s target market for choosing the right shaving tools.
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Electric shaver
Philips Norelco
Facial hair has the same tensile strength as a copper wire. Faced with such stubborn stubble, it’s no surprise that many people prefer electric shavers for keeping beards and mustaches in check. Jacob Schick’s electric razor first hit the U.S. market in 1931, and competitors have been innovating on blade number and design ever since. Philips Norelco introduced the iconic rotary blade in 1939, and we scanned a budget-friendly current model to learn how it works.
Fueled by two nickel-hydride rechargeable batteries, this DC motor transforms electrical energy into mechanical energy to power the shaver’s rotary blades. With CT, we can see the stationary magnets (the thick vertical bars on either side of this crop view) bracketing a wire coil. The switch directly below energizes each armature coil in turn, generating a magnetic field that reacts with the charges of the stationary magnet to create a rotating movement known as torque.
The motor rotates at a constant speed, turning a shaft that drives a plastic gear assembly connected to the three rotary blades. These springs allow the shaver heads to flex in four directions, ensuring a consistent and smooth shave as they glide over the face’s contours.
In both linear and rotary electric shaving systems, a foil makes contact with the skin while an “undercutter” blade moves underneath. True to their names, linear shavers move laterally, while rotary blades go in circles. The perforated holes in the foil aren’t sharp to the touch on the outside, but internally, they act as a second blade to cut each hair like a tiny pair of scissors.
These three rounded blade caps house 27 self-sharpening blades. Over the course of a year, a regularly used shaver will cut an average of 4.5 million hairs. It’s no surprise that after 12 months of use, shaving heads should be replaced to maintain peak performance.
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Epilator
Braun
Epilators aren’t exactly shaving devices. The word epilation means hair removal, so waxing, lasers, and tweezers all fall under that heading. But the epilator as we know it first hit the market in 1986 when an Israel-based company began marketing Epilady. Epilators remove hair four times shorter than waxing and leave skin smooth longer than shaving—often up to a month. Many epilators, like this Braun model, use a rotary tweezing barrel to grab and pluck individual hairs out from the root.
Without the plastic, the epilator looks like a farming implement, maybe a disc harrow or rotary tiller. But instead of blades, it has 40 micro-grip tweezers. The two metal bars above the tweezing barrel are part of the vibrating massage roller cap, which makes for a gentler epilation experience.
The 40 metal die-cut tweezers are mounted to a pin that not only holds them in place but also allows the entire epilator head to pivot in response to the body’s contours.
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Shave gel
Edge
Last but not least, we took a peek inside the unsung hero of shaving: the layer between you and the razor that keeps you safe and comfortable. Though warm water softens prickly hair, it evaporates too quickly. The secret to shaving cream and gel is surfactants—complex molecules with hydrophilic heads and hydrophobic tails that create and maintain the lather. Add to that anti-bacterial, perfume, and moisturizing components, and you have all of the ingredients for a modern shave gel.
In this bicompartmental can, the shave gel formula is packaged into a nylon bag and kept separate from the propellant. With shaving cream, there’s no bag, and the propellant combines with the product to foam upon release. It’s not a good idea to cut open a can like this, since the propellant is packed in there at two to eight times normal atmospheric pressure. Good thing CT offers a safe way to see inside.
The cap of the can consists of dense metal, guaranteeing a strong seal for the pressurized air inside. When you press down on the plastic pump, the actuator opens the valve to dispense the shave gel.
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