Five times stronger than steel - the safety material that revolutionized safety materials
DuPont created Kevlar in 1965 while searching for a fiber stiffer and stronger than nylon. The company made it commercially available by the early 1970s, and it quickly became famous as bullet-proof Kevlar vests and other forms of body armor worn by police and the military.
This safety material is classed as an organic fiber in the aramid (nylon) family and is currently available in three grades.
Kevlar's availability has grown to include sheet, fiber, floc and cut pieces or even as pulp.
The original grade is simply called Kevlar fabric - an excellent reinforcing material used in conjunction with rubber. Automotive tires are one of Kevlar's most familiar applications.
"Kevlar 29" is more of an industrial workhorse, used in brake linings, clutches and body armor. DuPont cooked up this version as a badly needed replacement for asbestos.
"Kevlar 49" has the greatest tensile strength of the three grades, and is used as a plastic reinforcing material. Boat hulls, airplane bodies and bikes are a few of the products improved by having stronger structures with lower weights.
Industrial safety has benefited greatly from the use of this safety material, predominantly in the manufacture of Kevlar gloves, as well as Kevlar helmets, coveralls, shirts, pants and even socks.
- The FDA has recognized it as a suitable material for contact with foods.
- Very light; its actual weight is .052 lb/cubic inch.
- Impressive chemical resistance [PDF].
- Clothes made of Kevlar can be washed in normal machines or dry-cleaned.
- Excellent cut resistance makes for very safe clothing and gloves.
- The strength-to-weight ratio is roughly five times stronger than steel on an equal weight basis.
- Heat and flame resistance is impressive, full degradation at roughly up to 9000 F.
- Clothing will be suitable for temperatures up to 350 F.
- Extreme winter temperatures of -50 F have almost no effect.
- Costs in the upper end of the price spectrum compared to other materials.
- Low UV resistance means staying indoors.
- Bleach degrades the material.
- Tends to buckle under compression.
- Only available through licensed sellers.
- Low abrasion resistance.
- Not good in chlorine.