To be fair, there are so many seemingly simple things that we take for granted. In fact, you might be holding or wearing or sitting on something right now which is actually way more complex and intricate than you might think it actually is. With this in mind, we can confidently say that nylon is easily one of the most underrated materials, at least in the eyes of average people.
If you’re wondering why parachutes and ropes are made from nylon, the answer might not be that surprising at all.
This is due to the fact that nylon is one pretty tough material, with its unique molecular structure giving it properties like elasticity and immense overall strength. At the same time, it’s incredibly light, which makes it a great solution for parachutes and different types of ropes or chords.
However, we’ll take a deeper look into this matter, explore the properties of nylon, and explain why it’s great for these particular uses, as well as some other ones.
Table of Contents
Physical and Chemical Properties of Nylon
So before we get into it, let’s tell a thing or two about nylon’s chemical and physical properties. Nylon is essentially a synthetic fiber. The person credited for its invention is Wallace Hume Carothers who worked in close cooperation with DuPont, the well-known chemical company that was in charge of the project of creating a strong fabric.
However, the word “nylon” actually refers to a group of different chemical compounds, the group of plastics. It’s a designator for a specific family of synthetic polymers known as polyamides. We can also refer to it as a synthetic thermoplastic linear polyamide, which is a fancier description of one pretty large molecule filled with specific kinds of bonds.
Technically, there are plenty of different material types under this category, all known under different designated names. The best-known and the most widespread one in practical use is the Nylon 66 type (or Nylon 6,6) which was the one developed by Wallace Carothers.
Of course, there are plenty of other types of nylon, and they’re all described by two numbers. This dual-number nomenclature, which goes after the letters “PA.” This refers to the word “polyamide” which is in this case interchangeable with the word “nylon.”
The process of creating specific nylon salts includes a reaction between dibasic acids and diamines. This is in close relation to the nomenclature of the specific nylon types.
So these numbers in the name actually indicate the number of carbon atoms between acid and amine groups. There are nylon types with only one number in the name, like the PA 6 (or Nylon 6), which indicates that this is a homopolymer based on one amino acid (also referred to as monadic).
If the molecule has the second number in its designated name, it indicates a dyadic homopolymer, meaning that it consists of two monomers, one being diamine and the other one dicarboxylic acid. The first number in the designated name refers to the number of carbons in the diamine, while the second number tells us how many carbon atoms are there in the acid.
But not to get too geeky about it, all of this results in a semi-crystalline material that’s very physically tough and that also comes with great thermal and chemical resistance. Of course, different types also come with a different range of properties, some of which are very useful for parachutes and some of which are useful for ropes.
Additionally, nylons have a tendency to absorb moisture. And the higher the moisture content, the more flexibility and impact resistance we get. But at the same time, the strength and stiffness decrease.
Chemically speaking, they can withstand most of the stuff, although stronger acids, different alcohol types, and alkalis can eventually harm it. They’re also very resistant to high temperatures, sometimes showing great properties at well over 100 degrees Celsius.
Generally speaking, nylons come with a tensile strength that spans from 90 to 185 newtons per square millimeter. Their density is usually about 1.15 grams per cubic centimeter.
Why Nylon Is Great Material for Ropes
Looking at the physical and chemical properties of nylon, it gets pretty obvious why they’re so good of a choice for ropes. This is mostly due to its incredible stretching capabilities and overall smoothness. Additionally, it’s also pretty resistant to abrasion and UV light, which can make it a great choice for any type of outdoor use.
These properties are also the main reasons why nylon is used for different types of rescue lines or fall protection systems. It’s also quite common for ropes used with winches, towing lines, anchors, tie-downs, or any similar settings.
The sheer strength combined with its flexibility and generally lower weight is the reason why it’s considered to be so safe. In fact, these days, it’s way more widespread compared to natural fiber ropes, which are, at this point, more of an aesthetic feature than anything else. True reliability is in nylon.
Why Nylon Is Great Material for Parachutes
And then we have parachutes. We can say pretty much the same thing about nylon and its use for them. However, there are a few other important properties that make the material useful in this regard. After all, creating drag and significantly reducing the speed of a falling object requires something that’s lightweight and extremely resistant to different types of stress.
Back in the old days, the late 18th century, we got the first incarnation of what we know as the modern parachute. These earliest examples were actually made out of linen that was stretched over wooden frames. Further developments included silk as the main material, which proved to be a much better choice for this use due to its lighter weight and overall strength.
Further development of the concept eventually led to the backpack design. Canvas and silk still served as the main materials during the two World Wars, although silk was generally much more practical.
Eventually, during World War 2, nylon entered service as the main material for the US troops. Of course, kevlar and dacron were also used for the purpose, but nylon just proved to work better in the end.
However, it’s important to note that parachutes are not just large stretches of nylon tied to a bunch of ropes. For this purpose, we have the “ripstop” nylon which also includes thicker threads added at regular intervals, ultimately creating a pattern of smaller squares. This way, any type of smaller tear that happens can be easily stopped from spreading.
Additionally, parachute ropes, or parachute chords, are also made of nylon. For this purpose, we have nylon kernmantle. This particular type of rope has also found practical use in some extreme settings, most notably during the 82nd Space Shuttle mission which included the reparation of the Hubble Space Telescope.
Aside from cords, nylon is also used for reinforcement tape, suspension lines, and harness straps. In combination with metal connectors, which are made out of forged steel, and stainless steel cable ripcords, you get one pretty safe construction.
Other Practical Implementations of Nylon
But parachutes and different kinds of ropes are far from the only things that nylon is used for. The whole list of practical implementation would be quite long, but some of the stuff includes:
- Instrument strings
- Fishing nets
- Mosquito nets
- Different types of luggage and backpacks
- Various clothing items
- Sports equipment
- Sleeping bags
- Plastic fasteners
- Various machine parts
- Extruded profiles
- Powder coating
- Food packaging
- Life vests
- Combat uniforms
The nylon’s use for instrument strings, for instance, started sometime in the mid-1940s. It was, in fact, classical guitarist Andrés Segovia who pointed out the shortage of quality guitar strings in the United States. Eventually, his complaints led to the practical implementation of nylon, developed by DuPont, for this particular purpose. Nylon strings eventually had their stage debut in 1944. Prior to that, catgut was one of the main materials for classical guitars.
Nylon properties were extremely useful for food packaging. Providing a proper oxygen barrier, the shelf-life of different foods is prolonged, especially if we’re talking about fresh and processed meat. Needless to say, this brought a revolution and significantly improved the quality of life for countless people around the globe.
Arguably, one of the most interesting uses of nylon was for the Remington Nylon 66 rifle. Made for 30 years, between 1959 and 1989, it presented one of the most important practical changes in the weapon industry. Synthetic materials were a pretty risky game at the time and wood was basically the main material for the gunstock. However, the properties of nylon eventually proved to be of great value for the weapon industry, eventually becoming the more reliable standard.
From this long list of products, it becomes pretty obvious that different nylon types are here to stay for quite a while. For most of the things that we need today, safety is one of the utmost important priorities. And, for this purpose, nylon seems to be without a contender.