Image credits: Photos.com.
Parachutes are designed to slow the movement of an object or personal as it falls through the air; they were initially used by the aviation industry for rescue purposes and in the military for troop deployment. Today, parachuting has become a popular recreational activity, and horizonal parachutes are employed to slow fixed wing aircraft and drag racing cars. These are activities where there is no place for error.
There are two types of parachutes; the first is a dome canopy which traps the air inside creating a region of high pressure that slows down movement in the opposite direction to the air flow. Their shape ranges from a hemisphere to a cone. The second is a rectangular parafoil or ram-air canopy; it is a series of tubular cells that act as a wing allowing the jumper to direct his/herself towards a target. The parachute’s descent depends on the material, and hence it is important that the material is light, flexible, and windproof. It has to be able to handle high altitude winds and other environmental elements. The material’s density, rigidity, and texture are the other key factors that will control the speed and provide a swing-free descent.
This article will look at the key materials used in parachute manufacture.
Materials used to make Parachutes
Leonardo Da Vinci is credited with the first design for a parachute; his drawings show a pyramid-shaped linen canopy held open by a square wooden frame and was designed as an escape device to be used by someone escaping from a burning building.
Canvas - The first choice for the parachute’s canopy was canvas. It is a very heavy-duty plain-woven fabric.
Silk – Canvas was replaced by silk, as silk happened to be lighter, stronger, thinner as well as fire resistant and easy to fold and pack. Silk was first used by J.P Blanchard in 1785 to make the first parachute without a rigid frame.
Nylon - Nylon replaced silk during the WW2 when supply of silk diminished. Nylon has since become a popular choice, as it has excellent wind resistance, good elasticity, mildew resistance, and is comparatively cheaper. The material is also lightweight and dries quickly. It is resistant to abrasion and chemicals. Due to its exceptional strength, it is also used to make straps of the parachute harness, reinforcing tape, and suspension lines.
Nylon fabric for parachutes is woven in a specialized manner with extra thick threads to create a pattern of small squares – this is known as ripstop nylon. When small tears occur in the canopy, these small squares prevent the tears from becoming bigger.
Kevlar – This is an extremely strong synthetic fabric that can be used in bullet-proof clothing. It is heat and flame resistant, therefore it does not lose its strength or deform at high temperatures. The tensile strength remains intact even when stored away for long periods.
Terylene - A type of polyester fabric that is now being used as a material for parachutes as it is very strong and heat resistant.
Other materials used include:
- Forged steel-plated with cadmium for metal connectors to prevent rusting
- Stainless steel cable for ripcords.
Parachute manufacturers are looking for ways to improve their products with better materials and designs. Fascinating research being performed involves creating a parachute with the ability to control the emergency descent of an entire aircraft. The fabric is being designed to have extremely low-porosity and high strength. With the rapid advancement in the materials world, we can hope to see some innovative materials in the future to make parachuting safer and more fun.
Updated on 13/08/18.