How BUNGEE Cords Work?
Bungee cord is the commonly used name for a cord with an interior that is made of elastic fibers blanketed in a woven sheath. Other names used to describe this type of rope are “shock cord” and “elastic cord.” Bungee cords provide a cost-effective alternative to metal chains and other rope needed to hang, lower, or raise certain goods.
The threads encapsulated in the core are made of natural or synthetic rubber and vary depending on the intended use of the cord. Natural rubber, oftentimes called latex rubber, has incredible extensibility, resilience, and tensile strength. However, there are disadvantages to this material, such that it has an adequate resistance to air and ultraviolet radiation from the sun. This is unlike synthetic rubbers that have a better resistance to sunlight and air, but moderate resilience and tensile strength.
In contrast, the outer casing is composed of a variety of materials including cotton, polypropylene, and nylon that are also meant to enable a consistent stretch the entire length of the cord. Commercial bungee cords are normally composed of a single layer of nylon, which is resistant to wear and tear, and has a higher tensile strength.
How you are planning to use your bungee cord dictates the kind you need to purchase. Some factors to consider include how much you need it to stretch. Generally, the thicker the cord, the stronger it will be. However, this can also mean it’ll be harder to stretch. Standard commercial bungee cords are available at 0.25-inch to 0.62-inch diameters. For military-grade bungee cords, this may vary. Nonetheless, the manufacturing process is relatively the same.
The natural or synthetic rubber is formed into long ribbons of rubber that are 0.09-inch thick, 0.25-inch wide, and up to 100 feet in length. The strands are pulled through an extruder that heats up the material and forms the desired shape. The number of ribbons dictates the diameter and tensile strength of the cord. Moreover, to prevent the strands from clinging to each other in warm weather, they are coated with powdered talc or soapstone. This process is repeated as the strands are being unwound from the coils during the braiding process.
The next step in the manufacturing process is braiding the cover. The free ends of the ribbons are brought together and fed through a machine called the braider that squeezes them into a bundle. As they are being formed, the machine is simultaneously stretching them in order to reduce the diameter of the strands so the covering can be wound tightly. The braider weaves the covering over the stretched bundle as it makes its way through the machine. This must be done with precision and accuracy to avoid dirt or other unwanted elements that may enter the gaps. The last part of the material process includes placing the end fittings on the cord. The ends are usually capped off with coiled wire achieved by using a wire coiler machine. The other end of this wire is normally bent into a j-shaped hook.
A step that cannot be overlooked is the quality control test of the bungee cord. All bungee cords are visually inspected for defects such as broken strands, stripping, stains on the outer covering, etc. Other than that, commercial bungee cords do not require further testing, while military-spec bungee cords are submitted to a number of tests to test resistance, percent elongation under various loads, a number of extension-contraction flex cycles, and breaking strength. Moreover, it is important to note that bungee cord performance can be affected by age. For example, military-grade bungee cords must be shipped within six months of their manufacturing date. This is indicated by a color coding system. However, this system varies by company and may not always be uniform. This is important to know because some colors may indicate the cord’s load capacity or age.
Commercial bungee cords are a straight-forward, cost-effective product that can be used in a number of industries, from aerospace to automotive. If you find yourself in need of bungee cords, or alternatively, aircraft, marine, and IT parts, Limitless Aerospace can offer you competitive quotes on the NSN parts, aviation parts, IT hardware parts, and more that we carry throughout our website. Limitless Aerospace is owned and operated by ASAP Semiconductor, the leading distributor of electronic components with access to an inventory of more than 2 billion units in stock and ready to ship with short lead times and competitive prices. We are set apart from many other companies with our dedication to getting parts to customers as fast as possible. ASAP Semiconductor is an FAA AC 00-56B accredited and ISO 9001:2015 certified enterprise. For a quick and competitive quote, email sales@limitlessaerospace.com; we are available 24/7x365.
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