Manufacturers and engineers often need a material that is more lightweight and flexible than metal while still providing durability and protection. Polyamide offers an outstanding solution. Its convenience, reliability and cost-effectiveness make it a mainstay in product manufacturing and across a range of industries.
Table of Contents
WHAT IS POLYAMIDE?
Polyamide is a synthetic polymer made of petroleum-based plastics that are held together with amide bonds. The molecules that make up polyamide are extremely long and heavy providing strength and elasticity. The most recognizable form of polyamide is nylon fabric. Nylon was first introduced by DuPont in the late-1930s as a stronger alternative to silk stockings.
Fabrics such as wool, silk and nylon are all examples of polyamides — wool and silk are natural polyamides, whereas nylon is synthetic. Synthetic polyamide thermoplastics are important in engineering because they offer high performance at a reasonable cost.
TYPES OF POLYAMIDES
Polyamides break down into three different families — aliphatic, semi-aromatic and aromatic polyamides, also known as aramids. Nylons are aliphatic polyamides. The strong, heat-resistant fiber known as Kevlar is an example of an aramid. Aramids tend to be sturdier and have better resistance properties than aliphatic nylon polyamides.
Polyamide may take a woven form when it is manufactured as a fabric, or it may take a harder, sturdier structure when cast as a resin. It may sometimes be braided for a unique blend of strength and flexibility.
Polyamide has several physical properties that make it well suited to production and industrial use:
- Abrasion resistance: Polyamide is highly resistant to abrasion and wear. This quality makes it exceptionally durable in high-contact areas.
- Chemical resistance: Cast polyamides offer robust resistance to chemicals, so they provide superior protection for wires and cables in caustic environments.
- Corrosion resistance: Polyamide provides effective corrosion protection against caustic materials. Polyamides are ideal for harsh settings — chemical processing facilities, refineries, wastewater treatment plants — that would corrode metals after only a few years.
- Electromagnetic resistance: Some specially engineered polyamides, such as the type used in our ROHRflex® conduits, offer electromagnetic (EMC) shielding for sensitive applications.
- Flexibility: Polyamides were specifically developed for exceptional flexibility. This flexibility makes polyamide products convenient to move, bend and fit into cramped spaces, and it allows for assembly and installation in places that could not accommodate rigid metal structures. Polyamide will remain flexible even after long periods of use or exposure to extreme temperatures.
- Flame resistance: Polyamides’ wide temperature range — aliphatic polyamides typically melt at about 500 to 550 K — gives them strong heat resistance. They resist catching fire and produce little smoke when they do. Some polyamides can self-extinguish flames if they catch fire.
- Low density: Nylon polyamide has a density of about 1.31 g/cm3.
- Lightness: Polyamide’s low density makes it an incredibly lightweight material. Its lightness makes it easy to craft, maneuver and install.
- Strength: When they hear about its incredible flexibility and lightness, some people wonder — is polyamide strong? Polyamide provides exceptionally high tensile strength and superior impact resistance. For instance, strength tests have shown that although a forklift can crush a polyvinyl chloride (PVC)-jacketed metallic conduit system and pierce its insulation, a polyamide system easily resists piercing and withstands even heavy forklift pressure.
- Ultraviolet light resistance: Though ultraviolet (UV) light can damage some materials, polyamide resists its deteriorating effects. It can perform well in sunlight for decades.
Polyamide Advantages and Disadvantages
Below, we’ll discuss some of polyamide’s most notable pros and cons regarding its usage in modern applications.
Advantages of Polyamide
Polyamide offers several advantages because of its unique physical properties:
- Assembly time: Polyamide products are typically much quicker to assemble than their competitors. They are less bulky and easier to maneuver, and they fit with accessories like connectors easily. Whereas metal products are time-consuming to cut, polyamides allow for speedy cutting and assembly. Assembling polyamide cable protection systems, for instance, takes only one-fifth of the assembly time of PVC-jacketed metallic systems.
- Cost-effectiveness: Polyamides are exceptionally cost-effective. Because they are easy to transport, they incur fewer installation costs than other materials, and they have relatively low production expenses compared with metals.
- Durability: Polyamide’s many resistance properties make it highly durable. It will last for years without requiring excessive maintenance.
- Ingress protection: Polyamide provides an effective seal and will not leak. Unlike materials such as PVC and other plastics, it is also unattractive to rodents because it doesn’t preserve scents, so pests will not likely be tempted to gnaw through it. Rodent-resistant braided sleeving is a particularly useful option for addressing pest problems.
- Machineability: For industrial purposes, polyamide is often cast instead of woven. After casting, facilities can machine the cast pieces into various intricate components.
- Noise dampening: Polyamide is an effective sound insulator, so it makes an excellent choice for loud settings where noise reduction can help facilitate productive work or minimize annoyance to nearby residents.
Disadvantages of Polyamide
Polyamide also has a few disadvantages. It can sometimes absorb water, which is unfavorable because wetted polyamide has up to 50% less tensile strength than dry polyamide. However, some polyamides — including the cast versions typically used in industrial operations — are designed specifically to resist water absorption. Polyamide can also sometimes shrink when cast. On the whole, though, it is an effective protector and excellent choice for many industrial applications.
Polyamide Resin Uses
Polyamide is common in textiles like clothing and carpets. It also often features in the production of items that require both strength and flexibility, including fishing line, electrical connectors, gears, guitar picks and strings and medical implants.
Industrial Cable Protection Systems
Polyamide technology is frequently used in the conduits of industrial cable protection systems, as well as in fittings and connectors.
Industrial polyamide cable protection systems are generally superior in performance to the more common PVC-jacketed metallic conduits. The polyamide systems used in cable protection are highly engineered and specially modified for high impact resistance and flexibility. They also provide reduced assembly times and greater convenience.
Globally, polyamide cable protection systems are standard in the manufacturing, rail and transit and wind industries. In the United States, though, this technology has been slower to catch on, and many electrical and mechanical engineers lack training in its advantages and uses.
Other Industry Applications of Polyamide
Polyamide cable protection systems also have a range of industry applications beyond those that require cable protection. Some industrial uses include the following:
- Automotive: In the automotive industry, polyamide often forms air intake manifolds, engine covers, valve covers and airbag containers, as well as external components like handles, grilles, wheel covers and fuel caps and lids. These components once used metal, but polyamide makes for lighter, more fuel-efficient cars and cuts down production costs.
- Food and beverage: The food and beverage industry uses polyamide systems to promote good hygiene in areas where components may come into contact with food. These systems are common in food-packaging areas and production plants.
- Robotics: Robotics requires highly flexible and durable components, and polyamide provides practical solutions. It is also useful for wire and cable protection in robotics.
Contact AerosUSA for All Your Polyamide Cable Protection Needs
To see the benefits of polyamide components in your industrial operations, partner with AerosUSA. Our polyamide ROHRflex® conduits and FLEXAquick® connectors offer superior cable protection. We also supply various supplementary parts like fittings, clamp systems, cable entry systems, braids and sleeves, guide chains, ground straps and plastic and metal conduits.