The advantages of flexible nylon

By Tony Hollands, National Sales Manager of PMA-UK

Think of strength, resistance and protection and the first material that springs to mind is likely to be metal. But as flexible nylon-based cable protection systems become the preferred choice in industry, metal conduit may soon become a thing of the past.

With uses in rail, transport and construction industries, as well as in power plants, factories, refineries and laboratories, flexible cable protection systems are more than just tubular casing. Providing protection from damage to cables on CCTV cameras, signalling equipment and in manufacturing facilities, the properties of a successful conduit product must exhibit strength, flexibility and durability.

The merits of flexible nylon make it the ideal material for uses such as those listed above. As one of the most commonly used polymers, nylon was first produced in 1935 by Wallace Carothers whilst working at the chemical company DuPont. With the material’s properties including abrasion resistance, rigidity, resistant to fungus, animals and rot as well as being of a superior strength, flexible nylon has become the perfect choice for electrical contractors.

The benefits of nylon

With developers of cable-protection systems having a number of important boxes to tick, including protection from the elements and being capable of functioning in hazardous situations, flexible nylon conduit has proven itself to be resistant to temperature fluctuations by performing in sub-zero temperatures and all weather, from snow to torrential rain and achieving an IP rating of IP69K.

The pros don’t end there; with nylon devices providing the solution for material-sensitive situations, such as applications in factories where metal cannot be used. 

And if you thought flexible nylon couldn’t give the same level of protection in hazardous environments as steel alternatives, think again because with ATEX approval recently being granted for a purely nylon-based flexible system, the doors have been opened to new ways of thinking.

The science of nylon

The properties of a flexible nylon conduit enable it to spring back from impact, adjusting with ease and giving flexibility on systems specifically designed to provide ingress protection to vulnerable umbilical cabling which connects moving objects, such as signalling devices, cameras and machinery.

When it comes to adapting to surroundings and reacting to pressure, despite being strong, metal conduit is difficult to cut, heavy, expensive and when pressure is applied, it lacks the elasticity to reform its existing shape.

As specialists in the development of nylon-based systems, we’ve worked on the improvement of the material’s performance in harsh or hazardous environments, and with a temperature range from -50°C to +120°C – the versatility, adaptability and flexibility of the material are incredible.

As testimony, we’ve recently been awarded an increased protection rating of IP69K, which means that our products can withstand high pressure water (Up to 100 bar) and temperature – which just goes to show how durable nylon can be.

With flexible nylon cable protection being implemented in the UK’s construction, transport, mechanical engineering and automation services, and a number of accreditations being granted to the producers of nylon systems, it’s no surprise that recognised bodies are including plastics in their recommendations for those who want the quality of their appliances to reflect their high standards of work.

Rodent troubles

There are other less-obvious advantages to using nylon cable protection systems, which although obscure, provide an advantage which may be worth millions to some companies.

It’s well-known that rodents are a major culprit of causing technical failure and disruption on railways due to their habit of gnawing through cable protection and damaging the wires within. However, research shows that products manufactured from polyamide are completely resistant to the small teeth of pests such as rats.

This huge benefit is not down to any strange-tasting chemicals, it’s actually due to the innate properties of nylon, which although recognised for having a fantastic memory when returning to shape after an impact, are very good at forgetting when it comes to scents and smells.

Rodents mark their territory rigorously. So much so, that when a car which has been marked by a rodent is parked in a different place to usual – and in the territory of another rodent – the local animal will try to remove all traces of the ‘intruder’.

Raw materials which are softer, such as cable insulation or PVC tubing, and materials with a rougher surface are very good at retaining the marking smells of rats for longer – meaning that there is a far greater danger that other rodents will bite away all traces of that scent in order to defend their territories.

With polyamide, this risk is significantly reduced because urine and other marking substances don’t adhere to its smooth, shiny surface. It really is as simple as that.

A further explanation for the gnawing behaviour of rodents is the gathering of raw material for nest building. With their sharp teeth, rats and other rodents are capable of biting through almost any type of material, including metal.

Despite this behaviour being instinctive, it is thought that polyamide is considered an unattractive building material due to its natural taste and the effort required to bite into it, due to its hard and elastic properties on which teeth are inclined to slip. This also means that the larger the conduit, the more difficult it is for an animal to bite into its surface. These findings have been confirmed by an institute in Florida, whose research showed that even when rodents began to nibble into polyamide, they very quickly lose interest.

The latest innovations

Now with flexible nylon making its mark on a wide range of industries throughout the UK, new products are constantly becoming available to suit a number of applications.

With PMA currently focusing on developing products which are engineered particularly towards applications in hazardous environments, non-metal conduit manufacturers are also competing in terms of offering more cost effective solutions than those currently on offer, such as PEEK based conduits.

An emphasis is also being placed on providing low friction methods to enable easy cable insertion, again with the aim of driving down time and labour costs.  With development continually underway to enhance and improve the range of cable protection systems available, the aim is placed on saving electrical contractors time and money, whilst providing them with products of superior quality, which consistently out-perform more traditional materials.

Easily installed (no sawing necessary), resistant and affordable, it’s no wonder more people are putting their faith in flexible nylon and waving goodbye to metal cable protection.

www.pmacableprotection.co.uk