A recent chemical factory explosion in Germany went largely unnoticed by most of the world when it occurred on 31 March 2012. But within a week, news of the explosion and its global ramifications caught the manufacturing world’s attention. The factory, operated by Evonik Industries, produced a quarter of the world’s supply of cyclododecatriene (CDT), a key ingredient of Nylon-12. Nylon-12 is used extensively in the automotive industry for fuel and brake lines, and the electrical industry for solar panels and insect-resistant cables.
Why does this incident affect the electrical cable industry?
For decades, Nylon-12 has been the preferred protective sheathing on underground power and telecommunications cables to mitigate termite attack. In such applications, the gloss surface finish and hardness of the extruded nylon barrier layer denies a purchase point for termites to commence a destructive attack, while being flexible enough to allow the cable to be wound on drums and reticulated through installations.
Nylon-12, already in short supply before the Evonik explosion, has become virtuality unobtainable for volume manufacture. With the German plant not expected to supply CDT again until late 2012, it may be early 2013 before cable manufacturers will be able to deliver volume quantities of Nylon-12-sheathed termite-resistant cables.
Are there alternatives available?
Notably, Australian cable standard AS/NZS 1429.1 states that “where protection from insect attack is required an extruded jacket of polyamide 11 or 12 or copper, brass or stainless steel tapes helically applied, or other suitable means maybe incorporated in the cable construction”.
So there are a number of methods that can be successfully deployed to mitigate termite attack on cables and these should be selected based on their suitability to specific situations, applications and economic considerations.
Tapes of malleable materials such as brass or copper are an effective insect-barrier, however due to higher installation cost, the electrical industry generally prefers polymer-based termite protected cables.
Prysmian, a Voltimum founding member and leading electrical and telecommunications cable manufacturer, has for many years offered several cable-construction types to mitigate termite attack, including Nylon-12 sheathing, metallic tapes and Termitex® treated sheathing, each designed to service market needs and applications.
Termitex® repellent sheath is a suitable alternative to Nylon-12 and metallic tapes for use in the Australian market. It is a proven termite repellent incorporated as a sheathing layer in many cable constructions (in place of the nylon barrier sheathing layer). Termitex® resulted from years of research conducted in Prysmian laboratories in collaboration with world renowned organisations such as the CSIRO.
Key benefits offered by Termitex®:
- Does not require special handling;
- Does not require large installation radii;
- Efficacy is not compromised by surface scratches, scuffs & abrasions;
- Eco-friendly, bio-degradable;
- Insoluble in water; and
- Very effective against even the most destructive termites.
What to do now
If you have been specifying Nylon-12-sheathed termite-resistant cables, the good news is that the CDT shortage should not create a crisis for you – there are viable alternatives. It is however, critical for specifying engineers and those sourcing termite-protected cables to ensure they carefully weigh-up their specific requirements to ensure genuinely fit-for-purpose cables are being evaluated.
Where alternative offers are being considered, care must be taken to ensure the protective measures incorporated in the cables meet Australian OH&S requirements and that the form of protection can be assessed correctly against the more vigorous termite species found in Australia, such as Mastotermes Darwiniensis. Be careful of cables with unsubstantiated claims of termite-resistance – always request verifiable proof of protection.
Most importantly, anyone charged with the responsibility of sourcing cables for termite-prone installations should contact reputable Australian cable manufacturers for advice. They can provide you with a list of reliable options and assist you in finding the most suitable solution.
Risk of termite activity throughout Australia
