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The Nitralife
truck nitrogen unit is available for hire
to operators. |
The high incidence of road fatalities caused directly by tyre failure is a fact of South African motoring life and while both shocking and tragic, it may have more than a little to do with ignorance about what constitutes a healthy tyre, writes
Paul Collings.
Most people are aware of the benefits a healthy diet. While the adage "we are what we eat" may be a cliché, it is by and large, true. In the world of tyres, the same rule applies. Some gasses (being 'tyre food') are better for tyres than others in terms of safety and longevity.
Tyre virus
The introduction of the pneumatic rubber tyre for motorized vehicles in the late 19th century was a technological breakthrough that vastly improved vehicle handling and driver comfort. And, most of the tyre was made up of air, which is free. What wasn't realized until several decades later was that air itself is made up of gasses which, once inside a tyre, become rather dysfunctional and unhealthy for rims and the rubber that encases them.
According to Rob Sowry of Nitralife, "air comprises about 78% nitrogen, 21% oxygen and 1% other gasses. It's oxygen that is the main culprit when it comes to blowouts, tyre deflation and the corrosion of rubber linings and rims."
Maintaining correct tyre pressure is one of the cardinal rules of truck safety and failure to do so not only leads to premature tyre wear but also to tyre blowouts.
"The loss of tyre pressure over time, even when tyres are in good condition, is due to the fact that oxygen attacks the butyl layer in the rubber and seeps out of the tyre. Under-inflated tyres deform to a point where sidewalls bulge and begin to ripple under use," adds Sowry. "This rippling effect causes friction which heats the oxygen inside the tyre. Eventually, the combination of rising heat and a weakening (deformed) tyre structure causes the tyre to suddenly blow out and often, catch fire."
The process of compressing air for tyre inflation purposes results in the formation of water vapour, another corrosive element inside the tyre. Both oxygen and water vapour contribute to the ageing of the rubber, belt separation, the rusting of steel bands and rims as well as causing valves to leak through the trapping of dust particles, says Sowry.
Rolling rubber ARV
The number of tyre blowouts in South Africa's commercial transport sector can be substantially reduced by using pure nitrogen as the tyre inflation medium, Sowry says.
"Nitrogen is an inert gas which means it doesn't move through rubber the way oxygen does. It doesn't heat up either and is totally non-combustible, which is why it is used in airliner wheels and Formula One racing car tyres," Sowry continues. "Nitrogen is dry and therefore doesn't rust metals or age rubber. Most importantly, it maintains tyre pressure and therefore the integrity of the tyre."
While oxygen and water vapour may be considered tyre 'viruses', nitrogen could well be construed as the 'anti retroviral' for rolling rubber. Sowry's company, Nitralife, has developed a machine that extracts oxygen and water vapour from the compressed air generator, leaving pure nitrogen to pass into the tyres being inflated. "The air passes through a porous membrane which separates the gasses, returning oxygen and water vapour to the atmosphere. The remaining nitrogen will constitute 95% of the tyres inflation volume, which is perfect for maintaining correct pressure, enhancing tyre life and safety."
Testimony tells
Nitrogen is beginning to make its presence felt in both the truck transport industry and amongst car drivers, says Sowry. "Large fleets like Fast n Fresh and Ekapa Mining are realizing significant benefits since switching to nitrogen-filled tyres. Downtime due to on-road blowouts has all but been eradicated and tyre scrapping has been reduced by as much as 32%. Tyre maintenance procedures have been streamlined because pressure consistencies have improved by more than 10% to the point where 95% of all fleet tyres are optimally inflated at any given time."
With high operating costs and slim margins the perennial bane of truck transport, does Nitralife's solution make financial sense? "It certainly does. Tyre life is improved and downtime is reduced. But it really makes sense when you think of the lives it can save," concludes Sowry.
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