Truck operators should carefully select suspension components.

Truck owners usually switch to polyurethane bushing and components exactly to avoid damaging trailers and becoming stranded, says Fred Evans, suspension expert and MD of Polyflex Seals, a leading manufacturer of polyurethane suspension parts. But if they buy inferior quality alternatives, they may actually get decreased life compared with even the original rubber parts.

“The only way that transport managers and fleet owners can tell if they are buying quality components is to buy quality locally manufactured parts from companies like Urethane SA, whose Polyflex brand has been manufactured and sold in the country for nearly 30 years.

Suspensions save transport companies millions in tyre wear

“In addition, it is worth finding out whether the polyurethane parts are made from thermosetting (cast) plastics, which provide far stronger bonds than the more easily manufactured and weaker thermoplastic (injection moulded) equivalents. Another way is to look for clear polyurethane parts which can be easily examined for faults, bubbles and more,” explained Evans. In the case of Polyflex, all the components were now manufactured without colouring pigments, which gave them a clear honey colour.

“We realised that unscrupulous suppliers were using colouring pigments and translucent polymers to hide serious faults…”

“Our parts were previously coloured yellow, and in the 4×4, trucking and motoring industry were known for their trademark yellow colouring. However, we realised that unscrupulous suppliers were using colouring pigments and translucent polymers to hide serious faults, and took the decision to make ours clear so that buyers can rather see what they are buying.”

The molecular structure of cast thermosetting polyurethane is more stable and durable and can exceed the lifespan of injection moulded products by up to double

In the SA transport industry the use of polyurethane bushings and components is estimated to save transport companies millions of Rands in tyre wear thanks to the increased service life of suspensions. A number of the major trailer manufacturers specify Polyflex suspension components on trailers destined for heavy-duty applications – where heavy loads are to be carried, roads are bad or where destinations require some dirt road travel (such as bakery and milk delivery trucks) and, especially, cross-border operators.

The molecular structure of cast thermosetting polyurethane is more stable and durable and can exceed the lifespan of injection moulded products by up to double. Considering, in most cases, that the cost saving of thermoset products versus injection moulded alternatives is usually a mere 10% higher, the risk of failure could cause the loss of a load or destroy a truck’s tyres in a single trip.