Belt conveyor idlers made of recycled plastic
Since steel tubes have been available as tube rounds, idlers have been mainly made from this raw material as they can be manufactured in series at reasonable cost. Compared to these steel tubes, solid bars made of pure plastic or suitable plastic tubes are still too expensive. Rising energy costs, raw material shortages and the possibility of recycling waste plastics, however, are increasingly interesting reasons for using of idlers made of recycled solid plastic (Fig. 1). There are many grades of quality. Mixed waste that is not suitable for producing high-grade granulate can, for example, be pressed to replacement elements for concrete components (grey) or wooden posts (brown). “Impure” recycled plastic is currently available in large quantities and therefore cheap. A process for further refining of this material to low-price idlers has already been patented (DE102006040883B4). Idlers made of recycled solid plastic are already in efficient use in the diameters 89, 100, 108, 133, 150, 159, 180, 200, (250) and are continually further developed in line with application conditions and requirements.
Idlers with solid recycled plastic idler bodies have the following advantages:
• No extremely sharp edges that can damage the rubber belts
• Now hollow bodies with condensation water
• Spherical or conical idler bodies for better centring of the belts and guiding round bends (Fig. 2)
• Idler bodies with turned grooves, e.g. to hold support rings
• Profiled running surface for perfect grip, even with high-speed belt conveyors
• Reduced running noise (around 15 dBa lower)
• Arrangement of more than one idler body on one shaft so as to obtain low-price guide idlers or to give new functions to idlers with support rings
• Electronically neutral and anti-magnetic
• Resistant to rust and acid and completely environmentally neutral
Peter Blaha, Aschheim (D), +49 89-9 03 26 49,
foerderschuettgut@arcor.de
