Focus Industry

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,


Related articles:

Issue 11/12/2008

Design of Heavy-Duty Idlers for the Upper Run of Belt Conveyors Part I: Idler Requirements

1. Introduction Compared to alternative transport options, the transport of bulk solids on continuous conveyors boasts significant advantages with regard to availability, cost efficiency and flexible...

Issue 04/2009

Design of Heavy-Duty Idlers for the Upper Run of Belt Conveyors Part III: Operational Design of an Idler

1. Introduction With the growing requirements for the efficiency and environmental compatibility of conveying systems, focus is increasing on the optimization of belt conveyor components (Fig. 1)....

Issue 03/2009

Design of Heavy-Duty Idlers for the Upper Run of Belt Conveyors Part II: Engineering Design of Idlers

1. Introduction Idlers play a key role in the cost-efficient operation of belt conveyors. The stresses on the idler in heavy-duty belt conveyors present a particular challenge with regard to idler...

Issue 03/2024 Responsive

Conveyor belt tracker improves production and safety

Martin Engineering has launched the next generation of tracking technology for a global marketplace. The company designed the highly responsive Martin® Tracker™ HD (heavy-duty) belt conveyor...

Issue 06/2011

Patently round

Analysing the service life of idlers

1?Calculating bearing lifetime The trouble-free operation of an idler depends essentially on the mobility of the deep groove ball bearing. For this reason, in the calculation of the lifetime of an...