The invisible danger

Ozone and ultraviolet light shorten the life of conveyor belts

1 The effects of ozone and ultraviolet light magnify and accelerate day to day wear and damage

2 The beginning of the end: “Innocent” looking ozone cracks in the surface of the rubber

3 Close up of cracks: Pollution problems – fine particles of dust penetrate the cracks and are then discharged (shaken out) on the return (underside) run of the belt

4 The cracks are always oriented at right angles to the strain axis

5 Transversal cracks deepen under the repeated stress of passing over the pulleys and drums

6 Dunlop’s ozone testing cabinet

7 Samples are checked for cracking at two-hourly intervals

8 Some rubber literally disintegrates within hours

There are many factors that determine the service life of a conveyor belt. These include constant abrasion from the material being conveyed and damage from heavy, sharp rocks falling on the belt or tearing and ripping when a hard, sharp object is caught and penetrates the belt. In addition, there are two other factors that have a major impact on the life of a rubber conveyor belt: Ozone (O₃) and ultraviolet light (UV).

Regardless of the purchase price, it is primarily the length of working life that ultimately determines the true cost of a conveyor belt. Factors such as abrasion due to the material being conveyed, damage caused by noticeable heavy, sharp lumps of rock, or tearing and ripping when hard, sharp-edged chunks of material are jammed or penetrate the belt are recognised as normal wear and tear.

However, what is not well known are two other inescapable factors that have a huge influence on the operational lifetime of a rubber conveyor belt. Those factors are ozone (O₃) and ultraviolet light (UV)....