Correlation between hardening of rubber and steel wires encapsulated within the rubber

[Metallic007]

Dear all

I am taking part in maintenance of a bucket elevator (vertical)in a cement mill. The conveyor consisted of a thick rubber with steel cords/wires encapsulated within. The strength of the belt largely derive from the steel cords/wires. I have been told by the supplier that we have to monitor the hardness of the rubber belt regularly and when the hardness reaches a certain value a replacement is required. The hot operation environment would cause the rubber to harden over time.


I am curious on why should the rubber belt be replaced when the rubber getting hardened.

And is there a correlation between the hardening of rubber with the encapsulated steel cords/wires (e.g. fatigue, wear)?


What I understand is that the higher the temperature, the faster the hardening of the rubber. As rubber hardens, it becomes less flexible.

If it is less flexible, wouldnt it be good to the steel wires as there is less flexing? Or it would need a greater flexing stress to flex the rubber and the encapsulated steel cords during the operation?

Many thanks

 

[EdStainless]

As the rubber hardens it will both wear faster and it will crack.
When it cracks it will allow material to contact the steel cords.
This will lead to corrosion and failure of the cords.
You wouldn't drive on tires with cracks in them.
This leads to a dangerous situation.

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P.E. Metallurgy, Plymouth Tube

 

[metengr]

Hardened rubber looses ductility which develops cracks,and tearing leading to failure.

 

[IRstuff]

Additionally, when the rubber hardens, its friction coefficient goes to crap, which is probably why my fan belts are squealing...

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