Oil resistant belts are generally formulated using a Nitrile rubber compound. The final application will determine the ultimate rubber compound selected. Other physical requirements such as heat resistance, abrasion resistance, ozone and weather resistance will play a roll in determining the final rubber compound selected. The compound selected will optimize the blend of physical properties required.
Using standard belts in applications requiring oil resistance will result in swelling and deformation of the conveyor belt. This will produce tracking problems and product spillage as well as low service life. In extreme cases, when poor quality or an incorrect belt is used in oil intensive applications, this may result in “reverse troughing”. In this instance the carry cover of the conveyor belt will swell when in contact with the oil, resulting in a convex configuration that will cause material to spill off the conveyor belt. Care must
be taken to ensure all operational conditions are considered when choosing the appropriate grade of oil resistant belting. Factors such as high or low oil contact, as well as operating temperatures, belt speed and abrasion must all be considered to ensure the longest operational service life.
Applications for oil resistant belts include carrying parts and components coated with machine oil, heavy oil treated coal in cooking plants and electric power generating plants. Two cover grades for belts can be specified for belts requiring moderate oil and fi re resistance.
A grain and vegetable oil resistant compound is also available that is electrically conductive to dissipate static electric conditions. HTN grade is recommended for conveying hot asphalt with temperatures up to 175 C ( 350 F ) where both oil and heat resistance are required.