Compounding of ethylene-propylene polymers for electrical applications

Compounding is the technology of converting the raw rubber resin into useful materials through the addition of various ingredients. The resulting composition is called a compound. A typical compound usually has the following ingredients: ethylene-propylene rubber, filler/reinforcing agent(s), plasticizer, antioxidants/ stabilizers, flame retardants, process aids, ion scavenger coupling agent, curing coagent, and curative. Proper selection of the ingredient(s) in each category requires that consideration be given to the desired physical, electrical and environmental properties, as well as cost, ease of mixing, chemical stability and ease of processing. Frequently these considerations may require compromises in one characteristic in order to improve another. In the following discussion, factors to be considered in the proper choice of each ingredient for the compounding of ethylene-propylene polymers are explored.<>