of effective amounts of oleic acid and low molecular weight polyethylene as processing aids application_number US 19375180 A description the processing aid of the present invention is useful in connection with fluoroelastomers classified as copolymers of vinylidene fluoride and hexafluoropropylene these copolymers are typically vulcanized with the aid of a metal oxide such as magnesia and a blocked difunctional amine as a curing agent the fluoroelastomer may include various amounts of fillers and a low amount of a processing aid the processing aid of the present invention comprises a mixture of oleic acid and low molecular weight polyethylene other fatty acids such as stearic do not provide equivalent results the polyethylene a waxy material preferably has a molecular weight within the range of 1500 to 10 000 a m u atomic weight units with about 4 000 a m u providing optimum results the amount of oleic acid relative to the amount of polyethylene employed can be varied and still obtain acceptable results a suitable range being in the order of about 0 25 to about 4 parts oleic acid to one part of the low molecular weight polyethylene in order to facilitate handling and incorporation of the processing aid into the fluoroelastomer it is preferred that a thickener be included in the mixture the thickener is preferably a relatively inert inorganic solid in powdered form that is compatible with the fluoroelastomer and other additives suitable fillers include metal oxides such as zinc oxide aluminum oxide calcium oxide magnesium oxide lead oxide and others such as diatomaceous earth calcium silicate talc and mixtures thereof typically an addition of from about one to about 15 percent by weight of thickener to the processing aid will provide the desired consistency as a preferred formula the processing aid may.