Method for increasing resistance to treeing in polymeric insulating layer
AssigneeAluminum Company of America
InventorsSandra G. Sachtleben, John R. Kirkland
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Abstract
A method for increasing resistance to treeing in a polymeric layer comprising an insulating layer on a metal conductor. Pellets of an organic polymeric material also containing an organo silane treeing inhibitor are exposed to ultraviolet radiation, and pellets having portions fluorescing above a predetermined threshold level are separated from the remainder. The remaining pellets are blended together and applied to a metal conductor to form a coating on the conductor. In a preferred embodiment, the organic polymeric material is high molecular weight polyethylene, and the ultraviolet radiation has a wavelength of about 3000 to 4000 A.
Claims10
A method for enhancing the purity of a plurality of discrete pellets comprising an organic polymeric material and an organo silane treeing inhibitor, said method comprising the steps of
- (a) exposing at least one of said pellets to ultraviolet radiation, thereby to cause fluorescence in a portion of an exposed pellet comprising an undesired impurity;
- (b) detecting fluorescent light from a pellet containing an undesired impurity;
- and
- (c) separating from the remainder of the pellets a pellet including a portion demonstrating fluorescence, thereby to increase resistance to treeing in a polymeric insulating layer manufactured from said remainder of the pellets.
Dependencies are inferred from the claim text.