pre-impregnated
/ˌpriːɪmˈprɛɡneɪtɪd/adjective
Of a material: impregnated with a substance prior to further processing or use; specifically (a) (of paper insulation) impregnated with oil and resin before use in electric cables; (of a cable) containing such insulation; (b) (of reinforcing material) impregnated with synthetic resin before use.
Origin
1930s; earliest use found in Journal of the Institute of Electrical Engineers. From pre- + impregnated. In later use probably partly also from pre-impregnate + -ed.