Adhesion between rubber compound and copper-film-plated steel cord

Four copper-film-plated steel cords (abbreviated hereafter as copper-plated cord) with different thickness of copper film from 32 to 90 nm were prepar ed and their adhesion properties with rubber compound were investigated. Ad hesion properties improved with the decrease in the thickness of the copper film. Unaged pull-out force and rubber coverage of copper-plated cords wer e inferior to those of brass-plated cord, but adhesion degradation was sign ificantly slower on copper-plated cords resulting in better adhesion after humidity aging of 15 days and salt solution aging of 5 days. The excellent adhesion stability of copper-plated cords can be explained by the suppressi on of the excessive growth of copper sulfide and the inhibition of dezincif ication due to the small amount of copper plating and the lack of metallic zinc at the outer surface.