... factory price carbon black N220, N330, N550, N660 Carbon Black Type: N220, N330, N550, N660Carbon Black N220Characteristic: Good ... : Enhanced carbon black; Tire tread, high quality industrial rubber products and high load conveyor belt. Carbon Black N330Characteristic: ... Extruding bar, seal and mould rubber product. Carbon Black N660Characteristic: It features lower reinforcing ability, smaller ...