PVF (Polyvinyl Fluoride) coated steel Bundy tube has been adopted for brake lines, transmission cooler lines and power steering hard tubes by auto make like Volkswagen, Mazda, Nissan, Kia, Hyundai, and many others.
PVF coating of Bundy tubes typically looks dark green and nearly black. It has very good corrosion resistance.
In the manufacture process, the tubes shall be firstly electro-plated with zinc , chromated to enhance the zinc plating performance, and then coated with a layer of PVF to finally isolate the metal from outside environment.
|Process||Electroplated Zinc, Trivalent Chromate, PVF Coating|
|Zinc Thickness||8μm, 13μm, 25μm|
|PVF Thickness||Average 20μm, 8μm min|
|Salt Spray Test||White Rust: 240hr to 480 hr
Red Rust: 3000hr to 6000 hr