... Cardboard transmission is achieved by the method of vacuum suction, it equipped with high pressure air blower as well as a ... corrugated roll is made of 52CrMo precision forging alloy steel, with the treatment of hardening and tempering, grinding, laser-quenching, ... spraying tungsten carbide, make the hardness up to HVC1200.Equipped with spay wetness adjusting deivce to avoid paper cracking and keep ...