A coating rod coating system is a system used to produce coated materials. It precisely controls coating thickness through a wetting station and a metering bar. The system is designed to ensure close contact between the roll and the metering bar, and coating results are optimized by controlling the winding angle and tension.
The web passes through the metering bar, which can be stationary or rotate slowly. A common practice is to rotate the bar slowly in the opposite direction of the web’s movement to prevent liquid solidification and ensure uniform wear. System design must account for the effects of winding angle (15° for high tension, 25° for low tension) and web tension.
An automatic release function (“slip-off”) automatically separates the roll from the coating rod when the machine stops, preventing liquid solidification. Smooth bars can be used to eliminate etched patterns or assist in leveling, while multi-bar combinations (such as series connections of bars with different diameters) can be used for precise control of coating thickness.
A complete coating station design must also account for the discharge, filtration, and suction of the coating solution, as well as wet edge control.