Nozzle and nozzle processing method

摘要

A nozzle and processing method thereof which provides suppression of vertical stripes due to foreign matter or aggregates in the paint or dust deposits on the base material. In one embodiment of the present invention the nozzle includes an upstream lip, a downstream lip in a curvature shape projecting to the base material side, and a slit formed by the upstream lip and downstream lip. A side edge of the downstream lip is formed in a curvature shape having a radius of a curvature in a range of 4 to 45 mu m, and by this edge, even a paint of high viscosity which hardly flows can smoothly flow into the gap between the downstream lip and base material. Aggregates in the paint or dust deposits on the base material therefore are not caught in the edge.