crowned roller

例句：

1. 1.The crown roller is used to smooth the surface of a metal object before painting.
   皇冠滚轮用于在涂漆前平滑金属物体的表面。
2. 2. The crown roller was designed to make the painting process more efficient.
   皇冠滚轮的设计是为了使绘画过程更加高效。
3. 3.The crown roller was used to remove any imperfections from the surface of the metal object.
   皇冠滚轮被用来从金属物体的表面去除任何瑕疵。