瓶颈部分 meaning in English

bottle neck

The track in leading line is redesigned for its acute curvature change , which is the bottleneck during spiral machine . the new track has avoided blade ' s gnaw and tool swaying . and a new track with high quality is calculated
针对高速螺旋铣的加工效率瓶颈部分? ?缘头处曲率剧烈变化的几何特征，重新设计了缘头处的走刀轨迹，避免了缘头处的啃切与刀轴晃动，计算出高质量的多坐标加工刀位轨迹。