Needle Detection: Needle Detection (检针)
A quality control step that uses magnetic or X-ray equipment to find broken needles, staples and metal fragments left in garments and trims. Zippers pass through a detector before packing, and any alarm triggers isolation and re-inspection of the batch. Sensitivity must be verified with test cards at the start and end of each shift. Records of checks and rejected pieces are kept, because metal contamination is a serious safety risk.