Sewing: Sewing (缝制)
The operation that attaches a zipper to the garment or product. Stitch type, needle size, thread tension, seam allowance and presser foot choice affect appearance, flatness and strength. Stitches that cross the teeth can break them or block the slider, so the seam must run close to but not over the tooth row. Operators check for puckering, skipped stitches and waviness, and finished seams are pulled to confirm security.