Broken thread and poor stitch
(1) The machine needle has burrs or bends, and the looper tip and looper hole have burrs.
(2) Suture. Poor suture quality.
(3) Cooperate. The gap between the needle and the looper, the speed of the hooking time.
Solution
(1) Replace the needle, and properly grind the looper tip and looper hole when the looper is not seriously worn.
(2) Replace the stitches with good quality. If there is no condition, you can also lubricate with silicone oil, and reduce the sewing speed appropriately.
(3) Adjust the gap between the needle and the looper and the hooking time.
