- Sewing thread problems
(1) Check whether the quality of the sewing thread is qualified. Sutures that are moldy, spoiled, or have nodules are most likely to break.
(2) Check whether the selected sewing thread matches the needle. The sewing thread is too fine due to insufficient toughness. A thin machine needle with too thick sewing thread will make the sewing thread unable to pass through the needle hole smoothly and be cut.
(3) Check whether the upper thread tension is too tight. If the tension is too tight, the thread will break easily.
(4) Check whether the needle hole of the machine has accumulated debris, which causes the sewing thread to be transported unsmoothly and breaks.
- Needle problem
(1) Check whether the sutures are melted due to needle heat, especially when using chemical fiber sutures, due to the high-speed running of the sewing machine, the needle repeatedly pierces the fabric and generates heat, causing the chemical fiber sutures with lower melting points to be melted.
(2) Check whether the hook position of the hook is proper. If the hook is too close to the needle hole, it is easy to break the suture when taking the thread.
- Other issues
(1) Check whether the needle and needle plate are firmly installed. A loose needle or needle plate will cause the needle and needle plate to touch each other, and the thread will be broken.
(2) Check all the places where the upper thread passes (including loops, needle holes, hooks, needle plate holes, presser foot holes, etc.) for bends and defects to avoid the sewing thread from being broken.
(3) Check whether the bobbin thread spool is too full or unevenly wound. The bobbin thread bobbin is too full or the bobbin thread is not evenly wound, and the bobbin thread is not conveyed smoothly, which may cause the bobbin thread to break.
In addition, poor gestures of the operator or lack of rhythm in the speed of the vehicle will pull the fabric and cause the upper thread to be cut by the feed dog, or cause the thread take-up hook to move unevenly and tear the upper thread.