1. Causes and solutions of the sewing machine section thread:
1. The cause of the failure: the edge of the needle hole of the needle has an acute angle or needle groove hair;
Solution: Use or replace a new needle after polishing the needle hole.
2. The cause of the failure: the thread-passing holes of the upper thread are partially pulled, so that the suture is blocked during movement;
Solution: it can be polished with sand leather or coated with polishing paste on the thread Polished and polished.
3. Cause of failure: fine thread for sewing thick material;
Solution: replace the thread accordingly.
4. Cause of failure: The strength of the suture is too poor;
Solution: Replace the suture.
5. Cause of failure: The pressure on the thread is too tight, so that the suture is bruised or the thread is broken;
Solution: The thread-clamping mule should be loosened properly.
6. Cause of failure: the inner groove of the rotary hook has an acute angle, the suture is bruised or the thread is broken; Replace the hook with a new one.
7. Cause of failure: The hook of the rotary hook and the notch of the shuttle frame do not fit properly;
Solution: Adjust the fit of the hook of the rotary hook to make the upper thread pass smoothly.
8. The cause of the failure: the needle is overheated and the chemical fiber thread is fused;
Solution: The chemical fiber thread should be cooled by machine needle or suture (silicone oil).
9. Cause of failure: There are burrs and acute angles on the edge of the needle hole of the needle plate, which may damage the suture;
Solution: It can be polished with yarn rope and polishing paste, but it cannot be pulled. Too large, too large will cause jumpers.
10. Cause of failure: The position of the needle is wrong;
Solution: Adjust the needle to the correct position.
11. The cause of the failure: the needle is bent;
Solution: replace the needle with a new one.
12. Causes of failure: the up and down stroke of the needle bar is incorrect, the thread take-up on the needle bar crank and the crank positioning mule are not positioned in the groove of the thread take-up crank or the positioning direction is wrong;
SOLUTION: The wrong positioning direction should be corrected after repositioning.
Second, the solution to the broken bottom thread of the sewing machine:
1. The cause of the failure: the bobbin thread is too full, too loose, too messy, and the bottom thread is In the process of sewing, the thread does not come out smoothly, causing the thread to break;
Solution: The winder can be corrected to make the winding on the bobbin even, compact and neat.
2. The cause of the failure: the bobbin is too large or the concentricity of the bobbin is not good, and the operation is not flexible;
Solution: properly improve the match between the bobbin case and the bobbin.
3. Cause of failure: The position of the feed dog is too low, and the distance between the quick opening at the bottom of the feeding dog and the outlet of the bottom thread is too small, so that the bottom thread and the quick opening at the bottom of the tooth have contact friction;
Solution: Adjust the height of the feed dog reasonably, or remove the feed dog and use fine sand to polish the quick opening at the bottom of the tooth.
4. The cause of the failure: the bobbin skin pressing bottom thread opening is fast due to wear and tear;
Solution: replace the bobbin skin with a new one.
5. The reason for the failure: the edge of the hook skin is hairy, and the bottom thread is scraped;
Solution: the edge of the hook skin is not polished.
6. The cause of the failure: the bobbin skin and the bobbin case shell do not fit well, there is a gap in the fit, and the tension of the thread outlet is not good;
Solution: Reasonably adjust the bobbin skin and the bobbin case shell Match the clearance, so that the tension of the bottom thread outlet does not change.
