Jumper is a phenomenon of sewing machine in sewing process, because the hook at the bottom of the machine can't pick up the surface line or surface line after being picked up and slid off, so it can't form continuous line step continuously.This is mainly due to the failure of the movement time or movement position between the needle and the hook. Of course, it is also possible that the needle can not form the coil and lead to the jumper.Jumper line can be found from the following aspects:
1、The problem of the needle:
(1)check the thread through the needle plate or not;
(2)check the accuracy of the installation of the needle;
(3)check the size of the needle of the machine,the height of the needle bar adjustment is accurate or not and whether the needle is attached to the top of the needle bar;
(4)check whether the needle is distorted;
(5)check whether the needle is match with the time of the hook movement;complete coordination of the movement time of the needle and hook,the hook can be accurately sew;
(6)check whether the needle is suitable for the thickness of the sewing thread;
(7)check the eye of the needle whether clog due to the chemical fiber melt glue chip and the plug that can not be normal suture conveying, unable to form a coil.
2、The problem of the pressing foot:
Check whether the installation of pressing foot is too high and the feed speed is too fast or not. The pressing foot installed too high will makes the strength of the pressing foot press out of the fabric,at this time,the fabric will oscillate with the presser foot,so that it can't compress the surface line to form the coil.The delivery speed of the presser foot is too fast.When conveying the fabric,it will quickly take away the line and the fabric,and the hook can't hook the surface line.
3、The problem of the thread:
(1)check whether the sewing thread is too thick, the coarse and thin, or the texture of the stitch too soft;
(2)check whether the tension of the line is too tight,the tension of the surface line is too tight,the needle wire ring formed under the machine tool is too small, and the hook can not be taken.
(1)check whether the hook is defective,the defect hook can not sew up the stitches.
(2)check whether the pin hole is too large.
(3)check the feed and shuttle bed deposit with cotton dust or not;
To solve the problem of jumping line and broken line, we should take different measures to deal with the jump line and the broken line.
(1)Not using a needle with damage,the needle should be checked regularly and replaced in time.
(2)Add a blowing device next to the needle to accelerate the heat dissipation of the needle.
(3)Use a needle with special surface treatment.During stitching,it can reduce friction resistance between fabrics,inhibit high fever generated by machine needles,prevent needles from hot melt,suture and melt sticky chemical fiber chips,avoid jumpers and broken line.