Jumper is the sewing machine in the suture process, because the hook at the bottom of the machine can not check the upper thread or upper thread was hooked and then slipped off, unable to form a continuous line of a phenomenon. This is mainly due to the movement of the needle and the hook does not match the movement time or position caused. Of course, it is also possible that the needle can not form a coil and cause a step jumper. There jumper, you can find the following reasons:
First, the machine needle problem
- check the upper thread wear or wear a bit less than a bit.
- check the needle is installed correctly, such as needle-mounted slot installed anti-or skewed.
- check the needle type is applicable, needle bar height adjustment is accurate, and check the needle is close to the top of the needle bar. Needle installation is too high or too low, will affect the hook to take the line.
- check the needle is distorted. When stitching with a misaligned needle, the hook can not be snapped due to the formation of the loop away from the hook. Slight bending of the needle is difficult to identify directly with the naked eye, the needle can be turned on the platform, you can identify.
- check the machine needle and hook movement time is consistent. The movement of the needle and hook fully cooperate with the time, the hook can accurately check the suture.
- Check the needle and sewing thread thickness is appropriate. Large sewing needles with fine sewing thread can also cause jumpers. This is because the needle of the large needle is longer and wider, and the hole of the pricked fabric is larger, so that the fine sewing thread has a larger space to move. If the hook is beyond the range of the hook.
- Check whether the machine needle needle eye due to melt-stuck chemical fiber sewing thread and blocked, so that the suture can not be normal delivery, can not form a coil.
Second, the pressure foot problem
- Check if the presser foot is installed too high and the feed speed is too fast. The presser foot to install too high, will make the foot pressure to send the fabric of the lack of strength, this time with the presser foot fabric will shock, so that can not be pressed to form the upper thread coil; press foot to send cloth too fast, in the delivery fabric, The face line and the fabric with the fast away, the hook can not hook the upper thread.
Third, the sewing thread problems
- check the sewing thread is too thick, uneven thickness or texture of the suture is too soft.
- Check the tension of the upper thread is too tight. The upper thread tension is too tight, in the machine under the needle coil is too small to form, the hook can not tick.
Fourth, other issues
- Check whether the hook is defective. Defective hooks can not hook the suture.
- check the needle hole is too large. Many manufacturers in the production of thin material, the reunification of the needle with a small, there is no timely replacement of the matching needle plate. Too large needle hole to the fabric by the needle into the needle with or from the hole position, can not be pressed to form a coil sewing thread, can also lead to jumper.
- check feed cloth, shuttle bed, etc. whether there is silt with cotton dust, should pay attention to keep clean and clean, so as not to affect the formation of step-by-step.