What happens if thread tightness ratio is not ideal?

1. First try to adjust the tension of the bottom thread or advance the hook time of the rotary shuttle. Although the thread tension will be slightly improved, it is prone to needle skipping.

2. The root cause of affecting the thread tightness is whether the thread take-up assembly of the sewing equipment fits perfectly with the rotary shuttle.

The mechanic usually adopts the method that removes some thread take-up components in the old machine and preserves them. In case of special circumstances, they will be grafted onto the equipment with problems.

Although the method can solve the fault, the process is too cumbersome, it is impossible to have enough old machines for disassembly all the time.

3. In another way, since the problem is the breakage caused by the stretching of the fabric, the maintenance idea can be considered from the aspect of fabric delivery.

If you slow down the cloth feeding time, the suture breakage will be more serious when stretching the fabric.

The cloth feeding time lags behind the setting out and take-up of the thread take-up rod, that is, when the cloth feeding is not finished, the thread take-up has been completed, resulting in the thread consumption per unit needle pitch surface line being less than the normal value. Therefore, the wire tightness is significantly reduced.

At this time, just adjust the cloth feeding time faster, and the thread breakage phenomenon of the above suture will disappear, and the problem will be solved naturally.

If the machine is still floating at this time, the coordination between the thread take-up rod and the rotary shuttle should be considered.

If the timing of the thread feeding and taking up of the thread take-up rod and the thread hooking and off-line of the rotary shuttle is perfect, the bottom thread tension will not be very large, and the stitch will be normal.

Therefore, it is recommended to use a high-quality rotary shuttle or fine-tune the movement time and upper and lower limit positions of the thread take-up rod to meet the sewing requirements.