Difference Between Reverse Seam And Normal Seam Of Single Needle Sewing Machine

Reverse seam break is a common phenomenon. It is a topic that every maintenance personnel must seriously consider and face carefully.

Here, it is a common phenomenon that the single seam stitching machine is a common phenomenon, and it is a "topic". The purpose is to broaden our thinking, to understand and explain this phenomenon easily, and to reduce the occurrence of this phenomenon in the practical work.

The single seam sewing machine is divided into two categories according to the working conditions.

The first type is the reverse seam that is entirely on the work piece. The second kind is the incomplete seam gap that is not entirely on the work piece.

When studying the reverse slit, we should first understand the main cause of the broken line, and the continuous seam is the foundation of the reverse seam.

The needle and suture quality is not good; the stitches do not match the machine needles; there are sharp edges burrs or thread strained grooves in all the crossed parts of the presser foot, needle shuttle, rotary shuttle, and sending the step teeth; the quality of the rotary hook positioning hook is not good (the geometric shape is not conducive to the take-up of the take-up rod); the quality of the rotary spindle is not good (some can not guide the needle thread to slide smoothly around the shuttle bowl spindle core sleeve, some hook lines are too thick and too blunt, some of which are not slippery and frictional resistance); the timing of the needle bar and the rotary shuttle is not correct; the timing of the needle bar and the lifting pin is not suitable; the sewing time needle temperature is too high. There are many reasons for the failure of positive seams.

After all these problems have been solved, there is basically no problem with general seams.

Inverted seam and

The biggest difference is that the stitches are different.

The stitch is a standard lock stitch, which is like a twisting rope.

The inverted stitch still does not know its official name, and here it is called the fastener trace, because the line around the bottom line is a dead knot, like the first knob of the shoelace.

It is obvious that the requirement for the alignment is higher, requiring sewing thread to have higher strength, even evenness, more smooth and soft characteristics.

The second difference between reverse and positive stitches is that the timing of the needle bar and the lifting gear is not the same.

During the reverse seam, it is possible to catch the needle punched cloth in the instant of pressing and lifting the spanner. If the cloth tooth is still exposed on the surface of the needle plate at this time, the needle will oscillate along with the seam material, which is one of the reasons for breaking the broken pin.

In order to avoid this happening, we must adjust the eccentricity of the delivery tooth according to the requirements of the reverse seam, so that the sewing needle does not move with the needle when it presses and raises the movement of the seam spanner.

This adjustment avoided the problem of the instantaneous swing of the needle, but it caused another problem.

The third difference between reverse and vertical stitching is that the frictional resistance of shuttle running is smaller and more smooth, so that when the take-up rod is tightened, the frictional resistance of the shuttle can be operated with minimum weight.

Only in this way can the pressure of the pressure reducer be reduced to the minimum and not out of the sleeve.

Because the frictional resistance is the force of the shuttle bowl (or shuttle frame and shuttle bladder) close to the spinning hook. The greater the force, the tighter the pressure spring on the pressure plate is, the greater the chance of disconnection.

The fourth difference between the stitching and the positive stitching is that the stitching is different from the needle position, especially under the pinhole.

The friction in two directions requires that the needle is smooth and omnidirectional without any burrs.