Discussion On Stitching And Sewing Of Sewing Machine With Single Needle Sewing Machine

 

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 Normal seam 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 positive joints 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 reverse seam and positive seam 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.

 

The four major differences between inverted seam and normal seam determine the difficulty of reverse seam operation. The objective conditions in actual production determine whether the seam can be carried out smoothly. It is the most economical and effective way to reduce the speed of sewing down properly when using the high quality machine needles and sewing thread in addition to the maintenance personnel who are able to adjust and repair the machines within the limits of their ability. Why do I say this? Because of the low speed, the requirements for machine needles, sewing threads and rotary shuttles are correspondingly reduced. It is possible to reduce the speed at high speed because the maintenance personnel can only adjust the maintenance machines within the limits of their ability. The maintenance personnel can not improve the quality of the stitches, and the sewing thread can not reach the use of the inverted joints, so the maintenance personnel have no way to do so. Besides, a very good spinning shuttle has good, medium and high quality shuttles that are able to withstand the same slit speed as the sewing speed. It can withstand such a continuous test of rotary shuttles. I am afraid that according to experience, we should choose dozens of miles. Considering most of the funds, most factories will abandon this road. If you use a high quality machine needle, it is easy to do so. It is also difficult to use high quality sewing thread, because the money immediately goes out with the sewing thread. Besides, the good line is not easy to buy. It is the easiest way to achieve the goal without spending money, that is to say, the proper way to reduce the seam speed is not to adjust and maintain the machine.

 

Experience has proved that by adjusting and repairing the machine, and properly reducing the speed of the seam, we can meet the requirement of completely sewing the work piece.

 

In order to understand this problem, we should review the sewing principle of single needle sewing machine. Single needle sewing machine needle slot to the left side of the operator, working machine through the machine needle long slot to shuttle shuttle suture and recoverable seam, and provide the shuttle hook line on the right side of the needle, the formation of the ideal line of the necessary conditions for two lines, the first is the needle from the lower dead point to rise, the second is the needle on the right side of the sewing thread and sewing material enough friction between the sewing thread to prevent the sewing needle rising upward when the needle is rising, it is said that sewing thread depends on the sewing material tube bundle, only sewing thread can be formed in the case of the sewing material bundle and the needle from the bottom dead point rise. At the same time, only under the condition of sewing material and tube bundle, the stitching rules will be completed. On the other hand, the rules of sewing thread may be unruly if the tube bundles left the sewing material. Coupled with manual operation and man-machine cooperation, the same machine will do nothing if it does not work well.

 

The incomplete operation on the work piece is sometimes done by continuous operation and has good results. That is to say, the two live away from each other very closely, and two live joints are used to control the suture of the air gap.

 

In daily work, a single needle sewing machine operator should be advised to avoid being unable to operate continuously. Inverted seam Because there is no theory to support empty stitches. It may be possible for individual operators to be short and occasional, but they can not be used as a standard to require all machines to do so.

 

Through the above discussion, we know that the reverse stitching on the work piece can be done by adjusting and repairing the machine, using high quality machine needles, sewing thread and reducing the speed appropriately. It is possible to complete the continuous seam operation on the work piece (i.e. the inverted needle gap), so that it is very possible to separate the individual operation from the broken line, which is a normal phenomenon.