The Problem Of Thread Breakage Caused By Two Hooks In Sewing

As is known to the sewing machine industry, the pmission ratio of the upper spindle and the rotary spindle of the lock stitch sewing machine is 1:2 due to the need to allocate the action cycle in design.

That is to say, the upper axle will rotate for a week, and the spindle must be turned for two weeks.

Therefore, in the sewing process, the needle is rotated for two weeks at a time, and the hook loop operation is completed in one week. Once the shuttle is hooked up to the surface line once a week, that is, the needle punching material is once, and the hook hook is two times. Then it will conflict with the face line and cause the seam to break.

This is possible when sewing the uneven thickness of the seam material: the reason is from the forming process of the lock stitch:

1. The process of lock stitching is briefly described. The lock stitch is made up of interlacing between the face line and the bottom line in the stitching material.

When sewing machine works, the needle guide line passes through the seam material and rises up after reaching the lower limit position. As there is friction between the sewing material and the suture, the surface line can not be randomly raised simultaneously, but is stuck in the sewing machine.

Below, under the action of elasticity, the sides of the needle are expanded to form rings.

Then, the spindle point of the shuttle can reach the needle at the point of movement, pass through the face line loop, and continue to rotate in the course of movement.

When it comes to its own radius, it jumps over the enlarged line like a rope skipping.

The downward movement is the take-up of the take-up rod and the feeding of the cloth teeth to allow the movements to be carried out smoothly enough. The shuttle is still rotating at the original speed for a week, but no longer hooks.

Due to the take-up effect of the take-up rod, the surface line ring which was originally enlarged and leaped by the spinning shuttle rapidly reduced until the bottom line drawn from the heart of the shuttle spindle was pulled into the sewing material to form a single interleaving.

When the needle reaches the upper limit position, the sewing machine starts again and again, and repeats the above action process again, so as to form a continuous and regular lock line stitch on the sewing material.

2. The difference of hook line time when the material thickness changes.

The key content of adjusting the sewing machine is to adjust the so-called hook line time. The usual adjustment standard is that when the needle drops to the lowest position, when the 2.2mm is lifted up, the spindle tip reaches the center line of the machine needle and 2mm from the upper edge of the needle hole.

Of course, this is not static.

Because the purpose of adjusting the hook time is to hook the surface line when the spindle tip is formed with the best and stable best ring, thereby avoiding the phenomenon of jumping needle.

Because the slit material is generally used for thin thread, the stitch itself is soft, and the friction force of the sewing material is small. When the thick material is used, the thick thread must be used. The stitch itself is more rigid and the friction force between the sewing material and the sewing material is large. Therefore, the sewing thread thickness is different at the same time, and the time of forming the best thread loop is different. This requires adjusting the hook line according to the specific circumstances, so as to get the ideal sewing effect.

Experienced sewing workers and operators know that when the material is slit, the spindle must be "fast". When the material is thick, the spindle must be "slow".

The reason is not difficult to understand.

When sewing thin material, the stitches are thin and soft, and the needle slightly rises from the bottom limit, and the sewing threads will expand to the sides of the machine needle to form a wire loop.

Moreover, because the friction between the sewing material and the suture is small, and when the needle continues to ascend, the randomness of the relative position between the stitching material and the suture is large. Besides, the stitch is fine and soft, the wire ring is easy to deflect, and it becomes difficult to maintain stability.

Therefore, a slight advance adjustment of the spindle tip relative to the movement of the needle will help to improve the reliability of the hook line.

On the contrary, when the thick material is slit, the sewing material is thick and firm, and the machine needle can form a full line ring when the lower limit position is raised higher.

In addition, the friction between the seam and the sewing thread is large, and the sewing material is thicker and hard. Even if the needle lift is higher, the stitches are more and the line ring will not be deflected, and it is still stable.

Therefore, it is more beneficial to prevent jumping needle when the movement of the spindle tip is relative to the movement of the needle.

3.

Types and functions of the moon circle

When sewing time is adjusted according to sewing requirements, the time when the stitch runs around the shuttle spindle from the spinning spindle is also determined.

When the thick material is slit, the point of the shuttle spindle is adjusted later than that of the machine needle, and the time of the thread loop from the spinning spindle is delayed. In addition, when the thickness of the material is thick, the line is the largest and the remaining line is less.

However, when the material is slit, the spindle tip is adjusted ahead of the machine needle, and the time that the thread loop is released from the spinning spindle is often earlier than the time when the spindle tip reaches the center line of the machine needle in the idle circle. In addition, when the sewing material is thin, the consumption line is less, and the remaining lines are more. It is very easy to catch the phenomenon that the spindle tip hooks again from the spin shuttle in the idle circle again, and there is an abnormal two hook line.

When the hook is normal hook line, the take-up rod is at the stage of laying off. After the thread loop is lifted out of the rotary shuttle, the take-up rod will start to take up the line quickly.

If there is a two hook line, it will inevitably conflict with the take-up line of the take-up rod, which will definitely lead to disconnection.

In order to avoid the two hook line, effective measures were taken in the design of the shuttle structure.

By comparing the rotating shuttles of slit thick and slit sewing machines, it is found that the structure of the moon circle is obviously different from vertical horizontal shuttle, horizontal horizontal shuttle or vertical shuttle.

The circular circle of the sewing machine rotary shuttle only forms the shuttle gallbladder through the slot, and the tail ends are short flat.

In this way, the thick thread will be removed from the spinning spindle earlier, and the take-up action of the take-up rod will be dragged into the sewing material as soon as possible.

The moon circle of the slit sewing machine is not the same. The tail ends of the sewing machine are serpent tail, and the length is longer and the contraction is gradual.

The circular circle of slit sewing machine rotary shuttle not only plays a role in forming the shuttle gallbladder through the slot, but also bears the responsibility of guiding off line at the end of the shuttles. Observing that it can be found that the surface line loop of the sewing thin material is first turned to the tail of the moon circle when it is released from the spin shuttle, and then slips out from the tapered tail when the spinning shuttle continues to rotate.

Because the angular position of the tip of the moon's tail is later than that of the shuttle, the line loop from the end of the moon's circle will not be caught by the spindle at any rate.

Thus, the two hook line is reliably avoided.

If no matter how to adjust, the surface line is always not good, the reverse side of sewing material appears floating line, then check whether the moon circle is not suitable.