5 thread overlock sewing machine: Adjustment of needle skipping and thread jamming of sewing needle fabric

It processes knitted fabrics, and the fabrics are particularly soft. When sewing with a 5 thread overlock sewing machine, the phenomenon of "needle skipping" and "thread jamming" of the machine are often encountered.

In garment production enterprises, the general 4 thread machine processes knitted fabrics, and the 5 thread overlock sewing machine processes woven fabrics. However, with the development of the times, the technological requirements of garment production have also changed. It is required to process Knitted Fabrics with 5 thread sewing machine, the fabrics are particularly soft. During sewing, the phenomenon of "needle skipping" and "thread jamming" of the machine is often encountered.

Key point 1:

Distance between chain stitch bending needle and machine needle

Under normal circumstances, the distance between the 5 thread chain stitch bending needle and the machine needle is between 1.6 mm and 1.8 mm. However, when processing knitted fabrics, because the fabrics are particularly soft, the fabrics will run up and down with the machine needle, so it is not easy to pick up the thread ring, which is particularly easy to cause needle skipping. Therefore, when we process Knitted Fabrics, we should adjust the distance between the 5 thread chain stitch bending needle of the overlock sewing machine and the machine needle to 2.0mm-2.2mm. If the distance is too large, the empty step on the machine will not form chain lines; If the distance is too small, the needle will jump, so its distance must be adjusted.

Key point 2:

Forward and backward movement of chain stitch looper

When making knitted fabrics, the amount of movement before and after the bending needle is too large. When the machine needle drops, it will not be inserted into the five-thread ring, resulting in needle skipping. Therefore, we should adjust the front and rear positions of the chain stitch bending needle in place, that is, the gap between the bending needle and the machine needle is 0.01mm when the needle is hooked. After the machine needle returns, insert it into the back of the bending needle, and the gap between the machine needle and the bending needle should be small.

During adjustment, we can open the cover next to the presser foot lifting rod and see that there is a screw in the middle. Loosen the screw with an Allen screwdriver and move the connecting rod adjusting the front and rear movement of the chain stitch bending needle upward to reduce the front and rear movement of the chain stitch bending needle, and then tighten the screw.

Key point 3:

The gap between chain stitch bending needle and machine needle

The normal gap between the 5 thread chain stitch bending needle and the machine needle is between 0.05mm-0.1mm, but when making knitted fabrics, the machine needle thread ring is not easy to form, so we need to adjust the plane gap between the chain stitch bending needle and the machine needle to 0. If the clearance is adjusted to 0, it is easy to break the needle when making a thicker joint. At this time, we should adjust the needle guard, that is, turn the chain stitch bending needle tip to the center of the needle so that the plane clearance between it and the needle is 0. At this time, the clearance between the needle guard and the needle tip is also 0.