Sewing is the process of synthesizing sewing materials into various products that people need by making continuous seams (or continuous seams by hand) by sewing machines. The needle thread in the sewing thread is moved by the needle of the sewing machine through the continuous puncturing of the sewing material, and interweaves with the shuttle thread to form a stitch.
In the sewing process, the speed is high, the friction is more, and it is easy to be damaged, so the performance requirements and mechanism requirements of the industrial sewing machine thread are higher than that of the manual sewing thread.
It not only ensures the smooth formation of seams during the sewing process, but also ensures the fastness after the seams are formed.
1. Performance requirements of sewing machine thread: The performance requirements of industrial sewing machine sewing thread not only meet the quality performance requirements of sewing thread, but also strictly meet the following requirements:
1. Line uniformity: refers to the thickness of the line and the uniformity of the material. During the sewing process, the stability of the thread tension directly affects the stability of the seam. When the sewing thread passes through the hook of the sewing machine, if the uniformity of the thread is not good, the needle thread and the hook thread will be damaged. The tension is unstable and will affect the seam.
At the same time, when the suture passes through the needle hole of the needle machine, the friction force will suddenly increase due to the appearance of thick nodes of the suture. In severe cases, the thick nodes will bend the needled material when it touches other parts, causing the needle to break. ; Defects of thin branches will cause the suture to be pulled and elongated, resulting in skipped stitches or broken threads when the suture is retracted.
2. The softness of the thread: It means that a certain degree of softness is conducive to sewing, which can make the stitches neat and beautiful, while the hard stitches will cause the stitches to not tighten or appear.
3. Thread strength: refers to the tensile force that the suture can withstand during the sewing process, and can meet the requirements of the sewing material with the fastness of the seam on the upper stroke of the sewing material after sewing.
Among them, the upper thread needs to be rubbed with the needle, sewing material and the surface of the hook for many times to form a seam, so that its strength is reduced. The strength of general sewing thread is reduced by about 18%. When small needle stitches are sewed, when a small section of suture is formed into stitches, it will be rubbed with the needle and the sewing machine hook about 90 times before it is sewn onto the sewing material, so that the sewing thread needs to reach a similar Strength can be used as a suture for needlework.