Suture, thread used for sewing. Generally made of cotton thread, chemical fiber thread, metal wire and so on. Sewing thread is used to sew various clothing materials and has dual functions of practicality and decoration. The quality of the suture not only affects the sewing effect and processing cost, but also affects the appearance quality of the finished product.
Needle thread: the thread passing through the needle hole of the machine.
Shuttle thread: the suture drawn from the bobbin through the bobbin case.
Looper thread: The suture that passes through the looper hole.
Stretching thread: The suture on the back of the sewing material is compounded to form the necessary looper thread for stitching.
Covering thread: the suture covering the front of the sewing material for reinforcement and decoration.
Five basic elements
The five basic elements of sewing machine stitches are: texture, diameter, direction of rotation, twist, and number of strands.
1. Texture: According to the texture, the suture can be divided into two categories: natural fiber and synthetic fiber (mainly chemical fiber);
2. Common diameter: Regardless of whether the suture is single-strand or multiple-strand based on the worsted thread, it can be assumed that the cross-section of the suture is regarded as a circle, which approximates a parameter of the diameter;
3. Rotation: It is a parameter introduced to increase the stitch strength and sewing regularity, which can be divided into left and right rotation. The simple way to distinguish is to hold the suture with one hand and twist the hanging part with the other hand. The twisting direction is the direction of thread rotation (left-handed thread is more common);
4. Twist: Most sutures are made by twisting two or more fiber threads in one direction. If the twist is large, the strength will increase, while the stability of the sewing will be weakened accordingly. The phenomenon of thread pick-up and emergence during the sewing process will occur. increase;
5. Number of strands: refers to the number of clusters that make up the suture.
Classification of sutures
1. Natural fiber suture
(1) Cotton suture
Features: high tensile force, high form stability, high temperature resistance, poor elasticity, good seamability, large shrinkage rate
(2) Silk suture
Features: toughness, high elasticity, wear resistance, suitable for animal fiber cloth, expensive
2. Synthetic fiber suture
Features: high strength, wear resistance, no shrinkage, antiseptic mildew, limited heat resistance
3. Natural/synthetic fiber mixed suture/blended thread
Features: strong seamability, high tensile force, strong wear resistance
