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Right and left twist in industrial sewing threads

Yarn twist means that in order to make the yarn have certain physical and mechanical properties such as strength, elasticity, elongation, luster, hand feeling, etc., the cotton yarn must be changed by twisting, and the yarn twisting is realized by the fiber structure. The relative angular displacement between them makes the originally straight and parallel fibers inclined to the yarn axis to change the yarn structure. Twist triangle, in which the width and cross-section of the slivers change, from flat ribbons to cylindrical yarns.

Choosing the correct twist for the industrial sewing thread used in your application is an important consideration in how smoothly your manufacturing process works. That is why it’s important to know the difference between left-twist and right-twist industrial sewing threads.

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Six definitions of a twist

  • The definition of a twist: the yarn rotates 360 degrees around its axis, which is a twist.
  • The definition of a twist: the number of twists of the sliver within the specified length before untwisting, the unit of Tex is 10cm; the unit of the metric is 1m; the unit of imperial is 1inch
  • Definition of twist coefficient: It is a measure of the degree of twisting of the yarn, which is proportional to the twist angle, and it is a measure of the tightness of yarns with different linear densities.
  • Definition of twist direction: when the sliver is in a vertical position, the oblique direction of the helix is formed by the rotation of the units that make up the sliver around the axis of the sliver.
  • S-twisting definition: The inclination direction of the fiber in the sliver is consistent with the middle part of the letter S. It is a right-handed or clockwise twisted yarn.
  • Z-twisting definition: The inclination direction of the fiber in the sliver is consistent with the middle part of the letter Z, which is the twisted yarn in the left-hand direction or counterclockwise direction.

Twist in sewing thread manufacturing process

In order to understand twists and the correct application for each type, it may be helpful to first present an overview of the sewing thread manufacturing process. Beginning with either short fibers or continuous filaments, fibers are twisted together to produce fine yarns. This is known as a “singling twist” and is what gives thread its flexibility and strength. In order to balance threads when two or more plies, or individual threads, are combined to make the finished thread, a reverse twist is applied. Without this reverse twist, the yarn would separate into individual plies when used in sewing.

Twist in the sewing process

The process of sewing applies an additional twist to the thread as it passes through the machine. Most sewing machines use a single needle; threads with a left twist, or Z-twist, are designed to pass through these needles with ease. The sewing process tends to increase the twist of this thread.

Right twist and left twist

In industrial sewing threads, the terms “right twist” and “left twist” refer to the direction of the twist in the thread. A right twist means that the fibers in the thread are twisted in a clockwise direction, while a left twist means that the fibers are twisted in a counterclockwise direction.

Most industrial sewing threads are made with a right twist, which is the standard twist direction for most threads. However, some applications may require a left twist thread, such as when sewing certain materials or when using certain types of needles.

Left twist threads are less common than right twist threads and may be harder to find. They are typically used for specific applications, such as when sewing leather or canvas. Left twist threads can also be used when sewing with certain types of needles that require a left twist thread for proper stitching.

  • If threads with a right twist, or S-twist, are used in these single-needle machines, the sewing process can actually untwist these threads. The result is a snarled mess which puts a quick halt to the manufacturing process. S-twist threads are appropriate for use in double-needle machines engineered specifically for use with right-twist threads.
  • The direction of a thread‘s twist doesn’t affect its strength, but it will seriously impair the thread’s performance when it is used on an unsuitable machine. For that reason, it is important to choose a thread that was designed and engineered for use on your particular machines.

In general, it’s important to choose the right twist direction for your specific application and to use a high-quality industrial sewing thread that is designed for your specific sewing machine and application. By using the right thread and twist direction, you can ensure a more successful and efficient sewing process.

Works Cited: Left Twist Vs. Right Twist Industrial Sewing Thread