Fiber length and yarn quality

First, the length

Length is one of the main quality indicators of fiber materials and is an important factor in determining the value of spinning fibers.

(I) The relationship between fiber length and yarn quality

The relationship between fiber length and yarn quality is very close. Mainly in the following aspects.

1. Fiber length and yarn strength are in the yarn. If the fiber length is longer, the contact length between the fiber and the fiber is longer. When the yarn is affected by external force, the fiber is not easy to slip off. At this time, the yarn is pulled due to tension. The number of fibers slipped off is small, so the yarn strength is high. The change of fiber length has different effects on the rise and fall of yarn strength. When the length of the fibers constituting the yarn is short, the influence of the length on the yarn strength is relatively large. In the commonly used textile fibers, the length of the cotton fibers is short, and therefore, the length thereof has a great influence on the yarn strength. The regularity of the fiber length also affects the yarn strength. When the percentage of short fiber in raw cotton is higher than 15%, the yarn strength will decrease significantly.

2. Fiber Length and Yarn Density There is a limit to the density of the spun yarns of fibers of various lengths. Under the premise of ensuring that the yarn has a certain strength, the longer the fiber length, the smaller the limit linear density of the yarn being spun, that is, the finer the yarn being spun; the shorter the fiber length, the greater the limit linear density of the spun yarn. That is, the thicker the yarn being spun. For example, a fine velveteen cotton with a length of 25 mm or less can generally only be spun with a medium or thick yarn of 30 tex or more, and a fine velveteen cotton with a length of about 29 mm. The limit linear density of a spinning yarn is 10 tex. In spun yarn, long-staple cotton must be used. The longest fiber in long-staple cotton can be spun to 3tex.

3. The length of the fiber and the evenness of the resulting sliver The longer the length of the fiber and the higher the length of the sliver, the better the sliver is.

When the length of the fiber is very short and the length of the fiber is poor, the dryness of the fiber is deteriorated and the quality of the yarn decreases.

4. When the length of the fiber is longer than that of the yarn hairiness fiber, the fiber end on the yarn is less exposed, the hairiness of the yarn is less, and the surface is smooth. On the contrary, the yarn surface has more hairiness.