12 Jun The effect of yarn hairiness on fabrics
The hairiness of the yarn causes several problems in fabrics due to the following reasons, hence; it is necessary to be controlled:
1) Essentially, the hairiness of the yarn is one of the factors that determines the quality of yarn. The higher hairiness of the yarn results in the lower quality of the yarn. The presence of the lint in yarn creates a bad appearance in the fabric. According to the report of the Uster standards, 15% of the faults in fabrics are due to the hairiness of yarns. Creation of unwanted strips in the direction of the wraps and wefts is due to the high hairiness of the yarn or its variation. Periodic changes in the yarn’s hairiness lead to the formation of alternating thin and thick bands in fabric.
(2) When a yarn with high degree of hairiness is used in fabric wraps, long protruded fibers of yarns cause engagement of the yarns and cling to each other. Such a condition prevents the easy separation of the fabric warps at the creation of sheds, and thus increases the number of tears in the warp threads and adds to the fabric imperfections.
3) The use of yarns with high degree of hairiness in sewing process increases thread breakage.
4) The presence of high-tufted yarns in the fabrics causes printing of the lines and curvatures of the design pattern cannot be accurately applied to the fabrics and lead to an interference of patterns.
5) The higher the yarn’s hairiness, the higher the tendency to the hairiness of the fabric, which causes unseemly appearance in the fabric.
6) Increasing the hairiness of the yarn increased air resistance around the spinning yarn balloon. According to conducted researches, it has been estimated that with increasing the yarn hairiness, the friction coefficient increases. Consequently, the amount of air resistance increases during the revolving of yarn balloon in the circular spinning machines. Studies have shown that by singeing of the excessive hairiness of the yarns, the air resistance reduces up to 26% for cotton yarns and up to 33% for wool yarns. In general, a practical result excessive hairiness of yarns is elevated energy consumption.
Positive effects of yarn hairiness
With all the negative points mentioned about the hairiness of the yarn, a question may arise whether the yarn hairiness has any positive effect?
The answer to this question is yes. The hairiness of the yarn has a positive effect on the comfort feeling of the fabric texture and its warmness. This fact can be easily realized from the comparison of the produced yarns from filament fibers and discontinuous fibers that have the same size and material.
Fabrics made from filament fibers have a plastic touch feeling due to not having hairiness. The warmth of woolen fabrics, such as all types of scarfs, flannel fabrics and wool knitted garments, is largely due to the presence of hairiness in their yarns, as well as fullness properties of fabric and coverage of fabric surface.
In air jet knitting machines, the use of yarns with hairiness increases the friction with the air and thus provides better conditions for transferring the wefts inside the sheds. Studies have shown that, as the yarn friction increases with air, the speed of interlacing of wefts can also increase. Therefore, it is seen that the absence of lint in the yarn is not perfectly desirable, and there is always a need for a specific amount of hairiness in the yarn.
Methods for reducing yarn hairiness:
Hairiness can be reduced through the following methods:
Singeing of yarn or fabric
Yarn waxing during spinning (open-end, spindle spinning and winding)
Yarn lubrication, especially for wool and cotton yarns during the winding phase
Enzyme addition process