Hand knitting yarns require higher dryness, good flexibility, good strength and extensibility, twist, knitting in the formation of knitted fabrics in the process, the yarn to be complex mechanical effects, such as stretching, bending, Friction and so on. In order to ensure the normal production and product quality, knitting yarn should meet the following requirements:
First, the yarn should have a certain strength and extensibility
The strength of the yarn is an important quality index for knitting yarn. As the yarn in the preparation and weaving process to withstand a certain tension and repeated load action, therefore, knitted yarn must have a certain strength. In addition, the yarn in the process of knitting into the loop, but also subject to bending and torsional deformation, it also requires knitting yarn with a certain degree of extension, in order to facilitate the knitting process into the loop, and reduce yarn breakage.
Second, the yarn should have a good softness
The softness of the knitted yarn is higher than that of the woven yarn. Because the soft yarn is easy to bend and twist, and make the fabric in the coil structure evenly, the appearance of clear and beautiful, but also to reduce the weaving process of yarn breakage and damage to the ring machine parts.
Third, the yarn should have a certain twist
In general, the twist of the knitted yarn is lower than that of the woven yarn. If the twist is too large, the yarn's softness is poor, weaving is not easy to be bent, twisted, but also prone to kink, resulting in weaving defects, so that the needle is damaged; In addition, the twist too large yarn will affect the elasticity of knitted fabric , And the coil is skewed.
But the twist of the knitting yarn can not be too low, otherwise it will affect its strength, increase the weaving of the broken head, and the yarn bulky, the fabric easy to pilling, reduce the performance of knitted fabric. Therefore, the correct choice of twist is a reasonable choice of yarn an important way. The use of knitted fabrics is different, twist requirements are also different.
(1) Han cloth requirements smooth, tight, smooth surface, clear lines, yarn twist to be larger, can be close to the same line density woven warp standard.
(2) coat yarn twist should be taken larger, to enhance the crisp, to improve the pilling phenomenon.
(3) cotton cloth, elastic cloth requirements feel soft, flexible, yarn twist should be slightly lower, generally with the same line density woven weft twist under the deviation. Pullover knitted fabric yarn, in order to facilitate the brushed, and the pile thickness uniformity, twist requirements smaller.
Fourth, the yarn density to be uniform, less yarn defects
Yarn line uniformity of uniformity that yarn uniformity of yarn, knitting yarn is an important quality indicators. The uniform yarn is conducive to knitting and to ensure the quality of the fabric, so that the coil structure is uniform and the cloth is clear.
Yarn is also an important indicator of yarn with cloth. If the yarn has a thick section, the weaving can not pass smoothly, resulting in yarn breakage or damage to the machine parts, and easy to form on the cloth "bar", "cloud spot" to reduce the quality of knitted fabrics; Details, where the intensity is insufficient, easy to break, affecting the quality of the fabric and reduce machine productivity. Because the knitting machine on the road into the loop at the same time into the yarn into the circle, so not only requires the yarn thickness of each uniform, and the difference between the thickness of the yarn should be strictly controlled, otherwise it will form a horizontal stripes on the cloth, Shadow and other flaws, reduce fabric quality.
5, the yarn should have a good hygroscopicity
The ability of the yarn to absorb moisture in the air is called hygroscopicity. A variety of fiber moisture absorption capacity is very different, and the size of the amount of moisture with the air temperature and humidity vary. For the production of yarn yarn, should have a certain degree of hygroscopicity. In the same relative humidity conditions, good moisture absorption of the yarn, in addition to its good conductivity, but also conducive to the yarn twist back to the stability and extension of the increase, so that the yarn has a good weaving performance.
Six, the yarn to have a good finish and a small coefficient of friction
Knitted yarn should be as much as possible without impurities and grease, etc., and should be very smooth. Not smooth yarn, the mechanical friction of the mechanical damage, easy to damage the parts, and the workshop fly more, not only affect the health of workers, but also affect the productivity of knitting machines and fabric quality.