Knitting yarns require higher dryness, good flexibility, certain strength and elongation, and twist. In the process of forming knitted fabrics on knitting machines, the yarns are subjected to complex mechanical actions such as stretching, bending, twisting and rubbing. Wait. In order to ensure the normal production and the quality of the products, the 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 indicator for the yarn for knitting. Since the yarn is subjected to a certain tension and repeated loading during preparation and weaving, the knitting yarn must have a certain strength. In addition, the yarn is subjected to bending and torsional deformation during the knitting process, and therefore the knitting yarn is required to have a certain elongation so as to be bent into a loop during the knitting process and to reduce yarn breakage.

Second, the yarn should have good softness

The softness of the yarn for knitting is higher than that of the yarn for weaving. Because the soft yarn is easy to bend and twist, and the coil structure in the knitted fabric is uniform, the appearance is clear and beautiful, and the yarn breakage during the weaving process and the damage to the looping mechanism are also reduced.

Third, the yarn should have a certain degree of twist

In general, the knitting yarn has a lower twist than the woven yarn. If the twist is too large, the softness of the yarn is poor, it is not easy to be bent and twisted during weaving, and it is easy to cause kinking, which causes woven woven fabric and damages the knitting needle; in addition, excessively twisted yarn affects the elasticity of the knitted fabric. And make the coil skewed.

However, the twist of the knitting yarn should not be too low, otherwise it will affect its strength, increase the breakage during weaving, and the yarn is bulky, so that the fabric is easy to pilling and reduce the wearing performance of the knitted fabric. Therefore, the correct choice of twist is an important way to rationally choose yarn. Knitwear has different uses and different twist requirements.

(1) The jersey fabric is required to be smooth, compact, smooth in surface and clear in texture. The yarn has a larger twist and can be close to the warp yarn standard for the same linear density weaving.

(2) The yarn width of the outer garment should be larger to enhance the stiffness and improve the pilling phenomenon.

(3) Cotton cloth and elastic cloth are required to be soft and elastic, and the twist of the yarn should be slightly lower. Generally, the lower deviation of the weft yarn width of the same-line density weaving is used. The yarn for the piled knit fabric is made for the purpose of easy brushing, and the thickness of the pile is uniform, and the twist requirement is smaller.

In addition, the size of the twist varies with the yarn density.

Fourth, the linear density of the yarn should be uniform, and the yarn defect should be less.

The uniformity of yarn linear density, that is, the uniformity of the yarn strands, is an important quality indicator for knitting yarns. The evenly-spun yarn facilitates the knitting process and ensures the quality of the fabric, so that the coil structure is uniform and the cloth surface is clear.

Yarn is also an important indicator of yarn for card clothing. If there are thick knots on the yarn, the weaving will not pass smoothly, causing yarn breakage or damage to the machine parts, and it is easy to form "horizontal strips" and "cloud spots" on the cloth surface to reduce the quality of the knitted fabric; The details are insufficient strength here, easy to break, affecting the quality of the fabric and reducing machine productivity. Because the knitting machine has a multi-way looping system and the yarn is looped at the same time, not only the thickness of each yarn is required to be uniform, but also the difference of the thickness of the yarn between the roads is strictly controlled, otherwise horizontal stripes will be formed on the cloth surface. Shadows and other diseases reduce fabric quality.

Fifth, the yarn should have good hygroscopicity

The ability of a yarn to absorb moisture in the air is called hygroscopicity. The hygroscopic capacity of various fibers varies greatly, and the amount of moisture absorption varies with the temperature and humidity of the air. Yarns used in knitting production should have a certain hygroscopicity. Under the same relative humidity conditions, the yarn with good hygroscopicity, in addition to its good electrical conductivity, also contributes to the stability of the yarn twist and the improvement of the elongation, so that the yarn has good weaving properties.

Sixth, the yarn should have a good finish and a small coefficient of friction

Knitting yarns should be as free of impurities and grease as possible, and should be smooth. The non-smooth yarn has a great damage to the machine parts, which is easy to damage the machine parts, and there are many flying flowers in the workshop, which affects the health of the workers and affects the productivity of the knitting machine and the quality of the fabric.