Knitted yarn requires higher evenness, good softness, certain strength, extensibility and twist, and is formed on the knitting machine During the knitting process, the yarn is subjected to complex mechanical effects, such as stretching, bending, twisting, friction, etc. In order to ensure the normal production and product quality, knitting yarn should meet the following requirements:
1. The yarn should have a certain strength and extensibility
Yarn strength is an important quality indicator of knitting yarn.Since the yarn is subjected to a certain tension and repeated loads during the preparation and weaving process, the knitting yarn must have a certain strength. In addition, the yarn is also subject to bending and torsional deformation during the knitting process, so the knitting yarn is also required to have a certain degree of extensibility to facilitate bending into loops and reduce yarn breakage
2. The yarn should have good softness
Knitting yarn requires higher softness than woven yarn.Because soft yarns bend and twist easily and make the loop structure in knitted fabrics uniform , the appearance is clear and beautiful, and it can also reduce yarn breakage and damage to the looping machine parts during the weaving process.
3. The yarn should have a certain twist
Generally speaking, the twist of knitting yarn Lower than woven yarn. If the twist is too large, the softness of the yarn will be poor, and it will be difficult to bend and twist during weaving. It will also easily produce kinks, causing weaving defects and causing damage to the knitting needles. In addition, the yarn with too much twist will Threads can affect the elasticity of knitted fabrics and cause the loops to skew. But the twist of the knitting yarn cannot be excessive Low, otherwise it will affect its strength, which increases breakage during weaving and makes the yarn bulky, making the fabric prone to pilling and reducing the wearing performance of knitted fabrics. Therefore, the correct selection of twist is an important part of the rational selection of yarn. Important ways. Knitted fabrics have different uses and twist requirements. (1) Jersey cloth is required to be smooth, compact, with a smooth surface and clear texture. The twist of the yarn should be larger, which can be close to the same linear density woven warp standard. (2) The twist of the yarn for outerwear should be larger. To enhance stiffness and improve pilling. (3) Cotton wool fabrics and elastic fabrics are required to feel soft and elastic, and the twist of the yarn should be slightly lower. Generally, the lower deviation of the twist of the weft yarn for weaving with the same linear density is used. The yarn for pile knitted fabrics , in order to facilitate brushing and make the pile thickness uniform, the twist requirement is smaller. In addition, the degree of twist also varies with the linear density of the yarn. 4. The linear density of the yarn should be uniform and the yarn defects should be few Yarn linear density uniformity is yarn Evenness of evenness is an important quality indicator of knitting yarn. A yarn with even dryness is beneficial to knitting processing and ensures fabric quality, making the coil structure uniform and the cloth surface clear. Yarn defects are also a part of the yarn used in card clothing important indicators. If there are thick spots on the yarn, the knitting will not pass smoothly, causing yarn breakage or damage to the machine parts, and it is easy to form “horizontal stripes” and “cloud spots” on the cloth surface, reducing the quality of the knitted fabric; such as If there are details on the yarn, the strength is insufficient and it is easy to break, affecting the quality of the fabric and slowing down the machine. Productivity. Because there are multiple loop-forming systems on the knitting machine that feed yarn into loops at the same time, not only the yarn thickness in each loop is required to be uniform, but the thickness difference between the yarns in each loop must also be strictly controlled, otherwise horizontal lines will be formed on the cloth. Defects such as stripes and shadows reduce fabric quality. 5. The yarn should have good hygroscopicity Yarn’s ability to absorb moisture in the aircalled hygroscopicity. The moisture absorption capabilities of various fibers vary greatly, and the amount of moisture absorbed varies with the temperature and humidity of the air. Yarns used in knitting production should have a certain degree of hygroscopicity. Under the same relative humidity conditions, yarn with good hygroscopicity, in addition to its better electrical conductivity, is also conducive to the stability of the yarn twist and improvement of extensibility, so that the yarn has good Knitting performance. 6. The yarn should have good smoothness and small friction coefficient Knitting yarn should be as free from impurities and Oil stains, etc., and should be smooth. Unsmooth yarn causes severe wear and tear on machine parts, easily damaging machine parts, and there are a lot of flying flowers in the workshop, which affects the health of workers , and affects the productivity of knitting machines and the quality of fabrics.
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