Summary：Knitting requires higher evenness (i.e. uniformity of yarn thickness), good softness, certain strength, extensibility an...
Knitting requires higher evenness (i.e. uniformity of yarn thickness), good softness, certain strength, extensibility and twist (yarn twist is relatively low). In the process of forming knitted fabric on the knitting machine, the yarn will be subjected to complex mechanical effects, such as stretching, bending, twisting, friction, etc. In order to ensure normal production and product quality, knitting yarn shall meet the following requirements:
1. The yarn shall have certain strength and extensibility
Yarn strength is an important quality index of knitting yarn. Because the yarn is subjected to certain tension and repeated load in the process of preparation and weaving, the knitting yarn must have certain strength. In addition, the yarn is subject to bending and torsion deformation in the knitting process, so the knitting yarn is also required to have certain extensibility, so as to facilitate the bending process and reduce yarn breakage.
2. The yarn should have good softness
The softness of knitting yarn is higher than that of woven yarn. Because the soft yarn is easy to bend and twist, the coil structure in the knitted fabric is uniform, the appearance is clear and beautiful, and the yarn breakage and damage to the looping machine parts in the weaving process can be reduced.
3. The yarn should have a certain twist
Generally speaking, the twist of knitting yarn is lower than that of 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 also easy to produce kink, resulting in weaving defects and damage to the knitting needle; In addition, the yarn with too much twist will affect the elasticity of the knitted fabric and skew the loop. However, the twist of knitting yarn should not be too low, otherwise its strength will be affected, the end breakage during weaving will be increased, and the yarn bulkiness will make the fabric easy to fuzz and pilling, and the wearability of knitted fabric will be reduced. Therefore, the correct selection of twist is an important way to reasonably select yarn. The twist requirements are also different for different purposes of knitted fabrics.
Sweat cloth shall be smooth, compact, smooth and clear, and the twist of yarn shall be larger, which can be close to the standard of warp yarn for weaving with the same linear density. The twist of coat yarn should be larger to enhance straightness and improve pilling. Cotton wool cloth and elastic cloth are required to be soft and elastic. The twist of yarn should be slightly lower. Generally, the lower twist deviation of weft for weaving with the same linear density is adopted. The yarn used for cashmere knitted fabric requires less twist in order to make it easy to pull down and make the pile thickness uniform.
In addition, the twist varies with the yarn linear density.
4. The linear density of the yarn should be uniform and the yarn defects should be less
The uniformity of yarn linear density, that is, the uniformity of yarn evenness, is an important quality index of knitting yarn. Yarn with uniform evenness is beneficial to knitting
