How can I quickly judge the quality of a batch of yarn when it comes to me?
This is a very practical and good question. If there is no instrument, try the following five steps:
1. First, observe the surface for impurities, oil stains, rust stains, coarse knots, heterochromatic fibers, neps, etc;
2. Draw out a length of yarn to observe whether it is even (fat), dry (thin);
3. Pull the strength to feel whether there is toughness;
4. All the above three points are OK. You can go to the loom for proofing to see whether it is good for weaving and the overall fabric quality;
5. At the same time, cut a piece of yarn, mix it with warm water and a little detergent, and then simply measure the color fastness. The above simple steps involve five important indicators of yarn quality: yarn defect, evenness, strength, twist and color fastness; The five points complement each other to determine the quality grade of yarn. The following contents are expanded. I hope they are also useful to you.
1)、 The yarn defect refers to the defect of the yarn, which will affect the appearance and flatness, such as coarse and fine knots, colored yarn, coarse knots, impurities, greasy yarn, rust stains, etc. Yarn defects can be measured by yarn defect tester.
2)、 Slightness refers to the degree of uniform yarn thickness. The thickness of the same count of yarn should theoretically be uniform. However, during the spinning process, if the operation is improper and the process is not meticulous, uneven yarn thickness will occur, resulting in cloud spots of varying depth in the finished product.
3)、 The strength of strong yarn refers to the tenacity and fastness of a yarn. In spinning, raw materials must undergo certain tension and load, and the spun yarn must have certain strength to ensure the normal knitting process. The strength of the yarn can be measured by a single yarn strength machine, which is generally expressed by breaking strength (the force used at the moment when the yarn is pulled off on the strength machine, in CN/tex (gf/tex).
4)、 Twist In a roving machine, the yarn is drawn and twisted at the same time. The purpose of twisting is to make the yarn have better strength. Twisting is like winding a yarn, with tight or loose control. If the twist is too high, the yarn is twisted and braided during weaving, the elasticity of the fabric is reduced, and it is easy to form small braid knot defects on the fabric surface. In addition, too many knots are also easy to damage the parts of the loom. If the twist is too low, it will affect the strength of the yarn, and the breakage rate will rise. The blocking workers will continue to knot the yarn, and the yarn production rate will be low, and the output will be reduced; Too many fabric knots will also affect the appearance quality of knitwear. The twist of yarn can be measured by a twist meter.
5)、 Color fastness refers to the fading degree of dyed yarn under the action of external washing, ironing, friction, light, saliva immersion, water stains, sweat stains, chemical agents, etc. in the use or processing process. It is a routine test item in yarn quality test. Dark color, light color, bright color, fluorescent color, clip color and other colors need to maintain a certain degree of fastness to meet the needs of wear and durability. The yarn color fastness can be sent to the testing department for testing various color fastness indicators.
