Basically, it is based on physical indicators and appearance defects. However, the physical index items and appearance defects of different kinds and different uses of yarns are different. Yarn quality standards include national standards (approved and issued by the National Science and Technology Commission), ministry standards (approved and issued by the Ministry of Textile Industry), and corporate standards (promulgated by the provincial and municipal industrial departments). The basis for the assessment of common yarn quality and the classification of grades are as follows: Quality assessment of cotton yarn Cotton yarn refers to all cotton yarns. A batch of production of three shifts a day and night to assess. Its products are divided into excellent, first, second and third grades. Excellence is equivalent to the international advanced level, and the first class is equivalent to the international general level. Cotton yarn rating project 1. Single yarn breaking strength coefficient of variation 2. 100m weight variation coefficient 3, dry evenness 4, one gram of cotton grains 5, a gram of neat impurity total grains Cotton rating basis: 1.2.4.5. Appraisal method: According to the lowest one of 1 to 5, wait and see if 1.2. Exceeds the range, regardless of one or two exceeds, descends first, drops to second grade to do so. Excellent cotton yarn plus 100,000 meters of yarn is used as a grading indicator. 1. Single yarn (line) breaking strength, breaking strength coefficient of variation The single yarn was measured 60 times and the strands tested 30 times. Substituting the coefficient of variation formula can be obtained. The n>50 or n<50 formula is different. 2. 100m weight variation coefficient 30 yarns, 1 meter per week, 100 weeks. 30 Weigh separately and substitute the coefficient of variation formula. Based on this, look up the product in the specification table. 3. 100 meters weight deviation Actual special number and design number The percentage of deviation between the two is called the weight deviation or the special number deviation. The actual assessment is measured by the hundred-meter weight deviation. 4. Dryness uniformity Either the coefficient of variation of the evenness of the strip (measured with an electronic homogenizer) or the uniformity of the dryness of the black stripe may be used. When there is a dispute, the former shall prevail. Blackboard strip evenness measurement: 10 randomly selected bobbins, evenly shake 10 blackboards, each one 250mmx220mm, and compare them with the standard standard photographs in order, according to their shadows, thick sections, and severe defects. Severe irregularities, etc., were assessed separately. Better than or equal to excellent is rated as excellent, better than or equal to first-class, inferior to first-class or severely inferior as second-class, and severely irregular in regularity as third-class. Finally, according to the proportions of the top ten, the first, the second, and the third among the ten blackboards, the evenness of the bars is determined. 5. The number of 1g cotton neps and the total number of 1g inner neat impurities The number of neps pellets and trash pellets in the 10 positive and negative dots, the total number of neps na and the nb impurity total nb in 10 boards can be calculated as follows: 1g number of cotton neps = na/ Ntex x10 1g Total Neps Impurities = (na+nb)/Ntex x10 6. One hundred thousand meters of yarn Yarn yarn refers to the major flaws attached to the yarn. It is divided into short thick sections (more than 100% thicker than the normal, less than 200px in length), long thick sections (more than 45% thicker than normal, and lengths greater than 200px), and long thin knots ( 30 to 70% finer than normal and greater than 200px). Affect the quality of the fabric, causing short head. The test requires a large sample size, otherwise it is not easy to find, so take 100,000 meters long. It is done on the yarn gauze. Birthday Cake Crowns,Crystal Birthday Girl Princess Crowns,Girls Princess Crystal Tiara Crown,Round Crystal Birthday Cake Crowns YiWu Home Of Crowns Co.,Ltd , https://www.crystal-crowns.com
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Yarn quality assessment includes both intrinsic quality and appearance quality: