Improving yarn quality begins with micronaire value

Posted 2021-05-01 DaYaoTextile

Micronaire is a transliteration of English micronaire. Micronaire value is a comprehensive index reflecting the linear density and maturity of cotton fibers. It is one of the important internal quality indicators of cotton fibers and is closely related to the use value of cotton fibers. The intrinsic quality indexes of cotton fiber mainly include fiber length, fiber linear density, fiber strength and fiber maturity.

马克隆是英文Micronaire的音译，马克隆值是反映棉花纤维线密度与成熟度的综合指标，是棉纤维重要的内在质量指标之一，与棉纤维的使用价值关系密切。棉花纤维的内在品质指标主要有纤维长度、纤维线密度、纤维强度和纤维成熟度。

Classification of Micronaire Value

The micronaire value is divided into three levels: A, B and C, and B is the standard level. Grade A ranges from 3.7 to 4.2, with the best quality; Grade B ranges from 3.5 to 3.6 and 4.3 to 4.9; Grade C ranges from 3.4 to below and from 5.0 to above, with the worst quality. The specific measurement method is to use an airflow meter to measure the air permeability of cotton fibers with constant weight after being pressed into a fixed volume. The larger the value, the thicker the cotton fibers and the higher the maturity.

马克隆值分为A、B、C三级，B级为标准级。A级取值范围为3.7～4.2，品质最好；B级取值范围为3.5～3.6和4.3～4.9；C级取值范围为3.4及以下和5.0及以上，品质最差。具体测量方法是采用一个气流仪来测定恒定重量的棉花纤维在被压成固定体积后的透气性，并以该刻度数值表示，数值越大，表示棉纤维越粗，成熟度越高。

The relationship between micronaire value and yarn quality

Cotton fibers with high micronaire value can withstand mechanical strikes, easily remove impurities, evenly yarn, smooth appearance, fewer defects, and high yield of finished products. However, if the micronaire value is too high, the yarn strength will be affected. Cotton fibers with low micronaire value tend to have poor maturity, harmful defects and poor dyeability. Therefore, only cotton with moderate micronaire value can give consideration to both sides and obtain more comprehensive economic benefits.

The relationship between micronaire value and yarn quality can not be generalized. It is closely related to yarn size. Roving yarn has high micronaire value and good yarn quality; fine count yarn, especially Superfine Count yarn, requires low micronaire value and good yarn quality; the number of fibers per unit cross-section of roving yarn is large, and the strength of fibers directly affects yarn strength. The number of fibers per unit cross-section of yarn count is small, and the number of fibers directly affects yarn strength.

The micronaire level is a linear density index range. The original unit is 10 g/inch to 6 g/inch. Because of the instability of the test, the current micronaire value is treated as dimensionless value.

马克隆值高的棉纤维能经受机械打击，易清除杂质，成纱条干均匀，外观光洁，疵点少，成品的制成率高。但马克隆值过高，会影响成纱强力。马克隆值过低的棉纤维往往成熟度差，容易产生有害疵点，染色性差。所以只有马克隆值适中的棉花，才能兼顾两方面，获得较全面的经济效益。

马克隆值与成纱质量的关系，不能一概而论，与成纱纱号的粗细密切相关。粗号纱高马克隆值，纤维成纱质量好；细号纱特别是特细号纱要求比较低马克隆值，成纱质量好；纱号粗单位截面纤维根数多，纤维的强力直接影响成纱强力，纱号细单位截面纤维根数少，纤维的根数直接影响成纱强力。

马克隆值级是一个线密度指标范围，原来的单位为10 g/英寸～6 g/英寸，由于测试的不稳定性，现在的马克隆值作为无量纲值处理。

The relationship between micronaire value and spinning process

In order to spin yarns of certain thickness and fineness, so that the yarn has a certain strength, to withstand various stresses in the process, and to give textiles the necessary performance, the yarn cross-section must have a certain minimum number of fibers. Therefore, roving yarn is spun with roving fibers and fine yarn is spun with fine fibers. Under the same other conditions, the finer the fiber, the higher the yarn strength and the better evenness. However, the finer the fibers, the easier they twist and break during processing, and the easier they form neps.

Micronaire value is a comprehensive reflection of cotton linear density and maturity. Therefore, it is closely related to yarn quality and spinning process. Cotton fibers with high micronaire value can withstand mechanical strikes, easily remove impurities, evenly yarn, smooth appearance, fewer defects, and high yield of finished products. However, if the micronaire value is too high, the yarn strength will be affected. Cotton fibers with low micronaire value tend to have poor maturity, harmful defects and poor dyeing performance. Therefore, only cotton with moderate micronaire value can give consideration to both sides and achieve more comprehensive economic results.

High maturity cotton fibers have good strength, can withstand processing and cleaning machinery, easy to remove impurities, not easy to produce neps and strands, high yield of finished products. The cotton fibers with poor maturity are liable to form more harmful defects and the rate of finished products is low. Cotton fibers with high maturity have high yarn strength and good evenness. However, over-mature cotton fibers have poor cohesion, yarn strength and evenness. Cotton fibers with high maturity have good color absorption and uniform dyeing.

The spinning test of USDA and the experience of textile mills at home and abroad show that the low micronaire value will result in more steel dropping and deterioration of yarn appearance, but it can improve yarn strength and number of spinnable yarns. On the contrary, it will cause the decrease of cotton yarn cohesion, increase broken ends of cotton yarn and reduce the number of spinnable yarns, but it can reduce the amount of dropping cotton and improve yarn appearance.

Therefore, cotton with micronaire value of 3.5-4.9 will be regarded as normal micronaire value cotton in the world. Especially for cotton whose micronaire value ranges from 3.7 to 4.2, the price will be increased. This is the reason why cotton with 3.7-4.2 micronaire value is classified as grade A in the new standard, while cotton with less than 3.5 and more than 5.0 is classified as grade C.

要纺制一定粗细的纱线，使纱线具有一定的强力，以承受工艺中的各种应力，赋予纺织品必要的使用性能，纱线横截面内必需具有一定的最低根数的纤维。所以，粗纤维纺粗支纱，细纤维纺细支纱。在其他条件相同的情况下，纤维越细，成纱强力越高，条干均匀度越好。但是，纤维越细，在加工过程中越容易扭结和折断，容易形成棉结。

马克隆值是棉花线密度和成熟度的综合反映。因此，它与成纱质量和纺纱工艺都有密切的关系。马克隆值高的棉纤维能经受机械打击，易清除杂质，成纱条干均匀，外观光洁，疵点少，成品的制成率高。但马克隆值过高，会影响成纱强力。马克隆值过低的棉纤维，往往成熟度差，容易产生有害疵点，染色性能差。所以，只有马克隆值适中的棉花，才能兼顾两个方面，获得较全面的经济效果。

成熟度高的棉纤维强力好，能经受加工和清棉机械打击，易清除杂质，不易产生棉结和索丝，成品制成率高。成熟度差的棉纤维，则容易形成较多的有害疵点，成品制成率也低。成熟度高的棉纤维，成纱强力高，条干均匀度也较好。但过成熟的棉纤维，抱合力差，成纱强力和条干均匀度反而不好。成熟度高的棉纤维，吸色性好、织物染色均匀。

美国农业部的纺纱试验和中外纺织厂的使用经验均表明，马克隆值低，会产生较多的清钢落棉，纱线外观恶化，但能提高纱线强力和可纺号数，反之，会引起棉纱抱合力的下降，增加棉纱断头，降低了细纱可纺号数，但能降低落棉量，改善纱线外观。

所以，国际上将马克隆值为3.5～4.9的棉花，作为正常马克隆值棉花。特别是马克隆值在3.7～4.2范围内的棉花，从价格上还要加价。这也就是新标准中，将3.7～4.2马克隆值的棉花定为A级，而3.5以下和5.0以上的定为C级的原因

Significance of Micronaire Value

Micronaire value can provide accurate basis for cotton blending in textile mills to ensure excellent cotton use; it can improve and stabilize the quality of yarn by dividing it into micronaire value indicators; micronaire value indicators are simple to operate, clear data and persuasive in testing; micronaire value is related to yarn quality and spinning process, cotton with moderate micronaire value has high yarn strength, good spinning quality and cloth. The appearance of cotton surface is good and durable. When cotton grade is appraised, the micronaire value index can reduce the quality disputes between buyers and sellers and effectively prevent the phenomenon of sub-optimal.

马克隆值可为纺织厂配棉提供准确依据，保证优棉优用；按马克隆值指标分等分存，能提高和稳定纱布质量；马克隆值指标在检验中，仪器操作简单，数据明确，具有说服力；马克隆值与成纱质量和纺纱工艺有关，马克隆值适中的棉花成纱强力高，纺纱质量好，布面外观较好，坚实耐穿；在鉴定棉花品级时，加上马克隆值指标，可以减少买卖双方在质量上的纠纷，能有效防止以次充好现象。

单词小课堂

transliteration：transliteration

译音;字译，音译

maturity：[məˈtʃʊərəti] 

成熟;完备;（票据等的）到期;[地]壮年期

permeability： [ˌpɜ:mɪə'bɪlətɪ] 

渗透性;磁导率;可渗透性

cohesion：[kəʊˈhi:ʒn] 

凝聚，内聚;（各部的）结合;[力]内聚力;[植]连着

persuasive：[pəˈsweɪsɪv] 

有说服力的;劝诱的;动听