Determination and calculation of fiber length
1. Hand-pulled length and length grade The so-called hand-pulled length refers to the fiber length with the largest number of fibers in raw cotton measured by hand-pulled ruler, referred to as length. It means taking out a small amount of cotton samples from the cotton being inspected, pulling them by hand and sorting them so that the cotton fibers are straight, parallel and arranged in an orderly manner. Finding the representative mode length is the hand length. The hand pull length is divided into seven levels: 1mm, 25mm, 26mm, 27mm, 28mm, 29mm, 30mm, and 31mm. 28mm is the standard length level. The grading range is shown in Table 1-1. The length of grade five cotton is greater than 27mm, and the length is calculated as 27mm; the length of grade six and seven cotton is calculated as 25mm. The length of cotton is inspected using the manual ruler measurement method. The length of the batch of samples is inspected one by one, and one sample is inspected for each sample. There are two methods of hand pulling: the one-end method and the two-end method. The main factor that affects the accuracy of the hand-pulling length is the hand-pulling method, including the number of cotton bundles taken, the long and short discards during the pulling process, and the finished cotton. number of bundles. During the inspection, take about 10g of a representative cotton sample, divide it equally with both hands, extract the fibers, and then sort it into a straight cotton bundle of about 60mg without silk clumps, debris and free fibers, with the width of the cotton bundle about 20mm; On the black velvet board, use a special fiber ruler to cut the threads at both ends of the cotton. The tangent position is based on the black velvet pull, and the distance between the two tangents is measured (both ends are aligned, the fiber length is measured directly, and the black velvet board is not exposed), and the measurement result is kept to one decimal place (in millimeters) , record the inspection results in this way. Calculate the arithmetic mean of the length of each sample in the batch and the percentage of each length grade, retaining one decimal place. The length grade corresponding to the average length is determined as the length grade of the cotton batch.
2. The main body length, also called the mode length, refers to the group of lengths that account for the most weight or number of fibers in the fiber length distribution. Since this method is weighted, the main body length must fall in the group with the largest weight, but the group length must be in the group with the largest weight. The group spacing is 2mm. To determine where the main body length is in the group, it needs to be determined based on the weight relationship between the heavier group and its adjacent two groups. The calculation formula for body length is:
AAANHJJGHSFW
Extendedreading:https://www.alltextile.cn/product/product-73-230.html
Extendedreading:
Extendedreading:
Extendedreading:
Extendedreading:
Extendedreading:
Extendedreading:
ExtendedReading:
Extendedreading:
Extendedread
