GB/T 18147.3-2015Test method for hemp fiber—Part 3: Test method for length of hemp fiber (English PDF)

3.1 Average length

The average value obtained by weighting the mass of each group of fibers which are measured in groups by length.

3.2 Short fiber content

The percentage of the mass of short fibers shorter than a certain length limit in the hemp fiber TO the total fiber mass. respectively, so that the fibers become relatively straight bundle which is neat at one end.

9.2 Testing

9.2.1 Method A - Length measurement by comb sorter (applicable to slivers)

9.2.1.1 Arrange the sorted straight fiber bundles on the top of the lower comb piece of the comb sorter group by group, with the neat end flush with the first comb piece; use a pressing fork to press the fibers straightly into the lower comb piece.

9.2.1.2 Press the upper comb piece into the lower comb piece.

9.2.1.3 Use a clip to extract the fibers from the longest end of the fibers, by as small amount as possible and as many times as possible, so as to avoid taking out short fibers.

9.2.1.4 Twist the extracted fibers into small strands by groups and place them in a metal box or a black clearer in sequence. After each extraction of a group, put down a lower comb piece, until each group of fibers is extracted.

9.2.1.5 Starting from the shortest group, weigh the mass of each group of fibers on the balance in turn, and record it.

9.2.2 Method B - Manual grouping and weighing method

9.2.2.1 Press out a straight-line trace on the black clearer; hold the neat end of the neatly arranged straight fiber bundle; fold the other end into a pen tip; use a clip to extract the fibers from long to short; arrange the fibers evenly on the black clearer along the straight line from left to right, where the fibers are required to be straight and parallel; use a measuring scale to measure the length of the fibers.

9.2.2.2 Regulations for grouping of fiber length: […]