รายละเอียดเอกสาร

This is a projection method (1) by which the weighted average fiber length of a pulp may be measured relatively quickly and easily.   If 1 is the length of any fiber in a sample of pulp, w its weight, and if N fibers are measured, their total length (1) being L, the numerical or arithmetical average length is 1/N or L/N; their weighted average length by length = (l 2 )  l and their weighted average length by weight (lw)/ w.   The numerical or arithmetical average fiber length of paper pulps is a not a commonly used value, since the pulps consist of whole tracheids and shorter elements down to submicroscopic lengths, which are included in the arithmetic fiber length and there tends to be a larger quantity of them as fiber length decreases. The stated average is especially meaningless if the least length arbitrarily adopted as the lower length limit for a "fiber" or particle is not also given. The shortest fibers contribute very little to the total measured length, but numerically they are just as important and influence the final result of an arithmetical average just as much as the longest fibers. ....