Abstract
In view of the mechanical approach for the roller drafting, the problem of the unsteady motion of the fibers, which is most important to analyse the drafting wave or the irregularity of the sliver, has been taken up. The main part of this paper is devoted to explain the relation between the irregularity of the sliver before drafting and the one after drafting by taking the simple case. Consequently, the author has shown that the irregularity after drafting depends on the wave length of the irregularity before drafting and the draft ratio. Besides it has been explained that the distribution function, which was used in the steady roller drafting, ρ(x), plays an important role on the analysis of the irregularity, The practical considerations will be presented in detail in the subrequent issue of the periodical.
