The Measurement of the Uniformity of Spaces between Dents in Loom Reeds

Abstract

Variations in dent spacing give variations in the spacing of warp yarns with the result that visible streaks sometimes occur in the fabric. To determine the maximum deviation of the dent spacing that can he allowed without causing visible warp streaks in a given fabric, a photometric measuring instrument has been designed. and with this instrument individual spaces between the dents are registered as bars on a photographic film. In evaluating the irregularity of dent spacing from the shadow patterns of reed gratings (equidistant, parallel-lined glass plates) on reeds, these patterns have been photographed and then graded according to the correlation observed between the number of warp streaks and the photometric variation of dent spaces. In order to determine the quality of a reed quickly and simply in a mill. reed gratings are recommended to obtain patterns from the reeds in question for comparison with the set of standard graded photographic patterns.