EFFECT OF TIGHTNESS FACTOR ON LOOP GEOMETRICAL STRUCTURE OF SINGLE FABRIC KNITTED ON FLAT WEFT KNITTING MACHINES

Abstract

Tightness factor, which is defined as the ratio of looplength to yarn diameter, is an important
technological parameter in knitting production because it has strong impact on fabric structure and
properties. This work aimed to investigate the effect of tightness factor on the wale spacing, course
spacing and the suitable geometrical loop model for single fabric knitted on flat weft knitting
machines. Two groups of fabric sample were used: the single fabric knitted on manual V-bed
machine from acrylic yarn Nm26/2x2 with seven levels of tightness factor (22.8, 24.6, 25.9, 26.3,
28.5, 30.4 and 32.0); the single fabric knitted on automatic V-bed machine from acrylic/cotton yarn
Ne28/2x2 with five levels of tightness factor (16.5, 17.2, 18.0, 19.1 and 20.1). The results showed
that when tightness factor increased, both the wale spacing and course spacing increased. The
loop with tightness factor in range of 22.8 to 32.0 was in good fit with loop model proposed by
Dalidovich, which included the loop leg incline. The loop with tightness factor in range of 16.5 to
20.1 was quite similar to the model proposed by Pierce.