41--DIMENSIONAL PROPERTIES OF THE ALL-WOOL 1 x 1 RIB STRUCTURE.

A geometrical model of the smallest repeating unit or structural knitted cell (SKC) of the fully relaxed 1 x 1 rib structure is proposed. This model, based on an elastica configuration, suggests that the dimensions of the SKC are independent of the yam flexural rigidity and yarn-deformative forces but are dependent on the ratio of structural-cell stitch length (l_u) to yam diameter. Over the practical knitting range, however, this dependence is small. A series of four non-dimensional parameters, or u-values, is introduced to specify the dimensional properties of this structure. The average numerical values of these parameters are calculated. A comprehensive experimental analysis of fully relaxed 1 x 1 rib fabrics shows that the experimental w-values are close to those established theoretically. Full relaxation is obtained by tumble-drying the structures from a wet state for 1 hr at 70°C, this being followed by conditioning in a standard atmosphere. No felting is observed during this relaxation procedure. Empirical u-values of the fully relaxed state are found to be independent of most yam and machine variables. A small dependence on the machine-tightness factor (K) is noted, however. [ABSTRACT FROM AUTHOR]