The plain-knitted structure is shown to be a rationally determinate structure only in the fully-relaxed state; in any other state, the nature of the knitted loop is dependent on the yarn's physical properties, mechanical processing, and knitting variables. The fully-relaxed state is only found after the fabrics have been thoroughly wetted-out, briefly hydroextracted, and tumble-dried. In this state, the K(1-4) values are constant and predictable and independent of yarn or machine variables. In any other fabric state, values of K (1-4) may vary considerably and have little commercial value. Fabric thickness is shown to be independent of loop length and dependent only on yarn diameter in the fully-relaxed state only.

Experimental evidence confirms the existence of a fixed knit-cell configuration of completely-relaxed weft-knitted wool fabrics. In this fabric condition, achieved after considerable mechanical agitation in the presence of water, the k or u parameters are constant and independent of the tightness factor. Fabric dimensions, therefore, are governed largely by loop length, as predicted by Munden, but a small effect of fiber quality (fineness) on the completely-relaxed mean values of the k or u is found.Theoretical models of the knitted loop configuration, designed basically for idealized yarns, predict only approximately the observed dimensional behavior of weft-knitted wool fabrics.

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The 1×1 rib and half-cardigan structures, like the plain-knitted structure, are shown to be rationally determinate structures only in the fully-relaxed state; in any other state, their dimensional behavior is dependent on the yarn's physical properties and previous knitting and wet-finishing history. The fully-relaxed state is reached only after the fabrics have been thoroughly wetted-out, hydroextracted, and tumble-dried for 1 hr at 70°C. In this state, the courses and ribs per in. of the 1×1 structure are directly proportional to 1/ L, as predicted by Munden's original theory for the plain-knitted structure, but this theory does not account for the complete dimensional behavior of this structure, as K1 is not strictly a constant. However, K 4 is a constant at 1.76±0.15 and independent of both loop length and yarn count. For the 2X2 rib, no true dimensional stable state is found with wet relaxation and tumble-drying.

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