The Dimensional Properties of Knitted Wool Fabrics

Abstract

Tumble-drying from the wet fabric state is shown to be a reasonable means of fully-relaxing rib structures. By this technique, an approximate discrimination can be made between dimensional changes due to relaxation and felting of allwool rib structures. Upon washing from the fully-relaxed state, untreated fabrics felt immediately due primarily to loop-length changes and not by changes in loop shape. Felting rates depend strongly on machine tightness factor (MTF) and to a lesser extent on fiber quality and yarn twist.To ensure machine washability of rib structures to within the limits of ± 8% area shrinkage and ± 5% linear shrinkage over 10 machine-wash and tumble-dry cycles, yarns must be treated against felting at a high level of treatment. Further dimensional changes in washing from the fully-relaxed state are due to residual relaxation and not felting. Occasional fabrics, particularly loosely knit structures, exceed these chosen shrinkage limits. To guarantee machine washability of rib structures, a fully-relaxing procedure of two cycles of wetting and tumble-drying is recommended.Under most conditions of relaxation and washing, the dimensional behavior of shrink-resist-treated rib structures is anisotropic, i.e., length shrinkages are generally associated with width expansion. A possible reason for this behavior is presented in this paper.

New weft knitting process: Morphological, physical and mechanical characterisation of the innovative knitted fabrics

“…The cover factor of a structure made with several yarns knitted in one fabric is as follows, adapted from Knapton and Fong 13 :…”

“…As regarding literature 13 our cover factors are very high because, we have several yarns and we consider each yarn as a layer.…”

The Dimensional Properties of Knitted Wool Fabrics

“…The general relaxation behavior of double-knit wool structures appears to be no different from that of the simpler structures [7,8]. Less information on the effects of specific fiber and yarn variables on doubleknit fabric dimensional behavior is currently available, but the limited studies so far published indicate that the shape of the structural knit-cell of relaxed double-knit wool fabric structures appears fixed and largely independent of K. Certainly, once these fabrics are in their completely-relaxed condition, Munden's classical geometry equations can once again be used to approximately predetermine their dimensions (7~.…”