The anomalous behaviour of polyamide 6.6 fibres textured by false twist to different physico-chemical techniques (as the critical dissolution time, CDT), compared with those obtained in polyester fibres, was attributed to a cracking of the. surface and/or to an increase in fibre porosity. This cracking appears when original fibre is treated at high temperature and it is due to the breakage of the skin/core structure of polyamide 6.6. This cracking has been demonstrated by the determination of drying kinetics in a thermogravimetric test that has been developed for this fibre
Knitted wool and wool/nylon blend dyed fabrics were treated with low temperature plasma (LTP) to achieve optimum shrink-resistance without impairing surface topography, colour or fastness to washing of the fabrics. As LTP tends to impair handle of the fabrics, both wool and wool/nylon blend fabrics were submitted to industrial softening and/or biopolymer treatments after LTP treatment, leading to hydrophilic wool and wool/nylon blend fabrics with improved shrink-resistance without any colour changes and good fastness to washing. The results obtained were compared with those obtained by
an industrial shrink-resist treatment.