Felting Shrinkage of Plain-Knitted Wool Fabrics

Abstract

The dependence of felting shrinkage rate upon yarn count, cover factor, shrink proofing level, and severity of washing action has been examined, using plain-knitted wool fabrics. The investigation was a factorial arrangement with 54 combinations of factors for each of two shrink-proofing treatments. The results were subjected to analyses of variance. The felting shrinkage rate was lowered by increasing the cover factor, by increasing the level of shrinkproofing treatment, and by decreasing the severity of washing. Samples made from fine yarn shrank at a lower rate than those of heavier count. There were two significant interactions between the factors for each set of data. These showed that (i) the shrinkage rates of the fabrics made from the fine yarns were more sensitive to change of cover factor than were those of the coarser yams, and (ii) an increased level of shrinkproofing treatment increased the sensitivity of the samples to the severity of the mechanical agitation during washing. The results may be used for predicting shrinkage rates in knitted fabrics. An example is given.

Knitted Wool Fabrics of Different Structures: Tightness and Felting Shrinkage

“…Felting shrinkage is dependent upon a large num= ber of factors, the most critical associated with the fabric structure being the &dquo;cover factor.&dquo; Some recent results [1] reveal the dependence of felting shrinkage rates upon cover factor for plain-knit fabrics; similar results have been reported by other authors. From these and other unpublished data, it can be shown that this relationship is described satisfactorily by the equation where R is area shrinkage rate, c is cover factor, and A and B are constants.…”

“…Two washes were done in an agitator machine having a stationary drum and a central vertical agitator, oscillating at 60 c/min. Other details of this test have been described previously [1]. The third was carried out in a &dquo;Cubex&dquo; machine, the details of which have also been described [2], but the liquor level was altered to 10 liters, greatly increasing the severity of the wash action.…”

“…,~~rnplete shrinkage-time curves were obtained for each fabric, and the slope of each curve was extracted, as reported previously [1]. The felting shrinkage rates for the six fabrics are shown in Table I ; those for the agitator are the averages for the first two runs, individual values of which did not differ for each pair by more than 10%.…”

Relaxation Shrinkage of Worsted Yarns

“…The details of the wash conditions have been given , previously [2]. , The reference dimensions from which length and width changes of the samples were calculated were those of the wet-relaxed state.…”

“…Single fibers may affect and control filtration performance through their geometric properties, surface finish, electrical properties, hardness, and other mechanical properties. The mechanism of capture of a particle by a single fiber has received the attention of many workers, who have examined the role of diameter [2][3][4], shape ES, 6J, surface [7,8], modulus [9], and hardness [9], as well as the ambient relative humidity (10) and the electrical charge on the fiber [11]. When a gas stream is passed through a filter medium, there are three basic mechanisms of particle capture: direct interception,…”