Wool : 15 stereoscopic views

Project maps the history of wool in the Western Disrict region, using historic stereoscopic images documenting this history, obtained through searching archives in Geelong, Melbourne and internationally.

Feltability of cashmere and other rare animal fibres and the effects of nutrition and blending with wool on cashmere feltability

Felting is a unique attribute of animal fibres used for the production of a range of industrial and apparel textiles. Felting can be an adverse attribute as a consequence of dimensional shrinkage during laundering. As there is little objective information regarding the feltability of rare animal fibres or the factors which may affect felting three investigations were undertaken. A survey (n = 114) of the feltability of cashmere from different origins of production, cashgora, quivet, camel hair, llama, guanaco, bison wool, cow fibre and yak wool quantified the large variation between and within these fibre types. Cashmere from some origins and cashgora produced higher feltball density than the other fibres. Different nutritional management of cashmere goats (n = 35) showed that cashmere grown by poorly fed goats had a lower propensity to felt compared with cashmere grown by better fed goats. A consequence of the progressive blending of cashmere (n = 27) with a low propensity to felt superfine wool (high fibre curvature) increased the propensity of the blend to felt, but when the same cashmere was blended with low curvature superfine wool, there was little or no effect on feltability. The mechanisms which lead to variance in feltability of these fibres were quantified with multiple regression modelling. The mechanisms were similar to those reported for wools, namely variations in the resistance to compression, fibre curvature and mean fibre diameter, with likely effects of fibre crimp form. It is possible to source cashmere and other animal fibres which have different propensities to felt and therefore to produce textiles which are likely to have different textile properties.

Adapting ultrasonic assisted wool scouring for industrial application

Scouring is the first stage of wool processing and is essential for determining the quality of fiber. Traditional aqueous scouring is a method that emulsifies and removes contaminants (such as wool grease, suint, and dirt) from the fiber surface; however, it promotes wool felting and is energy and water intensive. This study has shown that modification of the traditional wool scouring line by introducing an ultrasonic device could be a viable alternative for the wool scouring industry. A standard six-bath wool scouring line was retrofitted with two ultrasonic panels working at 80 kHz in bath 2. Scouring was carried out in three modes: conventional mode without the transport rake, ultrasonic mode without the transport rake, and conventional mode with the transport rake. Fiber samples after scouring were measured for color index, residual grease content, and residual ash content. Ultrasonic scouring was found to improve removal of grease and ash from the wool fiber. Modifications were proposed for the design of an industrial scouring line including the addition of fiber transport and dunking rollers and number of baths for the installation. © The Author(s) 2014.

Photostability of wool fabrics coated with pure and modified TiO2 colloids

The surface of wool fabrics was coated with TiO2 and TiO2-based nanocomposite colloids and the impact of this coating on the photostability of wool was investigated. TiO2 along with TiO2/Metal and TiO2/Metal/SiO2 sols were synthesized through a low-temperature sol-gel method and applied to fabrics. Composite colloids were synthesized through integrating the silica and three noble metals of silver (Ag), gold (Au) and platinum (Pt) into the synthesis process of sols. Four different molar ratios of Metal to TiO2 (0.01%, 0.1%, 0.5% and 1%) were used to elucidate the role of metal type and amount on the obtained features. Photostability and UV protection features of fabrics were evaluated through measuring the photo-induced chemiluminescence (PICL), photoyellowing rate and ultraviolet protection factor (UPF) of fabrics. PICL and photoyellowing tests were carried out under UVA and UVC light sources, respectively. PICL profiles demonstrated that the presence of pure and modified TiO2 nanoparticles on fabrics reduced the intensity of PICL peak indicating a lower amount of polymer free radicals in coated wool, compared to that of pristine fabric. Moreover, a higher PICL peak intensity as well as photoyellowing rate was observed on fabrics coated with modified colloids in comparison with pure TiO2. The surface morphology of fabrics was further characterized using FESEM images.

Reducing photoyellowing of wool fabrics with silica coated ZnO nanoparticles

Though ZnO nanoparticles (NPs) are an excellent UV absorber, their photocatalytic activity greatly limits the application areas of these particles. Under sunlight exposure, ZnO NPs used as a UV absorber can accelerate the wool yellowing process by generating free radicals. To reduce this photocatalysis effect, a physical barrier has been fabricated by coating the ZnO NPs with a silica layer (ZnO@SiO2), hence providing good UV-shielding with low photocatalytic activity. The structure and optical properties of ZnO and ZnO@SiO2 NPs were characterized by transmission electron microscope (TEM) and UV–Vis spectrum. The photocatalytic activity of ZnO and ZnO@SiO2 NPs was evaluated by photo-degradation of Rhodamine B. The ZnO and ZnO@SiO2 NPs were applied to knitted wool fabrics using the dip coating method. The treated wool fabrics were characterized by a scanning electron microscope (SEM) and the photoyellowing level of treated fabrics after exposure under simulated sunlight was evaluated by a Datacolor Spectraflash spectrophotometer. The ZnO@SiO2 NPs demonstrated excellent protection of wool against photoyellowing.

Effects of site of assessment and variation in wool quality traits on the tactile assessment of textural greasy wool handle

Variation in textural greasy wool handle across the fleece of Merino sheep was explored. Results demonstrate that there were significant differences across nine sites on the fleece. The inclusion of the covariates fibre diameter, fibre diameter co-efficient of variation, staple length, dust penetration, staple structure, greasy wool colour and resistance to compression, helped to explain some of the variation in textural greasy wool handle between sites such that site of assessment was no longer a significant factor (P ≤ 0.065). However, in practice, those involved with clip preparation or sheep selection based on textural greasy wool handle assessment are unlikely to have these measurements available. The results highlight the importance of nominating a site of assessment when recording textural greasy wool handle. © CSIRO 2014.

Associations between the physiological basis of fabric-evoked prickle, fiber and yarn characteristics and the Wool ComfortMeter value

The association between the incidents counted by the measurement wire of the Wool ComfortMeter (WCM) and the previously published neurophysiological basis for fabric-evoked prickle have been investigated for lightweight knitted woolen fabrics. The fiber lengths and diameters capable of triggering the fabric-evoked prickle sensation were calculated using Euler’s buckling formula, and it is suggested that fibers as fine as 10 mm are capable of triggering the prickle response if they have a short enough free length protruding from the surface. Good agreement was found between the sensory assessed human prickle sensation and the wearer prickle response predicted using the WCM outputs, especially when the latter were transformed using Stevens’s Psychophysical Power Law.

Relationships between wearer assessment and the instrumental measurement of the handle and prickle of knitted wool fabrics

The relationships between wearer-assessed comfort and objectively measured comfort and handle parameters were investigated using 19 pure wool single jersey garments made of single ply yarns. Wearer trials were used to determine prickle discomfort, and whether wearers “liked” the garments. Fabrics then were objectively evaluated using the Wool HandleMeter, which measures seven primary handle attributes; and the Wool ComfortMeter (WCM), to predict a wearer's perception of fabric-evoked prickle. Wearer responses and the relationships within and between objective measurements and the effect of fibre, yarn and fabrics attributes were analysed by general linear modelling. Mean fibre diameter, fibre diameter coefficient of variation, yarn count, fabric thickness, fabric density, fabric mass per unit area and decatising affected one or more handle parameters. The best model for predicting wearer prickle discomfort accounted for 90.9% of the variance and included only terms for the WCM and WCM2. The WCM was a good predictor whereas mean fibre diameter was a poor predictor of whether wearers “liked” garments. Wearer assessment of prickle and whether or not wearers “liked” fabrics were independent of fabric handle assessment. The results indicate that the handle and comfort properties of lightweight, wool jersey fabrics can be quantified accurately using the Wool HandleMeter and the Wool ComfortMeter. For fabric handle, fibre and yarn characteristics were less important than changes in the properties of the fabric.

Improving the photostability of bleached wool without increasing its yellowness

Bleached wool is rapidly yellowed by exposure to the UV radiation present in sunlight. The conventional application of a water-soluble hydroxyphenyl benzotriazole UV absorber (such as UVFast W) to bleached wool reduces its rate of photoyellowing but has a negative impact on the whiteness of the bleached wool, largely cancelling out the improvements in whiteness achieved during bleaching. However, if the UV absorber is applied to peroxide-bleached wool from a reductive bleach bath, white wool with improved photostability to sunlight and UV radiation can be obtained.