Processing and quality of cashmere tops for ultra-fine wool worsted blend fabrics

This study has focussed on three main areas. First, an evaluation of the physical attributes of cashmere tops available to commercial spinners; second, the influence of processing variables on the efficiency of producing cashmere tops from raw Australian cashmere; and third, the influence of design of cashmere ultrafine wool blends on the fibre curvature of tops. Testing the physical attributes of cashmere tops from traditional and new sources of supply, was followed by statistical analyses based on factors of origin, processor and other determinants. The analyses demonstrated important processor effects and also that cashmere from different origins shows commercially important variations in fibre attributes. It was possible to efficiently produce Australian cashmere tops with Hauteur, tenacity, extension, softness and residual guard hairs quality attributes equivalent to those observed in the best cashmere tops. The blending of cashmere with wool resulted in a reduction of the mean fibre curvature of the blend compared with the unblended wool. The present work demonstrated that the fibre curvature properties of blended low crimp ultrafine wool tops were closer to the properties of pure cashmere tops than were tops made from blended standard high crimp ultrafine wool. The attributes of textiles made from the relatively rare Australian low curvature cashmere could enhance the marketability of both Australian cashmere and low curvature wool.

The effect of pH on wool fiber diameter and fabric dimensions

Wool fabrics are often treated under conditions of varying pH in dyeing and finishing processes. It is known that in air the dimensions of wool fabrics change with the amount of fiber swelling at different regain. In this work, it has been shown that a similar relationship between fiber swelling and fabric dimensions existed in water at different pH values. The diameters of Merino and Corriedale wool fibers in water at different pH values were measured with an OFDA 2000 fiber diameter analyzer, fitted with a specially constructed accessory liquid cell. The results showed that the mean diameters of swollen wool fibers in water varied with pH. Minimum swelling was obtained in the range pH 5-7. It was found that the dimensions of wool fabric in water were dependent on the pH. The changes in fiber diameter in water could be attributed to changes in ionic interactions between charged acid and basic groups in wool protein with variations in pH.

Process for the production of ultrafine powders

A process for the production of ultrafine powders consisting of individual particles with sizes in the range of 1 nm to 200 nm, which is based on the mechanical milling of two or more non-reacting powders. The process includes subjecting a suitable precursor metal compound and a non-reactant diluent phased to mechanical milling which through the process of mechanical activation reduces the microstructure of the mixture of the form of nano-sized grains of the metal compound uniformly dispersed in the diluent phase. Heat treating the milled powder converts the nano-sized grains of the precursor metal compound into a desired metal oxide phase. Alternatively, the precursor metal compound may itself be an oxide phase which has the requisite milling properties to form nanograins when milled with a diluent. An ultrafine powder is produced by removing the diluent phase such that nano-sized grains of the desired metal oxide phase are left behind. The process facilitates a significant degree of control over the particle size and size distribution of the particles in the ultrafine powder by controlling the parameters of mechanical activation and heat treatment.

Wear attributes of cashmere single jersey knitted fabrics blended with high and low crimp superfine merino wool

In a replicated experiment, we investigated the impact of cashmere in blends with superfine wools on the wear attributes of single jersey knitted fabrics. We also investigated the relative performance of low crimp/low fiber curvature superfine wool when compared with cashmere and also when compared with traditional high crimp/high fiber curvature superfine wool in pure and blended knitted fabrics. Wool type, blend ratio and fabric structure affected fabric air permeability, resistance to pilling and change in appearance, relaxation shrinkage, hygral expansion, and dimensional stability during laundering. The responses to variation in fiber crimp were much greater than previously reported. The fabric properties of low crimp wool differed significantly from those made from high crimp wool, and low crimp wool fabric properties differed significantly from, but were closer to, the fabric properties of cashmere, compared with high curvature wool.

Assessment of the pilling propensity of wool knitwear

This study addresses a major issue facing the wool industry - the formation of entangled fibres or pills on wool knitwear. By examining the factors that contribute to the inconsistent pilling results, ways of improving the test procedures have been identified. This will have practical implications for the textile industry.

Photochromic wool fabric by sol-gel coating

This thesis investigates the possibility of producing photochromic wool fabrics using a silica sol-gel coating method. Silicas made from sol-gel methods are uniquely suited to host photochromic dyes for developing colour-changing wool. The achieved photochromic effects have opened a new product area for fashion effects on wool textiles.

Controlling and predicting the pilling propensity of knitted wool fabrics

This thesis tackles an important quality issue in the wool industry - the pilling of wool knitwear. Through artificial neural network modelling, the important fibre, yarn and fabric attributes that affect fabric pilling have been identified. A predictive model on fabric pilling has been developed, which will assist the wool industry in the management and control of fabric pilling.

A study of dimensional changes in wool fibres and fabrics

Wool fabric dimensional properties were found to be influenced by the temperature and pH of the fabric, and on the fabric tension during pressure steaming. The results show that improvements can be made to standard methods for measuring fabric dimensional properties, and to the design of commercial finishing steaming equipment.