The effect of descaling process on the properties of wool fibers

Wool is one of the important fibres in the textile industry, however, it has some technical problems such as felting shrinkage and wettability. Such problems are mainly due to the presence of wool scales on the fibre surface. Therefore, this thesis aims at the studying the removal of the wool scales with the following objectives: (1) To compare the existing commercial/laboratory methods and evaluate the descaling effect on the properties of wool fibre by instrumental and analytical techniques, (2) To improve the existing methods by means of both physical and chemical techniques so as to suit the commercial uses, (3) To study the mechanism of descaling processes and compare the change in physico-chemical properties of the descaled wool, and (4) To optimise the selected descaling methods by experimental design for technology development and quality improvement in the wool industry.; In order to fulfil the objectives, different descaling methods were firstly reviewed (Chapter 2) and only four descaling methods namely (i) potassium permanganate in saturated salt solution treatment, (ii) sodium metabisulphite treatment, (iii) Basolan DC (chlorination)/Basolan Micro MW treatment (polymer deposition) combined treatment and (iv) low temperature plasma (LTP) treatment were studied thoroughly (Chapter 3). The wool fibres treated by these methods were assessed by two parameters which were fibre damage and feltability in order to determine their optimum experimental condition.; It was found that low temperature plasma treatment showed the best modification effect among the other treatments. Three non-polymerising gases ware used for the plasma treatment but their influence on the properties of wool fibre were different. The properties studied included the following aspects: (i) dyeing (Chapter 4), (ii) felting and shrinkage (Chapter 5), (iii) physico-chemical (Chapter 6) and (iv) performance, comfort (Chapter 7) and aesthetic (Chapter 7).; The dyeing properties of the UP treated wool fibres were significantly altered and the results of different dyeing properties obtained largely depended on the nature of the plasma gas used. In addition, the felting and shrinkage properties of wool were greatly unproved after the LTP treatment.; The study of physico-chemical properties provides a fundamental information on the surface behaviour of the wool fibre after LTP treatment. The changes in these properties will affect the wettability of the wool fibre to various extents depending on the nature of plasma gas used.; Fabric properties including performance, comfort and aesthetic properties were altered after LTP treatment but the extent of change was affected mainly by the nature of various plasma gas used.; Besides the study of properties, the chemical and physical compositions of the UP treated wool were also investigated (Chapter 8). The results show that the compositions of the wool fibre changed differently depending very much on the nature of plasma gas used. The chemical and physical composition study provided a fundamental information and molecular explanation about the effect of UP treatment on different properties of the wool fibre.; The surface feature of wool treated with different UP gases at various durations was examined by SEM (Chapter 9), and the morphological changes were found to be varied with the nature of plasma gas used.; Combined UP treatment and chemical methods (chlorination and polymer deposition) were also used for descaling wool fibre. The effectiveness of chemical, physical and their combined treatments on the wool fibre was investigated and compared.;...