Investigation of post-spinning yarn engineering

Investigates a novel post-spinning yarn engineering technique, using the original concept of drafting-against-untwisting, to produce fine yarns with improved properties such as hairiness. With this concept, a "parent" staple yarn is simultaneously "false" untwisted and drafted to make a much finer yarn, in a continuous process.

Variation of mohair staple length across Angora goat fleeces : implications for animal selection and fleece evaluation

The present study aimed to determine how the average mohair staple length (SL) differences between nine sampling sites vary between sex and flock, to identify differences in SL variability between sampling sites as a result of between-animal and between-sire variability and to determine SL correlations between sampling sites in between-animal and between-sire variability. Australian Angora goats (n=301) from two farms in southern Australia were sampled at 12 and 18 months of age at nine sites (mid side, belly, brisket, hind flank, hip, hock, mid back, neck and shoulder). Staples were taken prior to shearing at skin level and stretched SL determined. For each shearing, differences in SL between sampling sites, how these differences were affected by farm, sex and sire, and the covariance between sites for sire and individual animal effects were investigated by restricted maximum likelihood (REML) analyses. The median mid-side SL at 12 and 18 months of age was 110 and 130 mm, respectively, but the actual range in mid-side SL was 65–165 mm. There was an anterior–posterior decline in SL with the hock being particularly short. There was no evidence that the between-site correlation of the sire effects differed from 1, indicating that genetic selection for SL at one site will be reflected in SL over the whole fleece. However, low heritabilities of SL at the hock, belly and brisket or at any site at 12 months of age were obtained. There was more variability between sites than between sires, but the between-animal variation was greater. The hip and mid-back sites can be recommended for within-flock (culling) and genetic selection for SL due to their low sampling variability, moderate heritability and ease of location.

Recent developments in electrospinning of nanofibers and nanofiber yarns

Electropsipinning is a simple, but efficient and versatile, technology to produce polymeric nanofibers for diverse applications in both textile and non-textile areas. In this paper, recent research developments in electrospinning and electrospun nanofibers, especially thaose from the Centre for Material and Fiber Innovation, Deakin University, are introduced. Important findings on needleless mass-electrospinning and direct electrospinning of highly-twisted continuous manfiber yarns are presented.

Production and characterisation of nanofibre yarns and composites

This thesis propsed a novel method to produce and characterise nanofibre yarns and composites.  It contributed to the fundamental research in the field of nanofibre yarns.

Needleless electrospinning and direct electrospinning of nanofiber yarns

Electrospinning is a simple, but efficient and versatile, technology to produce polymeric nanofibers for widely diverse applications in both textile and non-textile areas [1]. This technique has been shown many advantages such as universality in processing polymeric materials, eases of controlling the fiber diameter and functionalizing nanofibers through adjusting solution composition for electrospinning, and flexibility to generate fibrous membranes of various geometries. Although the novel applications of electrospun nanofibers have been extensively explored [2], the technology development for mass electrospinning of nanofibers has been hampered.

Electrospinning of continuous nanofiber bundles and twisted nanofiber yarns

Spinning is a prehistoric technology in which endless filaments, shorter fibers or twisted fibers are put together to produce yarns that serve as key element to assemble multifarious structural designs for diverse functions. Electrospinning has been regarded as the most effective and versatile technology to produce nanofibers with controlled fiber morphology, dimension and functional components from various polymeric materials (Dersch et al., 2007, Frenot and Chronakis, 2003, Schreuder-Gibson et al., 2002). However, most electrospun fibers are produced in the form of randomly-oriented nonwoven fiber mats (Doshi and Reneker, 1995, Madhavamoorthi, 2005). The relatively low mechanical strength and difficulty in tailoring the fibrous structure have restricted their applications. With the rapid development in nanoscience and nanotechnology, yarns composed of nanofibers may uncover new opportunities for development of well-defined three dimensional nano fibrous architectures. This chapter focuses on recent research and advancement in electrospinning of nanofiber bundles and nanofiber yarns. The preparation, morphology, mechanical properties and potential applications of these fibrous materials are discussed in details.

Mechanical behavior of nano-micro composite core spun yarns

Strip twisted electrospun nanofiber yarns: Structural effects on tensile properties

Nanofiber yarns with controlled twist levels were prepared by twisting a narrow fibrous strip cut directly from electrospun nanofiber mats. The effects of fiber morphology, diameter and orientation, as well as the yarn twist level on the yarn tensile properties were examined. For the yarns made from randomly oriented fine uniform nanofibers (e.g., diameter 359 nm) and beaded nanofibers, the tensile strength increased with increasing the yarn twist level. Higher fiber diameter (e.g., 634 nm) led to the tensile strength having an initial increase and then decrease trend. The modulus increased with the twist level for all the yarns studied. However, the elongation at break increased initially with the twist level and subsequently decreased. The orientation of aligned fibers within the fiber strip greatly influenced the yarn tensile properties. When the fibers were oriented along the fiber length direction, both tensile strength and modulus were the largest.

Improving fiber trapping with a contact surface during the ring twisting of two cotton yarns

In this study, a geometrical model was introduced to improve the hair trapping via a surface contacting the yarn-twisting triangle during ring twisting of two single yarns. The fiber-trapping improvement with the contact surface was analyzed theoretically. Then, single Ne 80 ring cotton yarns were used to produce two-ply yarns under different ring-twisting conditions, namely conventional twisting, dry twisting of yarns with a plane surface, wet twisting of yarns with a plane surface, dry twisting of yarns with a grooved surface, and wet twisting of yarns with a grooved surface. Plied yarn properties, including yarn hairiness, strength, and irregularity, were tested. The Student Newman Keuls (SNK) test and variation analysis were also carried out in the SPSS program to study the effect of different contact surfaces on related yarn properties; the significance level was 0.05 for the SNK test and variation analysis. The hairiness of plied yarns was significantly reduced when twisting with the plane or grooved surface, especially for the wet twisting cases. This corresponds well with our model on improving fiber trapping.