Filament fibres yarn processing

Functional fibres, filaments and yams are the basic building blocks of electrotextiles. The textile industry has demonstrated a remarkable capability to incorporate both natural and man-made filaments into yarns and fabrics to satisfy a wide range of physical parameters which survive the manufacturing process and are tailored to specific application environments. Electronic components can be fabricated within and/or on the surface of filaments and can subsequently be processed into functional yams and woven into fabrics. Passive components such as resistors, capacitors and inductors can be fabricated in several different manners. Diodes and transistors can be made on long, thin, flat strands of silicon or formed in a coaxial way. Progress has been made in the development of fibre batteries and fibre-based solar cells. In addition, a variety of actuated materials (piezoelectric, etc.) can be made into multiple long strands (filaments) and subsequently be woven into fabric. 

The influence of the intrinsic polymer properties on the yam bulkiness is relatively small (low density and high stiffness are favourable) in contrast with that of the fibre, yarn and cloth constructions. Hence the significance of texturing (crimping) processes, which impart a greater bulkiness (crimp) to the compact filament yam. 

Weibull plots of various fibre properties, such as the filament count, modulus, elongation at break and the strength, can provide important information on the quality and performance of the manufacturing process. The results can be used to formulate a strategy for the improvement of the yarn properties. 

Basic yarn components along with conventional filaments/yarns constitute the feedstock of the weaving process. Selectively fed into a loom and manipulated through an advanced textile manufacturing process, this feedstock can be woven into a complex variety of designs that result in a structurally sound, environmentally compatible fabric that provides electrical and mechanical functionality. Electronic circuits can be formed from the selective interconnection of fibre components during the weaving process. 

The dimensional stabUity of synthetic yarns and textiles can be considerably enhanced by a thermosetting process, i.e. heat treatment under dry heat, steam or hot water. Thermosetting may be undertaken either with or without applied tension. Thermally treated filament yarns and staple fibres show less heat shrinkage, have a reduced tendency to crimp and show improved recovery from creasing. 

PO materials look increasingly set to enter some important new markets just as the number of established end-uses has begun to mature. The technologies for the production of high tenacity yarns and the high speed extrusion of relatively fine PP fibres and filaments, as well as nonwoven processes such as melt blowing, create opportunities for further development and exploitation of the many valuable properties of these and related classes of materials [39, 115, 131, 767-777]. 

---