Tension Control In Narrow Fabric Weaving

The textile industry has had a revival in the last few years thanks to the increased use of composites. Composites are made by infusing fabric webbings with thermoset resins. The fabrics are made by interlacing high tensile advanced fibres. Advanced fibres are man-made fibres designed for high performance in demanding environments. The webbings are formed by using three different methods of interlacing: weaving, braiding and knitting. All of these techniques require a degree of yarn tension control for a good quality fabric because advanced fibres are easily damaged by excessive yarn tension. The cause of the sensitivity of advanced fibres to tension is their low extension. Textile industry standard yarns have extensions of 5% or above while advanced fibres have an extension lower than 5%. The textile machinery available on the market at reasonable prices is used to weave advanced fibres which have been designed to work with textile standard yarns. This machinery can be modified to weave advanced fibre with substantially improved results but this requires a significant knowledge of the machines and requirements of the advanced fibres. The modifications would influence the yarn tension as it enters the machines and runs through the machine. This research aim is to generate brake weight charts to regulate yarn tension and optimise narrow fabric weaving; as a consequence manufacturing traceability will also be optimised. The brake weight charts will be derived by measuring and modelling various parameters like yarn tension, yarn friction, yarn crimp and yarn damage. The yarn tensioning devices analysed were warp beams braked by a hanging cord with weights. The braking force was increased by increasing the weights. This is typical of industrial machinery. Calculations show that, as the yarn wrapped on the warp beam decreases with time, the yarn tension increases. In practice a skilled weaver will reduce the brake weight as time progresses until the yarn on the warp beam is finished. However, this skill is developed experientially with little theoretical information to help optimize the weave. To assist in weave optimization a tension control a graph showing time against weight has been developed. A further tool to control yarn tension is the use of the ellipsoidal heddles set up. This is a new method developed in this research to setup heddles to ensure same yarn tension across the shed. This thesis shows that fabrics are constructed with multiple weave and each weave needs a particular length of yarn for the same fabric length. This finding show that each weaves needs its own tension device set at a particular tension. Maintaining correct tensions is a significant challenge for even the most skilled weavers, particularly when weaving advanced fibres. This thesis provides knowledge required to undertake yarn tension optimisation considering yarn tension, yarn crimp and coefficient of friction.

Name dc:type.qualificationname

PhD

Level dc:type.qualificationlevel

Doctoral

Grantor dc:publisher.institution

De Montfort University

Year dc:date.issued

2016

Author dc:creator

• Silva, Christopher Ugo

Licence

• https://dora.dmu.ac.uk/bitstreams/46928db1-862d-4814-951a-641bdb41f445/download