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Sectional warping is the most widely used warp preparation process in weaving. Winding all warp sections with the same length and same tension is a key factor for a good quality warp preparation. It is required that winding thickness (increase in radius due to warp winding) remains the same within and between warp sections. The purpose of this paper is to investigate winding thickness variations within and between warp sections, which can lead to quality problems in woven fabrics.

A measurement system is developed and then an experimental investigation into winding thickness variations is carried out. Winding thickness is measured with respect to number of drum revolutions using a laser sensor with 20 microns resolution. The number of drum revolutions and drum angular position are measured by an incremental encoder. Both sensors are mounted on an industrial sectional warping machine. A real-time software written in C programming language collects and records the data for all sections of warp with respect to drum number of revolutions and then results are evaluated to determine winding thickness variations.

Results show that warp sheet thickness starts with a higher value and it decreases up to around 30 drum revolutions and then it remains constant or decreases very slightly which can be considered as insignificant from practical point of view. Warp sheet thickness (i.e. thickness of one warp layer) fluctuates within each section up to 10 percent CV with five drum revolutions average warp sheet thickness. There are also warp sheet thickness variations between warp sections up to 3 mm.

Considering the short of practical research results on winding thickness variations in the literature, results of this study will be an original contribution to understanding winding thickness variation level. Also, results presented in this paper can be used to develop control algorithms for thickness control in sectional warping machines.

Yarns of different types are unwound from bobbins in different processes like warping, weaving, doubling and re-winding. It is required that yarn tension remains constant during unwinding in all these processes. Otherwise, it ends with product quality and process efficiency problems. The purpose of this paper is to investigate experimentally the effect of balloon length on yarn tension change with respect to bobbin diameter during unwinding in an attempt to obtain a minimum yarn tension variation.

An experimental set up was built. Bobbin diameter was measured by a laser sensor and yarn tension was measured by a single yarn tension sensor. Both sensor outputs were interfaced to a PC via a DAQ cad. A software program was developed in C programming language to read and record the tension and bobbin diameter simultaneously. Experimental study was conducted with three different balloon lengths for both continuous filament and spun yarns of four different yarn numbers and five different unwinding speeds.

Results showed that yarn tension change with bobbin diameter was affected in different ways with balloon length depending on yarn number, unwinding speed and yarn type.

Available literature on the effect of balloon length on yarn tension bobbin diameter relation is limited and measurements were generally conducted for three different bobbin diameters. Yarn tension bobbin diameter relation is obtained in this research for at least eight different diameters and more for three different balloon lengths covering practical application ranges. The results obtained can be used in the design of tension control system for warping and winding machines as well as for setting these machines for optimum efficiency.

Examines the fourteenth published year of the ITCRR. Runs the whole gamut of textile innovation, research and testing, some of which investigates hitherto untouched aspects. Subjects discussed include cotton fabric processing, asbestos substitutes, textile adjuncts to cardiovascular surgery, wet textile processes, hand evaluation, nanotechnology, thermoplastic composites, robotic ironing, protective clothing (agricultural and industrial), ecological aspects of fibre properties – to name but a few! There would appear to be no limit to the future potential for textile applications.