The torque in single-spun yarns is an inherent property of the twisting and bending of staple fibres during the formation of yarn combined with the effect of applied tension on the yarn. The consequences of yarn torque are well known and are widely observed as yarn instability, e.g., yarn rotation under tension; local snarling and entanglement at low loads, and as distortion in fabric, i.e., ed...

This paper presents a study to identify the type and location of yarn periodical errors applying three different signal processing approaches based on FFT – Fast Fourier Transform, FWHT-Fast Walsh-Hadamard Transform and FDFI – Fast Impulse Frequency Determination. The errors determination is applied for the mass measurement of yarn using a capacitive sensor and for the measurement of yarn diame...

The influence of dyeing and spinning on the characteristics of cotton fibers and its impact on the properties of cotton mélange yarn has been investigated. Grey cotton fibers with mean fiber length and fineness of 29 mm and 4.2 micronair were pre-treated and dyed. Three ring yarns were spun from 100 % grey cotton (R.R.Y), 50-50 % blend of dyed and grey cotton (M.R.Y) and 100 % dyed cotton fiber...

This paper reports a comparative study between yarn mass and yarn diameter measurement systems using a differential capacitance tester and an optical coherent signal processing diameter tester respectively. A full description of the systems is presented along with their new contributions, namely 1mm length samples analysis for a capacitive tester and optical signal processing to eliminate the i...

Ceramic Matrix Composites (CMC) are promising future materials for jet aircraft engines. CMC parts are produced by piling fabric layers made of silicon carbide yarn. To detect defects in the parts, this study proposes a computational method in which each piece of yarn is recognized from volumetric models obtained by X-ray CT scanning. The method produces a set of curves, each of which represent...

The impact of card cylinder speed, card production rate and draw frame doubling on cotton yarn quality parameters was investigated by using the BoxBehnken experimental design. It was found that yarn tenacity, elongation and hairiness increase by increasing the number of draw frame doubling up to a certain level and then decrease by further increase in doubling. Yarn unevenness increased by incr...

In this paper, the theory of the ballooning yarn has been adapted to the loop spinning process. The aim of a numerical simulation of high-speed winding process consists in establishing the shape of the curve of rotating yarn in the section between the gripping line of drafting motion rollers and the place where the yarn is wound upon a tube, and in determining the tensile force in the yarn in t...