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...

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...

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...

Regarding the importance of ring spinning method among spinning systems, great potentials exist for research about on the improvement of the quality and properties of ring spun yarn. This study aims to improve yarn quality by changing the shape and dimensions of spinning triangle through forming a groove in the middle zone of the front darfting &#10roller with a curvature of 5 to 7 mm. For the ...

Yarn quality is judged according to the achieved values of tested yarn properties that are selected in dependence on yarn utilization. Quality level of the yarns can be assessed using the USTER® STATISTICS [2]. This tool is composed of graphs enabling users to compare their measured results of yarn (sliver, roving, fiber) with the corresponding worldwide established fibrous product quality refe...

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...

We present a balanced method for realistic rendering of towels and carpets from a normal viewing distance. Since the yarn loops on the surface of a towel contribute more to the appearance of a towel than the underneath skeleton yarns do, we model yarn loops with more accurate geometry and lighting models. To show the randomness in the shape of a yarn loop, we control the shape of yarn loops by ...

This paper defines a PID type yarn tension control run by a PLC system that is used to control the yarn tension below the twisting head of the novel air jet texturing and twisting (AJT) machine. In the standard sequence of the AJT, if the yarn is transported to the twisting and winding head with a low tension value, the yarn is bound to wrap around the shoulder below the twisting head and break...

Relative performance of the back propagation neural network (BPN) algorithm combined with genetic algorithm (GA) approach for the prediction/optimization of the properties of yarn produced on jet ring spinning system has been studied. Yarn samples of various linear densities have been produced on ring spinning machines using air-jet nozzles as retrofit by varying the nozzle parameter and the ya...