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 physical and dimensional characteristics, i.e. course wale spacing, stitch density, tightness factor, diameter, porosity, stability bursting strength of single jersey knitted items containing lycra yarn with the variations in length content have been examined a detail investigation on filament has discussed this study. Six different samples were identical cotton but contents length. After c...

A model for the strength of pure carbon nanotube (CNT) fibers is derived and parametrized using experimental data and computational simulations. The model points to the parameters of the subunits that must be optimized in order to produce improvements in the strength of the macroscopic CNT fiber, primarily nanotube length and shear strength between CNTs. Fractography analysis of the CNT fibers ...

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...