A New Photoelectric Device for the Measurement of Yarn Diameter and Yarn Evenness. Part II: The Measurement of Yarn Diameter and the Effect of Shape-error Factor (SEF) on the Measurement of Yarn Evenness

Abstract

The objective of this paper is to introduce a new method for yam-diameter and yarn-evenness measurement. The relationship between the diameter of a yarn with a circular cross-section and the output voltage of a sensor device is first derived. The yarn cross-section is then analyzed and the ellipticity of its best-fit ellipse calculated according to the actual yarn cross-section. A sensor device with two incident heams of light perpendicular to each other is described. It was adopted for yarn-diameter measurement with an elliptical cross-section. Finally, a shapeerror factor (SEF) in terms of the yarn cross-section is defined in order to improve the measurement of yarn evenness.The results show that the cross-sections of ring-spun and open-end-spun (O.E.) yarns are near to an ellipse and have an irregular outline. The ellipticities of the best-fit ellipses for ring-spun and O.E. yarn are 1.09 and 1.07, respectively. If a sensor device possesses one incident light beam, the measurement errors of yarn diameter of ring-spun and O.E. yarns are 2.43% and 2.23%, respectively. However, if a sensor device possesses two incident light beams, the measurement errors of yarn diameter of ring-spun and O.E. yarns can be reduced to 0.47% and 0.43%, respectively. Moreover, the shape-error factors (SEF) of ring-spun and O.E. yarns are 3.56 and 2.87, respectively. When the SEF is adopted, it is shown that the measurement of yarn evenness is effectively improved.

Measurement of eccentricity and twist in spun and plied yarns

“…Substituting Equation (9) into Equation (8) yields the following result given in Tsai and Chu (1996) …”

“…With recent advances in image processing, researchers (Cybulska, 1999;Tsai and Chu, 1996;Xu et al, 1993) were able to describe yarn structure more accurately. It was shown in Tsai and Chu (1996) that the cross-section of ring-spun and open-end (OE) yarns can be approximated as an ellipse, even though the actual shape may have an irregular outline.…”

Analysis of the transverse compressive behavior of cotton yarns and fabrics

“…Ring and rotor-spun fibers have an ellipse flattening ratio and are closer to ellipses. 14,15 The yarn used in weaving processes is typically stretched, curved, and flattened; the majority of methods categorized the yarn's cross-sectional shape as circular, and elliptical, and assumed that it had a constant cross-section. 16 This led to variations in the cross-sectional shape of the yarn depending on the types of fabrics and yarns used in the design.…”

Yarn Diameter Characterization Using Two Orthogonal Directions

“…7,8 The most commonly used modules are the diameter module of Uster Quantum-2, 9 the diameter module of Uster Tester 5, 10 and the Oasys from Zweigle. 7,8 The most commonly used modules are the diameter module of Uster Quantum-2, 9 the diameter module of Uster Tester 5, 10 and the Oasys from Zweigle.…”

“…Nowadays, to quantify diameter variations, commercial systems generally use optical methodologies. 7,8 The most commonly used modules are the diameter module of Uster Quantum-2, 9 the diameter module of Uster Tester 5, 10 and the Oasys from Zweigle. 11 These systems characterize the diameter of yarn by measuring the quantity of light from a red/green source blocked by the yarn.…”