Comparative Evaluation of Yarn Hairiness by Different Methods

In this study, 1.4 denier and 32 mm of fiber-length polyester and 30.2 mm fiber-length cotton (4.35 micronaire) rovings of 695 tex (αtex = 10.7) were blended with different polyester/cotton ratios (i.e. 17/83, 33/67, 50/50, 67/33, and 83/17). The yarns were produced at a spindle speed of 11,000 rev/min with a 42 mm ring diameter, where C-type half round travelers of 85 and 95 mg were employed in ring frames. The resulting 36 tex (αtex = 37.5) yarns were examined by measuring their tensile strength, elongation, count, twist, evenness, and hairiness. Then the yarns were knitted into fabrics to observe and evaluate pilling performance. The observations based on scanning electron microscope (SEM) images were concluded both on the hairiness and pilling values, depending on the blend proportions. Among the yarns produced, the best hairiness with the traveler of 95 mg weight was obtained from the blend yarn with a polyester/cotton ratio of 33/67 and the best pilling parameter was accrued from the knitted fabrics with a polyester/cotton ratio of 83/17.

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confidence: 99%

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confidence: 99%

Studies on Yarn Hairiness of Polyester/Cotton Blended Ring-Spun Yarns Made from Different Blend Ratios

Canoğlu

Tanir

2009

“…The amount of yarn hairiness decreased exponentially as their length increased. 23 Figure 7 shows that yarns spun by the grooved devices had a significant hairiness reduction after comparion with normal siro-spun yarn (Appendix I). This indicated that the friction in the grooves led to relative movements between the hairs and yarn body, then hairs were controlled, stretched and finally re-wrapped onto the yarn stem during the yarn formation process.…”

Section: Hairiness Comparison Of Yarns Spun With and Without A Rotarymentioning

confidence: 99%

Comparative study of ring yarn properties spun with static and rotary grooved contact surfaces

Liu

Chen

et al. 2017

Spinning with a static contact surface is an energy-saving method to reduce spun yarn hairiness; however, the spun yarn irregularity and tensile properties are deteriorated. To prohibit the deteriorations, this paper introduces a rotary grooved surface contacting ring spinning strand within the yarn formation zone. In theory, the modeling analysis of spinning with contact surface is conducted to reveal the prohibition mechanism of yarn irregularity and tensile property deteriorations for a rotary grooved surface. Theoretical analysis results indicated that groove-yarn surface friction could wrap the concentrated hairs onto yarn stem while block inflowing twists to the spinning strangle zone; the rotary grooved surface could reduce twist blockage and hair wrapping concentrations to better the situation after a comparison with the static grooved surface. Then, two kinds of specially-designed grooved cylinders (one was rotatable while the other was static) were used to validate the theoretical analysis. The experimental results showed that, unlike the static grooved cylinder which significantly deteriorated the original yarn unevenness CVm, the rotary achieved significant hairiness reduction without any significant deterioration of other yarn properties. This might be due to the decreased friction and twist propagation for the rotary grooved cylinder contacting the spinning strand. In this case, spinning with a rotary grooved cylinder was preferably applied in the first step to control ring spun yarn hairiness.

“…1,2 Since the yarn hairiness has a great impact on end-use products, methods for measuring yarn hairiness have been widely studied and developed. [3][4][5][6] Of these methods, optical measurements are the most common for evaluation of yarn hairiness, which can be grouped into two categories: number-based and length-based statistics. For number-based statistics, the numbers of hair fibers in lengths of 1-9 mm, that is, the distribution of hairiness lengths, are used to measure yarn hairiness; the length-based statistics counts the total length of protruding fibers over 10 mm, that is, the H index of hairiness.…”

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confidence: 99%

Analysis of detectable angles of yarn hairiness in optical measurements

Sun

Pan

Zhou

et al. 2016

Obstructed by the yarn core, the detectable length and the detection rate of a hairy fiber are mainly determined by the geometry of the yarn and the location of the fiber in an optical system. This paper presents a new theoretical method of analyzing detectable angles of yarn hairiness in optical measurements. Firstly, a cylindrical model of the yarn core is constructed by using the yarn diameter, and spiral lines on the cylinder are drawn using the twist angle of the yarn. Secondly, hairy fibers are simulated by short-line segments passing a spiral line and the Z-axis of the model. The yarn model is projected onto a plane under the assumption of a collimated light source, which is the condition similar to that of optical measurements. The yarn model is cut by a plane parallel to the axes of the Cartesian coordinate system ( XOY) at the emergence points of hairy fibers. Finally, the relationship between the hairiness length and other factors, such as the test length, yarn diameter and detectable angle (i.e. the angle at which hairy fiber can be detected) is established. It has been demonstrated that the detection angle dictates not only the length of each hairiness but also the rate of detectable hairiness in the scene. Given a detectable angle, the upper and lower limits of detectable hairiness lengths can be predicted. The verification results of the detection rate by three measurement methods indicate that the detection rates of optical measurements have a certain guidance function for correcting the hairiness results of optical measurements.