Simulation on fiber random arrangement in the yarn

Self Cite

Random fiber arrangement in slivers is the direct and intuitive factor resulting in sliver limit irregularity. In this study, by simulating the fiber arrangement in slivers, the effect of fiber configuration on sliver limit irregularity is investigated. The tracer fiber technique was employed to ascertain fiber straightness and the incidence of different fiber configurations in carded slivers. It is observed from the results that the majority of fibers are hooked in the carded sliver. It is fiber straightness rather than hook type that affects the sliver limit irregularity more; with the increase of fiber straightness, the sliver limit irregularity decreased. In addition, the simulation proposed in this study can not only portray fiber arrangement in slivers more practically, but also present sliver limit irregularity more accurately compared with the method mentioned in previous studies.

“…The detailed process of generating fiber left ends in a given sliver segment was the same as the method for straight fibers described by Jiang et al. 13…”

Section: Methodsmentioning

confidence: 99%

“…11,12 and Jiang et al. 13,14 built random-yarn models by Monte Carlo methods that can reflect how fibers arrange in a yarn directly and present the relationship between sliver limit irregularity and fiber characters.…”

mentioning

confidence: 99%

A study of fiber configuration in sliver fiber arrangement and its influence on sliver limit irregularity

Yang

Shen

Zhang

2019

Self Cite

“…Referring to Figure 1, the fiber arrangements of before, during and after drafting are described by the model of fiber arrangement. Firstly, the fiber arrangement in the sliver before the drafting process is provided when the nip line of the back roller is defined as the coordinate origin (0) along the sliver axis by the method of Jiang et al 20 Fibers are randomly distributed in a sliver with a given length based on Uniform Distribution. 21 The theory that the number of fiber heads in a given sliver segment submitted to Poisson Distribution has been proposed and applied in many researches.…”

Section: Modelingmentioning

confidence: 99%

Modeling fiber arrangement and distribution during the roller drafting process

Sun

Yang

2019

Self Cite

During the spinning process, the roller drafting operation plays a significant role in attenuating the sliver to an appropriate linear density. In this study, the model of fiber arrangement was applied to simulating the roller drafting process in order to shed light on the sliver dynamic behavior in the drafting zone. The drafting process was operated from the high-velocity motion of the first accelerated fiber to the high-velocity motion of the last accelerated fiber. The proposed model showed that the simulated sliver attenuation processes were highly corresponded to the actual sliver attenuation results. In addition, the results revealed that the draft ratio, gauge length, input sliver linear density and accelerated-point distribution form had effective influences on the attenuation curves of sliver linear density, whilst the delivery speed scarcely had any effect. The fiber distributions of various forms were also investigated specifically and quantitatively from the fiber arrangement during the drafting procedure in real time. Furthermore, the sliver dynamic was also described by the mean and CV of fiber velocities within the drafting zone. The obtained simulation results demonstrated that the draft ratio, gauge length and delivery speed had a bearing on the mean velocity of fibers, while the CV of fiber velocities was significantly influenced by the draft ratio, gauge length and input sliver linear density. Besides, the distribution pattern has a valuable contribution to the mean and CV of fiber velocities. In consequence, the new drafting model was validated to be effective in quantizing the drafting process.

“…All fibers in the yarn are fully extended in parallel along the yarn's length axis. [2][3][4][5][8][9][10] 2. Fiber fineness among different fibers can vary but be independent of fiber length.…”

Section: Assumptionsmentioning

confidence: 99%

“…7 Though this model has been widely employed in numerous mills and researches, it does not take the fiber length effect into account. The second type is the model based on Suh's theory, 5,8 in which the fiber length is considered as having an important impact on yarn unevenness. Theoretical yarn unevenness from Suh's theory can be expressed by…”

mentioning

confidence: 99%

The theoretical yarn unevenness of cotton considering the joint influence of fiber length distribution and fiber fineness

Kuang

Yuan-bo

2015

Self Cite

The theoretical yarn unevenness has been discussed by considering the joint influence of fiber length distribution and fiber fineness. For fiber length distribution, the fiber length density function was derived from the specific Weibull parameters obtained from actual fiber length measurements using an USTER AFIS instrument. Meanwhile, fiber fineness was added to Suh's model by expressing spun yarn irregularity in terms of fiber mass variation. Comparisons of the calculated value of theoretical yarn unevenness in this paper with the tested and previously researched ones for different cotton yarns have been made. It is shown that the theoretical yarn unevenness calculated in this paper could better reflect the effect of fiber length and fiber fineness on yarn unevenness. This might be the theoretical foundation for the prediction of theoretical cotton yarn unevenness on the basis of actual fiber length distribution and fiber fineness.