Efficacy of the Velocity Variance Model to Estimate the Thickness Irregularity in a Fiber Bundle Flow

집속 유동에서 속도분산모형과 집속체 불균제 예측성

  • Lim, Jung-H. (Department of Textile Engineering, Graduate School, Kyung Hee University) ;
  • Kim, Jong-S. (Laboratory for Intelligent Process and Control, Kyung Hee University) ;
  • Huh, You (Department of Mechanical Engineering, College of Engineering, Kyung Hee University)
  • 임정호 (경희대학교 대학원 섬유공학과) ;
  • 김종성 (경희대학교 지능공정 및 제어연구실) ;
  • 허유 (경희대학교 공과대학 기계공학과)
  • Received : 2011.11.07
  • Accepted : 2011.12.09
  • Published : 2011.12.31

Abstract

This study reports on the output linear density that was attained by simulation for various levels of draft roller gauge and draft ratio, based on the dynamic model with approximated sinusoidal velocity variance model to specific fiber length distributions to test the model feasibility, while a random variation for the input bundle linear density was provided. Results from model simulation showed that a process resonance could take place, when the draft roller gauge or draft ratio reached the critical values, because there were fundamental frequencies which spread in the irregularity of the bundle linear density, giving rise to some resonance. Thus, the irregularity of the output linear density began increasing steeply. From the view point of the output linear density as a whole, the irregularity decreased, as the draft roller gauge increased. A process resonance occurred in the range of draft roller gauge between 1.25 and 1.5 multitudes of the (maximal) fiber length. Length distribution led to a lower fundamental frequency (longer fundamental wavelength) than the uniform fiber length. High draft ratio yielded high irregularity in the output bundle. Especially, the process resonance occurred between the draft ratio 20 and 30. In the draft ratio range higher than 30, the output included wide-ranged regularly oscillatory components of irregularity that corresponded to the integer-multiple of the fundamental frequency, which shifted to a higher value, when the fiber length was distributed. In addition, the approximated sinusoidal velocity variance model turned out to be adequate to estimate the irregularity of the bundle linear density with both the uniform and the quadratic fiber length distribution.

Keywords

Acknowledgement

Supported by : 한국연구재단

References

  1. G. A. R. Foster and J. G. Martindale, "The Form and Length of the Drafting Wave in Cotton Rovings", J Text Inst, 1946, 37, T1-12. https://doi.org/10.1080/19447024608659798
  2. H. Balasubramanian, P. Grosberg, and Y. Turkes, "Studies in Modern Yarn Production", Textile Institute, Manchester, 1968, pp.169-180.
  3. B. Dutta and P. Grosberg, "The Dynamic Response of Drafting Tension to Sinusoidal Variations in Draft Ratio under Conditions of Sliver Elasticity in Short-staple Drafting", J Text Inst, 1973, 64, 534-542. https://doi.org/10.1080/00405007308630289
  4. G. Mandl and H. Noebauer, "The Influence of Cotton- Spinning Machinery on the Random Irregularity of Sliver and Yarns - Part I, II, III", J Text Inst, 1977, 68, 387, 394, 400.
  5. H. R. Plonsker and S. Backer, "The Dynamics of Roller Drafting", Text Res J, 1967, 37, 673-687. https://doi.org/10.1177/004051756703700807
  6. P. R. Lord and M. Govindaraj, "Dynamic Measurement of Mechanical Errors in Sliver- Drawing", J Text Inst, 1990, 81, 195-206. https://doi.org/10.1080/00405009008658346
  7. Y. Huh and J. S. Kim, "Modeling the Dynamic Behavior of the Fiber Bundle in a Roll-Drafting Process", Text Res J, 2004, 74, 872-878. https://doi.org/10.1177/004051750407401006
  8. Y. Huh and J. S. Kim, "Steady-Flow Characteristics of Bundle Fluid in Drawing", Transaction of KSME, Vol. B, 2006, 30, 612-621.
  9. J. S. Kim and Y. Huh, "Stability of Bundle Flow Dynamics", Text Sci Eng, 2008, 45, 89-96.
  10. J. S. Kim and Y. Huh, "Simulating the Bundle Thickness Output from the Fiber Length Distributed Bundle Drawing Process", Text Sci Eng, 2008, 45, 382-394.
  11. J. S. Kim and Y. Huh, "Operation Adjustment and Sliver Thickness Variation in Roller Drafting", Text Sci Eng, 2011, 48, 203-213.