A Computer Simulation Approach for Engineering Air-Jet Spun Yarns

1997 ◽  
Vol 67 (3) ◽  
pp. 223-230 ◽  
Author(s):  
Rangaswamy Rajamanickam ◽  
Steven M. Hansen ◽  
Sundaresan Jayaraman
Keyword(s):  
Computer Simulation ◽  
Computer Simulations ◽  
Fiber Length ◽  
Experimental Investigations ◽  
Simulation Approach ◽  
Air Jet ◽  
Fiber Fineness ◽  
Spun Yarns ◽  
Yarn Count ◽  
Wrap Angle

A computer simulation approach for engineering air-jet spun yarns is proposed, and the advantages of computer simulations over experimental investigations and stand-alone mathematical models are discussed. Interactions of the following factors in air-jet spun yarns are analyzed using computer simulations: yarn count and fiber fineness, fiber tenacity and fiber friction, fiber length and fiber friction, and number of wrapper fibers and wrap angle. Based on the results of these simulations, yarn engineering approaches to optimize strength are suggested.

Air-Jet Texturing of Spun Cotton Yarns for Improved Comfort

1992 ◽  
Vol 62 (3) ◽  
pp. 169-174 ◽  
Author(s):  
J. Srinivasan ◽  
A. K. Sengupta ◽  
V. K. Kothari
Keyword(s):  
Length Distribution ◽  
Fiber Length Distribution ◽  
Air Jet ◽  
Air Stream ◽  
Spun Yarn ◽  
Fiber Fineness ◽  
Fiber Packing Density ◽  
Spun Yarns ◽  
Cotton Yarns ◽  
And Migration

We have studied the importance of yarn structural variants such as fiber packing density, fiber fineness and length distribution, mean fiber extent, and migration parameters in deciding the bulking potential of a spun yarn structure with air-jet texturing. Three variants of carded yarns, combed yarns, and yarns made from combed sliver which is again carded in both 100% spun and composite spun forms with three different twist levels show that fiber-to-fiber distance and frictional hindrance may have a significant influence on the relative local velocities of the fibers in the turbulent air stream, which would affect the texturing behavior. We have observed that spun yarns with uniform fiber length distribution, higher fiber extent, and more fiber parallelization, such as combed yarns, have less bulk during texturing. Yarns with higher packing and migration have higher frictional hindrance with less fiber-to-fiber distance. They are therefore subjected to reduced flow asymmetry and produce yarns with reduced bulk.

A Model to Explain the Variations of “End-of-Range” Defect Densities with Ion Implantation Parameters

1992 ◽  
Vol 279 ◽  
Author(s):  
L. Laanab ◽  
C. Bergaud ◽  
M. M. Faye ◽  
J. Faure ◽  
A. Martinez ◽  
...  
Keyword(s):  
Ion Implantation ◽  
Computer Simulations ◽  
Point Defects ◽  
Numerical Optimization ◽  
Experimental Investigations ◽  
Shallow Junctions ◽  
Quantitative Explanation ◽  
Defect Densities

ABSTRACTComputer simulations in conjunction with TEM experiments have been used to test the different models usually adopted in the literature to explain the formation of “End Of Range”(EOR) defects which appear after annealing of preamorphized silicon layers. Only one survives careful experimental investigations involving Si+, Ge+, Sn+ amorphization at RT and LNT. The “excess-interstitial” model appears relevant at least for a semi-quantitative explanation of the source of point-defects which after recombination and agglomeration, lead to the formation of these defects. This model may be used for the numerical optimization of conditions for the production of high performances ullra-shallow junctions.

Computer Simulation of an Synthetic Ultraviolet Absorbent in the Interface of DMB and DMF

2010 ◽  
Vol 146-147 ◽  
pp. 966-971
Author(s):  
Qi Hua Jiang ◽  
Hai Dong Zhang ◽  
Bin Xiang ◽  
Hai Yun He ◽  
Ping Deng
Keyword(s):  
Computer Simulation ◽  
Computer Simulations ◽  
Density Functional ◽  
Density Functional Method ◽  
Mean Field ◽  
Functional Method ◽  
Dynamic Density ◽  
Interface Phase ◽  
Simulation Results

This work studies the aggregation of an synthetic ultraviolet absorbent, named 2-hydroxy-4-perfluoroheptanoate-benzophenone (HPFHBP), in the interface between two solvents which can not completely dissolve each other. The aggregation is studied by computer simulations based on a dynamic density functional method and mean-field interactions, which are implemented in the MesoDyn module and Blend module of Material Studios. The simulation results show that the synthetic ultraviolet absorbent diffuse to the interface phase and the concentration in the interface phase is greater than it in the solvents phase.

Gamma ray imaging using coded aperture masks: a computer simulation approach

1991 ◽  
Vol 30 (5) ◽  
pp. 549 ◽  
Author(s):  
J. Jimenez ◽  
Pedro Olmos ◽  
J. L. de Pablos ◽  
J. M. Perez
Keyword(s):  
Computer Simulation ◽  
Gamma Ray ◽  
Coded Aperture ◽  
Simulation Approach ◽  
Gamma Ray Imaging

An Air Texturing Process for Hybridization of Different Reinforcement Filament Yarns by Commingling Process

2006 ◽  
Vol 532-533 ◽  
pp. 333-336 ◽  
Author(s):  
Bok Choon Kang ◽  
Chathura Nalendra Herath ◽  
Jong Kwang Park ◽  
Yong Hwang Roh
Keyword(s):  
High Performance ◽  
Process Development ◽  
Glass Fibers ◽  
Air Pressure ◽  
Practical Applications ◽  
Advantages And Disadvantages ◽  
Significant Parameter ◽  
Air Jet ◽  
Yarn Count ◽  
Air Nozzle

Carbon, aramid and glass fibers are inherently superior to conventional textile fibers in terms of mechanical properties and other characteristics. However, each material has its inherent advantages and disadvantages and it is usually recommended to hybridize them to fully benefit of their high performance in practical applications to many products. This paper is concerned with an air texturing process for hybridization of different reinforcement filament yarns. A normal air texturing machine was selected for process development and modified to suit testing purposes. The modified process for hybridization was introduced mainly in terms of air-jet nozzles employed in experiments. With the proposed air texturing process machine, three types of air-nozzle were applied to the experimental work. Three different filament materials were employed in experiments and they are carbon (CF), aramid (AF), and glass (GF). As matrix materials, polyether-ether (PEEK), polyester (PES), and polypropylene (PP) were selected and experimented. Hybrid yarns produced form the proposed process was evaluated optically in terms of bulkiness, arranging, breaking, and mixing, respectively. The experimental results were also summarized in terms of relationships between applied air pressure and yarn count, and variation in count. As a whole, it was concluded from the experiments that the proposed texturing process could be successfully applied to the practical hybridization of different reinforcement filament yarns. It was also revealed from the experiments that the air pressure in the proposed process is not a significant parameter on the pressing in terms of yarn count.

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