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이경민,전두환,전상후,Lee, Kyoung Min,Chun, Du Hwan,Chun, Sang Hoo 한국섬유공학회 2015 한국섬유공학회지 Vol.52 No.3
Sound absorbing materials are generally categorized as porous-type absorbers and panel-type absorbers. In addition, their absorbing mechanism is typically described as a conversion of sound energy into heat energy through the dynamic behavior of the material. Thus one of the important parameters influencing the sound absorption characteristics is the density of the material. This study investigated the sound absorption characteristics of a mesh fabric based on the mesh density and fabric layering structure. Four different mesh densities (130, 180, 200, and 230 T) combined with five different layering structures were investigated to help understand the mechanism and effect of the sound absorption characteristics. The results indicate that a panel-type absorber has better sound absorption characteristics within a lower frequency range, whereas a porous-type absorber performs better at a higher frequency. In addition, the increased fabric density of the mesh fabric shows a better performance in terms of sound absorption. An empirical equation between the sound absorption coefficient and the fabric density was also derived for further design applications.
허유,전두환,김종성,Huh You,Chun Du-Hwan,Kim Jong-S. 한국섬유공학회 2006 한국섬유공학회지 Vol.43 No.2
Modern weaving machines have the beat-up mechanism whose front position is predetermined mechanically. Therefore the relative position between the reed front and the clothfell plays an important role in producing the high quality fabrics with uniform weft density distribution. This research reports on the results from the simulation that was conducted on the basis of the theoretical model about the fabric weft density dynamics, including the factors such as beat-up motion and warp tension. Results showed that the weft density change was very sensitive to the initial clothfell position. The clothfell position was relocated toward the machine front during the machine restart and then it approached the steady state value. A low initial warp tension led to a narrow pickspace, too. Even though the warp tension and the beat-up force changed for a long period of time after the machine restarted, the weft interval variation and the clothfell position change were stabilized early, while the clothfell position showed an overshooting behavior for a low initial warp tension under a high level of process tension condition. Initial weft interval condition showed no influence on the dynamic behavior of the weft density.