In order to find the effect of state device installed on a carding machine on card sliver quality, card slivers produced in conditions of different voltages and gauges were tested by USTER AFIS. The results show that,...In order to find the effect of state device installed on a carding machine on card sliver quality, card slivers produced in conditions of different voltages and gauges were tested by USTER AFIS. The results show that, when the gauge is 1 nun, most parameters of card sliver quality are better when voltage is 600 V than those when no voltage is applied. The contents of nep, trash, visible foreign matter （VFM） and short fiber content by number （SFCn）, short fiber content by weight （SFCw）, immature fiber content （IFC） of card sliver decrease by 5.9%, 16.7%, 12.5%, 5.3%, 4.8% and 1.6%, respectively, but seed coat nep （SCN） content of card sliver doesn＇t decrease. When the electrostatic plate gauge is 2 mm and electrostatic voltage is 4000 V, the removal efficiency of neps and SCN is remarkable, decreasing by 8.7% and 25% respectively. Card sliver quality is hardly improved under any voltage when the gauge between electrostatic plate and cylinder is 3mm.展开更多
We present a new analytical model for electrostatically actuated microbeams to explore the size effect by using the modified couple stress theory and the minimum total potential energy principle. A material length sca...We present a new analytical model for electrostatically actuated microbeams to explore the size effect by using the modified couple stress theory and the minimum total potential energy principle. A material length scale parameter is introduced to represent the size-dependent characteristics of microbeams. This model also accounts for the nonlinearities associated with the mid-plane stretching force and the electrostatical force. Numerical analysis for microbeams with clamped-clamped and cantilevered conditions has been performed. It is found that the intensity of size effect is closely associated with the thickness of the microbeam,and smaller beam thickness displays stronger size effect and hence yields smaller deffection and larger pull-in voltage. When the beam thickness is comparable to the material length scale parameter,the size effect is significant and the present theoretical model including the material length scale parameter is adequate for predicting the static behavior of microbeam-based MEMS.展开更多
基金Supported by Fund of Scientific and Technological Key Project Plan of Liaoning Province , China(No.2003220026)Fund of Education Depart ment of Liaoning Province,China(No.05L147)
文摘In order to find the effect of state device installed on a carding machine on card sliver quality, card slivers produced in conditions of different voltages and gauges were tested by USTER AFIS. The results show that, when the gauge is 1 nun, most parameters of card sliver quality are better when voltage is 600 V than those when no voltage is applied. The contents of nep, trash, visible foreign matter （VFM） and short fiber content by number （SFCn）, short fiber content by weight （SFCw）, immature fiber content （IFC） of card sliver decrease by 5.9%, 16.7%, 12.5%, 5.3%, 4.8% and 1.6%, respectively, but seed coat nep （SCN） content of card sliver doesn＇t decrease. When the electrostatic plate gauge is 2 mm and electrostatic voltage is 4000 V, the removal efficiency of neps and SCN is remarkable, decreasing by 8.7% and 25% respectively. Card sliver quality is hardly improved under any voltage when the gauge between electrostatic plate and cylinder is 3mm.
文摘We present a new analytical model for electrostatically actuated microbeams to explore the size effect by using the modified couple stress theory and the minimum total potential energy principle. A material length scale parameter is introduced to represent the size-dependent characteristics of microbeams. This model also accounts for the nonlinearities associated with the mid-plane stretching force and the electrostatical force. Numerical analysis for microbeams with clamped-clamped and cantilevered conditions has been performed. It is found that the intensity of size effect is closely associated with the thickness of the microbeam,and smaller beam thickness displays stronger size effect and hence yields smaller deffection and larger pull-in voltage. When the beam thickness is comparable to the material length scale parameter,the size effect is significant and the present theoretical model including the material length scale parameter is adequate for predicting the static behavior of microbeam-based MEMS.
