Warp is a nonlinear viscoelastic material. The loom efficiency was reduced considerably by the increase of the frequency of weak places in the warp. Warp should vibrate with low-frequency to reduce the friction times....Warp is a nonlinear viscoelastic material. The loom efficiency was reduced considerably by the increase of the frequency of weak places in the warp. Warp should vibrate with low-frequency to reduce the friction times. The objective of this research was to establish the transverse/longitudinal vibration differential equations of warp and analyze the fluctuation process of warp movement by nonlinear method. Based on variable separation method, the time variable was separated from space variable, and the numerical solutions of vibration equations were obtained by the fourth-order Runge-Kutta method. Finally, the influencing factors and variable trends on warp vibration were discussed. The methods on control warp vibration were introduced, which could guide the engineering practice. The most important way to reduce warp vibration is quick adjustment of warp tension.展开更多
The degnmming pretreatment mechanism was investigated to improve degnmming performance and the spinnability of degummed fibers. Apocynum was treated with redox system in the degumming pretreatment process and the pret...The degnmming pretreatment mechanism was investigated to improve degnmming performance and the spinnability of degummed fibers. Apocynum was treated with redox system in the degumming pretreatment process and the pretreatment parameters had been optimized, besides the effects of pretreatment on property index of degnmmed apocynum fiber were investigated. The results showed that the redox system degumming process reduced alkali boiling time and had good advantages over the traditional degumming process in extraction rate, single fiber length and strength. SEM was used to test the longitudinal morphology changes of fibers before and after pretreatment. At the same time, pretreatment solution was analyzed by UV spectra and electron paramagnetic resonance spectrometer （ESR）, and its pH value was also tested. The results showed that the pretreatment solution could release acid constantly to keep the stability of the pH which caused the swelling and dissolution of pectic substances in apocynum bast. Meanwhile, pretrcatment solution could activate the free radicals from apocynam bast and reduce the activation energy of non- cellulosic composition in apocynum bast.展开更多
In order to give a true reflection of the spatial structure of woven fabric, a circular mathematical model is established based on the Peirce＇s model and the principle of the coordinate transformation. The circular m...In order to give a true reflection of the spatial structure of woven fabric, a circular mathematical model is established based on the Peirce＇s model and the principle of the coordinate transformation. The circular model uses arcs and tangent lines as the yarn flexion shape and selects the circle as the yarn cross-section. Then, a new elliptical cross-section mathematical model is rapidly built by the Jaeobian transformation of the circular model. The Matiab software is used for the 3D simulation. It is shown that 3D simulations of woven fabrics with different weft and warp yarn counts, weft and warp densities, structure phases, weaves and flattening coefficients are successfully realized by Matiab basing on the elliptical mathematical model.展开更多
基金Natural Science Foundation of Shaanxi Province,China(No. 09JK456)
文摘Warp is a nonlinear viscoelastic material. The loom efficiency was reduced considerably by the increase of the frequency of weak places in the warp. Warp should vibrate with low-frequency to reduce the friction times. The objective of this research was to establish the transverse/longitudinal vibration differential equations of warp and analyze the fluctuation process of warp movement by nonlinear method. Based on variable separation method, the time variable was separated from space variable, and the numerical solutions of vibration equations were obtained by the fourth-order Runge-Kutta method. Finally, the influencing factors and variable trends on warp vibration were discussed. The methods on control warp vibration were introduced, which could guide the engineering practice. The most important way to reduce warp vibration is quick adjustment of warp tension.
基金Fund of Anhui Province Science Research Projects,China (No. 1106b0105062 )Natural Science Foundation of Anhui Provincial Education Department,China (No. KJ2012B026)Open Fund of Key Laboratory of Advanced Textile Materials and Manufacturing Technology(Zhejiang Sci-Tech University),Ministry of Education,China(No. 201105)
文摘The degnmming pretreatment mechanism was investigated to improve degnmming performance and the spinnability of degummed fibers. Apocynum was treated with redox system in the degumming pretreatment process and the pretreatment parameters had been optimized, besides the effects of pretreatment on property index of degnmmed apocynum fiber were investigated. The results showed that the redox system degumming process reduced alkali boiling time and had good advantages over the traditional degumming process in extraction rate, single fiber length and strength. SEM was used to test the longitudinal morphology changes of fibers before and after pretreatment. At the same time, pretreatment solution was analyzed by UV spectra and electron paramagnetic resonance spectrometer （ESR）, and its pH value was also tested. The results showed that the pretreatment solution could release acid constantly to keep the stability of the pH which caused the swelling and dissolution of pectic substances in apocynum bast. Meanwhile, pretrcatment solution could activate the free radicals from apocynam bast and reduce the activation energy of non- cellulosic composition in apocynum bast.
文摘In order to give a true reflection of the spatial structure of woven fabric, a circular mathematical model is established based on the Peirce＇s model and the principle of the coordinate transformation. The circular model uses arcs and tangent lines as the yarn flexion shape and selects the circle as the yarn cross-section. Then, a new elliptical cross-section mathematical model is rapidly built by the Jaeobian transformation of the circular model. The Matiab software is used for the 3D simulation. It is shown that 3D simulations of woven fabrics with different weft and warp yarn counts, weft and warp densities, structure phases, weaves and flattening coefficients are successfully realized by Matiab basing on the elliptical mathematical model.
