Experimental Study on Falling Process of Melt Electrospinning Fiber

2013 ◽  
Vol 561 ◽  
pp. 36-40 ◽  
Author(s):  
Yong Liu ◽  
Zhao Xiang Liu ◽  
Liang Deng ◽  
Ying An ◽  
Xue Tao He ◽  
...  
Keyword(s):  
Experimental Study ◽  
High Speed ◽  
High Speed Video ◽  
Melt Electrospinning ◽  
Straight Line ◽  
Spinning Process ◽  
Three Stages ◽  
Line Movement

As one directly method to produce nanofibers, electrospinning has been studied extensively. However, the buckling phenomenon is not understood completely especially to the process of melt electrospinning. The authors carried out a series of experimental study on this phenomenon with high speed video. This is the first article of the research, in which we defined three stages to the whole spinning process according to the time. The specialties of each stage were list out. The falling process was divided into straight-line movement, spiral swinging, and deposits on the collector three sections. The buckling reasons were provided.

scholarly journals Thermocapillary rupture of a horizontal liquid layer on a silicon substrate

2019 ◽  
Vol 196 ◽  
pp. 00041
Author(s):  
Dmitry Kochkin ◽  
Valentin Belosludtsev ◽  
Veronica Sulyaeva
Keyword(s):  
Experimental Study ◽  
Contact Line ◽  
High Speed ◽  
Video Camera ◽  
Phase Contact ◽  
High Speed Video ◽  
High Speed Video Camera ◽  
Three Phase ◽  
Breakdown Phenomenon ◽  
Dry Spot

This paper is an experimental study of thermocapillary breakdown phenomenon in a horizontal film of liquid placed on a silicon nonisothermal substrate. With the help of a high-speed video camera the speed of the three-phase contact line was measured during the growth of a dry spot.

scholarly journals Bubble Melt Electrospinning for Production of Polymer Microfibers

Polymers ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 1246 ◽  
Author(s):  
Ye-Ming Li ◽  
Xiao-Xiong Wang ◽  
Shu-Xin Yu ◽  
Ying-Tao Zhao ◽  
Xu Yan ◽  
...  
Keyword(s):  
High Speed ◽  
Fiber Diameter ◽  
Heating Temperature ◽  
Polymer Melt ◽  
Taylor Cone ◽  
Ultrafine Fibers ◽  
Melt Electrospinning ◽  
Spinning Process ◽  
Metal Needle ◽  
Polymer Microfibers

In this paper, we report an interesting bubble melt electrospinning (e-spinning) to produce polymer microfibers. Usually, melt e-spinning for fabricating ultrafine fibers needs “Taylor cone”, which is formed on the tip of the spinneret. The spinneret is also the bottleneck for mass production in melt e-spinning. In this work, a metal needle-free method was tried in the melt e-spinning process. The “Taylor cone” was formed on the surface of the broken polymer melt bubble, which was produced by an airflow. With the applied voltage ranging from 18 to 25 kV, the heating temperature was about 210–250 °C, and polyurethane (TPU) and polylactic acid (PLA) microfibers were successfully fabricated by this new melt e-spinning technique. During the melt e-spinning process, polymer melt jets ejected from the burst bubbles could be observed with a high-speed camera. Then, polymer microfibers could be obtained on the grounded collector. The fiber diameter ranged from 45 down to 5 μm. The results indicate that bubble melt e-spinning may be a promising method for needleless production in melt e-spinning.

Effect of Different Factors on Falling Process of Melt Electrospinning Jet

2013 ◽  
Vol 745-746 ◽  
pp. 407-411 ◽  
Author(s):  
Yong Liu ◽  
Zhao Xiang Liu ◽  
Liang Deng ◽  
Ke Jian Wang ◽  
Wei Min Yang
Keyword(s):  
High Speed ◽  
Video Camera ◽  
Forming Process ◽  
High Speed Video ◽  
Melt Electrospinning ◽  
High Speed Video Camera ◽  
Environment Temperature ◽  
Voltage Limit ◽  
Solution Electrospinning ◽  
Dominant Influence

The falling process of melt electrospinning jet is different from those of solution electrospinning in which there is apparent solvent volatilization. In order to study the factors influencing on the forming process of fibers in melt electrospinning, dropping process of fibers is recorded and analyzed via high speed video camera in the article. Results showed that there was an optimal spinning temperature for melt electrospinning of the polymer; the greater the voltage was, the more obvious stretching action on jet was. However, the voltage did not exceed a certain value, because there was a spinnable voltage limit corresponding to every receiving distance. When the spinning distance was generally short, the jet swinging radius decreased with increasing spinning distance; when the spinning distance was long, the jet was subject to the influence of the environment temperature easily. The changes of viscosity had dominant influence on the motion of jet.

scholarly journals Studying of the characteristics of a single bubble under subcooled liquid boiling

2021 ◽  
Vol 2088 (1) ◽  
pp. 012048
Author(s):  
N V Vasil’ev ◽  
Yu A Zeigarnik ◽  
K A Khodakov ◽  
S N Vavilov ◽  
A S Nikishin
Keyword(s):  
Experimental Study ◽  
Laser Heating ◽  
High Speed ◽  
Heat Removal ◽  
Frame Rate ◽  
Vapor Bubbles ◽  
Heat Conductance ◽  
Subcooled Liquid ◽  
High Speed Video ◽  
Surrounding Liquid

Abstract An experimental study of the characteristics of single (solitary) bubbles obtained by means of focused laser heating of the surface during the boiling of two subcooled liquids with significantly different properties: water and refrigerant R113 has been carried out. To obtain the most complete detailed information, the technique of synchronized high-speed video filming of the process in two mutually perpendicular planes with a frame rate of up to 150 kHz was used. It is shown that during the boiling of a subcooled liquid, the main mechanism of heat removal from the bubble dome into the surrounding liquid is an unsteady heat conductance. Differences in the behavior of solitary vapor bubbles in the case of boiling of two liquids (water and refrigerant R113) are shown.

APPLICATION OF THE EARLY DAMAGE DIAGNOSTICS TECHNIQUE TO EXAMINATION OF THE AVIATION PANEL

2019 ◽  
Vol 85 (6) ◽  
pp. 53-63 ◽  
Author(s):  
I. E. Vasil’ev ◽  
Yu. G. Matvienko ◽  
A. V. Pankov ◽  
A. G. Kalinin
Keyword(s):  
Acoustic Emission ◽  
Damage Detection ◽  
High Speed ◽  
Early Stage ◽  
Video Data ◽  
High Speed Video ◽  
Damage Diagnostics ◽  
Subsurface Defect ◽  
Sensitive Coating ◽  
Early Damage

The results of using early damage diagnostics technique (developed in the Mechanical Engineering Research Institute of the Russian Academy of Sciences (IMASH RAN) for detecting the latent damage of an aviation panel made of composite material upon bench tensile tests are presented. We have assessed the capabilities of the developed technique and software regarding damage detection at the early stage of panel loading in conditions of elastic strain of the material using brittle strain-sensitive coating and simultaneous crack detection in the coating with a high-speed video camera “Video-print” and acoustic emission system “A-Line 32D.” When revealing a subsurface defect (a notch of the middle stringer) of the aviation panel, the general concept of damage detection at the early stage of loading in conditions of elastic behavior of the material was also tested in the course of the experiment, as well as the software specially developed for cluster analysis and classification of detected location pulses along with the equipment and software for simultaneous recording of video data flows and arrays of acoustic emission (AE) data. Synchronous recording of video images and AE pulses ensured precise control of the cracking process in the brittle strain-sensitive coating (tensocoating)at all stages of the experiment, whereas the use of structural-phenomenological approach kept track of the main trends in damage accumulation at different structural levels and identify the sources of their origin when classifying recorded AE data arrays. The combined use of oxide tensocoatings and high-speed video recording synchronized with the AE control system, provide the possibility of definite determination of the subsurface defect, reveal the maximum principal strains in the area of crack formation, quantify them and identify the main sources of AE signals upon monitoring the state of the aviation panel under loading P = 90 kN, which is about 12% of the critical load.

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