Spinneret rotating

For mobile liquids, the use of this kind of controllable instruments is practically impossible. For these liquids, the non-controllable measurement techniques are available only and in general an apparent transient viscosity will be obtained. Nevertheless these measurements are still of great value, because in many cases they approximate industrial process conditions. Mostly used is the spinning line rheometer, where an elastic liquid is pressed through a spinneret and the liquid is pulled from the die by winding the filament around a rotating drum or by sucking the tread into a capillary tube. This is schematically shown in Fig. 15.25. A serious problem is the translation of the obtained data to the extensional viscosity. Many other non-controllable devices are discussed by,... 

The spinneret was heated to 162°C and kept 1/2" above the spin bath liquid. After passage under a guide at the bottom of the spin bath, the fiber was passed over a water wash roll, a neutralizing roll rotating in 4% aqueous sodium carbonate solution, through a water bath at 95°C, over another wash roll, a steam-heated drying roll and was finally hot-stretched at 357°C over a hot shoe. The fiber obtained at 1010 fpm had a tenacity of 14.4 gpd, an elongation of 7.2% and an initial modulus of 303 gpd. 

Spinneret, the radial distance of spinning The distance from the center of the rotating disk to the center of pipette or syringe position was i = 4 to 14 cm. 

Figure 8. Melt extrusion of mesophase pitch fibers with a rotation screw and multi hole spinneret [6] reproduced with permission from Noyes Publications, Park Ridge, NJ.

Filament yarn in the spinning of manufactured filaments, fiber-forming substances in the plastic or molten state, or in solution, are forced through the fine orifices in a metallic plate called a spinneret, or jet, at a controlled rate. The solidified filaments are drawn-off by rotating rolls, or godets, and wound onto bobbins or pirns. There are several methods of spinning manufactured filaments ... 

Andrady et al. [89] patented a spinneret configuration which also operates with plenty of capillary holes. The scheme can be seen in Figure 10.12. Holes are located on cylinder superficies and the collector is also cylindrical and concentric with the spinneret. The solution can be fed into the spinneret through a conduit or even manually. The flow rate can be regulated by adjusting the rotation speed and/or the pressure within the spinneret tube. High output rates can be achieved, but the collector surface is limited or can be extended only in a complicated way. 

Figure 10.12. Scheme of rotating capillary spinneret [89], 1 power supply, 2 solution feed conduit, 3 spinneret, 4 charged electrode, 5 capillaries along the superficies of the tube, 6 collector electrode... 

Bubble electrospinning is also an interesting method. It was invented and reported by Liu and He [92-94] in China, Smit and Sanderson in South Africa [95] and by Reneker et al. [96] in the United States at almost the same time in 2008. The invention scheme drawn by Reneker can be seen in Figure 10.15 and Figure 10.16. Bubble electrospinning can operate with even a static reservoir or with a rotating spinneret, and moreover, the gas inlet can be diverse. 

Figure 10.16. Bubble electrospinning apparatus with a rotating spinneret [96]...

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