Polymer solution surface tension forces

For liquids of low viscosity, a useful measurement technique is the tensiometer, schematically represented in Fig. 2.56. Here, the surface tension is related to the force it takes to pull a platinum ring from a solution. Surface tension for selected polymers are listed in Table 2.12 [71 ], for some solvents in Table 2.13 [58] and between polymer-polymer systems in Table 2.14 [71],... 

The process makes use of electrostatic and mechanical forces to spin fibers from the tip of a fine spinneret. The spinneret is maintained at a positive or a negative charge by a direct current (DC] power supply. When the electrostatic repelling force overcomes the surface tension force of the polymer solution, the liquid spills out of the spinneret and forms an extremely fine continuous filament. ... 

Surface tension-driven breakup into droplets is rarely important in melt spinning, where the large viscous and elastic forces overwhelm the surface tension forces, ft is an important mechanism in the formation of the dispersed phase in polymer blends, and it is important in solution processing. The surface tension-driven breakup of a viscoelastic filament has been analyzed using both thin filament equations and a transient finite element analysis, but we will not pursue the topic here because it is not relevant to our present discussion. 

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