Study of flow and heat transfer characteristics and LIGA fabrication of microspinnerets

This investigation analyzes the flow, the heat transfer characteristics and the LIGA fabrication of a microspinneret. An experimental test model was built to elucidate the flow in the micronozzle. A numerical solution covers the range from Re = 10⁻⁸ to 1.0, proving that the flow characteristics of the micronozzle are similar to those of the test model. The Peclet number in the test model can be adjusted to a value close to that of the micronozzle. The LIGA fabrication technique, including lithography, electroforming and molding, is a new technique for fabricating many precise microstructures. The other advantages of the LIGA technique to make nozzles are the generation of a high aspect ratio and the flexibility of the nozzle's geometry. The textile industry employs several microspinnerets with high aspect ratios and different nozzle geometries, and represents an ideal context for applying the LIGA technique.