|
SCO is an independent consulting office specializing in the areas of polymer processing and fiber formation by providing consulting services and software development.
|
Chapter 12 & 13. Flow in Spiral Die (1) & (2) |
|
[Simulation Analysis for Polymer Processing by PC (7), Japan Plastics, Vol.50, No.5, P.96 (1999) & Simulation Analysis for Polymer Processing by PC (8), Japan Plastics, Vol.50, No.6, P.120 (1999)]]
Spiral dies, which have built-in mandrels with spiral grooves, are frequently used to produce uniform films and sheets. The flow inside this type of die is a combination of flow in the groove direction and flow toward the die exit. The purposes of using spiral die are to attain improved mixing and uniform flow rate circumferentially, during polymer melt flows in the spiral groove and across the flight clearance in complicated manner. Procter presented a flow theory in a spiral die [11], but it is based on considerable simplifications. Here presents more sound theory, which was extended by the present writer, starting from Procter's. In chapter 12, the extended theory, simulation program using the theory and a calculation example are described in detail, in terms of flow and pressure drop in the spiral die. In chapter 13, theory to evaluate degree of mixing is presented, and at the end, a practical example of investigating the structure of the die, using the methods given in chapter 12 and chapter 13. [11] Procter, B., SPE J., 28, 34 (Feb.,'72) |