ISSN:
0032-3888
Keywords:
Chemistry
;
Chemical Engineering
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
,
Physics
Notes:
A rational computer-aided design procedure is presented for determining the optimum flow channel geometry of a flat film die, which yields a minimum pressure drop and produces a uniform transverse flow rate distribution. The three-dimensional die surface is generated by analytic expressions that represent a dumbbell-like contour. The die surface may be specified by several geometric parameters. The length of the transition zone turns out to be the controlling parameter. Because of the complicated geometric boundary, it is not possible to optimize the flow channel geometry explicitly; instead, a computer trial procedure is employed. The numerical computation is based on an isothermal three-dimensional flow model, which assumes power law behavior for the polymer melts. The calculated results indicate that for a particular polymer and a particular aspect ratio of slit, there may exist an optimum transition length from which the flow channel geometry of a flat film die may be uniquely defined.
Additional Material:
23 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/pen.760341308
