MODELING THE SECONDARY CAVITY OF 2-CAVITY DIES

Dies having two distribution cavities and slots are sometimes used in film-forming applications demanding high uniformity. The flow distribu tion accomplished by the primary cavity and slot is improved by the se condary cavity and slot, in the primary cavity, the main flow directio n is lengthwise, and the now resembles that in a duct, On the other ha nd, the main flow direction in the secondary cavity is in tile plane o f the cross section, Nonetheless, in previous literature, the same flo w equation is used for both cavities. The principal result of this wor k is a flow equal-ion for the secondary cavity that takes account of t he underlying cross now. Applying this equation shows that both Inerti a and pseudoplasticity adversely affect the performance of a secondary cavity and slot.