| abstract |
A method for manufacturing an ultra-thin polymeric film is disclosed. The method includes the steps of melt blending of a polymeric composition or a nanocomposite composition in an extruder. Next, the molten composition is conveyed through a flat die with a small die lip gap. A melt pump may also be used to provide a constant, non-pulsating flow of the melted composition through the die. The melted composition may be passed through a filtration device to remove contaminants that could adversely affect the dielectric performance of the film. Next, the film is stretched by passing the film through take-up rollers at relatively high take-up speeds. Then, the composition is cooled to form a film or sheet. The edges of the film may be trimmed, and the film wound up on a roll using a tension-controlled winding mechanism. A heated roll may be used to temper/anneal the film, thereby eliminating frozen-in internal stresses. |