Thin polymeric films for use as dielectrics

The various techniques whereby polymeric materials can be converted into usable film form are discussed. The limitation of these methods are considered, in particular the well-known extrusion lay-flat process. A method of film preparation by casting on to a suitable carrier is described and assessed. Properties relevant to electrical applications are discussed for polystyrene, styrene copolymers, polycarbonates, cellulosics and polyolefines.