The invention provides a process of making a continuous freeform thermoplastic dielectric film (25) that is evenly loaded with dispersed nanoparticles comprising the steps of; feeding thermoplastic granules (21) into an extruder (23), injecting a secondary feed (27) comprising a suspension of nanoparticles in a liquid carrier to create a nanocomposite, and extruding said composite onto cooled rollers (26) at a preset rate thereby enabling the crystalline structure of the nanocomposite film (25) to be controlled wherein the secondary feed (27) is mixed continuously by an ultrasonicator (29) whilst being injected into the extruder (23). By selecting the size of the nano particles based on their de Broglie wavelength in the crystalline polymer the dielectric can be produced in bulk to make high capacitance high energy density storage capacitors