He was denied a patent for the process because it had already been described in the comic .
In 1964 , Danish inventor Karl Kroyer salvaged a shipwreck by pumping expandable polystyrene foam balls into its hull .
Karl Kroyer was denied a patent for the process because it had already been described in the comic .
In 1964 , Danish inventor Karl Kroyer salvaged a shipwreck by pumping expandable polystyrene foam balls into its hull .