Patents Represented by Attorney John F. Siebeth
  • Patent number: 4644623
    Abstract: An apparatus for the manufacture of selectively apertured thermoplastic sheet or film, comprising a rotatable molding element means for receiving the film and which means has a predetermined pattern therein wherein as the film is contacted with the rotatable molding element means and a fluid pressure differential is applied to the surface of the film, a desired pattern of perforated areas and non-perforated areas are imparted to the film with each of said areas being continuous across the web of the film and alternating in the machine direction.
    Type: Grant
    Filed: April 11, 1985
    Date of Patent: February 24, 1987
    Assignee: Ethyl Corporation
    Inventors: Garland E. Raley, Dean M. Spear