Patents by Inventor David E. Murdock

David E. Murdock has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20030214067
    Abstract: The invention is extrusion equipment and a process. The extrusion equipment links two extruders (11, 15) together. The first extruder (11) is, desirably, a counter-rotating twin screw extruder. The first extruder (11) receives organic filler, preferably wood particles or fiber, having a variable moisture content. Moisture is withdrawn from the extruder barrel. A polymer is fed from a second extruder (15) into the barrel of the first extruder (11) after the polymer is heated, mixed, and melted in the second extruder (15). The second extruder (15) can be a single screw or twin screw extruder. The combined mixture of organic filler and polymer is further mixed alone or with optional additives. The mixture is vacuum vented to remove moisture and volatiles and then extruded through a die. Additional processing steps are optional depending upon the extruded product or profile being produced.
    Type: Application
    Filed: April 29, 2003
    Publication date: November 20, 2003
    Inventors: David E Murdock, Dale K Snead, Darrell S Dardenne, Ian W Mills
  • Patent number: 5807517
    Abstract: An apparatus for heating and blending thermoplastic material prior to delivering the material into the barrel of an extruder. The apparatus, has an elongated housing which contains two intermeshing feed screws that are driven to rotate in the same direction. Controlled heating is provided by electric band heaters which encircle the exterior of the housing, and electric cartridge heating elements fitted into aluminum cores that are received by an axial bore in each of the feed screws.
    Type: Grant
    Filed: April 8, 1997
    Date of Patent: September 15, 1998
    Assignee: Cincinnati Milacron Inc.
    Inventors: Siegfried R. Wissmann, William T. Schmitt, David E. Murdock
  • Patent number: 5750158
    Abstract: An apparatus for heating and blending thermoplastic material prior to delivering the material into the barrel of an extruder has an elongated housing which contains two intermeshing feed screws that are driven to rotate in the same direction. Controlled heating is provided by electric band heaters which encircle the exterior of the housing, and electric cartridge heating elements fitted into aluminum cores that are received by an axial bore in each of the feed screws.
    Type: Grant
    Filed: September 19, 1994
    Date of Patent: May 12, 1998
    Assignee: Cincinnati Milacron Inc.
    Inventors: Siegfried R. Wissmann, William T. Schmitt, David E. Murdock