Patents by Inventor David B. Ledford

David B. Ledford 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).

  • Patent number: 6416859
    Abstract: Polymeric compositions include a nonaqueous additive system having dispersant-coated pigments physically dispersed in a liquid nonaqueous polymeric carrier which may be added directly to a melt flow of a polymeric host material. The additive system employed in the polymeric systems is most preferably in the form of a particulate paste which can be added in metered amounts (dosed) to a melt flow of the polymeric host material prior to being spun into filaments. By providing a number of additive systems having a number of different additive attributes, and controllably dosing one or more into the melt flow of host polymeric material, shaped objects of the polymeric material (e.g., melt-spun filaments) having different additive attributes may be produced on a continuous basis without shutting down the shaping operation.
    Type: Grant
    Filed: October 17, 2000
    Date of Patent: July 9, 2002
    Assignee: BASF Corporation
    Inventors: Donald Caswell, Frank R. Jones, David B. Ledford, Stanley A. McIntosh, Gary W. Shore, Karl H. Buchanan, Wayne S. Stanko, G. Daniel Gasperson, Charles F. Helms, Jr.
  • Patent number: 6232371
    Abstract: Polymeric compositions include a nonaqueous additive system having dispersant-coated pigments physically dispersed in a liquid nonaqueous polymeric carrier which may be added directly to a melt flow of a polymeric host material. The additive system employed in the polymeric systems is most preferably in the form of a particulate paste which can be added in metered amounts (dosed) to a melt flow of the polymeric host material prior to being spun into filaments. By providing a number of additive systems having a number of different additive attributes, and controllably dosing one or more into the melt flow of host polymeric material, shaped objects of the polymeric material (e.g., melt-spun filaments) having different additive attributes may be produced on a continuous basis without shutting down the shaping operation.
    Type: Grant
    Filed: May 11, 1998
    Date of Patent: May 15, 2001
    Assignee: BASF Corporation
    Inventors: Donald Caswell, Frank R. Jones, David B. Ledford, Stanley A. McIntosh, Gary W. Shore, Karl H. Buchanan, Wayne S. Stanko, G. Daniel Gasperson, Charles F. Helms, Jr.
  • Patent number: 5834089
    Abstract: Synthetic filaments include a nonaqueous additive system having dispersant-coated pigments physically dispersed in a liquid nonaqueous polymeric carrier. The additive system is most preferably in the form of a particulate paste which can be added in metered amounts (dosed) to a melt flow of the polymeric host material prior to being spun into filaments. By providing a number of additive systems having a number of different additive attributes, and controllably dosing one or more into the melt flow of polymeric material, melt-spun filaments having different additive attributes may be produced on a continuous basis (i.e., without shutting down the spinning operation). The filaments may be included in yarns which are formed into carpet structures.
    Type: Grant
    Filed: March 3, 1997
    Date of Patent: November 10, 1998
    Assignee: BASF Corporation
    Inventors: Frank R. Jones, Stanley A. McIntosh, Gary A. Shore, Karl H. Buchanan, David B. Ledford, Wayne S. Stanko, G. Daniel Gasperson, Charles F. Helms, Jr.
  • Patent number: 5833893
    Abstract: Methods of continuously producing sequential lengths of different additive-containing melt-spun filaments include continuously supplying a melt-spinnable polymeric host material to orifices of a spinneret and controllably dosing at least one dispersible additive concentrate system containing a pigment in a liquid nonaqueous polymeric carrier to the melt flow of polymeric host material upstream of the spinneret orifices. In such a manner, a first polymeric mixture of the dispersible additive concentrate system and the polymeric host material is obtained which achieves an additive attribute. During a first time interval, the first mixture is extruded through the spinneret orifices; and thereafter, during a second subsequent time interval, the dosing of the at least one dispersible additive is changed so as to form a second mixture having a second additive attribute different from the first additive attribute while continuously supplying the melt flow of polymeric host material to the spinneret orifices.
    Type: Grant
    Filed: March 3, 1997
    Date of Patent: November 10, 1998
    Assignee: BASF Corporation
    Inventors: Frank R. Jones, Stanley A. McIntosh, Gary W. Shore, Karl H. Buchanan, David B. Ledford, Wayne S. Stanko, G. Daniel Gasperson, Charles F. Helms, Jr.
  • Patent number: 5800746
    Abstract: Nonaqueous additive systems which includes dispersant-coated pigments physically dispersed in a liquid nonaqueous polymeric carrier are added directly to a melt flow of a polymeric host material prior to spinning. The additive system is most preferably in the form of a particulate paste which can be added in metered amounts (dosed) to a melt flow of the polymeric host material prior to being spun into filaments. By providing a number of additive systems having a number of different additive attributes, and controllably dosing one or more into the melt flow of polymeric material, melt-spun filaments having different additive attributes may be produced on a continuous basis (i.e., without shutting down the spinning operation).
    Type: Grant
    Filed: March 3, 1997
    Date of Patent: September 1, 1998
    Assignee: BASF Corporation
    Inventors: Frank R. Jones, Stanley A. McIntosh, Gary A. Shore, Karl H. Buchanan, David B. Ledford, Wayne S. Stanko, G. Daniel Gasperson, Charles F. Helms, Jr.
  • Patent number: 5664455
    Abstract: A laboratory-scale device for assisting in the simulation of heat setting conditions includes a pair of laterally spaced-apart flexible heat-resistant cords (e.g., formed of aramid fibers) tensioned between forward and rearward rigid cross-support bars. At least one rigid tensioning bar is provided parallel to the support cords and extending between the cross-support bars so as to maintain the desired tension on the flexible heat-resistant cords. The tensioning bar thus allows for manual or automated lateral winding of the synthetic heat-settable fibers or yarns about the spaced-apart heat-resistant cords during preparation of the device for a laboratory test run. The tensioning bar may thereafter be removed once the device has been secured in position with the laboratory heat-setting oven. In such a manner, therefore, various effects on heat-setting conditions simulating can be investigated.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: September 9, 1997
    Assignee: BASF Corporation
    Inventors: Ann S. Johnson, John A. Kilpatrick, Lewis W. Davis, Jr., David B. Ledford, Larry D. Henderson, Phillip E. Wilson