Patents by Inventor David F. Dostal

David F. Dostal 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: 8382464
    Abstract: The present invention is directed to a device for the production of a cellular wood plastic composite material comprised of an orifice that conducts the composite material from the adapter of the extruder to the transition die plate in such a manner that a uniform flow of material reaches the transition die plate; a transition die plate that further directs the flow of material to a flow restriction die plate in a manner ensuring that equal amounts of material are delivered to all areas of the flow restriction die plate; a flow restriction die plate that provides sufficient resistance to material flow to increase the melt pressure of the portion of the material that is upstream in relation to the flow restriction die plate and controls the temperature increase caused by this restriction by dividing the flow into numerous suitably sized and shaped streams; a compression die plate that fuses the separate streams issuing from the flow restriction die plate into a single stream of material and maintains the melt
    Type: Grant
    Filed: September 17, 2007
    Date of Patent: February 26, 2013
    Assignee: Strandex Corporation
    Inventors: Brian D. Keller, David F. Dostal, Terry C. Laver, Alfred B. England
  • Patent number: 8157556
    Abstract: A system for controlling the dimensions of an extrudate exiting an extruder and for compensating for the variations in the extrusion rate of the extruder, expansion rate and rate of travel of the extrudate through sizing devices by changing the speed of an extrudate puller device, includes an extruder which extrudes the extrudate; a conveyor system comprising rollers and a series of sizing devices; a puller device for pulling the extrudate through the sizing devices; and a laser proximity measuring device to assist the system in keeping the desired shape of the extrudate. The laser proximity measuring device includes at least one pair of optical non-contact displacement transducers, a real time processor, and an interactive touch screen display unit. The transducers emit a laser beam which provides a laser point on the side of the extrudate.
    Type: Grant
    Filed: October 12, 2007
    Date of Patent: April 17, 2012
    Assignee: Strandex Corporation
    Inventor: David F. Dostal
  • Patent number: 7431872
    Abstract: A low-pressure CO2 tank or an air compressor with a refrigerated air dryer is attached to the vent zone of a standard twin-screw extruder. During extrusion, the gas is dissolved in the wood-plastic melt. The CO2 expands which foams the wood-plastic material.
    Type: Grant
    Filed: April 26, 2002
    Date of Patent: October 7, 2008
    Assignee: Washington State University
    Inventors: David F. Dostal, Michael P. Wolcott
  • Publication number: 20080088049
    Abstract: A system for controlling the dimensions of an extrudate exiting an extruder and for compensating for the variations in the extrusion rate of the extruder, expansion rate and rate of travel of the extrudate through sizing devices by changing the speed of an extrudate puller device, includes an extruder which extrudes the extrudate; a conveyor system comprising rollers and a series of sizing devices; a puller device for pulling the extrudate through the sizing devices; and a laser proximity measuring device to assist the system in keeping the desired shape of the extrudate. The laser proximity measuring device includes at least one pair of optical non-contact displacement transducers, a real time processor, and an interactive touch screen display. The transducers emit a laser beam which provides a laser point on the side of the extrudate.
    Type: Application
    Filed: October 12, 2007
    Publication date: April 17, 2008
    Inventor: David F. Dostal
  • Patent number: 7186102
    Abstract: A low-pressure CO2 tank or an air compressor with a refrigerated air dryer is attached either at or after the vent zone of a standard twin-screw extruder. During or after extrusion, the gas is dissolved in the wood-plastic melt. The CO2 expands which foams the wood-plastic material.
    Type: Grant
    Filed: October 27, 2003
    Date of Patent: March 6, 2007
    Assignee: Strandex Corporation
    Inventors: Terry C. Laver, Brian Keller, Alfred B. England, David F. Dostal
  • Publication number: 20040147625
    Abstract: A low-pressure CO2 tank or an air compressor with a refrigerated air dryer is attached to the vent zone of a standard twin-screw extruder. During extrusion, the gas is dissolved in the wood-plastic melt. The CO2 expands which foams the wood-plastic material.
    Type: Application
    Filed: March 18, 2004
    Publication date: July 29, 2004
    Inventors: David F. Dostal, Michael P. Wolcott