Patents by Inventor Yong Sang Yi

Yong Sang Yi 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).

  • Method of preparing hollow fiber-type separation membrane from high density polyethylene
    Patent number: 6436319
    Abstract: A method for preparing a hollow fiber-type separation membrane from high density polyethylene is provided, which includes the steps of: melt-spinning a mixture of a high density polyethylene and a diluting agent to produce a phase-separated undrawn hollow fiber; detecting a tensile strength of the undrawn fiber during an alternative and repetitive winding and unwinding procedure between two bobbins, said undrawn fiber being drawn during the alternative and repetitive winding and unwinding procedure; reducing a rotation speed of one of the two bobbins when the detected tensile strength is larger than a predetermined value; and increasing a rotation speed of one of the two bobbins when the detected tensile strength is smaller than the predetermined value to yield the hollow fiber-type separation membrane.
    Type: Grant
    Filed: January 13, 2000
    Date of Patent: August 20, 2002
    Assignee: Agency for Technology and Standards
    Inventors: Hyang Sun, Yong Sang Yi, Kyu Bong Rhee