Patents by Inventor Lin-Fa Lee

Lin-Fa Lee 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).

  • Steam draw-jet process for making partially-oriented polyamide yarns
    Patent number: 5284612
    Abstract: A coupled process for making partially-oriented polyamide yarn. Polyamide polymer is melt-spun at a withdrawal speed sufficient to produce a spun yarn having an elongation less than 175%. The spun yarn is subsequently subjected to a coupled drawing step in a draw zone to reduce the elongation to the range of 50 to 100%. In the draw zone, the yarn passes through an enclosure with a gaseous fluid jet having a temperature of at least about 190.degree. C. which impinges on the yarn in an intersecting relationship to the path of yarn travel.
    Type: Grant
    Filed: November 23, 1992
    Date of Patent: February 8, 1994
    Assignee: E. I. Du Pont de Nemours and Company
    Inventor: Lin-Fa Lee
  • Sheath-core cospun heather yarns
    Patent number: 4059949
    Abstract: A composite yarn exhibiting heather dyeing capability is comprised of two groups of filaments composed of two differently dyeable polymers wherein filaments of one group are homofilaments of one polymer and filaments of the other group are of a substantially concentric sheath core structure with the sheath being of the other polymer and the core being of the same polymer as the homofilaments. The yarn dyes to give a heather appearance which is different from the appearance expected based on the polymer composition of the yarn.
    Type: Grant
    Filed: September 2, 1976
    Date of Patent: November 29, 1977
    Assignee: E. I. Du Pont de Nemours and Company
    Inventor: Lin-Fa Lee
  • Process for sheath-core cospun heather yarns
    Patent number: 3992499
    Abstract: In cospinning two fiber-forming polymers to produce a composite heather yarn from filaments of different dyeability, the apparent weight ratio of one polymer in the yarn can be varied by spinning only a portion of that polymer as a monocomponent filament and hiding the remainder as the core of a sheath-core filament having the other polymer as its sheath. Thus, a wide range of apparent weight ratios of the two polymers in the cospun yarn is provided, without changing the flow rate of the two polymer solutions fed to the spinneret.
    Type: Grant
    Filed: February 15, 1974
    Date of Patent: November 16, 1976
    Assignee: E. I. Du Pont de Nemours and Company
    Inventor: Lin-Fa Lee