Patents by Inventor Narasimhan Raghupathi

Narasimhan Raghupathi 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: 6171984
    Abstract: This invention relates to generally to geosynthetic materials which can be used for earthen reinforcement, and more particularly to a novel geosynthetic material exhibiting less strain under an initial tensile load then presently available geosynthetic materials.
    Type: Grant
    Filed: December 3, 1997
    Date of Patent: January 9, 2001
    Assignee: PPG Industries Ohio, Inc.
    Inventors: John N. Paulson, Mikhail M. Girgis, Jeffrey A. Neubauer, Narasimhan Raghupathi
  • Patent number: 6139958
    Abstract: Chemically treated glass fibers having good processability are useful in producing fiber reinforced polymeric matrices, wherein the glass fibers have controlled wettability and are not detrimental to the weatherability of the fiber reinforced polymeric matrices. The chemically treated fibers have the dried residue of an aqueous chemical treating composition having a bisphenol A polyester film forming polymer compatible with and soluble in the matrix polymer, poly(vinyl acetate) polymeric film former, acryloxy-containing or methacryloxy-containing organo coupling agent in an effective coupling agent amount, cationic fiberous lubricant in an effective lubricating amount, with or without a cationic organic quaternary ammonium salt having alkoxy moieties, and with water in an amount to give a total solid for the aqueous chemical treating composition in the range of about 1 to about 30 weight percent.
    Type: Grant
    Filed: February 14, 1994
    Date of Patent: October 31, 2000
    Assignee: PPG Industries Ohio, Inc.
    Inventors: Narasimhan Raghupathi, Philip L. Schell, James C. Watson, David T. Melle
  • Patent number: 5141802
    Abstract: Chemically treated glass shapes have a moisture-reduced residue of a chemical treating composition having: a first film forming polymer that is a thermoplastic polyester film forming polymer, a second film forming polymer that is an acrylic-type copolymer, at least one organosilane coupling agent selected from epoxy functional organosilane coupling agents and amino-functional organosilane coupling agents and mixtures thereof, at least one cationic lubricant and a carrier. The ratio of amounts of the first film forming polymer to the second film forming polymer is in the range of around 1:1 to 99:1. The chemically treated shapes can be in the form of beads, flakes, chopped or milled fibers, continuous fibers, strands, or bundles of fibers and yarn, and mats of continuous strand and/or chopped strand.
    Type: Grant
    Filed: February 13, 1991
    Date of Patent: August 25, 1992
    Assignee: PPG Industries, Inc.
    Inventors: Luciano M. Parrinello, Narasimhan Raghupathi
  • Patent number: 4950532
    Abstract: Fiber reinforced thermoplastic parts having good surface characteristics are produced by a process involving: preheating fiber reinforced composite to achieve at least a flowable viscosity of the polymer, and (2) molding under controlled rheological conditions. The preheating is conducted on composites that are predominantly amorphous thermoplastic polymers, copolymers, polyblends or alloys reinforced with continuous glass fiber strand reinforcing mat. The amount of the mat present in the laminate is less than around 40 weight percent of the composite. The temperature of preheating is at least greater than the glass transition temperature of the polymer and less than the degradation temperature of the polymer to expand the composite.
    Type: Grant
    Filed: October 30, 1986
    Date of Patent: August 21, 1990
    Assignee: Azdel, Inc.
    Inventors: Balbhadra Das, Narasimhan Raghupathi, Thomas V. Thimons
  • Patent number: 4681802
    Abstract: Treated glass fibers having adequate protection for gathering into strands and when chopped being more dispersible in aqueous media. The treated glass fibers have a coating of an aqueous treating composition, wherein the solids have a cationic surfactant having one or more primary, secondary and/or tertiary amine moieties and one or more water dispersible, poly(oxyethylene-oxyalkylene) copolymer having an oxide ratio of about 78 to about 22 to about 99 to about 1 and an average molecular weight of at least 15,000, and one or more polar functional coupling agents. Optionally, the solids may also have one or more starches that are insoluble or only incompletely soluble in cold water. Glass fibers treated with the aqueous treating compositions and produced into wet or dry chopped glass fiber strands having lengths of about 1/16 of an inch (1.58 mm) to about 3 inches (76.2 mm), have good dispersibility in aqueous media with or without addition of dispersing agents.
    Type: Grant
    Filed: February 28, 1986
    Date of Patent: July 21, 1987
    Assignee: PPG Industries, Inc.
    Inventors: Peter C. Gaa, Jerry C. Hedden, Narasimhan Raghupathi
  • Patent number: 4592956
    Abstract: Treated glass fibers having adequate protection for gathering into strands and when chopped being more dispersible in aqueous media. The treated glass fibers having a coating of an aqueous treating composition, wherein the solids have a cationic surfactant having one or more primary, secondary and/or tertiary amine moieties and one or more water dispersible, poly(oxyethylene-oxyalkylene) copolymer having an oxide ratio of about 78 to about 22 to about 99 to about 1 and an average molecular weight of at least 15,000, and one or more polar functional coupling agents. Optionally, the solids may also have one or more starches that are insoluble or only incompletely soluble in cold water. Glass fibers treated with the aqueous treating compositions and produced into wet or dry chopped glass fiber strands having lengths of about 1/16 of an inch (1.58 mm) to about 3 inches (76.2 mm), have good dispersibility in aqueous media with or without addition of dispersing agents.
    Type: Grant
    Filed: October 5, 1984
    Date of Patent: June 3, 1986
    Assignee: PPG Industries, Inc.
    Inventors: Peter C. Gaa, Jerry C. Hedden, Narasimhan Raghupathi
  • Patent number: 4300410
    Abstract: Light weight component (FIG. 1) comprising hollow, tubular member (A) with load transmission means (B) at its ends and filaments (E) in a plastic matrix C encircling the member and transmission means may be used as tension compression member. The tubular member preferably is a pultrusion adapted to contain sufficient filaments to tensilely strengthen the component. The component may be made, for example, by winding or wrapping filaments about the member while load transmission means are at its ends.
    Type: Grant
    Filed: January 4, 1980
    Date of Patent: November 17, 1981
    Assignee: Ford Motor Company
    Inventors: Narasimhan Raghupathi, Edward A. Kure
  • Patent number: 4191718
    Abstract: Mechanical properties of compression molded composites having thick sections and made from molding compounds comprising thermosetting resin and reinforcing fiber in a thickened dispersion are improved by a preheating stage and mold cycle times that are longer than the time necessary to reach the highest peak exotherm temperature of the composite during molding. Slow post cooling allows for development of properties especially when mold opening times are shorter than that required for removal of all thermal gradients.
    Type: Grant
    Filed: December 19, 1977
    Date of Patent: March 4, 1980
    Assignee: Ford Motor Company
    Inventors: Pankaj K. Mallick, Narasimhan Raghupathi