Patents by Inventor Natalia V Levit

Natalia V Levit 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: 11077325
    Abstract: An article of protective clothing comprising a durable multilayer fabric laminate formed from i) a first flame resistant knitted fabric made from yarns, the fabric having an average fabric modulus of 8 grams-force of greater; ii) a flame-resistant nonwoven fabric having a machine direction and a cross direction, and consisting of a plurality of continuous filaments having a diameter of less than 1000 nm, the filaments in the fabric being substantially oriented parallel with the machine direction and having stretch and recovery in the cross direction; and iii) a second flame resistant knitted fabric made from yarns, the fabric having an average fabric modulus of 8 grams-force of greater; wherein the nonwoven fabric is positioned between and coextensive with the first and second flame-resistant knitted fabrics; the nonwoven fabric being attached to the first knitted fabric by a set of first attachment points, the attachment points defining a first unattached area having a first effective diameter; the nonwov
    Type: Grant
    Filed: March 10, 2017
    Date of Patent: August 3, 2021
    Assignee: DUPONT SAFETY & CONSTRUCTION, INC.
    Inventor: Natalia V Levit
  • Patent number: 9913504
    Abstract: The present invention relates to a flame resistant thermal liner comprising a nonwoven sheet comprising nanofibers of a synthetic polymer having an limiting oxygen index of at least 21, a mean flow pore of 10 micrometers or less, a thickness air permeability of 25 to 6000 cubic feet per min?micrometers (12 to 2880 cubic meters per square meter per min?micrometers), and an average thickness T1; and a thermally stable flame resistant fabric attached to an outer surface of the nonwoven sheet, the fabric having an average thickness T2; a surface of the thermally stable fabric being in contact with a surface of the nonwoven sheet; wherein T1 and T2 are selected such that the ratio of T1 to T2 is less than 0.75. The invention also relates to a flame resistant composite fabric comprising the flame resistant thermal liner and a garment comprising this flame resistant composite fabric.
    Type: Grant
    Filed: October 6, 2015
    Date of Patent: March 13, 2018
    Assignee: E I DU PONT DE NEMOURS AND COMPANY
    Inventors: Natalia V Levit, Richard Hall Young
  • Publication number: 20170281992
    Abstract: An article of protective clothing comprising a durable multilayer fabric laminate formed from i) a first flame resistant knitted fabric made from yarns, the fabric having an average fabric modulus of 8 grams-force of greater; ii) a flame-resistant nonwoven fabric having a machine direction and a cross direction, and consisting of a plurality of continuous filaments having a diameter of less than 1000 nm, the filaments in the fabric being substantially oriented parallel with the machine direction and having stretch and recovery in the cross direction; and iii) a second flame resistant knitted fabric made from yarns, the fabric having an average fabric modulus of 8 grams-force of greater; wherein the nonwoven fabric is positioned between and coextensive with the first and second flame-resistant knitted fabrics; the nonwoven fabric being attached to the first knitted fabric by a set of first attachment points, the attachment points defining a first unattached area having a first effective diameter; the nonwoven
    Type: Application
    Filed: March 10, 2017
    Publication date: October 5, 2017
    Inventor: NATALIA V. LEVIT
  • Patent number: 9735410
    Abstract: This invention provides a multi-layer article comprising a first electrode material, a second electrode material, and a porous separator disposed between and in contact with the first and the second electrode materials, wherein the porous separator comprises a nonwoven consisting essentially of a plurality of fibers of a fully aromatic polyimide. Also provided is a method for preparing the multi-layer article, and an electrochemical cell employing the same. A multi-layer article comprising a polyimide nonwoven with enhanced properties is also provided.
    Type: Grant
    Filed: November 5, 2014
    Date of Patent: August 15, 2017
    Assignee: E I DU PONT DE NEMOURS AND COMPANY
    Inventors: Pankaj Arora, Natalia V Levit
  • Publication number: 20160113340
    Abstract: The present invention relates to a flame resistant thermal liner comprising a nonwoven sheet comprising nanofibers of a synthetic polymer having an limiting oxygen index of at least 21, a mean flow pore of 10 micrometers or less, a thickness air permeability of 25 to 6000 cubic feet per min?micrometers (12 to 2880 cubic meters per square meter per min?micrometers), and an average thickness T1; and a thermally stable flame resistant fabric attached to an outer surface of the nonwoven sheet, the fabric having an average thickness T2; a surface of the thermally stable fabric being in contact with a surface of the nonwoven sheet; wherein T1 and T2 are selected such that the ratio of T1 to T2 is less than 0.75. The invention also relates to a flame resistant composite fabric comprising the flame resistant thermal liner and a garment comprising this flame resistant composite fabric.
    Type: Application
    Filed: October 6, 2015
    Publication date: April 28, 2016
    Applicant: E I DU PONT DE NEMOURS AND COMPANY
    Inventors: NATALIA V LEVIT, RICHARD HALL YOUNG
  • Publication number: 20150125737
    Abstract: This invention provides a multi-layer article comprising a first electrode material, a second electrode material, and a porous separator disposed between and in contact with the first and the second electrode materials, wherein the porous separator comprises a nonwoven consisting essentially of a plurality of fibers of a fully aromatic polyimide. Also provided is a method for preparing the multi-layer article, and an electrochemical cell employing the same. A multi-layer article comprising a polyimide nonwoven with enhanced properties is also provided.
    Type: Application
    Filed: November 5, 2014
    Publication date: May 7, 2015
    Inventors: Pankaj Arora, Natalia V. Levit
  • Publication number: 20130022858
    Abstract: This invention relates to separators for batteries and other electrochemical cells, especially lithium-ion batteries, having a shutdown mechanism. The separator is a laminate that contains a nonwoven nanoweb and a porous layer composed of a plurality of thermoplastic particles having particle size smaller than the mean flow pore size of the nanoweb. The shutdown layer melts and starts to flow at a desired temperature, and restricts the ion flow path, resulting in a substantial decrease in ionic conductivity of the separator at the desired shutdown temperature, while leaving the separator intact.
    Type: Application
    Filed: January 19, 2012
    Publication date: January 24, 2013
    Applicant: E.I. DU PONT DE NEMOURS AND COMPANY
    Inventors: Stephen Mazur, Simon Frisk, Natalia V. Levit
  • Publication number: 20130017431
    Abstract: This invention relates to separators for batteries and other electrochemical cells, especially lithium-ion batteries, having a shutdown mechanism. The separator comprises a nonwoven nanoweb comprising a coating composed of a plurality of thermoplastic particles having particle size larger than the mean flow pore size of the nanoweb. The coating flows at a desired temperature, and restricts the ion flow path, resulting in a substantial decrease in ionic conductivity of the separator at the desired shutdown temperature, while leaving the separator intact.
    Type: Application
    Filed: January 19, 2012
    Publication date: January 17, 2013
    Applicant: E. I. DU PONT DE NEMOURS AND COMPANY
    Inventors: SIMON FRISK, NATALIA V. LEVIT, PANKAJ ARORA
  • Publication number: 20130005940
    Abstract: A nanoweb that contains a plurality of nanofibers wherein the nanofibers contain a fully aromatic polyimide that is characterized by having a crystallinity index (CI) and a degree of imidization (DOI). The product of the DOI and the CI is between 0.08 and 0.25 or above a lower limit to obtain a desired tensile strength and/or toughness. The nanoweb may for example have a tensile strength per unit basis weight of greater than 15 kg/cm2 per gram per square meter unit of basis weight.
    Type: Application
    Filed: June 26, 2012
    Publication date: January 3, 2013
    Applicant: E I DU PONT DE NEMOURS AND COMPANY
    Inventors: T. Joseph Dennes, Glen E. Simmonds, Pankaj Arora, Natalia V. Levit
  • Patent number: 8025124
    Abstract: A passive distributed vibration absorber that utilizes multiple discrete mass elements and a viscoelastic layer and that effectively attenuates vibration in modally dense structures excited by a broadband input noise excitation. and is tunable to multiple natural frequencies in such modally dense vibrating structures including low frequencies.
    Type: Grant
    Filed: October 31, 2008
    Date of Patent: September 27, 2011
    Assignee: E. I. du Pont de Nemours and Company
    Inventors: Natalia V Levit, Mark Allan Lamontia, David M Mellen, Joseph A King, Jr., Kathleen Kondylas, Christopher R Fuller
  • Publication number: 20090173570
    Abstract: An acoustically absorbent ceiling tile includes a core of acoustically absorbing material having two major surfaces, and a facing for covering the core on at least one major surface. The facing comprises a porous flash spun plexifilamentary film-fibril sheet having a coherent surface and comprising a plurality of pores having a pore diameter between about 100 nm and about 20,000 nm and a mean pore diameter of less than about 20,000 nm. The facing has highly diffuse reflectance of light, and a reflectance of greater than about 86%. The use of the facing improves the acoustic absorption of ambient sound at frequencies below about 1200 Hz. The facing provides a barrier to moisture and particles including microorganisms so that the ceiling tile is suitable for use in environments in which cleanliness is critical.
    Type: Application
    Filed: December 19, 2008
    Publication date: July 9, 2009
    Inventors: Natalia V. Levit, Eric W. Teather
  • Publication number: 20090173569
    Abstract: An acoustic absorber includes a core of acoustically absorbing material having two major surfaces, and a facing for covering the core on at least one major surface. The facing comprises a porous flash spun plexifilamentary film-fibril sheet having a coherent surface and comprising a plurality of pores having a pore diameter between about 100 nm and about 20,000 nm and a mean pore diameter of less than about 20,000 nm. The use of the facing improves the acoustic absorption of ambient sound at a frequency below about 1200 Hz. The facing provides a barrier to moisture and particles including microorganisms so that the absorber is suitable for use in environments in which cleanliness is critical.
    Type: Application
    Filed: December 19, 2008
    Publication date: July 9, 2009
    Inventors: Natalia V. Levit, Eric W. Teather
  • Publication number: 20090113843
    Abstract: A passive distributed vibration absorber that utilizes multiple discrete mass elements and a viscoelastic layer and that effectively attenuates vibration in modally dense structures excited by a broadband input noise excitation and is tunable to multiple natural frequencies in such modally dense vibrating structures including low frequencies
    Type: Application
    Filed: October 31, 2008
    Publication date: May 7, 2009
    Inventors: Natalia V. Levit, Mark Allan Lamontia, David M. Mellen, Joseph A. King, JR., Kathleen Kondylas, Christopher R. Fuller