Patents by Inventor Pieter Jan Lemstra

Pieter Jan Lemstra 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: 9205589
    Abstract: The present invention relates to a process for the preparation of polymer filaments having a high tensile strength and modulus by extrusion of a solution of a solvent and linear high-molecular weight polymer and subsequent spinning and quenching of the filaments thus formed, wherein after spinning and quenching the as-spun filaments are stretched under contact with steam for removing the solvent from filaments being stretched.
    Type: Grant
    Filed: October 5, 2011
    Date of Patent: December 8, 2015
    Assignee: POLYMER RESEARCH & DEVELOPMENT
    Inventors: Pieter Jan Lemstra, Robert Marc Fifield, Altug Altay
  • Publication number: 20130241105
    Abstract: The present invention relates to a process for the preparation of polymer filaments having a high tensile strength and modulus by extrusion of a solution of a solvent and linear high-molecular weight polymer and subsequent spinning and quenching of the filaments thus formed, wherein after spinning and quenching the as-spun filaments are stretched under contact with steam for removing the solvent from filaments being stretched.
    Type: Application
    Filed: October 5, 2011
    Publication date: September 19, 2013
    Applicant: POLYMER RESEARCH & DEVELOPMENT
    Inventors: Pieter Jan Lemstra, Robert Marc Fifield, Altug Altay
  • Patent number: 6433120
    Abstract: A method for processing ultra-high molecular weight polyethylene (UHMWPE) of at least 400,000 by heating under an elevated pressure, followed by cooling, wherein UHMWPE having a lamellar thickness <12 nm and a melting temperature at atmospheric pressure >141° C. is used, by carrying out the heating under an elevated pressure via a transient hexagonal phase, which phase is represented by the hatched area in the Figure, which lies below the equilibrium line of the phase transition orthorhombic phase—liquid phase, which area is enclosed by points (P1, T1′), (P2, T1′), (P2, T2) and (P1, T1 ), wherein T1 and T2 represent the equilibrium temperatures associated with pressures P1 and P2 respectively, followed by heating to melting and cooling to ambient temperature.
    Type: Grant
    Filed: October 27, 1999
    Date of Patent: August 13, 2002
    Assignee: Technische Universiteit Eindhoven
    Inventors: Sanjay Rastogi, Pieter Jan Lemstra, Peter Paul Koets