Search Patents
  • Microchip apparatus
    Publication number: 20020185379
    Abstract: The present invention provides an improved microchip measurement apparatus 15 comprising an external reservoir 24 connected via an input line 28 and output line 29 to a well 21 disposed on the microchip 20. The reservoir and well are preferable sealed and a pump 26 is connected to the input line so as to enable a continuous flow of liquid from the reservoir to the well. Advantageously, the present invention allows for the volume of liquid in the well to be kept constant, thereby improving the overall measurement accuracy.
    Type: Application
    Filed: April 12, 2002
    Publication date: December 12, 2002
    Applicant: Agilent Technologies, Inc.
    Inventors: Walter Schrenk, Tobias Preckel
  • Microchip apparatus
    Patent number: 7186382
    Abstract: A system and method for providing an improved microchip measurement apparatus comprising an external reservoir connected via an input line and output line to a well disposed on the microchip. The reservoir and well may be sealed and a pump connected to the input line so as to enable a continuous flow of liquid from the reservoir to the well. In addition, the volume of liquid in the well may be kept constant, thereby improving the overall measurement accuracy.
    Type: Grant
    Filed: April 12, 2002
    Date of Patent: March 6, 2007
    Assignee: Agilent Technologies, Inc.
    Inventors: Walter Schrenk, Tobias Preckel
  • Interfacial surface generator
    Patent number: 5094788
    Abstract: Method and apparatus are disclosed for making multilayer film having a prescribed gradient in, or distribution of, the thicknesses of one or more materials through the thickness of the film.
    Type: Grant
    Filed: December 21, 1990
    Date of Patent: March 10, 1992
    Assignee: The Dow Chemical Company
    Inventors: Walter J. Schrenk, Ranganath K. Shastri, Ralph F. Ayres, Daniel J. Gosen
  • Multilayer coextrusion process for producing selective reflectivity
    Patent number: 4094947
    Abstract: Multilayer film or sheet prepared by coextrusion is extruded wherein the thickness of the inner layers is varied by varying the flow of one component to the central portion of the sheet while diverting that portion to an external portion of the sheet or film.
    Type: Grant
    Filed: September 3, 1976
    Date of Patent: June 13, 1978
    Assignee: The Dow Chemical Company
    Inventors: Turner Alfrey, Jr., Walter J. Schrenk
  • Method of making a hollow light pipe
    Patent number: 4806289
    Abstract: A hollow light conductor with enhanced light-transmitting properties is formed by the coextrusion of polymeric materials. The hollow light conductor comprises a continuous annular core layer encased in inner and outer cladding layers.
    Type: Grant
    Filed: January 16, 1987
    Date of Patent: February 21, 1989
    Assignee: The Dow Chemical Company
    Inventors: Larry J. Laursen, Virgil W. Coomer, Walter J. Schrenk
  • Layer thickness gradient control in multilayer polymeric bodies
    Patent number: 5389324
    Abstract: Methods and apparatus for generating, and then precisely controlling, layer thickness gradients in multilayered polymeric reflective bodies are provided. The creation of such gradients is useful in tailoring multilayer bodies to reflect and/or transmit desired wavelengths of light. Both thermal and mechanical methods, as well as combinations thereof, are used.
    Type: Grant
    Filed: June 7, 1993
    Date of Patent: February 14, 1995
    Assignee: The Dow Chemical Company
    Inventors: Ray A. Lewis, David M. Wisniewski, Ravi Ramanathan, Walter J. Schrenk
  • Method of making a polymeric optical waveguide by coextrusion
    Patent number: 4871487
    Abstract: A quadrangular optical waveguide is formed by the coextrusion of polymeric materials. The waveguide comprises a solid light conducting core which is encased in a cladding layer having a lower index of refraction. Taps may be formed in the waveguide by a heated probe to deflect light out of the waveguide.
    Type: Grant
    Filed: January 16, 1987
    Date of Patent: October 3, 1989
    Assignee: The Dow Chemical Company
    Inventors: Larry J. Laursen, Virgil W. Coomer, Walter J. Schrenk
  • Method of preparing blown thermoplastic articles having multiaxial orientation
    Patent number: 4122138
    Abstract: A method for manufacturing blown articles is disclosed wherein the article is manufactured from a parison having a high degree of multi-axial orientation. The method permits molecular orientation within the parison to be superposed with orientation imparted during the blowing step, whereby a blown article of greatly improved properties is manufactured.
    Type: Grant
    Filed: January 6, 1975
    Date of Patent: October 24, 1978
    Assignee: The Dow Chemical Company
    Inventors: Kenneth J. Cleereman, Walter J. Schrenk, Grant W. Cheney
  • Multilayer film indicator for determining the integrity or authenticity of an item and process for using same
    Patent number: 5095210
    Abstract: A multilayer film indicator, mechanism and process for using the indicator for determining the integrity, authenticity, or conformance of an item to an original state, involving the measurement and comparison of the condition of the indicator to an identifiable original quality of the indicator. The identifiable original quality of the indicator is produced by the optical interactions of layers of diverse thermoplastic materials within a laminate of the indicator and is not readily visible to the naked eye.
    Type: Grant
    Filed: April 6, 1990
    Date of Patent: March 10, 1992
    Assignee: The Dow Chemical Company
    Inventors: John A. Wheatley, Walter J. Schrenk
  • Lamellar polymeric body
    Patent number: 5217794
    Abstract: A lamellar polymeric body which may be reflective and which contains no metals and method of making it are provided. The body can be fabricated and/or post-formed into a variety of parts without alteration of its appearance. The body includes discontinuous layers of at least one polymeric material within a matrix of another polymeric material, which polymers differ in refractive index. The layers of the polymeric material may be either optically thick, optically thin, or optically very thin.
    Type: Grant
    Filed: January 22, 1991
    Date of Patent: June 8, 1993
    Assignee: The Dow Chemical Company
    Inventor: Walter J. Schrenk
  • Method and apparatus for producing multilayer plastic articles
    Patent number: 5628950
    Abstract: Methods and apparatus are provided for making multilayer plastic articles. Initially, two or more streams of diverse thermoplastic materials are provided. Layers are formed from these streams and are arranged in a layered first composite stream. The first composite stream may be directly formed into a desired configuration by a molding process or may be manipulated to form a second composite stream having an increased number of layers before being formed into the desired configuration. The resulting articles are comprised of a number of discrete and substantially continuous layers.
    Type: Grant
    Filed: September 30, 1994
    Date of Patent: May 13, 1997
    Assignee: The Dow Chemical Company
    Inventors: Walter J. Schrenk, Ranganath K. Shastri, Herbert C. Roehrs, Ralph E. Ayres, Mark A. Barger, Jeffrey N. Bremmer
  • Methods and apparatus for generating interfacial surfaces
    Patent number: 5094793
    Abstract: Method and apparatus for generating interfacial surfaces in a fluid mass which:(a) divide a first stream of the fluid mass into a plurality of branch streams, redirect or reposition the branch streams, expand and contract the branch streams in a symmetrical fashion, and recombine the branch streams to form a second stream of the fluid mass; or(b) divide a first stream of the fluid mass into a plurality of branch streams, redirect or reposition the branch streams, recombine the branch streams to form a second stream of the fluid mass, and expand and contract the second stream in a symmetrical fashion.
    Type: Grant
    Filed: December 21, 1990
    Date of Patent: March 10, 1992
    Assignee: The Dow Chemical Company
    Inventors: Walter J. Schrenk, Ranganath K. Shastri, Ralph E. Ayres, Daniel J. Gosen
  • Two component infrared reflecting film
    Patent number: 5360659
    Abstract: The present invention provides a two-component infrared reflecting film which reflects light in the infrared region of the spectrum while suppressing second, third and fourth order reflections in the visible spectrum. The film comprises alternating layers of first (A) and second (B) diverse polymeric materials having a six layer alternating repeat unit with relative optical thicknesses of about .778A.111B.111A.778B.111A.111B. The polymeric materials differ from each other in refractive index by at least about 0.03.
    Type: Grant
    Filed: May 24, 1993
    Date of Patent: November 1, 1994
    Assignee: The Dow Chemical Company
    Inventors: Charles B. Arends, Walter J. Schrenk, Ray A. Lewis, Ravi Ramanathan, John Wheatley
  • Method and apparatus for producing multilayer plastic articles
    Patent number: 5380479
    Abstract: Methods and apparatus are provided for making multilayer plastic articles. Initially, two or more streams diverse thermoplastic materials are provided. Layers are foraged from these streams and are arranged in a layered first composite stream. The first composite stream may be directly formed into a desired configuration by a molding process or may be manipulated to form a second composite stream having an increased number of layers before being formed into the desired configuration. The resulting articles are comprised of a number of discrete and substantially continuous layers.
    Type: Grant
    Filed: November 9, 1992
    Date of Patent: January 10, 1995
    Assignee: The Dow Chemical Company
    Inventors: Walter J. Schrenk, Herbert C. Roehrs, Ranganath K. Shastri, Ralph E. Ayres, Mark A. Barger, Jeffrey N. Bremmer
  • Infrared reflective optical interference film
    Patent number: 5103337
    Abstract: The present invention provides an optical interference film, made of multiple layers of polymers, which reflects wavelengths of light in the infrared region of the spectrum while being substantially transparent to wavelengths of light in the visible spectrum. The optical interference film includes multiple alternating layers of at least first, second, and third diverse, substantially transparent polymeric materials A, B, and C, with the layers being of an optical thickness of between about 0.09 and 0.45 micrometers. Each of the polymeric materials has a different index of refraction, n.sub.i, and the refractive index of the second polymeric material is intermediate the respective refractive indices of the first and third polymeric materials.
    Type: Grant
    Filed: July 24, 1990
    Date of Patent: April 7, 1992
    Assignee: The Dow Chemical Company
    Inventors: Walter J. Schrenk, John A. Wheatley
  • Method for producing injection molded multilayer articles
    Patent number: 5202074
    Abstract: A method of making a multilayer plastic article by forming a multilayer stream of diverse thermoplastic materials and injection molding the multilayer stream directly into the article. The multilayer stream can be formed by coextrusion of the materials or by coextrusion followed by layer multiplication in one or more interfacial surface generators/static mixers. The coextruded stream, or a multiplied stream from the one or more ISG's, can also be divided into substreams and the substreams thereafter recombined prior to being injection molded so that the layers in one such substream are angularly oriented with respect to the layers in another substream.
    Type: Grant
    Filed: April 11, 1991
    Date of Patent: April 13, 1993
    Assignee: The Dow Chemical Company
    Inventors: Walter J. Schrenk, Ranganath K. Shastri, Herbert C. Roehrs, Ralph E. Ayres
  • Polymeric interference film
    Publication number: 20010046086
    Abstract: A birefringent interference polarizer which may be fabricated from readily available materials using established coextrusion techniques is provided. The polarizer has a level of light absorption near zero and can be fabricated to polarize and reflect light of specific wavelengths while transmitting light of other wavelengths. The polarizer includes multiple alternating oriented layers of at least first and second polymeric materials having respective nonzero stress optical coefficients which are sufficiently different to produce a refractive index mismatch between the first and second polymeric materials in a first plane which is different from the refractive index mismatch between the first and second polymeric materials in a second plane normal to the first plane. The refractive index mismatch in the first plane is preferably at least 0.03.
    Type: Application
    Filed: July 24, 2001
    Publication date: November 29, 2001
    Applicant: 3M Innovative Properties Company
    Inventors: John A. Wheatley, Walter J. Schrenk
  • Elastomeric optical interference films
    Patent number: 4937134
    Abstract: The present invention provides improved elastomeric interference films which are readily coextruded, have improved transparency, and have greater mismatches of refractive indices than those of the prior art. An improved elastomeric optical interference film comprising at least 100 alternating layers of at least first and second divergent substantially transparent elastomeric polymeric materials is provided. Adjacent layers of the first and second polymeric materials differ from each other in refractive index by at least about 0.05, and the thickness of the layers is from about 0.05 to about 0.5 micrometers. Stretching the films results in different wavelengths of light being reflected.
    Type: Grant
    Filed: April 17, 1989
    Date of Patent: June 26, 1990
    Assignee: The Dow Chemical Company
    Inventors: Walter J. Schrenk, William E. Shrum, John A. Wheatley
  • Relective polymeric body
    Patent number: 5122905
    Abstract: A multilayered reflective body which is thermoformable and capable of being fabricated into relatively thick parts while maintaining a uniform reflective appearance is provided. The reflective polymeric body includes at least first and second diverse polymeric materials of a sufficient number of alternating layers of the first and second polymeric materials such that at least 30% of the light incident on the body is reflected. A substantial majority of the individual layers of the body have an optical thickness of at least 0.45 micrometers, and adjacent layers of the first and second polymeric materials differ from each other in refractive index by at least about 0.03. The reflective body may be fabricated into sheets, mirrors, noncorroding metallic appearing articles and parts, reflectors, reflective lenses, and the like.
    Type: Grant
    Filed: January 11, 1990
    Date of Patent: June 16, 1992
    Assignee: The Dow Chemical Company
    Inventors: John A. Wheatley, Walter J. Schrenk
  • Infrared reflective optical interference film
    Patent number: RE34605
    Abstract: The present invention provides an optical interference film, made of multiple layers of polymers, which reflects wavelengths of light in the infrared region of the spectrum while being substantially transparent to wavelengths of light in the visible spectrum. The optical interference film includes multiple alternating layers of at least first, second, and third diverse, substantially transparent polymeric materials A, B, and C, with the layers being of an optical thickness of between about 0.09 and 0.45 micrometers. Each of the polymeric materials has a different index of refraction, n.sub.i, and the refractive index of the second polymeric material is intermediate the respective refractive indices of the first and third polymeric materials.
    Type: Grant
    Filed: December 11, 1992
    Date of Patent: May 10, 1994
    Assignee: The Dow Chemical Company
    Inventors: Walter J. Schrenk, John A. Wheatley
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