Patents by Inventor Wai Ming Choi

Wai Ming Choi 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: 11103833
    Abstract: Described is a polyethylene membrane and in particular an ultra-high molecular weight polyethylene member that provides a high air permeability and is hydrophobic. The membranes have small pores and are suitable for sterilization by exposure to gamma radiation. The membranes can be made by methods that involve one or more of stretching the membrane and grafting hydrophobic monomers onto the membrane surface. A perfluorinated monomer, such as perfluoro-n-octyl acrylate, can be grafted to one or more surfaces of the membrane. The membrane have a high flow rate compared to unstretched or ungrafted membranes.
    Type: Grant
    Filed: March 17, 2017
    Date of Patent: August 31, 2021
    Assignee: ENTEGRIS, INC.
    Inventors: Wai Ming Choi, Jad Ali Jaber, Vinay Goel, Vinay Kalyani, Anthony Dennis
  • Publication number: 20200406201
    Abstract: Described is a polyethylene membrane and in particular an ultra-high molecular weight polyethylene member that provides a high air permeability and is hydrophobic. The membranes have small pores and are suitable for sterilization by exposure to gamma radiation. The membranes can be made by methods that involve one or more of stretching the membrane and grafting hydrophobic monomers onto the membrane surface. A perfluorinated monomer, such as perfluoro-n-octyl acrylate, can be grafted to one or more surfaces of the membrane. The membrane have a high flow rate compared to unstretched or ungrafted membranes.
    Type: Application
    Filed: March 17, 2017
    Publication date: December 31, 2020
    Inventors: Wai Ming CHOI, Jad Ali JABER, Vinay GOEL, Vinay KALYANI, Anthony DENNIS
  • Patent number: 10150087
    Abstract: A purifier for removing metal, such as chromium, from an organic solvent is disclosed. The purifier comprises a housing having a fluid inlet and a fluid outlet in fluid communication with the fluid inlet; a volume of ion-exchange resin disposed within the housing downstream of the fluid inlet; and a filtration member downstream of the volume of ion-exchange resin, the filtration member comprising at least one microporous membrane having a substantially neutral surface and a microporous polytetrafluoroethylene membrane downstream of the at least one microporous membrane. A method for removing metal, including chromium, from an organic solvent using a purifier of the invention is also disclosed.
    Type: Grant
    Filed: August 12, 2015
    Date of Patent: December 11, 2018
    Assignee: Entegris, Inc.
    Inventors: Saksatha Ly, Wai Ming Choi
  • Patent number: 9457322
    Abstract: Embodiments of the invention include a liquid filter member that includes a layer of polymeric nano fibers overlying a microporous membrane. A pressure drop of the filter member is substantially the same, or is less than, a pressure drop of the microporous membrane and the filter member has a particle retention in the presence of surfactant that is greater than the particle retention of the microporous membrane alone under the same test conditions.
    Type: Grant
    Filed: April 12, 2010
    Date of Patent: October 4, 2016
    Assignee: Entegris, Inc.
    Inventors: Wai-Ming Choi, Kiminori Kataoka
  • Publication number: 20160166960
    Abstract: Filter media are provided having improved conductivity to enhance filtration efficiency and/or dissipate static charge, and methods for making the same. In one exemplary embodiment, the filter media can include a filtration substrate, and at least one conductive coating disposed on at least a portion of the filtration substrate. In use, the conductive coating is coupled to an energy source and it is effective to emit ions when energy is delivered thereto to increase the efficiency of the filtration substrate and/or to dissipate or eliminate static charge generated during filtration.
    Type: Application
    Filed: November 11, 2015
    Publication date: June 16, 2016
    Applicant: Hollingsworth & Vose Company
    Inventors: Wai Ming Choi, Karin N. Soper
  • Publication number: 20150343391
    Abstract: A purifier for removing metal, such as chromium, from an organic solvent is disclosed. The purifier comprises a housing having a fluid inlet and a fluid outlet in fluid communication with the fluid inlet; a volume of ion-exchange resin disposed within the housing downstream of the fluid inlet; and a filtration member downstream of the volume of ion-exchange resin, the filtration member comprising at least one microporous membrane having a substantially neutral surface and a microporous polytetrafluoroethylene membrane downstream of the at least one microporous membrane. A method for removing metal, including chromium, from an organic solvent using a purifier of the invention is also disclosed.
    Type: Application
    Filed: August 12, 2015
    Publication date: December 3, 2015
    Inventors: Saksatha Ly, Wai Ming Choi
  • Patent number: 9192942
    Abstract: Filter media are provided having improved conductivity to enhance filtration efficiency and/or dissipate static charge, and methods for making the same. In one exemplary embodiment, the filter media can include a filtration substrate, and at least one conductive coating disposed on at least a portion of the filtration substrate. In use, the conductive coating is coupled to an energy source and it is effective to emit ions when energy is delivered thereto to increase the efficiency of the filtration substrate and/or to dissipate or eliminate static charge generated during filtration.
    Type: Grant
    Filed: January 14, 2014
    Date of Patent: November 24, 2015
    Assignee: Hollingsworth & Vose Company
    Inventors: Wai Ming Choi, Karin N. Soper
  • Publication number: 20150144557
    Abstract: A purifier for removing metal, such as chromium, from an organic solvent is disclosed. The purifier comprises a housing having a fluid inlet and a fluid outlet in fluid communication with the fluid inlet; a volume of ion-exchange resin disposed within the housing downstream of the fluid inlet; and a filtration member downstream of the volume of ion-exchange resin, the filtration member comprising at least one microporous membrane having a substantially neutral surface and a microporous polytetrafluoroethylene membrane downstream of the at least one microporous membrane. A method for removing metal, including chromium, from an organic solvent using a purifier of the invention is also disclosed.
    Type: Application
    Filed: March 15, 2013
    Publication date: May 28, 2015
    Applicant: Entegris, Inc.
    Inventors: Saksatha Ly, Wai Ming Choi
  • Publication number: 20150001146
    Abstract: A filtration member comprising a nanofiber layer and two nanoporous membrane layers is disclosed. The filtration member can be used to remove particles and gels from photoresist and other fluids by a combination of sieving and non-sieving particle retention mechanisms.
    Type: Application
    Filed: May 9, 2012
    Publication date: January 1, 2015
    Applicant: Entegris, Inc.
    Inventors: Raul A. Ramirez, Wai Ming Choi
  • Publication number: 20140190353
    Abstract: Filter media are provided having improved conductivity to enhance filtration efficiency and/or dissipate static charge, and methods for making the same. In one exemplary embodiment, the filter media can include a filtration substrate, and at least one conductive coating disposed on at least a portion of the filtration substrate. In use, the conductive coating is coupled to an energy source and it is effective to emit ions when energy is delivered thereto to increase the efficiency of the filtration substrate and/or to dissipate or eliminate static charge generated during filtration.
    Type: Application
    Filed: January 14, 2014
    Publication date: July 10, 2014
    Applicant: Hollingsworth & Vose Company
    Inventors: Wai Ming Choi, Karin N. Soper
  • Publication number: 20130043183
    Abstract: Versions of the invention include electron beam treated microporous halocarbon membranes, particularly fluoro-carbon membranes, and methods for treating one or more surfaces of a polymeric porous halocarbon membrane with electron beams. The modified porous membrane is stable, resists dewetting, and retains its mechanical properties and chemical inertness.
    Type: Application
    Filed: April 26, 2011
    Publication date: February 21, 2013
    Inventors: Jijun Ge, Wai Ming Choi
  • Publication number: 20120061314
    Abstract: Embodiments of the invention include a liquid filter member that includes a layer of polymeric nano fibers overlying a microporous membrane. A pressure drop of the filter member is substantially the same, or is less than, a pressure drop of the microporous membrane and the filter member has a particle retention in the presence of surfactant that is greater than the particle retention of the microporous membrane alone under the same test conditions.
    Type: Application
    Filed: April 12, 2010
    Publication date: March 15, 2012
    Inventors: Wai-ming Choi, Kiminori Kataoka
  • Publication number: 20080042322
    Abstract: Disclosed is: (i) a platen-stroke actuator of a molding system, (ii) a molding system having a platen-stroke actuator, (iii) a method of a platen-stroke actuator of a molding system, (iv) a molding-system controller of a molding system having a platen-stroke actuator, (v) an energization unit couplable to a molding-system controller of a molding system having a platen-stroke actuator, (vi) an article of manufacture of a molding system having a platen-stroke actuator and/or (vii) a network-transmittable signal of a molding system having a platen-stroke actuator, amongst other things.
    Type: Application
    Filed: August 15, 2006
    Publication date: February 21, 2008
    Inventors: Christopher Wai-Ming Choi, Alex Teng
  • Publication number: 20070296121
    Abstract: Disclosed are: (i) a molding-system drive, and (ii) a molding system having a molding-system drive, amougst other things.
    Type: Application
    Filed: June 7, 2006
    Publication date: December 27, 2007
    Inventor: Christopher Wai-Ming Choi
  • Publication number: 20070296281
    Abstract: Disclosed is an electrical motor.
    Type: Application
    Filed: June 7, 2006
    Publication date: December 27, 2007
    Inventor: Christopher Wai-Ming Choi
  • Patent number: 7176648
    Abstract: An energy management control apparatus for a molding machine that includes a first electrically-driven prime mover configured to drive at least a first molding machine device, and a second electrically-driven prime mover configured to drive at least a second molding machine device, includes a common DC link configured to provide DC energy to the first electrically-driven prime mover and to the second electrically-driven prime mover. A slave axis is configured to supply and absorb energy from to/from the common DC link.
    Type: Grant
    Filed: May 18, 2004
    Date of Patent: February 13, 2007
    Assignee: Husky Injection Molding Systems Ltd.
    Inventor: Christopher Wai-Ming Choi
  • Patent number: 7097939
    Abstract: Gel-forming battery separators and methods for constructing them. Particles are embedded into pores of a porous support to form a composite. The chemical make-up of surfaces of the particles includes a silanol group. The composite, when contacted with an effective amount of liquid electrolyte, is capable of forming a gelled matrix that includes electrolyte residing within the porous support. Batteries and methods of forming batteries featuring gel-forming separators are also disclosed. No pre-mixing of siliceous material with electrolyte is required facilitating battery construction.
    Type: Grant
    Filed: July 13, 2001
    Date of Patent: August 29, 2006
    Assignee: Hollingsworth & Vose Company
    Inventors: Anthony L. Ferreira, Norman Lifshutz, Wai Ming Choi
  • Patent number: 6955865
    Abstract: A non-woven sheet of polyolefin fibers having opposed major surfaces is disclosed. Some areas of one or both of the major surfaces are hydrophilic as a consequence of an acrylic graft polymerized with the surfaces of the fibers in those areas while the fibers in other areas of that major surface are free of the graft and, as a consequence, remain hydrophobic. A battery separator composed of at least two such non-woven sheets is also disclosed, as well as batteries having a separator composed of at least one such non-woven sheet. Also disclosed is a non-woven sheet of polyolefin fibers where opposed major surfaces of the sheet are hydrophilic as a consequence of such an acrylic acid graft, but the ion exchange coefficients of the two major surfaces are different.
    Type: Grant
    Filed: May 6, 2002
    Date of Patent: October 18, 2005
    Assignee: Hollingsworth & Vose Company
    Inventor: Wai Ming Choi
  • Patent number: D568893
    Type: Grant
    Filed: September 28, 2005
    Date of Patent: May 13, 2008
    Assignee: Husky Injection Molding Systems Ltd.
    Inventor: Christopher Wai-Ming Choi
  • Patent number: D577030
    Type: Grant
    Filed: August 19, 2005
    Date of Patent: September 16, 2008
    Assignee: Husky Injection Molding Systems Ltd.
    Inventor: Christopher Wai-Ming Choi