Patents by Inventor Wai M. Choi
Wai M. 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: 8663358Abstract: 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: GrantFiled: May 9, 2011Date of Patent: March 4, 2014Assignee: Hollingsworth & Vose CompanyInventors: Wai M. Choi, Karin N. Soper
-
Publication number: 20110265312Abstract: 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: ApplicationFiled: May 9, 2011Publication date: November 3, 2011Applicant: Hollingsworth & Vose CompanyInventors: Wai M. Choi, Karin N. Soper
-
Patent number: 7964012Abstract: 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: GrantFiled: August 2, 2006Date of Patent: June 21, 2011Assignee: Hollingsworth & Vose CompanyInventors: Wai M. Choi, Karin N. Soper
-
Patent number: 6680144Abstract: A method for producing a battery separator is disclosed. The method comprises applying a coating of an ethylenically unsaturated monomer to the fibers of a non-woven sheet and polymerizing the monomer in situ on the fiber surfaces. The non-woven sheet is from 50 to 3000 microns thick, and is composed of polyolefin fibers having an average fiber diameter from 0.5 to 5 microns and a surface area from 0.2 to 30 square meters per gram.Type: GrantFiled: May 6, 2002Date of Patent: January 20, 2004Assignee: KVG Technologies, Inc.Inventor: Wai M. Choi
-
Patent number: 5618642Abstract: A battery separator having sodium sulfate incorporated therein in order to reduce and/or eliminate hydration short problems in batteries. The preferred method of adding sodium sulfate directly to the separator is via the use of sodium sulfate-containing silica as a separator filler added during the process of manufacturing the separator. The present invention is also directed to a battery separator containing a relatively high level of sodium sulfate, and to batteries which incorporate such separators.Type: GrantFiled: June 6, 1995Date of Patent: April 8, 1997Assignee: Daramic, Inc.Inventors: Abbas Samii, Wai M. Choi
-
Patent number: 5478677Abstract: A battery separator for tubular positive electrodes composed of a microporous, composite sheet product having first and second major surface, formed from a uniform mixture of a polymer, a filler, a processing aid a porous form stable layer at least partially embedded in either the first or second major surface and having a series of vertical tubes arranged across its surface. The tubular sleeve/separator can be formed of individual tubes, flat sheets formed into a series of tubes or sheets containing half tubes and which are aligned and bonded together to form the series of tubes.Type: GrantFiled: January 18, 1995Date of Patent: December 26, 1995Assignee: Daramic, Inc.Inventors: Wai M. Choi, Ingo W. Schmidt
-
Patent number: 5384211Abstract: A battery separator formed into an envelope and having improved oxidation resistance is disclosed. The sealed edge along the bottom of the envelope and preferably also along the vertical side edges of the envelope has a greater amount of a processing aid, such that the treated area has from a 5 to 100%, preferably 5 to 20% and more preferably 10 to 100% greater amount of processing aid than the average of the rest of the envelope. One embodiment is to impregnate the treated area with additional processing aid. One embodiment is to impregnate the treated area with additional processing aid. A further embodiment is impregnate a porous layer with additional processing aid and locate that porous layer adjacent and preferably in intimate contact with the treated edge. A third embodiment is to add an amount of processing aid into the battery box before inserting the enveloped plates and allowing the envelopes to absorb the aid.Type: GrantFiled: September 27, 1993Date of Patent: January 24, 1995Assignee: W. R. Grace & Co.-Conn.Inventors: Wai M. Choi, Werner Boehnstedt
-
Patent number: 5154988Abstract: A battery separator for use in deep cycle traction batteries, such as golf cart batteries. The separator is formed of a microporous, mainly polymeric layer, preferably in the form of a synthetic paper; a glass mat layer adjacent one surface of the microporous layer; and a coating on one or both sides of the mircoporous layer/glass mat combination. The coating is preferably formed of natural rubber which positively affects top-of-charge behavior and reduces the possibility of antimony poisoning, thus providing for longer and improved battery performance and life.Type: GrantFiled: March 18, 1991Date of Patent: October 13, 1992Assignee: W. R. Grace & Co.-Conn.Inventors: Wai M. Choi, James K. Kung
-
Patent number: 4734344Abstract: The present invention is a sheet material for use in alkaline batteries as a separator or interseparator. The sheet is formed of about 30 to about 70 percent polyolefin synthetic pulp, from about 15 to about 65 percent alkali resistant inorganic filler and from about 1 to about 35 percent of one or more long fibers, wherein at least some, if not all of the fiber is a water swellable polyvinyl alcohol based fiber and any remaining long fiber is a nonwater swellable fiber. The water swellable fiber during processing of the sheet forms a gel-like network when contacted by water which retains the filler and bonds the remaining materials together. The resulting sheet has increased tensile strength and alkali resistance and is especially useful in automated battery manufacturing processes.Type: GrantFiled: May 19, 1986Date of Patent: March 29, 1988Assignee: W. R. Grace & Co.Inventor: Wai M. Choi
-
Patent number: 4699857Abstract: A battery separator in the form of a microporous membrane composed of a substantially uniform composition of a polymer mixture of ultra high molecular weight polyolefin, polyethylene terpolymer and polyvinyl chloride, in combination with at least one plasticizer for the polymer mixture and an inert filler.Type: GrantFiled: October 15, 1986Date of Patent: October 13, 1987Assignee: W. R. Grace & Co.Inventors: Richard T. Giovannoni, James K. J. Kung, Wai M. Choi
-
Patent number: 4369236Abstract: The instant invention is directed to a sheet product capable of forming an improved battery separator. The present sheet product is formed from a thin, acid-stable, porous material and has a first and a second major face with a plurality of separate, continuous, open channels on each major face such that each channel on each major face defines a separation between two channels on the other major face. Further, each channel defines an imaginary median line with at least some portions of at least some channels extending laterally with respect to the imaginary median line and each channel has at least one continuous contour line in the form of straight line segments such that every portion of each channel is capable of being at an acute angle of not greater than 70 degrees from an imaginary vertical line orientated from bottom to top of a battery containing the sheet product.Type: GrantFiled: March 4, 1981Date of Patent: January 18, 1983Assignee: W. R. Grace & Co.Inventors: Dennis D. O'Rell, Wai M. Choi, Nan J. Lin