Including Evacuating Patents (Class 53/408)
  • Patent number: 7316101
    Abstract: A vacuum sealing method and system for evacuating air from and sealing a flexible plastic bag of the type having a mating male rib and a female sealing channel closure along the length of the bag opening. A flowable liquid is applied to the female channel.
    Type: Grant
    Filed: August 27, 2005
    Date of Patent: January 8, 2008
    Inventors: Vincent Nguyen, David W. Vice
  • Patent number: 7096648
    Abstract: A method for packaging electronic components wherein each of the electronic components having a first surface and an opposite second surface is placed in each of a plurality of pockets of a first film, bottom of each of the pocket has a protrusion that contacts the second surface of the electronic component, the pockets of the first film with the electronic components therein is covered with a second film, a pressure difference between the pockets as covered with the second film and an exterior of the pockets is created so that part of the second film is stuck to the first surface of each electronic component by the pressure difference to secure the electronic components within the pockets.
    Type: Grant
    Filed: December 20, 2004
    Date of Patent: August 29, 2006
    Assignee: Oki Electric Industry Co., Ltd.
    Inventor: Seiichi Kawada
  • Patent number: 7093710
    Abstract: An ink-package assembly including an ink package fluid-tightly containing a mass of an ink, and a sealing wrapper fluid-tightly enclosing the ink package, wherein an interior space of the sealing wrapper is charged with an inert gas such as a helium gas, which has a lower degree of solubility in the ink, than the air. The interior space of the sealing wrapper is evacuated to a reduced pressure of ?20 kPa and ?60 kPa with respect to the atmospheric pressure, as needed. The ink package includes an ink bag and is provided with a spout having a passage, and a cap for closing the passage. Where the sealing wrapper is evacuated, the ink package preferably further includes an ink-bag casing accommodating the ink bag, and a reinforcing structure interposed between the casing and the ink bag, to prevent deformation of the ink bag. Also disclosed is a method of producing the ink-package assembly.
    Type: Grant
    Filed: October 29, 2003
    Date of Patent: August 22, 2006
    Assignee: Brother Kogyo Kabushiki Kaisha
    Inventors: Yoichiro Shimizu, Bing Wang
  • Patent number: 7051493
    Abstract: A multilayer film, which is particularly suited to packaging of cheese on a Hayssen® RT packaging machine, has a first layer comprising cyclic olefin copolymer having a glass transition temperature of at least 125° C., and a second layer comprising at least one member selected from the group consisting of cyclic olefin copolymer having a glass transition temperature of at least 125° C., polyamide, polyester, and polystyrene. The first and second layers are on opposite sides of a tensile axis of symmetry of the film. The film exhibits from 0 to 45 degrees of transverse edge curl, a yield point of at least 1200 psi at a temperature of 85° C., and an elongation at break of from 0 to 300 percent at 85° C.
    Type: Grant
    Filed: August 21, 2002
    Date of Patent: May 30, 2006
    Assignee: Cryovac, Inc.
    Inventors: Hubert J. Cook, Janet W. Rivett, Gautam P. Shah, Richard M. Dayrit, Kelly R. Ahlgren
  • Patent number: 7048025
    Abstract: An inflator/sealer machine useful for inflating and sealing an inflatable cushion having a resistance wire that extends across the inlet of the inflatable cushion. The machine includes an inflation tube, a seal bar, and an anvil. The inflation tube is connected to a source of inflation fluid and has an outlet that is larger than the inflation aperture of the inflatable cushion. The inflation tube and anvil are adjustable between a tube/anvil engaged position and a tube/anvil disengaged position. In the tube/anvil engaged position, the inflation tube outlet opposes the anvil and can engage the inflation aperture of the inflatable cushion between the inflation tube and the anvil to inflate the cushion. The seal bar and the anvil are adjustable between a bar/anvil engaged position and a bar/anvil disengaged position. In the bar/anvil engaged position, the anvil opposes the seal bar to compress the inlet heat seal zone of the inflatable cushion between the anvil and the seal bar.
    Type: Grant
    Filed: April 11, 2003
    Date of Patent: May 23, 2006
    Assignee: Sealed Air Corporation (US)
    Inventors: Charles R. Sperry, Suzanne M. Scott, James M. Corliss
  • Patent number: 7013617
    Abstract: A method of filling and sealing a gas capsule having (i) a hollow body portion and (ii) an elongate hollow neck portion having a free open distal end extending from the body portion is disclosed. The method is accomplished by applying a filling cap to the open end of the neck portion while evacuating the capsule and refilling with helium. Two crimping steps while pressure is maintained finishes the filling and sealing method.
    Type: Grant
    Filed: October 31, 2003
    Date of Patent: March 21, 2006
    Assignee: The BOC Group, plc
    Inventor: Michael Ernest Garrett
  • Patent number: 6988613
    Abstract: A solid, stable composition containing a meiosis activating substance can be prepared by adding a protein or a phosphoglycid in the presence of an atmosphere having a low content of oxygen, for example in vacuo.
    Type: Grant
    Filed: February 5, 2002
    Date of Patent: January 24, 2006
    Assignee: Novo Nordisk A/S
    Inventors: Tina Meinertz Andersen, Lars Klingberg Muller
  • Patent number: 6916392
    Abstract: The invention provides methods of producing and servicing insulating glass units. Methods are provided for reducing the pressure differential on an IG unit, for changing the interior pressure within an IG unit, and for changing the gaseous interior composition within an IG. These methods can be practiced by forming a hole through at least one of the panes of an IG unit, and flowing gas through the hole. One method includes forming a hole through one of the panes of an IG unit, flowing gas through the hole, and sealing the hole with an optically clear sealant (e.g., a transparent resin). A number of methods for producing IG units are also provided. Further, several kits are provided for servicing IG units. There is also provided a method for detecting leaks in an IG unit by flowing an opaque gas into the unit and observing the unit to detect leaks of the opaque gas therefrom.
    Type: Grant
    Filed: April 9, 2002
    Date of Patent: July 12, 2005
    Assignee: Cardinal IG Company
    Inventors: Paul Trpkovski, Bernard J. Herron
  • Patent number: 6688081
    Abstract: A method and closure and container combination for packaging and sealing a commodity in a container that reduces headspace gases, in particular oxygen, allowing the packaged commodity to have a longer shelf life. The method is also useful for reducing stresses on containers that undergo filling at an elevated temperature and/or require in-container pasteurization or retort processes after fill and seal.
    Type: Grant
    Filed: December 18, 2001
    Date of Patent: February 10, 2004
    Assignee: Schmalbach-Lubeca AG
    Inventor: Timothy J. Boyd
  • Publication number: 20020134049
    Abstract: Air cell dunnage is disclosed which collapses for shipment and is constructed to be subsequently inflated for use. The air cell dunnage is a bubble sheet containing a multiplicity of gas cells and a base layer fused to the bubble layer. The bubble layer further includes conduits interconnecting selected groups of the selected cells and a common channel extending longitudinally on the sheet in fluid communication with each of the selected groups. The conduits provide access to selected groups of gas cells for collapsing and inflating the cells for shipment and use, respectively.
    Type: Application
    Filed: June 10, 2002
    Publication date: September 26, 2002
    Inventor: Ebrahim Simhaee
  • Patent number: 6423166
    Abstract: Air cell dunnage is disclosed which collapses for shipment and is constructed to be subsequently inflated for use. The air cell dunnage is a bubble sheet containing a multiplicity of gas cells and a base layer fused to the bubble layer. The bubble layer further includes conduits interconnecting selected groups of the selected cells and a common channel extending longitudinally on the sheet in fluid communication with each of the selected groups. The conduits provide access to selected groups of gas cells for collapsing and inflating the cells for shipment and use, respectively.
    Type: Grant
    Filed: April 22, 1999
    Date of Patent: July 23, 2002
    Inventor: Ebrahim Simhaee
  • Patent number: 6109004
    Abstract: A device for receiving, filling, and seal-welding a high-pressure vessel that can be received and clamped between an upper lid and a lower lid. A filling chamber is provided in the upper lid. The chamber is open on one side to a filling hole in the facing wall of the high-pressure vessel and sealed tightly at the other end by a disk made of transparent crystalline material. An interruptible filling line terminates in the chamber, and with a welding energy radiation source being located above the disk, whose radiation penetrates the crystalline material, is simpler in construction and universally applicable as well as operationally more economical. The upper lid, on its side facing the high-pressure vessel, has an annular seal which can be brought into tight contact with the facing wall of the high-pressure vessel.
    Type: Grant
    Filed: November 25, 1998
    Date of Patent: August 29, 2000
    Assignee: MBB Airbag Systems GmbH
    Inventors: Harald Bauer, Manfred Gebers, Peter Siebenrock
  • Patent number: 6030514
    Abstract: A target for sputtering is subjected to a surface treatment process and special packaging after target manufacture for improved sputtering performance and process and yield by reducing particulates. The sputtering target is first surface treated to remove oxides, impurities and contaminants. The surface treated target is then covered with a metallic enclosure and, optionally, a passivating barrier layer. The metallic enclosure protects the target surface from direct contact with subsequently employed packaging material such as plastic bags, thereby eliminating sources of organic materials during sputtering operations. The surface treatment of the target removes deformed material, smearing, twins, or burrs and the like from the target surface, reducing "burn-in" or sputter conditioning time prior to production sputtering of thin films.
    Type: Grant
    Filed: May 2, 1997
    Date of Patent: February 29, 2000
    Assignees: Sony Corporation, Materials Research Corporation
    Inventors: John A. Dunlop, Michael Goldstein, Gerald B. Feldewerth, Cari Shim, Stephan Schittny
  • Patent number: 5799469
    Abstract: In a method for the manufacture and/or filling of a two-chamber pressure pack comprising an outer container having a can wall, a bottom and a valve opening and of a bag having a bag bottom in the outer container for receiving a product, the outer container and bag enclose a space for receiving a gas. The space between outer container and bag is in this case filled with the gas prior to filling the bag with the product.
    Type: Grant
    Filed: April 30, 1996
    Date of Patent: September 1, 1998
    Assignee: Lechner GmbH
    Inventor: Gerhard Obrist
  • Patent number: 5797720
    Abstract: The device described here is for manufacturing a stack of cup-shaped containers coaxially inserted inside another, each with a side wall, on one end of which a base is arranged, and on the other end a flange (1), wherein the container is composed of a flexible material and the flange (1) is substantially stiffer than the side wall and the base.
    Type: Grant
    Filed: July 30, 1997
    Date of Patent: August 25, 1998
    Assignee: Tetra Laval Holdings & Finance S.A.
    Inventor: Michael Ruh
  • Patent number: 5457939
    Abstract: A process for packaging foodstuffs in substantially rigid containers. A desired quantity of foodstuff to be packaged is placed in the container, a quantity of aqueous liquid in an amount sufficient to generate, when boiled, a volume of vapor sufficiently in excess of the volume of the container to substantially completely displace all other gases from the container, is added. The container is closed but not sealed, so as to permit communication between the interior of the container and the ambient atmosphere. The container and its contents are warmed to a temperature sufficient to generate the volume of vapor when the container is subjected to a pressure lower than atmospheric pressure. The temperature is kept as low as possible so that no cooking of the foodstuffs occurs. After warming, the containers are exposed to a low pressure so that the liquid in the container boils. The boiling liquid generates vapor in the container sufficient to drive out and displace other gases from the container.
    Type: Grant
    Filed: September 1, 1993
    Date of Patent: October 17, 1995
    Assignee: Optimal Food Processing Research, Inc.
    Inventors: Jean-Francois M. Bardou, Roland Guezenne, Jean-Pierre Lhommond
  • Patent number: 5270033
    Abstract: A stabilized aqueous dentifrice composition capable of producing or, in the presence of saliva, leading to the production of antimicrobially effective concentrations of hypothiocyanite ions (OSCN--) are herein described. The composition contains both an oxidoreductase enzyme and its specific substrate, for the purpose of producing hydrogen peroxide of at least the minimum effective concentration. The aqueous dentifrice compositions of the present invention can be stabilized against premature enzyme/substrate interaction by controlling the level of dissolved oxygen in the aqueous dentifrice carrier. Optionally, a peroxidase enzyme may be included to act upon the aforementioned hydrogen peroxide, thereby oxidizing salivary thiocyanate ions to produce the antimicrobial concentrations of hypothiocyanite ions (OSCN--).
    Type: Grant
    Filed: August 18, 1992
    Date of Patent: December 14, 1993
    Inventor: Robert E. Montgomery
  • Patent number: 5262151
    Abstract: A stabilized aqueous composition capable of producing or, in the presence of saliva or other humoral fluid, leading to the production of antimicrobially effective concentrations of hypothiocyanite ions (OSCN--) are herein described. The composition contains an oxidoreductase enzyme and its specific substrate, for the purpose of producing hydrogen peroxide of at least the minimum effective concentration, and in addition, catalase for the destruction of hydrogen peroxide to prevent premature oxidoreductase enzyme decomposition. Optionally, a peroxidase enzyme may be included to act upon the aforementioned hydrogen peroxide, thereby oxidizing thiocyanate ions to produce the antimicrobial concentrations of hypothiocyanite ions (OSCN--).
    Type: Grant
    Filed: August 24, 1992
    Date of Patent: November 16, 1993
    Inventor: Robert E. Montgomery
  • Patent number: 5155971
    Abstract: A packaging apparatus that seals a product within a container while under a controlled environment. The container, holding a product and having a lid tacked to the open end thereof leaving vents between the lid and the container. The container is enclosed within a chamber having a device for controlling the flow of fluid into and out of the chamber. The chamber and container are evacuated and then flushed with an inert fluid at least once. While the container is still within the chamber the lid is completely peelably sealed to the container.
    Type: Grant
    Filed: March 3, 1992
    Date of Patent: October 20, 1992
    Assignee: Autoprod, Inc.
    Inventor: Thomas J. Zopf
  • Patent number: 5111639
    Abstract: A method and apparatus are disclosed for sealing pallets of fresh product inside plastic bags and finishing the interiors of the sealed bags with a modified gaseous atmosphere. Conventional pallets loaded with cooled fresh produce are moved by an input conveyor automatically one at a time to an in-line squeeze station. A plastic bag at a convenient height is initially draped over an arm radiating from a novel bagger frame. A plurality of such arms extend from a rotatable hub so that bags can be moved into position above successive loaded pallets as they are needed. This apparatus permits the bagging of nearly twice as many pallets in a given time period.
    Type: Grant
    Filed: March 27, 1991
    Date of Patent: May 12, 1992
    Assignee: Transfresh Corporation
    Inventors: Kevin J. Bolejack, Frederick Forgnone
  • Patent number: 5107658
    Abstract: A reclosable package comprising interlocking closure strips positioned outside of a hermetic seal or seal area and the method for producing and filling same. The hermetic seal is of the easy-open or peelaway type so as to not destroy the integrity of the package or closure strips upon opening of the package.
    Type: Grant
    Filed: May 24, 1991
    Date of Patent: April 28, 1992
    Assignee: Oscar Mayer Foods Corporation
    Inventors: Gerald O. Hustad, Ray H. Griesbach
  • Patent number: 4905454
    Abstract: A method for providing a container with a controlled environment utilizes a first flow method for applying a first source of environment to the interior of the container, a second flow method for applying a second source of environment to the container, and methods for controlling application of the individual sources of environment such that the first and second sources of environment are applied simultaneously for at least some period of time. The method for providing a container with a controlled environment is useful, for example, in food packaging applications whereby oxygen is removed from the food containers and replaced with a substantially inert environment prior to sealing the containers. In a preferred method, a rotary drum-type apparatus is employed for exposing containers in a continuous sequence to the individual sources of controlled environment.
    Type: Grant
    Filed: April 21, 1988
    Date of Patent: March 6, 1990
    Inventors: John E. Sanfilippo, James J. Sanfilippo
  • Patent number: 4756140
    Abstract: A process of packaging goods, especially foodstuffs, comprising enclosing the goods in a sheet of thermoplastics material, preferably a bag, so as to form a package which presents two unsealed juxtaposed surfaces. The package is then placed in a container, one wall of which is made of deformable sheet material, preferably a sheet made of a silicone resin, which is stable at the sealing temperature of the thermoplastics material. The container is then connected to a source of vacuum and when the pressure has been reduced in both the container and the bag sufficient heat is applied to the deformable sheet in the vicinity of the juxtaposed surfaces to cause them to become sealed together. In a further embodiment of the invention vacuumization of the container including the bag is followed by the injection of a preserving gas such as carbon dioxide.
    Type: Grant
    Filed: October 31, 1986
    Date of Patent: July 12, 1988
    Assignee: FGL Projects Limited
    Inventor: Raymond Gannon
  • Patent number: 4717575
    Abstract: The present invention relates to a canned aqueous food product contained in a hermetically closed rigid container. According to the invention, the pressure inside of the container as measured at 20.degree. C. has a value between 3,300 and 6,600 pascals and the partial pressure of steam is at least equal to 40% of said pressure. The invention is in particular applicable to the canned food industry.
    Type: Grant
    Filed: March 21, 1985
    Date of Patent: January 5, 1988
    Inventor: Michel H. R. Larroche
  • Patent number: 4535586
    Abstract: A materials handling method includes the steps of closing and sealing a permanent reusable container to enclose a material in a fluid tight condition. The air in the container is then displaced with a substitute gas so that the material may be transported and stored in air free standard unit measures. The apparatus of the invention is directed to the generally rigid fluid tight container having at least one access opening and a door for closing and sealing the same. A valve mechanism on the container enables air to be removed from the container either by evacuation or substitution by another gas.
    Type: Grant
    Filed: October 27, 1980
    Date of Patent: August 20, 1985
    Assignee: Hawkeye Container Company
    Inventor: John W. Eberle
  • Patent number: 4522015
    Abstract: A phased aseptic sterilization and packaging process is disclosed wherein the solid component of a product is separately sterilized within the container in which the product is ultimately sealed. The liquid component is aseptically sterilized independently, and is aseptically filled into the container in a chilled condition to quench the hot solid component prior to final sealing of the container. A novel apparatus is provided for handling the containers during processing.
    Type: Grant
    Filed: January 6, 1983
    Date of Patent: June 11, 1985
    Assignee: Campbell Soup Company
    Inventor: William M. Hildebolt
  • Patent number: 4447373
    Abstract: A process of making a hollow article from polymeric material is taught. The article is molded in two parts. The two parts are caused to remain in their respective exterior molds. If the hollow article is to be filled with a desired material, a measured amount of filler material is added to one of the formed parts. The exterior molds are brought into opposed position and sealing relationship. The space between the exterior molds is purged with a purging gas and subjected to a partial vacuum. The exterior molds are then closed and subjected to a clamping pressure to join the part halves together and remove flash from the joint. Portions at least of the exterior molds are heated and then cooled. The exterior molds are then opened, and the finished filled article is removed therefrom.
    Type: Grant
    Filed: February 16, 1982
    Date of Patent: May 8, 1984
    Assignee: The Procter & Gamble Company
    Inventors: Charles W. Chappell, Eldon G. Spletzer
  • Patent number: 4409252
    Abstract: Food is packaged under a protective gas in synthetic containers having flexible lids. The sequence of the packaging steps is product filling, lid application, flushing with a protective gas, and sealing the lid. The flushing takes place wherein the lid is affixed to the container edge at at least one location, while one side of the lid is slightly lifted so that the protective gas can be blown therein.
    Type: Grant
    Filed: April 12, 1982
    Date of Patent: October 11, 1983
    Assignee: Messer Griesheim GmbH
    Inventors: Guido Buschkens, Peter Nobis
  • Patent number: 4406046
    Abstract: A process for the production of a sodium-filled valve in which the sodium is introduced into a hollow valve stem through a filling bore of relatively large diameter and which is sealed through a plug and/or usual welding. Subsequent to the closing off of the filling bore, the hollow inner space is evacuated through a passageway having a small cross-section and is thereafter sealed vacuum-tightly in a vacuum through either welding or soldering. Through the evacuation of the hollow space there is avoided any kind of oxydation of the sodium and thereby any change. Moreover, no froth or foam formation is encountered so as to facilitate the presence of an extremely constant heat transfer.
    Type: Grant
    Filed: September 4, 1980
    Date of Patent: September 27, 1983
    Assignee: MTU Motoren- und Turbinen-Union Munchen, GmbH
    Inventors: Peter Adam, Horst Meyer-Spradow, Lothar Reisinger
  • Patent number: 4389239
    Abstract: The activation of a mass of metal granules capable of storing hydrogen with the formation of hydride in a pressure vessel, instead of having to be activated before use by repeated heating in a hydrogen atmosphere followed by cooling and evacuation before the next heating, is activated in the pressure vessel used for storage by first heating a small portion of the granulate to the necessary activation temperature and then allowing the heat developed by the activation of that portion to produce the activation of the remainder of the granulate. It is found that it thus possible to provide complete activation with only one heating step. The small portion that is first activated may be a part of the granulate that is of a different composition that is easier to activate, for example, LaNi.sub.5, which can be activated at room temperature, or iron-titanium alloys that are capable of activation under 100.degree. C.
    Type: Grant
    Filed: June 9, 1981
    Date of Patent: June 21, 1983
    Assignee: Kernforschungsanlage Julich GmbH
    Inventors: Karl-Heinz Klatt, Siegfried Pietz, Helmut Wenzl
  • Patent number: 4294859
    Abstract: A process for packaging units of food in which the food units are placed on a bottom film and slits made in the film. The film with the food units thereon is passed into an open chamber, the chamber closed, and a vacuum drawn on it followed by back-filling with a substantially oxygen-free gas. The film with the food units thereon and a top film over the units is then subjected to vacuum and the top and the bottom films sealed. Alternately the package may be back-filled with oxygen-free gas prior to being sealed about the food unit. The disclosure includes also the steps of partially sealing food units between top and bottom films in a first chamber, back-filling with a substantially oxygen-free gas, then vacuumizing in a second chamber, and fully sealing the packages in a second chamber, or alternately back-filling with the oxygen-free gas before fully sealing.
    Type: Grant
    Filed: November 15, 1979
    Date of Patent: October 13, 1981
    Assignee: Armour and Company
    Inventors: Burton R. Lundquist, Thomas Macherione
  • Patent number: 4248275
    Abstract: A method is provided for rapidly distributing mixed gases throughout a partially evacuated ball mold. The invention is particularly useful in the pressurizing of tennis ball centers with a mixture of air and a low permeability gas. By this invention, the distribution of the low permeability gas throughout the mold can be accomplished by first partially evacuating air from the mold then injecting the mixed gases into the mold.
    Type: Grant
    Filed: February 9, 1979
    Date of Patent: February 3, 1981
    Assignee: The General Tire & Rubber Company
    Inventor: Thomas F. Reed
  • Patent number: 4240556
    Abstract: A double walled tubular flexible plastic package has an inflatable annular chamber surrounding an inner pocket. When an object is placed in the pocket and the chamber is inflated, the inner wall collapses inward to envelop the object. The inflation causes the flexible membrane to close off at the mouth of the pocket thereby substantially encapsulating the object being packaged. The object is essentially supported within a single air chamber thereby providing optimum cushioning from external forces and substantial insulation from external temperatures.
    Type: Grant
    Filed: February 23, 1978
    Date of Patent: December 23, 1980
    Inventor: Andrew S. Field
  • Patent number: 4166484
    Abstract: A method and apparatus are provided for rapidly distributing a first gas throughout a chamber that contains both the first gas and a second gas. The invention is particularly useful in the pressurizing of tennis ball centers with a low permeability gas, where the diffusion rate between the low permeability gas and air is very slow. By this invention, the distribution of the low permeability gas throughout the mold can be accomplished in a much shorter period of time by a mechanical mixing method and apparatus that involves circulating the mixture of gases inside the mold through a conduit and pump located outside the mold.
    Type: Grant
    Filed: January 20, 1978
    Date of Patent: September 4, 1979
    Assignee: The General Tire & Rubber Company
    Inventor: Thomas F. Reed
  • Patent number: 4148933
    Abstract: A food product, such as fruit or vegetables either whole or in pieces, or in the form of a pulp, or meat in pieces, is preserved by feeding hot liquid or steam into a contained body of the product to sterilize the product. Some liquid is retained in the product which is sealed in a container under aseptic conditions. The sterilization preferably takes place in the container in which the sterile product is ultimately sealed.
    Type: Grant
    Filed: August 30, 1977
    Date of Patent: April 10, 1979
    Assignee: In. Da. Te. Aktiengesellschaft
    Inventor: Viacheslav J. Janovtchik
  • Patent number: 4116336
    Abstract: A package containing a reference liquid for the calibration and/or quality control of blood gas analyzers. The reference liquid is enclosed in a flexible, gas-tight container without any gas bubbles in the container, and to avoid any danger of formation of gas bubbles, the total gas pressure in the liquid is kept below 600 mm Hg at 37.degree. C. The container is preferably a laminate bag of aluminum foil with interior layer of heat sealable plastic of low gas permeability, preferably a polyacrylonitrile copolymer.
    Type: Grant
    Filed: March 1, 1977
    Date of Patent: September 26, 1978
    Assignee: Radiometer A/S
    Inventors: Soren Kaj Sorensen, Carl Christian Holbek