Pre-expansion Of Foamed Polystyrene Patents (Class 264/DIG9)
  • Patent number: 6136396
    Abstract: An article comprised of a polymeric material bearing a coating. The coating comprises a residual layer formed by applying and allowing to dry a mixture containing from about 7.5 to about 23.5 weight percent of a humidity sensitive antistatic surfactant compound and from about 10 to about 30 weight percent of a water soluble ink. The article possesses an electrostatic potential of from about -5 to about +5 kilovolts as measured at one inch from the coating. A process for producing a formed article which is relatively free from the effects of static electricity. The process includes the steps of topically applying a mixture comprising a humidity sensitive antistatic surfactant compound to a stock comprising a foamed polymeric material, conditioning the foam stock in a humidity-controlled environment effective to reduce electrostatic potential of the stock to between from about -5 to about +5 kilovolts, and thereafter forming the article from the conditioned foam stock.
    Type: Grant
    Filed: August 8, 1997
    Date of Patent: October 24, 2000
    Assignee: Tenneco Packaging Inc.
    Inventor: Robin A. Gilmer
  • Patent number: 5883141
    Abstract: A process for preparing polyolefin resin pre-expanded particles comprising imparting expandability to polyolefin resin expanded particles having a crystal structure which shows two melting points in a DSC curve and heat expanding expanded particles having expandability, in which the relation between heat expansion temperature and the amount of a fusion preventing agent being attached to the surface of the polyolefin resin expanded particles is represented by the inequality: t-T.sub.V .ltoreq.49.1C-27.0 (t is heat expansion temperature, C is the amount of the fusion preventing agent being attached to the surface of the polyolefin resin expanded particles and T.sub.V is saddle temperature between two peaks showing two respective melting points in the DSC curve), and t is within the temperature range represented by the inequality: T.sub.L -30.ltoreq.t.ltoreq.T.sub.V (T.sub.V is the same as defined above and T.sub.L is lower melting point of the two melting points).
    Type: Grant
    Filed: March 23, 1998
    Date of Patent: March 16, 1999
    Assignee: Kaneka Corporation
    Inventors: Tsuyoshi Mihayashi, Hideshi Ito
  • Patent number: 5830922
    Abstract: Partially expanded polyolefin granules are post-expanded by a process comprising charging a vessel containing foamed polyolefin beads having a bulk density of from 20-450 g/l with an inert gas under a pressure of from 2-25 bar and at a temperature of from T.sub.m -150.degree. C. to T.sub.m -40.degree. C. over a period of from 1-48 h, and then continuously or discontinuously transferring the pressurized foam beads into an apparatus in which a fluidized bed is created, where the beads expand further at a temperature of from T.sub.m -75.degree. C. to T.sub.m +20.degree. C.The resultant foamed beads are suitable for producing foamed moldings.
    Type: Grant
    Filed: February 20, 1998
    Date of Patent: November 3, 1998
    Assignee: Huels Aktiengesellschaft
    Inventors: Reinhard Wirobski, Bernd Guenzel
  • Patent number: 5821272
    Abstract: Post-treatment method of polyolefin resin pre-expanded particles comprising: introducing the polyolefin resin pre-expanded particles foamed by using an inflammable blowing agent into an extraction vessel filled with steam previously; feeding an additional steam into the extraction vessel; extracting the inflammable blowing agent gas from the polyolefin resin pre-expanded particles; discharging the resulting steam which contains the extracted inflammable blowing agent gas from the extraction vessel continuously or intermittently; and liquefying the steam to separate and recover the inflammable blowing agent gas. According to the post-treatment method of polyolefin resin pre-expanded particles, the inflammable blowing agent can be extracted from the pre-expanded particles in a short period of time and the extracted inflammable blowing agent can be re-used.
    Type: Grant
    Filed: January 20, 1998
    Date of Patent: October 13, 1998
    Assignee: Kaneka Corporation
    Inventors: Shinobu Ochikoshi, Hisatoshi Fukui, Kyoichi Nakamura, Hideya Mizuike, Naruhiko Akamatsu
  • Patent number: 5385698
    Abstract: A method is disclosed for heating pre-expanded foundry pattern molding beads of polystyrene or the like in a stream of hot air to reduce the vapor-forming expansion agent content for the purpose of producing more dimensionally accurate, molded foam bead casting patterns.
    Type: Grant
    Filed: April 23, 1992
    Date of Patent: January 31, 1995
    Assignee: Saturn Corporation
    Inventors: Gary E. Bishop, Patrick J. Van Ryckeghem
  • Patent number: 5271886
    Abstract: A process and apparatus for rapidly expanding and molding carbon dioxide-impregnated polymer particles is disclosed. The process involves expanding the impregnated particles in a moving stream of pressurized saturated steam or super-heated steam, directing the resulting stream of pre-expanded particles into a mold, and molding the particles into a foamed object. Apparatus suitable for use with the process is also disclosed.
    Type: Grant
    Filed: October 14, 1992
    Date of Patent: December 21, 1993
    Assignee: Arco Chemical Technology, L.P.
    Inventors: William Collom, Dennis Fuller, Joseph Kinslow, Bernard H. Meyer, Richard H. Immel
  • Patent number: 5240657
    Abstract: A method for making low density (0.8-2 lb/cu.ft.) expanded polymeric products uses blowing agent in an amount of only from 2 to 4.4 weight percent, the process emitting blowing agent during processing in an amount of from only about 0.3 to about 2.5 weight percent. The process uses 2 to 5 expansion steps together with a polymer having a particular polydispersity, weight average molecular weight and M.sub.z :M.sub.n, this polymer having a greater expandability than conventional polymers. The process requires only about half of the amount of blowing agent currently being used in commercially viable processes for making expanded polystyrene products. The process can be used with or without a molding step.
    Type: Grant
    Filed: October 15, 1991
    Date of Patent: August 31, 1993
    Assignee: BASF Corporation
    Inventors: William H. Harclerode, Eugene K. Zimmermann, Barry J. Pekich, John C. Knutsen, John V. Wiman, John C. Voss
  • Patent number: 5114640
    Abstract: A method for making low density (0.8-1.1 lb./cu.ft.) expanded polymeric products uses blowing agent in an amount of any from 2 to 4.4 weight percent and aging periods of from 1 to 80 hours after each expansion step. The process uses 2 to 5 expansion steps and a polymer having a particular polydispersity, weight average molecular weight and M.sub.z :M.sub.n, this polymer having a greater expandability than conventional polymers. The process requires only about half of the amount of blowing currently being used in commercially viable processes for making expanded polystyrene products. The process can be used with or without a molding step.
    Type: Grant
    Filed: October 15, 1991
    Date of Patent: May 19, 1992
    Assignee: BASF Corporation
    Inventors: William H. Harclerode, John C. Knutsen, Barry J. Pekich, John V. Wiman, John C. Voss
  • Patent number: 5115066
    Abstract: A polystyrene polymer as well as an expandable polystyrene formulation comprises a polystyrene polymer having a particular molecular weight distribution. The polymer itself exhibits a polydispersity of from about 1 to less tha 2.0, a weight average molecular weight of greater than about 200,000 to about 300,000, and an M.sub.z :M.sub.n of from about 2 to less than about 3.0. Furthermore, the polystyrene polymer is branched to from 0 to less than 5 weight percent.The expandable polystyrene formulation comprises a polystyrene polymer exhibiting a polydispersity of from about 1.0 to less than 2.5, a weight average molecular weight of from greater than about 180,000 to about 300,000, an M.sub.z :M.sub.n of from about 2 to about 4.5. The polystyrene polymer is present in an amount of from about 94.5 weight percent to about 98 weight percent, based on the total weight of the formulation, and the polystyrene polymer is branched to from 0 to less than 5 weight percent.
    Type: Grant
    Filed: October 15, 1991
    Date of Patent: May 19, 1992
    Assignee: BASF Corporation
    Inventors: Eugene K. Zimmermann, Bernhard Wagner, William E. Volz, William H. Harclerode, John V. Wiman, John C. Voss
  • Patent number: 5112875
    Abstract: A polystyrene polymer as well as an expandable polystyrene formulation comprises a polystyrene polymer having a particular molecular weight distribution. The polymer itself exhibits a polydispersity of from about 1 to less than 2.0, a weight average molecular weight of greater than about 200,000 to about 300,000, and an M.sub.z :M.sub.n of from about 2 to less than about 3.0. Furthermore, the polystyrene polymer is branched to from 0 to less than 5 weight percent.The expandable polystyrene formulation comprises a polystyrene polymer exhibiting a polydispersity of from about 1.0 to less than 2.5, a weight average molecular weight of from greater than about 180,000 to about 300,000, an M.sub.z :M.sub.n of from about 2 to about 4.5. The polystyrene polymer is present in an amount of from about 94.5 weight percent to about 98 weight percent, based on the total weight of the formulation, and the polystyrene polymer is branched to from 0 to less than 5 weight percent.
    Type: Grant
    Filed: November 26, 1990
    Date of Patent: May 12, 1992
    Assignee: BASF Corporation
    Inventors: Eugene K. Zimmermann, Bernhard Wagner, William E. Volz, William H. Harclerode, John V. Wiman, John C. Voss
  • Patent number: 5110837
    Abstract: A method for making low density (0.8-1.1 lb/cu.ft.) expanded polymeric products uses blowing agent in an amount of only from 2 to 4.4 weight percent. The process uses 2 to 5 expansion steps together with a polymer having a particular polydispersity, weight average molecular weight and M.sub.z :M.sub.n, this polymer having a greater expandability than conventional polymers. The process requires only about half of the amount of blowing agent currently being used in commercially viable processes for making expanded polystyrene products. The process can be used with or without a molding step.
    Type: Grant
    Filed: November 26, 1990
    Date of Patent: May 5, 1992
    Assignee: BASF Corporation
    Inventors: William H. Harclerode, William E. Volz, John V. Wiman, John C. Voss, Barry J. Pekich, John C. Knutsen
  • Patent number: 5110524
    Abstract: A method for making low density (0.8-1.1 lb/cu. ft.) expanded polymeric products uses blowing agent in an amount of only from 2 to 4.4 weight percent. The process uses 2 to 5 expansion steps together with a polymer having a particular polydispersity, weight average molecular weight and M.sub.z :M.sub.n, this polymer having a greater expandability than conventional polymers. The process requires only about half of the amount of blowing agent currently being used in commercially viable processes for making expanded polystyrene products. The process can be used with or without a molding step.
    Type: Grant
    Filed: October 15, 1991
    Date of Patent: May 5, 1992
    Assignee: BASF Corporation
    Inventors: William H. Harclerode, William E. Volz, John V. Wiman, John C. Voss, Barry J. Pekich, John C. Knutsen
  • Patent number: 5110836
    Abstract: A method for making low density (0.8-1.1 lb/cu.ft.) expanded polymeric products uses blowing agent in an amount of only from 2 to 4.4 weight percent and aging periods of from 1 to 80 hours after each expansion step. The process uses 2 to 5 expansion steps and a polymer having a particular polydispersity, weight average molecular weight and M.sub.z :M.sub.n, this polymer having a greater expandability than conventional polymers. The process requires only about half of the amount of blowing agent currently being used in commerically viable processes for making expanded polystyrene products. The process can be used with or without a molding step.
    Type: Grant
    Filed: November 26, 1990
    Date of Patent: May 5, 1992
    Assignee: BASF Corporation
    Inventors: William H. Harclerode, John C. Knutsen, Barry J. Pekich, John V. Wiman, John C. Voss
  • Patent number: 5108673
    Abstract: A thermoplastic plastic granule having an expansion agent uniformly distributed within a plastic polymer-matrix and, containing additionally a cell-forming agent in a finely and uniformly distributed manner. Such thermoplastic granules are used for producing foamed molded bodies in a mold.
    Type: Grant
    Filed: January 17, 1991
    Date of Patent: April 28, 1992
    Assignee: Storopack Hans Reichenecker GmbH & Co.
    Inventor: Adolf Wegmann
  • Patent number: 5086078
    Abstract: A method for making low density (0.8-2 lb/cu.ft.) expanded polymeric products uses blowing agent in an amount of only from 2 to 4.4 weight percent, the process emitting blowing agent during processing in an amount of from only about 0.3 to about 2.5 weight percent. The process uses 2 to 5 expansion steps together with a polymer having a particular polydispersity, weight average molecular weight and M.sub.z :M.sub.n, this polymer having a greater expandability than conventional polymers. The process requires only about half of the amount of blowing agent currently being used in commerically viable processes for making expanded polystyrene products. The process can be used with or without a molding step.
    Type: Grant
    Filed: November 26, 1990
    Date of Patent: February 4, 1992
    Assignee: BASF Corporation
    Inventors: William H. Harclerode, Eugene K. Zimmermann, Barry J. Pekich, John C. Knutsen, John V. Wiman, John C. Voss
  • Patent number: 5049328
    Abstract: A process for making high-purity foam moldings without the use of organic blowing agents involves the use of inorganic gases such as carbon dioxide, nitrogen, air and other pneumatogens.The process involves the simultaneous impregnation and purification of the polymers with or without foaming. If foaming is not done in the extractor, the polymeric particles can be foamed in pre-expanders or expanded and molded in downstream equipment.
    Type: Grant
    Filed: July 2, 1990
    Date of Patent: September 17, 1991
    Assignee: Arco Chemical Technology, Inc.
    Inventors: Bernard H. Meyer, Joseph C. Kinslow
  • Patent number: 5017621
    Abstract: The present invention provides polypropylene resin pre-expanded beads formed by shrinking polypropylene resin pre-expanded beads originally having a bulk density of not higher than 0.0930 g/cc to give them a bulk volume ratio of 10-75% at normal temperature and normal pressure, a manufacturing method thereof and an expansion-molding method with the aforementioned pre-expanded beads. According to this invention, it is possible to greatly reduce storing and transporting costs per unit weight of pre-expanded beads.
    Type: Grant
    Filed: March 22, 1990
    Date of Patent: May 21, 1991
    Assignee: Kanegafuchi Kagaku Kogyo Kabushiki Kaisha
    Inventors: Hitoshi Shiiki, Minoru Tada, Kyoichi Nakamura
  • Patent number: 4889671
    Abstract: Prefoamed particles of a polyolefin resin are produced by dispersing starting particles of the polyolefin resin, which contains a volatile foaming agent, in a dispersant in a pressure vessel, heating the resultant dispersion to a temperature of at least the softening point of the starting particles in said pressure vessel and then opening the vessel at one end thereof so as to release the starting particles and dispersant into an atmosphere of a pressure lower than the internal pressure of the vessel. The release of the starting particles and dispersant is performed while feeding a heating liquid.
    Type: Grant
    Filed: May 11, 1988
    Date of Patent: December 26, 1989
    Assignee: Japan Styrene Paper Corporation
    Inventors: Hiroyuki Akiyama, Susumu Izawa, Hideki Kuwabara, Toru Yamaguchi
  • Patent number: 4868055
    Abstract: The present invention discloses a vinylidene chloride resin type in-mold foam molding having a broad cross-sectional area and a free shape, which is useful as thermal insulating plate materials or as anti-shock molded vessels, and also to foam particles, which are or expandable particles convenient for the preparation thereof. The present invention is also related to a series of advantageous foaming techniques for completion of such a molding.
    Type: Grant
    Filed: July 25, 1988
    Date of Patent: September 19, 1989
    Assignee: Asahi Kasei Kogyo Kabushiki Kaisha
    Inventors: Norihiko Sakata, Nobuo Miura
  • Patent number: 4861531
    Abstract: The present invention provides a process for production of expansion-molded articles in a mold of a linear low density polyethylene resin which comprises compressing pre-expanded linear low density polyethylene resin beads having two melting points when measured by differential scanning calorimetry and, when the melting point at a low temperature side and the melting point at a high temperature side are designated T.sub.ML and T.sub.MH respectively, between said two melting points and the peak fusion area at said T.sub.ML is designated A.sub.L and the peak fusion area at said T.sub.MH is designated A.sub.H satisfying:5%.ltoreq.A.sub.H /A.sub.L .ltoreq.
    Type: Grant
    Filed: February 16, 1988
    Date of Patent: August 29, 1989
    Assignee: Kanegafuchi Kagaku Kogyo Kabushiki Kaisha
    Inventor: Hirofumi Maeda
  • Patent number: 4830798
    Abstract: The present invention provides that, in a process for production of foamed articles of a polyproplene resin which comprises compressing pre-expanded beads of propylene resins under a gaseous pressure, filling a mold capable of closing but incapable of sealing with the compressed beads, then venting from the mold and heating and fusing with steam thereby to produce the molded article in the shape of the mold, the improvement wherein the pre-expanded beads of the polypropylene resins having two melting points when measured by differential scanning calorimetry and having a quantity of the peak fusion heat QH based on a melting point at a high temperature peak of the two melting points being 0.3 to 3.5 cal/g are introduced compressively into the mold so that a compressive rate is 10 to 60%.
    Type: Grant
    Filed: September 15, 1987
    Date of Patent: May 16, 1989
    Assignee: Kanegafuchi Kagaku Kogyo Kabushiki Kaisha
    Inventor: Hirofumi Maeda
  • Patent number: 4822542
    Abstract: This invention relates to a method and apparatus for improving not only the quality of the production of molded foamable thermoplastic resin particles converted into fusion-bonded materials but also the output by protecting the resin from atmospheric pressure by pressurizing the particles and heating the particles to soften the same.
    Type: Grant
    Filed: July 23, 1987
    Date of Patent: April 18, 1989
    Assignee: Japan Styrene Paper Corporation
    Inventors: Hedeki Kuwabara, Atusi Kitagawa, Masato Kanbe
  • Patent number: 4816199
    Abstract: A method is disclosed of making dimensionally stable, expanded polystyrene foam patterns comprising: (a) expanding a supply of beads comprised of polystyrene and a thermally responsive expanding agent, the expansion being accomplished in one or more stages by use of a gaseous heating agent (steam) to define a fused pattern body of the expanded beads, and (b) subjecting the fused pattern body to subatmospheric pressure (in the range of 5-20" of Hg) for a period of about 0.5-6 hours but no more than sufficient to accelerate and complete the migration of the trapped expanding agent out of the pattern body. The expanding agent can be selected from the group consisting of various forms of pentane or butane.
    Type: Grant
    Filed: November 4, 1986
    Date of Patent: March 28, 1989
    Assignee: Ford Motor Company
    Inventors: Bruno Matz, Dolores C. Kearney
  • Patent number: 4810730
    Abstract: This invention relates to a process for the production of high strength polybenzimidazole filaments and molded products made from such filaments. The filaments produced by this process contain from about 10 to about 50 percent by weight residual solvent and can be heated at a temperature of about 350.degree. C. to about 600.degree. C. to produce three-dimensional foamed articles.
    Type: Grant
    Filed: May 6, 1987
    Date of Patent: March 7, 1989
    Assignee: Hoechst Celanese Corp.
    Inventors: John S. Letinski, Gunilla E. Gillberg-LaForce
  • Patent number: 4810440
    Abstract: In a process for pre-expanding thermoplastic resin particles which comprises releasing into a low pressure zone a mixture of water and thermoplastic resin particles containing a volatile blowing agent, the mixture being maintained at an elevated temperature under pressure in a pressure vessel, the improvement which comprises releasing the mixture through a plurality of orifice plates in series in the direction of release of the mixture. According to the process of the present invention, the average cell diameter of the obtained pre-expanded particles is larger than that of the pre-expanded particles obtained by means of conventional methods.
    Type: Grant
    Filed: June 25, 1987
    Date of Patent: March 7, 1989
    Assignee: Kanegafuchi Kagaku Kogyo Kabushiki Kaisha
    Inventors: Hiroyuki Yoshida, Kyoichi Nakamura
  • Patent number: 4800050
    Abstract: A control process for foaming and fusing plastics in a foaming and fusing device, and a fusing device for carrying out the process, in which the control process works in cycles, each cycle consists of phases which are at least an injection phase, a heating phase, a fusion phase, a cooling phase and a mould release phase, such phases being started and completed depending on control criteria comprising a time period, a pressure or a temperature limit value for the conditions evolving in the device such control criteria belonging to a certain cycle comprising a control criteria set, and with each cycle quality values of predetermined characteristics determined by measurements taken from the respective plastic part or an agglomerate cake situated in the device, a new set of control criteria being generated for each new cycle from prior control criteria depending from the quality values measured with such prior cycle of the control process, wherein the quality values of each cycle are combined to a deviation which
    Type: Grant
    Filed: November 20, 1986
    Date of Patent: January 24, 1989
    Assignee: Ortwin Hahn
    Inventors: Ortwin Hahn, Johannes Hummler
  • Patent number: 4790967
    Abstract: A compact, self-contained apparatus and method for expanding loose fill foam material for packaging includes an eductor having a fan, a venturi chamber, and a wire mesh cage arrangement for automatically feeding expandable loose fill material to a hopper. The loose fill material is then uniformly fed through the hopper by air pressure in conjunction with gravity to an expansion chamber. The expansion chamber includes a stepped conveyance platform disposed over a stepped steam chamber, and a track arrangement for simultaneously conveying and tumbling the loose fill material across each conveyance platform step. A condensing unit disposed above the expansion chamber removes excess moisture from the expansion chamber and provides warm dry air to a discharge housing from which the expanded loose fill material is discharged from the expansion chamber.
    Type: Grant
    Filed: September 12, 1986
    Date of Patent: December 13, 1988
    Assignee: Compex Expanders S.A.R.L.
    Inventors: Erik T. Anderlind, Jean-Pierre Guillemard
  • Patent number: 4777000
    Abstract: An expansion-molded article of a polypropylene resin is produced by filling pre-foamed particles of the polypropylene resin, which have a crystalline structure featuring an inherent peak inherent to the polypropylene resin and a high-temperature peak on the temperature side higher than the temperature corresponding to the inherent peak on a DSC curve obtained by differential scanning calorimetry of the pre-foamed particles and a bulk density of 0.04 g/cm.sup.3 or higher and require melting energy of 8-12 J/g at the high-temperature peak, in a mold without applying any pretreatment to the pre-foamed particles to build up an internal pressure therein, and then heating the pre-foamed particles, whereby the pre-foamed particles are caused to expand into the expansion-molded article conforming with the mold. The pre-foamed particles may alternatively have a bulk density lower than 0.04 g/cm.sup.3 and require melting energy of at least 8 J/g.
    Type: Grant
    Filed: November 25, 1986
    Date of Patent: October 11, 1988
    Assignee: Japan Styrene Paper Corporation
    Inventors: Hideki Kuwabara, Masato Kanbe
  • Patent number: 4772441
    Abstract: Particulate styrene polymers containing blowing agents are prepared by a process in which an aliphatic hydrocarbon of 7 to 9 carbon atoms is added in an amount of from 0.01 to 0.5% by weight, based on the styrene polymer, before, during or after the polymerization. The particulate styrene polymers can be processed to foam blocks and moldings having a satisfactory smooth surface.
    Type: Grant
    Filed: June 19, 1987
    Date of Patent: September 20, 1988
    Assignee: BASF Aktiengesellschaft
    Inventors: Harro Voss, Klaus Hahn, Walter Manfred, Isidoor DeGrave
  • Patent number: 4725389
    Abstract: A method for foaming and sintering of foamable plastic employing a control method based on the detection of the softening time point during the sintering steam application in the sintering process step. The softening time point is detected by analysis of a change in the rising speed of the pressure or temperature, and the related pressure and temperature values are used for determining the maximum dismission temperature and pressure of the sintered product. The sintering time is determined in relation to the softening time point and the quality demanded. A feed back control to the prefoaming and drying process step is provided. A feed back control by means of a quality measurement at the sintered part to the sintering is provided. Incremental controls are provided for adaptive process optimization.
    Type: Grant
    Filed: January 21, 1986
    Date of Patent: February 16, 1988
    Assignee: Ortwin Hahn
    Inventors: Ortwin Hahn, Mohamed-Hussein Tiba
  • Patent number: 4721588
    Abstract: A closed circuit process for the production of expanded polystyrene foam is described, comprising the steps of: (a) pre-expanding raw polystyrene beads containing a blowing agent in a pre-expansion vessel; (b) storing the beads in one or more closed storage containers to allow the expanded beads to return to substantially atmospheric pressure; (c) molding the expanded beads to a desired configuration in a closed mold with steam; and (d) removing the thus-formed article from the mold and placing such in an aging room, wherein at each stage the blowing agent released from the beads is recovered, separated from any residual steam by means of a condensing system, and introduced into the burner of a steam generator, thereby serving as fuel for the process.
    Type: Grant
    Filed: June 9, 1986
    Date of Patent: January 26, 1988
    Assignee: Epsilon Holdings, N.V.
    Inventors: Edgar Burchard, Arturo Echeverria, Ignacio G. Sancho, Otto F. Plettner
  • Patent number: 4704239
    Abstract: A process is disclosed for the production of expanded particles of polymeric material wherein unexpanded particles of the material are contacted with a nitrogen-containing inorganic gas under a first pressure condition to impregnate the particles with the gas. The gas impregnated particles are heated to a temperature higher than the softening point of the material, and dispersed into a liquid medium. The resulting dispersion is subjected to a lower pressure to expand the particles. The expanded particles may be used as prefoamed particles for the molding of foamed articles.
    Type: Grant
    Filed: April 24, 1985
    Date of Patent: November 3, 1987
    Assignee: Japan Styrene Paper Corp.
    Inventors: Shohei Yoshimura, Toru Yamaguchi, Masato Kanbe, Hideki Kuwabara
  • Patent number: 4682989
    Abstract: The present invention provides a method of recovering volatile foaming agent contained in prefoamed beads of polyolefin resin characterized in that the volatile foaming agent contained in the prefoamed beads is recovered by bringing into contact with heated air prefoamed beads obtained by heating polyolefin resin beads containing the volatile foaming agent. According to the invented method it is possible to avoid not only aggravation of the working environments and atmospheric pollution but also risk of explosion etc. and, furthermore, material cost can be saved through reutilization of the recovered volatile foaming agent.
    Type: Grant
    Filed: October 21, 1985
    Date of Patent: July 28, 1987
    Assignee: Kanegafuchi Kagaku Kogyo Kabushiki Kaisha
    Inventors: Hirofumi Maeda, Naruhiko Akamatsu
  • Patent number: 4676939
    Abstract: A process for the production of expanded particles, which comprises providing an aqueous dispersion containing expandable particles which are formed of a polypropylene resin and which contain a blowing agent and an expansion aid and maintained at a temperature higher than the softening point of the resin and under a pressurized condition, and subjecting the dispersion to a lower pressure so that the expandable particles are expanded. The expansion aid is organic or inorganic solids having a particle size of 0.1 to 150 .mu.m and a melting point higher than the temperature at which the expansion of the expandable particles is performed and serves to improve the expansion ratio.
    Type: Grant
    Filed: June 7, 1985
    Date of Patent: June 30, 1987
    Assignee: Japan Styrene Paper Corporation
    Inventor: Hideki Kuwabara
  • Patent number: 4618468
    Abstract: A process for controlling bead size in the production of expandable styrene polymers by suspension polymerization is carried out by adding protective colloids to the aqueous phase before polymerization begins, such protective colloids being used which are homogeneously soluble in water over the entire temperature range from 25.degree. to 125.degree. C. and in which the concentration range being employed shall not lower the boundary surface tension water/styrene below 18 N/mm.sup.2. Lastly, the protective colloids are selected according to their molecular weight and the weight ratio of aqueous to organic phase lies in the range of 0.9:1 to 1:1.25, preferably in the range of 1:1. A grain spectrum is maintained predominantly greater than 0.41 to less than 2.5 mm by varying the molecular weights of the protective colloids.
    Type: Grant
    Filed: August 27, 1984
    Date of Patent: October 21, 1986
    Assignee: Chemische Werke Huls Aktiengesellschaft
    Inventors: Josef K. Rigler, Horst Leithauser
  • Patent number: 4613626
    Abstract: This invention discloses a vinylidene chloride resin type in-mold foam molding having a broad cross-sectional area and a free shape, useful as thermal insulating plate materials or anti-shock molded vessels, and foam particles or expandable particles convenient for preparation thereof, and also a series of advantageous foaming techniques for completion of such a molding. The above foam molding can be prepared by bringing fine particles of a non-crystalline vinylidene chloride type resin obtained generally by suspension polymerization into contact with a volatile organic blowing agent thereby impregnating the resins with the blowing agent to form expandable resin particles, which are in turn subjected to expansion as such, or after forming into pre-expanded foam particles including expandable gas therein, by filling in a mold cavity which can be closed but not sealed, under heating to form a molding through fusion mutually between the expanded particles.
    Type: Grant
    Filed: June 20, 1985
    Date of Patent: September 23, 1986
    Assignee: Asahi Kasei Kogyo Kabushiki Kaisha
    Inventors: Norihiko Sakata, Nobuo Miura
  • Patent number: 4609512
    Abstract: A process for controlling bead size in the manufacture of expandable styrene polymers by suspension polymerization, wherein, referred to the aqueous phase, a concentration of ions of calcium, aluminum, metals of the 1st, 2nd, or 6th through 8th side groups of the period table of elements of 3.times.10.sup.31 5 to 3.times.10.sup.-2 % by mass is established, these metal ions being present as cations in the higher oxidation stage of water-soluble, inorganic salts.
    Type: Grant
    Filed: August 27, 1984
    Date of Patent: September 2, 1986
    Assignee: Chemische Werke Huls AG
    Inventors: Josef K. Rigler, Dirk Reese, Horst Leithauser
  • Patent number: 4596832
    Abstract: In producing a foam by foaming a melt-plasticized styrene/maleic anhydride copolymer resin, a process for producing a highly foamed styrene/maleic anhydride copolymer resin foam characterized by using as the blowing agent at least one compound selected from the group consisting of a carboxylate of a metal of group Ia of the periodic table of elements, a carbonate of a metal of group Ia, a carboxylate of a metal of group IIa and a carbonate of a metal of group IIa; or by first blending with said copolymer resin at least one compound selected from the group consisting of a carboxylate of a metal of group Ia of the periodic table of elements, a carbonate of a metal of group Ia, a carboxylate of a metal of group IIa and a carbonate of a metal of group IIa, then melt-blending the mixture, followed by extruding and granulating the blend to form a pre-expanded granular product, and thereafter foaming the granular product thus obtained.
    Type: Grant
    Filed: April 19, 1985
    Date of Patent: June 24, 1986
    Assignee: Dainippon Ink and Chemicals, Inc.
    Inventors: Nagao Ariga, Kyotaro Shimazu, Hiroyuki Sato
  • Patent number: 4592722
    Abstract: A method and apparatus for expanding particles of a lightweight aggregate material are disclosed. The apparatus comprises a housing having an upper chamber separated from a lower chamber by a partition having a plurality of openings. Hot air is introduced into the lower chamber and flows through the partition to fluidize particles introduced into the upper chamber. Means are provided for independently regulating the velocity of air through separate sections of the partition. Particles are introduced at the inlet end of the upper chamber. The particles are fluidized and transported toward the outlet end of the upper chamber by the air flow. The temperature of the air flow causes the particles to expand and become lighter. The velocity of the air flow through separate sections of the partition is adjusted to maintain uniform fluidization of the particle bed in the upper chamber.
    Type: Grant
    Filed: June 8, 1984
    Date of Patent: June 3, 1986
    Assignee: Lightweight Processing Co.
    Inventor: Harold Heckman
  • Patent number: 4579701
    Abstract: Low density expanded polystyrene is obtained by extended exposure of particles to atmospheric steam and aging the particles in air. Particles have wrinkled cell walls.
    Type: Grant
    Filed: September 24, 1984
    Date of Patent: April 1, 1986
    Assignee: The Dow Chemical Company
    Inventors: Chung P. Park, James T. Grimes
  • Patent number: 4550003
    Abstract: This invention discloses a vinylidene chloride resin type in-mold foam molding having a broad cross-sectional area and a free shape, useful as thermal insulating plate materials or anti-shock molded vessels, and foam particles or expandable particles convenient for preparation thereof, and also a series of advantageous foaming techniques for completion of such a molding. The above foam molding can be prepared by bringing fine particles of a non-crystalline vinylidene chloride type resin obtained generally by suspension polymerization into contact with a volatile organic blowing agent thereby impregnating the resins with the blowing agent to form expandable resin particles, which are in turn subjected to expansion as such, or after forming into pre-expanded foam particles including expandable gas therein, by filling in a mold cavity which can be closed but not sealed, under heating to form a molding through fusion mutually between the expanded particles.
    Type: Grant
    Filed: December 5, 1984
    Date of Patent: October 29, 1985
    Assignee: Asahi Kasei Kogyo Kabushiki Kaisha
    Inventors: Norihiko Sakata, Nobuo Miura
  • Patent number: 4540718
    Abstract: A pre-expanded particle suitable for foaming in a mold comprising polyolefin which has a characteristic property that an inclination of slope line obtained on a graph when logarithmic values of melt tension of the polyolefin are plotted as ordinate and reciprocals of absolute temperature at which the melt tension is measured are plotted as abscissa is less than 1,500 is provided. A foamed article produced from the pre-expanded particles has an excellent appearance, a flat surface and good mechanical strength, and is useful for wrapping material, insulating material, a container or a fender of cars.A process for preparing the above-mentioned pre-expanded particles is also disclosed.
    Type: Grant
    Filed: February 29, 1984
    Date of Patent: September 10, 1985
    Assignee: Kanegafuchi Kagaku Kogyo Kabushiki Kaisha
    Inventors: Kenichi Senda, Masao Ando, Kyoichi Nakamura, Tatehiko Nishida
  • Patent number: 4532263
    Abstract: A method for forming a molded polymer foam structure comprising expanding solvent imbibed polymer particles selected from the group consisting of a polyetherimide, a polycarbonate and a polyphenylene oxide-polystyrene blend and fusing the expanded particles together in a mold.
    Type: Grant
    Filed: December 12, 1983
    Date of Patent: July 30, 1985
    Assignee: Mobil Oil Corporation
    Inventors: Charles M. Krutchen, Wen-Pao Wu
  • Patent number: 4525485
    Abstract: A process for preparing pre-expanded particles of a thermoplastic resin which comprises; heating under an elevated pressure an aqueous dispersion comprising thermoplastic resin particles containing a volatile foaming agent and an aqueous medium in a pressure vessel; releasing the dispersion from the pressure vessel into a space within a sealed low-pressure vessel wherein the pressure is lower than that in the pressure vessel, whereby expanding the thermoplastic resin particles to give pre-expanded particles; and simultaneously recovering the foaming agent volatilized from the thermoplastic resin particles by discharging the foaming agent out of the space in the low-pressure vessel with controlling the pressure in the low-pressure vessel to substantially a given pressure. According to the process, the release of the volatile foaming agent into the air is prevented.
    Type: Grant
    Filed: September 6, 1984
    Date of Patent: June 25, 1985
    Assignee: Kanegafuchi Kagaku Kogyo Kabushiki Kaisha
    Inventors: Hirofumi Maeda, Kyoichi Nakamura, Hisatoshi Fukui
  • Patent number: 4524154
    Abstract: A process for preparing pre-expanded particles of a thermoplastic resin which comprises; heating under an elevated pressure an aqueous dispersion comprising thermoplastic resin particles containing a volatile foaming agent and an aqueous medium in a pressure vessel; releasing the dispersion from the pressure vessel into a space within a sealed low-pressure vessel wherein the pressure is lower than that in the pressure vessel and the space is sealed with an aqueous medium which exists in the lower portion of the vessel and communicates with the outside of the vessel, whereby expanding the thermoplastic resin particles to give pre-expanded particles; and sinking the resulting pre-expanded particles under the aqueous medium by means of a rotary impeller provided in the pressure vessel so that the pre-expanded particles are taken out of the low-pressure vessel through the aqueous medium towards the outside of the vessel, while recovering the foaming agent volatilized from the thermoplastic resin particles by disc
    Type: Grant
    Filed: September 6, 1984
    Date of Patent: June 18, 1985
    Assignee: Kanegafuchi Kagaku Kogyo Kabushiki Kaisha
    Inventors: Hirofumi Maeda, Kyoichi Nakamura, Toshihiro Hatamoto
  • Patent number: 4513106
    Abstract: A process for expanding expandable thermoplastic microspheres containing a blowing agent which will be volatilized at heating. A slurry of the unexpanded spheres is fed to a pressure zone together with steam whereby volatilization of the blowing agent occurs in the zone and the expanded microspheres are then allowed to leave the zone at a considerable pressure drop.
    Type: Grant
    Filed: November 22, 1983
    Date of Patent: April 23, 1985
    Assignee: KemaNord AB
    Inventors: Anders Edgren, Jan Soderberg, Bengt Bergstrom
  • Patent number: 4510106
    Abstract: A process of pre-foaming blowing agent-containing plastic materials, in which the plastic material particles which have been pre-foamed by the addition of heat are transferred without an intermediate resting stage from a sealed pre-foaming chamber into a drying and stabilizing chamber, with a vacuum being maintained during the drying and stabilizing operation.An apparatus for the performance of the process includes a pre-foaming chamber, beneath which there is provided a chamber in which the pre-foamed plastic material is dried and stabilized. The charging opening of the drying and stabilizing chamber is directly under the discharge opening of the pre-foaming chamber and is hermetically sealable by means of a slide valve.
    Type: Grant
    Filed: November 15, 1983
    Date of Patent: April 9, 1985
    Inventor: Kurt Hirsch
  • Patent number: 4504601
    Abstract: A process for producing pre-foamed particles of a polypropylene resin which comprises expanding original pre-foamed particles of a polypropylene resin, said original pre-foamed particles having the following relation2<E.sup.1/3 .times.n.sup.1/2 <45wherein E is the expansion ratio of the original pre-foamed particles, and n is the number of cells per mm.sup.2 of the cross section of the original pre-foamed particles,by (1) imparting expanding ability to the original pre-foamed particles and then heating them with a heated gas to the heat distortion temperature of the base resin of the pre-foamed particles or a higher temperature or (2) heating the original pre-foamed particles with steam to the heat distortion temperature of the base resin of the particles or a higher temperature with or without imparting expanding ability thereto, whereby pre-foamed particles having an expansion ratio higher than the original expansion ratio E are obtained.
    Type: Grant
    Filed: September 29, 1983
    Date of Patent: March 12, 1985
    Assignee: Japan Styrene Paper Corporation
    Inventors: Hideki Kuwabara, Shohei Yoshimura, Toru Yamaguchi, Yoshimi Sudo
  • Patent number: 4485193
    Abstract: Resilient foam particles and moldings are obtained employing a lightly crosslinked polymer such as a styrene polymer with volatile fluid foaming agent that has low permeability through the polymer. Multiple expansion will permit low density particles for molding.
    Type: Grant
    Filed: April 16, 1984
    Date of Patent: November 27, 1984
    Assignee: The Dow Chemical Company
    Inventors: Louis C. Rubens, Willard E. Alexander
  • Patent number: 4464484
    Abstract: Prefoamed polymer particles having excellent moldability are produced by a process comprising a step (impregnating step) of impregnating carbon dioxide or carbon dioxide and a volatile blowing agent in polymer particles, a step (dispersing step) of dispersing the polymer particles into a dispersion medium in a sealed vessel, a step (heating step) of heating the polymer particles to a temperature higher than the softening point of said polymer particles, and a step (releasing step) of opening one end of said vessel and simultaneously releasing the polymer particles and dispersion medium from inside the vessel to an atmosphere held at a pressure lower than that of the vessel. In this process, the impregnating step, dispersing step and heating step need not be altogether effected separately. These steps can be performed simultaneously in one and the same vessel.
    Type: Grant
    Filed: December 13, 1983
    Date of Patent: August 7, 1984
    Assignee: Japan Styrene Paper Corporation
    Inventors: Shohei Yoshimura, Hideki Kuwabara