With Immersion In Liquid Bath Patents (Class 264/562)
  • Patent number: 5607639
    Abstract: Method for the preparation of cellulose sheet by extrusion of a heated solution of cellulose in a tertiary amine-oxide, which method includes using an extrusion die with an extrusion orifice, characterised in that, immediately below the extrusion orifice there is provided an inlet for cooling gas to cool the extruded sheet. The method according to the invention is especially suitable for the preparation of cellulose tubular films.
    Type: Grant
    Filed: March 31, 1994
    Date of Patent: March 4, 1997
    Assignee: Lenzing Aktiengesellschaft
    Inventors: Stefan Zikeli, Friedrich Ecker, Ernst Rauch, Klaus Renner, Anton Sch onberg
  • Patent number: 5607638
    Abstract: A vacuum sizing apparatus and method of cooling and sizing plastic extrusions. In one embodiment the molten plastic extrudate enters a first vacuum chamber, passes into an ambient air environment, and then passes into a second water chamber. The first vacuum chamber includes entry and exit sizing plate manifolds to impart and maintain the size and shape of the plastic extrudate.
    Type: Grant
    Filed: June 6, 1995
    Date of Patent: March 4, 1997
    Inventor: Charles E. Cadwell
  • Patent number: 5549943
    Abstract: Tubular, biaxially stretched, heat shrinkable multilayer film food casings comprising inner and outer polyamide layers on either side of a core layer predominantly of one or more polyolefins such as VLDPE or EVA and a coextrusion process for making the film.
    Type: Grant
    Filed: September 23, 1992
    Date of Patent: August 27, 1996
    Assignee: Viskase Corporation
    Inventor: Stephen J. Vicik
  • Patent number: 5516270
    Abstract: A sizing tool for extruding plastic tubing is disclosed. The tool includes a peripheral wall having an inner surface that defines the outer dimension of a plastic tubing advancing from an extruder through the tool under influence of an internal pressure exceeding the pressure prevailing in the tool. The tool also includes a lubricating water channel system in the peripheral wall and extending along the tool length and having at least one opening communicating with the inner surface of said peripheral wall. The tool also includes a cooling medium channel system in the peripheral wall and extending along the length. The cooling medium channel system being substantially closed within the peripheral wall and being separate from the lubricating water channel system.
    Type: Grant
    Filed: May 12, 1994
    Date of Patent: May 14, 1996
    Assignee: JRT-Finland Oy
    Inventor: Reijo Lehtinen
  • Patent number: 5514325
    Abstract: The invention describes a process for cooling and if necessary calibrating elongated, especially continuously extruded objects (7) made of plastic as well as a cooling and calibrating device (5) for carrying out the process. With this the object (7) during its advancement in the longitudinal direction is exposed in consecutive regions (13 to 18; 86 to 89, 95 to 97) to a higher vacuum in each case and is cooled with respect to the initial temperature to a lower final temperature. The heat to be removed for cooling is extracted by a coolant washing round the object (7).
    Type: Grant
    Filed: February 21, 1995
    Date of Patent: May 7, 1996
    Assignee: C. A. Greiner & Sohne Gesellschaft m.b.H.
    Inventor: Franz Purstinger
  • Patent number: 5489406
    Abstract: A method of making a porous polymeric material by heating a mixture comprising polyvinylidene fluoride and a solvent system initially comprising a first component that is a latent solvent for polyvinylidene fluoride and a second component that is a non-solvent for polyvinylidene fluoride wherein, at elevated temperature, polyvinylidene fluoride dissolves in the solvent system to provide an optically clear solution. The solution is then rapidly cooled so that non-equilibrium liquid-liquid phase separation takes place to form a continuous polymer rich phase and a continuous polymer lean phase with the two phases being intermingled in the form of bicontinuous matrix of large interfacial area, and cooling is continued until the polymer rich phase solidifies. The polymer lean phase is removed from the solid polymeric material.
    Type: Grant
    Filed: December 8, 1992
    Date of Patent: February 6, 1996
    Assignee: Memtec Limited
    Inventors: Thomas W. Beck, Matthew B. Lee, Richard D. Grant, Robert J. W. Streeton
  • Patent number: 5480598
    Abstract: A nozzle assembly for forming hollow fibers, particularly a "Z-fiber" having longitudinally oriented trabeculae with the fiber wall, is provided. The nozzle assembly contains a replaceable nozzle cap, a replaceable seal-guide, and a retractable central bore used to supply core material for the hollow fibers. The Z-fibers are particularly useful in enabling cells, solutes, or the like, to enter the fiber wall and move longitudinally into the center of the fiber wall.
    Type: Grant
    Filed: September 17, 1992
    Date of Patent: January 2, 1996
    Assignee: Brown Univ. Research Foundation
    Inventors: Frank T. Gentile, Michael J. Lysaght, Nicholas F. Warner
  • Patent number: 5480295
    Abstract: A sizing device having a series of sets of sizing dies each composed of first and second die elements for use in extruding articles. Each die element is made of a plate having two opposite faces bounded by a peripheral edge. The edge further defines a notch through the plate. The notch in each die element has an open end extending inwardly to a closed end. The first and second die elements can be moved relative to each other from an open position in which the notches are unoccluded to a closed position in which first and second die elements overlie each other in the direction of extrusion and abut with the notches partly occluded by the abutting complementary die element. When the die is closed, the interior closed ends of the notches of the abutting elements of each die overlap to form a passage through the die that determines the shape of the extrusion. Support structure maintains the series of die sets at spaced apart locations in a vacuum extrusion chamber.
    Type: Grant
    Filed: August 30, 1994
    Date of Patent: January 2, 1996
    Assignee: The Laitram Corporation
    Inventor: Christopher G. Greve
  • Patent number: 5451364
    Abstract: In a method for forming a cellulose tube suitable for use as a food casing, in which a solution of nonderivatized cellulose, tertiary amine N-oxide and water is extruded through a die gap and the extruded tube downwardly flowed through an air length while being internally cooled, and passed into a water bath, the tube transverse direction tensile strength is substantially increased by drawing the extruded tube through an air length of at least about six inches.
    Type: Grant
    Filed: January 10, 1994
    Date of Patent: September 19, 1995
    Assignee: Viskase Corporation
    Inventors: Paul E. Ducharme, Jr., Edward M. Kajiwara, Norman A. Portnoy
  • Patent number: 5424023
    Abstract: The present invention has several aspects: an extrusion apparatus, a method of making a curved extrusion, and a curved extrusion made by the method. In broadest terms, the apparatus of the present invention comprises: (1) an extruding means, typically an extruder, adapted to produce an extrudate having a cross-section; (2) a plurality of guide members arranged so as to form a curvilinear path through which the extrusion is passed, each of the guide members having an aperture having substantially the same shape as the cross-section of the extrusion, whereby the plurality of guide members are adapted to form the extrusion into a curved shape while maintaining the cross-section of the extrusion; and (3) mechanical means adapted to conduct the extrusion through said plurality of guide members, such as an extrusion puller.
    Type: Grant
    Filed: June 3, 1993
    Date of Patent: June 13, 1995
    Assignee: Crane Plastics Company Limited Partnership
    Inventors: Bobby D. Riley, William Taylor
  • Patent number: 5395570
    Abstract: Extrusion of hollow membranes is improved by coextruding a coating fluid layer about the extrudate of heated polymer solution with its interior lumen forming extrudate. The coating fluid is disposed between the forming hollow fiber and a cooling fluid, and controls the rate of heat transfer to afford superior control over the structure and form of the hollow fiber produced in the invention. The coating fluid is typically the same material as the cooling fluid, and often is the same material as the solvent for the polymer in the heated polymer solution.
    Type: Grant
    Filed: February 5, 1993
    Date of Patent: March 7, 1995
    Assignee: Memtec Limited
    Inventors: Clinton V. Kopp, Robert J. W. Streeton, Paul S. Khoo
  • Patent number: 5340295
    Abstract: A vacuum sizing apparatus with a controlled vacuum is provided. The vacuum is precisely controlled by the use of a variable speed motor driven vacuum pump and a step motor controlled vent valve. An electrical circuit containing a microprocessor coordinates the speed of the motor driven vacuum pump with the position of the vent valve to give precise vacuum control within the vacuum chambers of the sizing apparatus. A closed sump tank contains water for the water system of the apparatus and is maintained at the same vacuum level as the vacuum chambers within the sizing apparatus.
    Type: Grant
    Filed: July 19, 1993
    Date of Patent: August 23, 1994
    Assignee: The Conair Group, Inc.
    Inventors: Ernest J. Preiato, Marion M. Meetze, Hoopes, Mark S., Robert H. Bessemer
  • Patent number: 5277851
    Abstract: A method of making a porous polymeric material by heating a mixture of a thermoplastic polymer and a cationic or non-ionic surfactant having a hydrophilic-lipophilic balance range of 4.0 to 6.0 to a temperature and for a time sufficient for the polymer and surfactant to mutually dissolve. The mixture is then cooled to a temperature so that non-equilibrium liquid-liquid phase separation takes place to form a bi-continuous matrix of the polymer and surfactant so that the polymer and surfactant form two intermingled separate phases of large interfacial surface area. The surfactant is then removed from the polymer. The porous polymeric material produced by the above method has a lacey or filamentous structure consisting of a plurality of polymer strands connected together at spaced apart locations along each strand.
    Type: Grant
    Filed: September 4, 1992
    Date of Patent: January 11, 1994
    Inventors: Douglas L. Ford, Clinton V. Kopp, Robert J. W. Streeton
  • Patent number: 5225139
    Abstract: A process of expanding plastics film is disclosed, together with an apparatus for performing that process, in which expansion of the plastics film is performed under the control of a liquid providing a stable hydraulic mass, by the downward extrusion and drawing of the plastics film, and the final expansion thereof, exclusively under the influence of the static and dynamic pressure of a hydraulic mass, at a position spaced downwardly of the extrusion head, the hydraulic mass being one that remains in a liquid phase at all temperatures encountered during the step of lateral stretching of the plastics film, to the exclusion of vaporization of the hydraulic mass.
    Type: Grant
    Filed: July 15, 1991
    Date of Patent: July 6, 1993
    Assignee: Plasticos Polyfilm S.A.
    Inventors: Jacob Wajsbrot, Flavio Derdyk, Rafael L. Echavarria Estevez
  • Patent number: 5171493
    Abstract: A process for the production of a porous organic material, in particular an organic semi-permeable membrane, provided with a plurality of separate passageways, comprising dissolving a polymer in a solvent, using a drawplate comprising needles having a shape conjugate with that of the passageways and external dimensions comprising between 0.7 and 1.2 times those of said passageways and an extrusion orifice of a conjugate fome to that of the extrudate and of internal dimensions comprising between 0.8 and 1.2 times those of said extrudate, injecting around the needles a solution having a viscosity greater than 500 millipascal-second, introducing into the interior of the conduits of the drawplate a centering fluid which is a non-solvent with respect to the polymer and able to precipitate the polymeric solution, causing the extrudate to travel from the output of the drawplate a distance da in a gaseous atmosphere which is non-precipitating with respect to the polymeric solution such that 500.times.e<da<0.
    Type: Grant
    Filed: December 22, 1989
    Date of Patent: December 15, 1992
    Assignee: Societe Lyonnaise des Eaux (Societe Anonyme)
    Inventors: Philippe Aptel, Jean-Michel Espenan
  • Patent number: 5089187
    Abstract: A process for the production of a porous organic material, in particular a semi-permeable membrane, comprising a plurality of separate passageways, including dissolving a polymer in a solvent, using a drawplate having needles of a shape conjugate with those of the passageways and of external dimensions between 0.7 and 1.2 times those of the passageways and an extrusion orifice of a shape conjugate those of the extrudate and of internal dimensions comprising between 0.8 and 1.2 times those of the extrudate, injecting around the needles a solution having a viscosity greater than 500 mPa.s and introducing a centering fluid into the interior of these needles, recovering the extrudate at the output of the drawplate in a precipitating medium in such a manner that the extrudate travels in the medium a distance such that 800.times.
    Type: Grant
    Filed: December 22, 1989
    Date of Patent: February 18, 1992
    Assignee: Societe Lyonnaise des Eaux, S.A.
    Inventors: Philippe Aptel, Jean-Michel Espenan
  • Patent number: 5084227
    Abstract: A process for cooling a heated polymer film by applying to both surfaces of the heated film, a cooling liquid adapted for wetting contact with the film surfaces. The viscosity of the layers of liquid adhering to the film surfaces is significantly reduced to facilitate removal of such liquid layers. The viscosity can be reduced by significantly raising the temperature of the adhering liquid layers after the film has been sufficiently cooled or by changing the adhering liquid to a different liquid of lower viscosity. Preferably, the liquid layers are removed for the film surfaces by conveying the liquid carrying film upwardly to cause the liquid layers to each form into a generally triangular shape with the vertex extending upwardly and blowing air stream downwardly against each such vertex.
    Type: Grant
    Filed: June 11, 1990
    Date of Patent: January 28, 1992
    Assignee: AGFA-Gevaert N. V.
    Inventors: Gery Vancoppenolle, Jan K. D. Keyzer, Walter J. Rens, Patrick R. Van Put
  • Patent number: 5078930
    Abstract: A method for continuously controlling the pressure in a bubble formed of a continuously extruded seamless blown thermoplastic film tubing which is being conducted generally upwardly through a cooling water bath. More particularly, the method contemplates controlling the internal bubble pressure through the intermediary of a Photohelic pressure controller which is utilized to monitor the differential prevailing between the internal bubble pressure and that of the water bath encompassing the bubble. The invention also relates to an apparatus for controlling the internal pressure of a bubble constituted from a seamless blown thermoplastic film which is extruded and conducted through an external cooling water bath, employing the method pursuant to the invention.
    Type: Grant
    Filed: July 30, 1990
    Date of Patent: January 7, 1992
    Assignee: Mobil Oil Corporation
    Inventor: F. John Herrington, Jr.
  • Patent number: 5035851
    Abstract: A method of producing an oxygen barrier film, and the resulting film, includes the coextrusion of a multi-layer extrudate having an outside ethylene vinyl alcohol copolymer layer which has been passed through a hot water system to soften and wet the ethylene vinyl alcohol copolymer. The wetted film can be more easily oriented to produce a shrinkable film.
    Type: Grant
    Filed: January 18, 1991
    Date of Patent: July 30, 1991
    Assignee: W. R. Grace & Co.-Conn.
    Inventor: Henry G. Schirmer
  • Patent number: 5028691
    Abstract: A process of cooling a heated polyethylene terephthalate film by applying cooling liquid to both surfaces of the heated film and, after the temperature of the film has decreased sufficiently, removing the cooling liquid from the film, wherein the cooling liquid has a pH value between 6 and 3.
    Type: Grant
    Filed: June 11, 1990
    Date of Patent: July 2, 1991
    Assignee: Agfa Gevaert, N.V.
    Inventors: Gery Vancoppenolle, Jan K. De Keyzer, Walter J. Rens
  • Patent number: 4978484
    Abstract: The present invention relates to a method of and an apparatus for manufacturing biaxially oriented film. A tubular original film which has been extruded by an extruding die is biaxially oriented by heat and air injected to the inside portion thereof being conveyed to nip rolls each having an individual circumferential speed. The temperature of heat to be applied to the film is controlled on the basis of the detected film thickness for the purpose of obtaining a uniform film thickness distribution. Furthermore, the film can be made uniform by adjusting the outer diameter of the bubble-shaped oriented film by adjusting the distance between two sets of nip rolls on the basis of the measured width of the film. In addition, when the thus-oriented film is subjected to a heat treatment, temperature of heat is arranged to be a predetermined temperature as to prevent adhesion of the films.
    Type: Grant
    Filed: March 30, 1989
    Date of Patent: December 18, 1990
    Assignee: Idemitsu Petrochemical Co., Ltd.
    Inventors: Masao Takashige, Teruyuki Iwai, Hidenobu Takeichi, Yasuo Takai, Yoshinori Sasaki, Masato Masuoka, Yuichi Ohki
  • Patent number: 4970034
    Abstract: Isotropic microporous polysulfone membranes can be prepared by using a particular combination of casting solution and precipitation solution formulations, and casting conditions. Both hollow fiber and flat membranes can be prepared in this manner. The membranes are skinless and are characterized by uniform porosity throughout the membrane.
    Type: Grant
    Filed: September 23, 1988
    Date of Patent: November 13, 1990
    Assignee: W. R. Grace & Co.-Conn.
    Inventors: Ann L. Ly, Chaokang Chu, Thanh D. Nguyen
  • Patent number: 4952265
    Abstract: In this mat consisting of filament loop aggregations, irregular form loops are formed in the upright direction by respectively winding to be coil-like many filaments coarse in the arranging intervals and made of a thermoplastic synthetic resin and are fused in the intersecting parts and the other loops are formed in the laterally fallen direction and are fused in the overlapping parts.
    Type: Grant
    Filed: April 12, 1988
    Date of Patent: August 28, 1990
    Assignee: Kabushiki Kaisha Risuron
    Inventors: Minoru Yamanaka, Tetsuo Amawa
  • Patent number: 4915886
    Abstract: A method is provided of manufacturing a skinless, nylon microporous hollow fiber membrane. The method comprises the steps of providing a nylon polymer dope solution and a quench liquid capable of solidifying and forming micropores in an extruded nylon polymer dope solution to produce a skinless, microporous nylon membrane. The quench liquid is placed into a vessel and a tube is provided which has a top and a bottom outlet. The bottom outlet of the tube is partially submerged in the quench liquid, the tube vertically extending therefrom. A spinneret is provided which has an outlet adjacent the top of the tube. The chemical quench liquid is raised in the tube until it is in substantial contact with the spinneret outlet. The nylon polymer dope solution is extruded in the form of a hollow fiber through the spinneret outlet directly into the quench liquid.
    Type: Grant
    Filed: December 20, 1988
    Date of Patent: April 10, 1990
    Assignee: Cuno, Incorporated
    Inventors: Ronald V. Repetti, Scott P. Yaeger, Chaokang Chu
  • Patent number: 4913757
    Abstract: A method of producing a mat consisting of filament loop aggregations. The first step is that of forming a first filament loop aggregation low in the filament density wherein many filaments are made. These by extruding a thermoplastic synthetic resin out of a T-die and arranging the resin longitudinally and laterally at intervals for continuous molding. The resin is deposited on a boiling water surface. The filament temperature is maintained close to the temperature at the time of molding by heating while the filament bundle is vertically lowered toward a cooling water surface and is sunk into water in the vertical direction.
    Type: Grant
    Filed: April 12, 1988
    Date of Patent: April 3, 1990
    Assignee: Kabushiki-Kaisha Risuron
    Inventors: Minoru Yamanaka, Tesuo Amawa
  • Patent number: 4871494
    Abstract: A process for forming high free volume, asymmetric gas separation membranes having graded density skins and macrovoid-free morphology from a solvent system comprising a Lewis acid, Lewis base, and a Lewis acid:base complex which dissolve hydrophobic polymers. The dopes have high total solids, high viscosity and low coagulation (g) values which enhance rapid gelation without the formation of macrovoids and which minimize densification. The dope solvent system complexes are readily disassociated by the coagulation medium and the component molecules are miscible in the medium which provides for rapid desolvation of the formed membrane thus providing a membrane having low residual solvent retention.
    Type: Grant
    Filed: July 6, 1987
    Date of Patent: October 3, 1989
    Assignee: Permea, Inc.
    Inventors: Robert E. Kesting, Alfred K. Fritzsche, Milton K. Murphy, Alan C. Handermann, Clint A. Cruse, Raymond F. Malon
  • Patent number: 4867934
    Abstract: A microporous nylon hollow fiber is prepared by extruding a nylon spinning solution through an annular slit of an orifice into a quench liquid while simultaneously introducing a core liquid into the inside hollow portion of the extruded spinning solution where the weighted densities of the spinning solution, quench liquid and the core liquid are regulated such that the average of the density of the core liquid and the spinning solution is about equal to the density of the quench liquid.
    Type: Grant
    Filed: December 23, 1987
    Date of Patent: September 19, 1989
    Assignee: Cuno, Inc.
    Inventors: Ronald V. Repetti, Stephen Troy
  • Patent number: 4863670
    Abstract: A method for the molecular orientation of plastic material by expanding a tube of plastic material, includes introducing the tube into a container filled with heated liquid, preferably water of a temperature of 70.degree.-100.degree. C. The tube is expanded by introducing a pressurized liquid into the tube. An apparatus for carrying out the method and a plastic material are also disclosed.
    Type: Grant
    Filed: November 10, 1983
    Date of Patent: September 5, 1989
    Assignee: Tetra Pak Developpement SA
    Inventor: Peter P. Hoj
  • Patent number: 4863662
    Abstract: A thermoplastic polymer yarn is spun into a spinning tube charged with a pressurized gas of more than 1 kg/cm.sup.2 G and withdrawn through a yarn exit provided with a unique sealing means which substantially prevents the charged gas from leakage but allows passage of the yarn out from the spinning tube. The resultant yarn has a high molecular orientation due to the improved quenching effect and the increase of resistance against yarn travelling of the charged gas.
    Type: Grant
    Filed: July 29, 1988
    Date of Patent: September 5, 1989
    Assignee: Toray Industries
    Inventors: Katsumi Hasegawa, Michio Ohno, Isoo Saito, Kotaro Fujioka
  • Patent number: 4824509
    Abstract: In order to apply pressure and heat to a sheet material as required in the manufacture of a laminated sheet material, the sheet material is conveyed in through an entrance opening of a pressure vessel, along through an interior space thereof, and out through an exit opening thereof, substantially filled with a pressure medium which is maintained at a temperature above its melting point in the interior space of the pressure vessel, but is maintained at a temperature below its melting point in the entrance and exit openings of the pressure vessel, so as to accomplish sealing in such zones by solidification of the pressure medium, whereby enabling continuously to treat a long sheet material under constant application of pressure and heat over a relatively long time period in which respective portions of the sheet material traverse the pressure vessel.
    Type: Grant
    Filed: January 13, 1986
    Date of Patent: April 25, 1989
    Assignee: Hitachi Chemical Co., Ltd.
    Inventors: Kenji Tonoki, Kazuyoshi Tsunoda, Haruki Yokono, Hisao Kono, Ryoji Yokoyama, Fumiaki Nakamura
  • Patent number: 4822540
    Abstract: A porous regenerated cellulose hollow fiber is obtained by a micro-phase-separation method. The hollow fiber is characterized in that the viscosity average molecular weight is at least 5.times.10.sup.4, each of the average pore diameter D.sub.1 on the inner wall surface of the hollow fiber and the average pore diameter D.sub.2 on the outer wall surface is 0.02 to 10 .mu.m, the in-plane porosity Pr on the outer wall surface is at least 10%, and the hollow fiber comprises a wall thickness portion having pores piercing therethrough between the inner wall surface and outer wall surface and a hollow portion extending continuously over the entire fiber length.
    Type: Grant
    Filed: May 27, 1986
    Date of Patent: April 18, 1989
    Assignee: Asahi Kasei Kogyo Kabushiki Kaisha
    Inventors: Seiichi Manabe, Michitaka Iwata, Mamoru Inoue
  • Patent number: 4820460
    Abstract: A quench bath, for quenching and solidifying an extruded hollow porous fiber of a liquid polymer solution in a chemical quenching solution, includes a shallow quench bath of a length for the generally horizontal part of the extruded fiber travel in the bath. A vertical extension tube with its lower end beneath the surface of the bath liquid holds a spinneret through which the fiber is extruded. The spinneret is sealed in the tube above the height of the liquid in the shallow bath. A vacuum drawn in the tube raises the liquid up to the spinneret. Also, the vacuum may be drawn by disposing the spinneret in a sealing piston which is raised through the tube to draw the vaccum in the tube behind the piston.
    Type: Grant
    Filed: April 27, 1987
    Date of Patent: April 11, 1989
    Assignee: CUNO, Incorporated
    Inventors: Ronald V. Repetti, Scott P. Yaeger, Chaokang Chu
  • Patent number: 4814120
    Abstract: A process for preparing collagen tubes includes extruding an aqueous gel containing about 1.5% native collagen through a cylindrical spinneret equipped with a central concentric tube designed to receive a part of a coagulation bath, followed by coagulation of the internal and external walls of the tube, leaving the spinneret in a coagulation bath constituted by about 70% acetone and 30% ammonia, followed by drying. Following drying, the collagen tube may be subjected to reticulation by dehydration carried out at about 80.degree. C. under a pressure of about 0.1 mm of Hg (vacuum) for about 24 hours. The reticulated collagen tube may eventually be subjected to a treatment which permits the introduction of azide groups onto the molecule without requiring that the collagen be coupled to any external molecule.
    Type: Grant
    Filed: April 21, 1987
    Date of Patent: March 21, 1989
    Assignee: Bioetica S.A.
    Inventors: Alain Huc, Rene Gimeno
  • Patent number: 4812269
    Abstract: Processes for producing semipermeable membranes in the form of hollow fibers are disclosed including extruding a solution of a block copolymer including at least one hydrophilic polymer and at least one hydrophobic polymer while simultaneously injecting a gaseous or vaporous center medium into the center bore of the hollow fiber extrudate, including coagulating the extrudate so formed therefrom. The preferred process includes using air or the components of air as the center medium and employing a polyethyleneoxide-polycarbonate block copolymer to form the hollow fiber membranes.
    Type: Grant
    Filed: August 6, 1987
    Date of Patent: March 14, 1989
    Assignee: Gambro Dialysatoren KG
    Inventors: Erich H. Harttig, Reinhold J. Buck, Hermann J. Gohl
  • Patent number: 4797246
    Abstract: A process is disclosed for the continuous manufacture of a perforated plastic film, where the plastic film is extruded directly from the extrusion unit either onto one roller of a pair of rollers or directly into the gap between a pair of rollers (a perforating/texturing roller and a back-up roller). The hot plastic film is perforated on a roller under the influence of a vacuum and shock cooling by the flow of cold air and the coolness of the back-up roller is carried out during the perforating step, and immediately thereafter. The film is preferably textured at the same time that it is perforated, the immediate cooling setting the texture in the film.
    Type: Grant
    Filed: January 25, 1984
    Date of Patent: January 10, 1989
    Inventors: Dietmar Reinke, Theo Schmidt
  • Patent number: 4755118
    Abstract: A cooling chamber for use in in-line association with a continuous extruder for rapidly cooling freshly extruded product, e.g. vinyl fluid hose, to prevent deformation of the fresh extrudate.
    Type: Grant
    Filed: July 16, 1987
    Date of Patent: July 5, 1988
    Assignee: Air Products and Chemicals, Inc.
    Inventors: Andrew P. Ondush, Roger A. Howells
  • Patent number: 4720368
    Abstract: A method of forming a fiber reinforced synthetic resin rod-like molding including a rod-like core portion having at least in the outer portion thereof a reinforcing fiber bundle integrally adhered together by a thermosetting resin and a thermoplastic resin layer coating the core portion is disclosed. The outer surface portion of the core portion and the inner surface portion of the thermoplastic resin layer are integrally adhered together due to an anchor effect generated by contacting between the thermosetting resin and the thermoplastic resin in a semifluid state under pressure.
    Type: Grant
    Filed: October 2, 1985
    Date of Patent: January 19, 1988
    Assignee: Ube-Nitto Kasei Co., Ltd.
    Inventors: Takayoshi Nakasone, Tetuo Sibagaki, Kenji Kozuka
  • Patent number: 4720384
    Abstract: Pharmaceutical compositions are provided which contain hollow fine tube drug delivery systems. The compositions comprise a pharmaceutically suitable carrier, preferably in the form of a capsule, tablet, suspension, or suppository, and at least one drug delivery system which consists essentially of (1) a polymeric tube having a membrane outer sheath and a hollow core, and (2) at least one drug compound contained within the core, said system contained in the composition in an amount sufficient to deliver a therapeutic amount of the drug contained therein at a predetermined rate over a predetermined period of time. By varying the polymer, the permeability of the outer sheath, the drug, the drug concentration in the hollow core of the tube, the tube diameter, the tube length, the tube core diameter, and the sealing of the tube ends, a wide variety of drug therapeutic amounts, rates and dosing times can be achieved.
    Type: Grant
    Filed: August 21, 1986
    Date of Patent: January 19, 1988
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: Robert C. Di Luccio, Ray B. Duggins, Eli Shefter
  • Patent number: 4683094
    Abstract: An improved method for the production of polyolefin film by extruding molten film from an annular die in a tubular form into an extrusion zone is disclosed wherein physical properties are enhanced by controlling polymeric crystalline growth. The method includes providing a liquid quench medium maintained at a constant temperature range in the extrusion zone immediately adjacent the annular die, extruding the molten film directly into the liquid quench medium, and then orienting the quenched film in a tubular bubble whereby the size and amount of crystalline growth is controlled.
    Type: Grant
    Filed: March 18, 1985
    Date of Patent: July 28, 1987
    Assignee: Mobil Oil Corporation
    Inventor: Gordon V. Sharps, Jr.
  • Patent number: 4680157
    Abstract: The invention provides a method for the preparation of a sheet of a crystalline thermoplastic resin, e.g. polypropylene, having excellent transparency and surface properties as well as thermoformability. The inventive method comprises quenching of a molten resin sheet extruded out of a T-die by introducing the same into a slit where cooling water is flowing at a velocity higher than the running velocity of the extruded molten resin sheet and then stretching the thus quenched resin sheet in a stretch ratio in the range from 1.02 to 1.5 times.
    Type: Grant
    Filed: July 19, 1985
    Date of Patent: July 14, 1987
    Assignee: Idemitsu Petrochemical Co., Ltd.
    Inventors: Atsushi Fujii, Kazuhisa Kaneda, Yoshihiro Tokiya
  • Patent number: 4668761
    Abstract: A polyacetal copolymer of continuous length is disclosed. The copolymer has an apparent density of 1.20 to 1.46 g/cm.sup.3, and a tensile modulus (X) of 19 GPA or more and a density change percentage (Y) of 85% or more. The relationship between the density change percentage (Y) and the tensile modulus (X) is defined by the following relationship:when 19.ltoreq.X.ltoreq.30, then Y.gtoreq.127.7-1.42X, and when X>30, Y.gtoreq.85.A method for producing this copolymer includes permitting a polymeric material in continuous length to pass through a pressurizing fluid and applying a substantially uniform pressure therearound. A drawing stress is applied to the material while heating it at a temperature not above its softening point, thus subjecting the material to high stretching.
    Type: Grant
    Filed: February 25, 1985
    Date of Patent: May 26, 1987
    Assignee: Asahi Kasei Kogyo Kabushiki Kaisha
    Inventors: Atsushi Aoshima, Tamikuni Komatsu, Sachio Enoki
  • Patent number: 4659534
    Abstract: A process for producing a thin-walled cylindrical body of an aromatic polyester, which comprises(A) heating a continuous thick-walled tubular body of an aromatic polyester by introducing it continuously into a heating zone while feeding a pressure fluid into the thick-walled tubular body,(B) expanding the heated thick-walled tubular body into a cylindrical form, and(C) continuously stretching and taking up the resulting cylindrical expanded body, while at least forming a fold-free portion in the expanded body in its longitudinal direction; and a thin-walled cylindrical body of an aromatic polyester characterized by a specific intrinsic viscosity, density, wall thickness, surface roughness (CLA), and difference of its refractive indices in the circumferential direction and in a direction perpendicular to the circumferential direction, and substantial freedom from folded marks which cannot be removed at a temperature of 80.degree. C.
    Type: Grant
    Filed: October 23, 1984
    Date of Patent: April 21, 1987
    Assignee: Teijin Limited
    Inventors: Tooru Matsubayashi, Seiichi Yamashiro
  • Patent number: 4659532
    Abstract: A process for providing film tubes with anti-blocking means in that the film tube is cooled internally by an aqueous suspension containing a suspended release agent directly after extrusion, the excess suspensions are sucked from the interior and the tube, which is additionally cooled on the exterior in a water bath, is freed of remaining liquid by squeezing rollers.
    Type: Grant
    Filed: July 30, 1985
    Date of Patent: April 21, 1987
    Assignee: Wolff Walsrode AG
    Inventor: Wolfgang Renger
  • Patent number: 4597932
    Abstract: Method of manufacturing synthetic resin pen nibs is disclosed, which pen nibs may suitably be employed in writing instruments for fine lettering or drawing fine lines. The pen nibs are formed of thermoplastic crystalline synthetic resin, e.g. polyethylene terephthalate resin, which is extruded from a molding die and subjected to rapid cooling to form a continuous rod in amorphous state. The rod is axially stretched under predetermined temperature condition to achieve oriented crystallization of the resin molecules, and is further heat-treated such that non-oriented fine crystals are dispersed and grown between oriented crystals and remaining amorphous regions. Pen nib thus obtained has highly improved physical and chemical properties.
    Type: Grant
    Filed: June 25, 1984
    Date of Patent: July 1, 1986
    Assignee: Aubex Corporation
    Inventors: Norigi Kurihara, Ryutaro Sakuda
  • Patent number: 4548778
    Abstract: A method of producing a thermoplastic sheet or film characterized in that a molten thermoplastic resin sheet extruded through a T-die is cooled by introducing it into a multi-stage slit in which a cooling water is flowing. The water level in the first slit of the multi-stage slit is maintained at as low a level as possible. The method produces various advantages over conventional methods; for example, the sheet or film is free from unevenness in thickness, wrinkles, and curls, and is of high uniformity, and the sheet or film can be formed by high-speed molding of at least 10 m/min. The sheet or film is suitable for use in wrapping of, for example, foods and medicines.
    Type: Grant
    Filed: September 26, 1983
    Date of Patent: October 22, 1985
    Assignee: Idemitsu Petrochemical Co., Ltd.
    Inventor: Atsushi Fujii
  • Patent number: 4543051
    Abstract: A vat under vacuum bears in its sidewall a sizing sleeve, the cylindrical downstream portion of which includes annular channels interconnected by distribution channels. Injection ducts leave the bottoms of the annular channels and open out in the inside surface of the sleeve. The interior of the sleeve communicates with the interior of the vat via rows of radial suction ducts. During operation, the injection ducts are supplied with water under pressure which forms a film between the outside of the tubing and the inside surface of the sleeve even when the tubing is pressed against that inside surface owing to the partial vacuum prevailing within the vat.
    Type: Grant
    Filed: December 14, 1982
    Date of Patent: September 24, 1985
    Assignee: Maillefer S.A.
    Inventor: Charles E. Maillefer
  • Patent number: 4356143
    Abstract: In an apparatus and a method for the curing of a continuous length of curable material, the length of material is passed through a curing chamber defined by a tubular body 47. This body 47 is disposed in the upper part of another heated tubular body 2 which contains a heat exchange liquid. This liquid is fed to one or more injectors disposed at one or both ends of the body 47, injected along the chamber and then allowed to drain back therefrom into the body 2. The body 2 contains a further tubular body 58 downstream of and partitioned from the tubular body 47. Body 58 also has an injector 60 through which water is injected to cool the length of material. Tubular body 47 may be provided with drain holes through which heat exchange liquid can be quickly drained at the end of a curing run. It may also be provided with air vents or a longitudinal slot in its upper part to release trapped air.
    Type: Grant
    Filed: March 9, 1981
    Date of Patent: October 26, 1982
    Assignee: General Engineering Radcliffe 1979 Limited
    Inventors: Alan H. Hill, Alan Lord
  • Patent number: 4354997
    Abstract: A process for simultaneously, biaxially orienting tubular ethylene polymer film by expansion and extension of the tube under particular conditions for heating the expanding tube, to give a heat shrinkable film. The heat shrinkable film has excellent heat shrinkability, shrinkage stress, transparency, heat sealability and impact resistance, and is very suited for use in shrink packaging.
    Type: Grant
    Filed: August 11, 1980
    Date of Patent: October 19, 1982
    Assignee: Kohjin Co., Ltd.
    Inventors: Tomoji Mizutani, Hitoshi Fukushima, Yoshihiro Sakamoto
  • Patent number: 4353861
    Abstract: In an apparatus and a method for the curing of a continuous length of curable material, the length of material is passed through a curing chamber defined by a tubular body 47. This body 47 is disposed in the upper part of another heated tubular body 2 which contains a heat exchange liquid. This liquid is fed to one or more injectors disposed at one or both ends of the body 47, injected along the chamber and then allowed to drain back therefrom into the body 2. The body 2 contains a further tubular body 58 downstream of and partitioned from the tubular body 47. Body 58 also has an injector 60 through which water is injected to cool the length of material. With this relatively compact arrangement curing may be achieved while thermal stresses in the apparatus are reduced.
    Type: Grant
    Filed: March 9, 1981
    Date of Patent: October 12, 1982
    Assignee: General Engineering Radcliffe 1979 Limited
    Inventor: Gustavo Caser
  • Patent number: 4340340
    Abstract: What is disclosed is an improvement in a system for producing a vacuum in which both liquid and gas streams are involved. Specifically, in one aspect the improvement is in a vacuum system for extruding plastic pipe having conventional extrusion apparatus, vacuum tank, mold and vacuum and liquid pumps with a chilled water flow system, the improvement being characterized by an outer housing connected intermediate the effluent water conduit and the liquid pump with a vacuum port connected with a vacuum pump; and an internal sleeve interiorly of the outer housing defining an annular space about the sleeve and directing the combined stream directly into the entrance to the liquid pump so that by inertia the liquid is sucked into the liquid pump whereas the gas is diverted by the vacuum pump to maintain the pressure without flooding the vacuum pump.
    Type: Grant
    Filed: December 18, 1980
    Date of Patent: July 20, 1982
    Assignee: Plastic Machinery Corporation
    Inventors: Glenn R. Brown, James S. McMillan