With Immersion In Liquid Bath Patents (Class 264/562)
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Patent number: 11618602Abstract: A process for making a shrink pouch having strong shrink tension in the pouch transverse direction and minimal or no shrink tension in the pouch longitudinal direction is provided. The process includes the steps of reinflating and cold-stretch orienting a previously collapsed blown film and feeding the cold-stretch oriented blown film in a flattened configuration into a side-fed pouch making machine, whereupon the longitudinal direction of the blown film becomes the transverse direction of the pouches thus formed, and vice versa. A shrink pouch having strong transverse shrink tension and little or no longitudinal shrink tension is also provided.Type: GrantFiled: March 10, 2022Date of Patent: April 4, 2023Inventor: Henry G. Schirmer
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Patent number: 9022764Abstract: A system for manufacturing an irrigation pipe comprises an extrusion unit, a calibrator unit, a cooling unit for cooling the irrigation pipe in a cooling liquid, and a traction unit for drawing the irrigation pipe in the cooling unit. The cooling unit comprises a device for detecting holes in the wall of the irrigation pipe and arranged for being immersed in the cooling liquid. The device for detecting holes comprises at least one optical transmitter and at least one optical receiver which define an optical barrier. The device is arranged so that the holes in the irrigation pipe located below the device produce gas bubbles which modify the optical barrier.Type: GrantFiled: May 24, 2012Date of Patent: May 5, 2015Assignee: Maillefer S.A.Inventors: Alain Wisler, Jean-Charles Zaramella
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Publication number: 20140367896Abstract: A method is provided for producing solid material filaments or films from a fluid of the material, by extruding the fluid by one or more extrusion openings and by solidifying the material in a precipitation bath. The formed material is guided between the extrusion openings and the precipitation bath by a lateral gas flow. The gas flow is subdivided into a hot partial flow and a cold partial flow. The material is initially brought into contact with the hot partial flow and subsequently with the cold partial flow prior to it being introduced into the precipitation bath. A device is also provided for extruding and forming materials.Type: ApplicationFiled: September 3, 2012Publication date: December 18, 2014Applicant: Aurotec GmbHInventors: Stefan Zikeli, Friedrich Ecker
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Patent number: 8512627Abstract: The present invention provides a method for the production of a poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) asymmetric hollow fiber membrane. The invention comprises preparing a dope solution of PVDF-HFP with an additive of lithium chloride or glycerol dissolved in a solvent such as N-methylpyrollidone (NMP). The dope solution is spun to form a PVDF-HFP asymmetric hollow fiber membrane.Type: GrantFiled: February 4, 2009Date of Patent: August 20, 2013Assignee: Nanyang Technological UniversityInventors: Rong Wang, David Tee Liang, Joo Hwa Tay
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Patent number: 8343414Abstract: A process and apparatus for multi-shot, liquid-resin-molding of continuous-fiber composite articles is disclosed. The process involves the step-wise fabrication of an article wherein continuity of the fibers is maintained between the multiple workpieces of the finished composite article.Type: GrantFiled: July 18, 2011Date of Patent: January 1, 2013Assignee: Lockheed Martin CorporationInventors: Alan K. Miller, Stephen L. Bailey, Theodore Rosario, Jr.
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Patent number: 8337744Abstract: A method and apparatus for maintaining constant compaction pressure in a vertically oriented resin transfer molding apparatus.Type: GrantFiled: November 22, 2010Date of Patent: December 25, 2012Assignee: Lockheed Martin CorporationInventors: Alan K. Miller, Theodore Rosario, Michael M. Garcia
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Patent number: 8197745Abstract: A permselective asymmetric hollow fiber membrane for the separation of toxic mediators from blood, a process for the preparation of such a membrane, and the use of such a membrane in hemodialysis, hemodiafiltration, and hemofiltration for treatment of toxic mediator-related diseases.Type: GrantFiled: February 14, 2012Date of Patent: June 12, 2012Assignee: Gambro Lundia ABInventors: Reinhold Buck, Hermann Goehl
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Patent number: 8025834Abstract: A process and apparatus for multi-shot, liquid-resin-molding of continuous-fiber composite articles is disclosed. The process involves the step-wise fabrication of an article wherein continuity of the fibers is maintained between the multiple workpieces of the finished composite article.Type: GrantFiled: June 15, 2009Date of Patent: September 27, 2011Assignee: Lockheed Martin CorporationInventors: Alan K. Miller, Stephen L. Bailey, Theodore Rosario, Jr.
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Patent number: 7879283Abstract: A sizer assembly for providing a shaped polymeric article in an extrusion process includes a sizer body having a product profile channel corresponding to the shaped polymeric article formed therethrough. The sizer body includes a plurality of cooling liquid inlet slots forming an opening substantially around the product profile channel and a plurality of vacuum slots forming an opening substantially around the product profile channel for removing cooling liquid expelled from said cooling liquid inlet slots.Type: GrantFiled: August 31, 2009Date of Patent: February 1, 2011Assignee: Certainteed CorporationInventors: Kevin D. Hartley, Robert C. McEldowney, Thomas G. Gilbert, Thomas A. Gates
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Patent number: 7811507Abstract: A hydrophilic semipermeable hollow-fibre membrane for blood treatment, with an integrally asymmetric structure based on a synthetic polymer. The hollow-fiber membrane possess on its inner surface a separating layer and an adjoining open-pored supporting layer, and has an ultrafiltration rate in albumin solution of 5 to ?25 ml/(h·m2·mmHg). The hollow fiber membrane is free from pore-stabilizing additives and has a maximum sieving coefficient for albumin of 0.005 and a sieving coefficient of cytochrome c that satisfies the equation SCcc?5·10?5·UFRAlb3?0.004·UFRAlb2+0.1081·UFRAlb?0.25.Type: GrantFiled: February 15, 2005Date of Patent: October 12, 2010Assignee: Membrana GmbHInventors: Friedbert Wechs, Arne Gehlen, Bodo Von Harten, Richard Kruger, Oliver Schuster
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Patent number: 7722796Abstract: Methods of fabricating continuous nanofibers include the steps providing a column, flowing an extrusion liquid through the column, and flowing a precursor liquid through the extrusion liquid, wherein the flowing precursor liquid has a viscosity less than the viscosity of the extrusion liquid. The method further includes reducing the diameter of the flowing precursor liquid by extruding the precursor liquid through the extrusion liquid, wherein the diameter of the precursor liquid is reduced by a factor of at least 5, and forming a continuous nanofiber by solidifying the extruded precursor liquid.Type: GrantFiled: September 6, 2006Date of Patent: May 25, 2010Assignee: Wright State UniversityInventor: Henry D. Young
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Patent number: 7504034Abstract: A method of producing a hollow fiber membrane includes discharging a polyvinylidene fluoride solution comprising a polyvinylidene fluoride resin and a poor solvent at a temperature above a phase separation temperature into a cooling bath at a temperature below the phase separation temperature to coagulate the polyvinylidene fluoride resin. The hollow fiber membrane comprises a polyvinylidene fluoride resin having spherical structures that have an average diameter in the range of 0.3 to 30 ?m.Type: GrantFiled: October 17, 2006Date of Patent: March 17, 2009Assignee: Toray Industries, Inc.Inventors: Shin-Ichi Minegishi, Masahiro Henmi, Toshiyuki Ishizaki, Koichi Dan
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Patent number: 7479248Abstract: The invention relates to a vessel prosthesis or patch, made from a biocompatible polymer with microporous, finely-fibrillated structure and a method for improving the e-modulus of said vessel prostheses or patches. According to the invention, the vessel prostheses or patches are subjected to a full stretching (extension) with a degree of extension between 30% and 250% and subsequent restoration.Type: GrantFiled: September 17, 2003Date of Patent: January 20, 2009Assignee: Adiam Life Science AGInventors: Josef Jansen, Engin Kocaman
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Publication number: 20080143024Abstract: In a method and apparatus for producing polystyrene tubular shrink film via film blow molding, a polystyrene plastic material is extruded into a circular tubular film, which is cooled and then uniformly heated in a special hot water tank to become softened. Hot air is then blown into the softened tubular film, and two sequentially arranged speed-controlled pressure guide roller sets are set to two different operating speeds, so that the softened tubular film is transversely and longitudinally stretched and thinned to form a stretched tubular film, which is then passed through a setting treatment system to form a thermally set tubular film and be finally wound in a take-up system into a roll for storage. The method and apparatus is simple, low cost, and easy to operate, and the product thereof is environment friendly to help in economic development.Type: ApplicationFiled: December 14, 2006Publication date: June 19, 2008Inventor: Chui-Hsian WEI
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Patent number: 7368526Abstract: Functionalized porous poly(aryl ether ketone) articles are prepared by reacting ketone groups in the backbone of poly(aryl ether ketone) polymer with a primary amine reagent. Preferred functional primary amines are primary aliphatic amines or substituted hydrazines containing one or more target functional groups including polar groups, such as hydroxyl groups, ˜OH, amino groups, ˜NH2, ˜NHR, ˜NRR?, and ethylene oxide groups, ˜OCH2CH2—, negatively or positively charged ionic groups, such as ˜SO3?, ˜COO?, and ˜NH4+ groups, hydrophobic groups such as siloxane or perfluorcarbone groups, and non-polar groups, such as linear or branched hydrocarbon groups. The functionalized porous poly(aryl ether ketone) article can be prepared by reacting primary amine with a pre-formed, shaped porous poly(aryl ether ketone) article or by functionalizing the surface of a non-porous precursor article that is subsequently converted into a porous article.Type: GrantFiled: October 10, 2006Date of Patent: May 6, 2008Assignee: Porogen CorporationInventors: Youxin Yuan, Yong Ding
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Publication number: 20070296125Abstract: A method of manufacturing an inflatable cuff is provided. The method includes the acts of stretching a tube, creating a positive pressure within the tube, changing the amount the tube is stretched, heating the tube, and increasing the positive pressure within the tube such that a portion of the tube in blown outward to form a cuff.Type: ApplicationFiled: June 22, 2006Publication date: December 27, 2007Inventors: Joel Colburn, Roger Caluya
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Patent number: 7229580Abstract: The preparation and use of novel porous poly(aryl ether) articles is disclosed. The porous articles are prepared from blends of poly(aryl ether) polymers with polyimides by selectively decomposing the polyimide phase. The preferred reagents used to decompose the polyimide phase include monoethanolamine and tetramethylammonium hydroxide. The porous articles can be configured as a single layer or as a multilayer article. The porous articles of the present invention are unique that at least one of the layers exhibits a narrow pore size distribution. The articles of the present invention can be used as a porous media for a broad range of applications, including porous membranes for fluid separations, such as microfiltration, ultrafiltration, and gas separation, as a battery separators, and as a sorption media.Type: GrantFiled: April 30, 2004Date of Patent: June 12, 2007Assignee: PoroGen CorporationInventor: Youxin Yuan
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Patent number: 7176273Abstract: Functionalized porous poly(aryl ether ketone) articles are prepared by reacting ketone groups in the backbone of poly(aryl ether ketone) polymer with a primary amine reagent. Preferred functional primary amines are primary aliphatic amines or substituted hydrazines containing one or more target functional groups including polar groups, such as hydroxyl groups, ˜OH, amino groups, ˜NH2, ˜NHR, ˜NRR?, and ethylene oxide groups, ˜OCH2CH2—, negatively or positively charged ionic groups, such as ˜SO3?, ˜COO?, and ˜NH4+ groups, hydrophobic groups such as siloxane or perfluorcarbone groups, and non-polar groups, such as linear or branched hydrocarbon groups. The functionalized porous poly(aryl ether ketone) article can be prepared by reacting primary amine with a pre-formed, shaped porous poly(aryl ether ketone) article or by functionalizing the surface of a non-porous precursor article that is subsequently converted into a porous article.Type: GrantFiled: November 3, 2004Date of Patent: February 13, 2007Assignee: PoroGen LLCInventors: Youxin Yuan, Yong Ding
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Patent number: 6887408Abstract: Porous poly(aryl ether ketone) (PAEK) articles are prepared from PAEK/polyimide blends by selective chemical decomposition and subsequent removal of the polyimide phase. Porous PAEK articles exhibit highly interconnected pore structure and a narrow pore size distribution. The porous PAEK articles of the present invention can be utilized as a porous media for a broad range of applications, including membranes for fluid separations, such as microfiltration, ultrafiltration, nanofiltration, and as a sorption media.Type: GrantFiled: April 30, 2004Date of Patent: May 3, 2005Assignee: PoroGen LLCInventor: Youxin Yuan
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Patent number: 6881361Abstract: The invention relates to a method for producing shaped bodies, especially threads or foils, from at least one polymer of the groups consisting of polysaccharide, polysaccharide derivative or polyvinyl alcohol by forming a solution of the polymer that contains an additive in a solvent containing amine-N-oxide, extruding the solution and precipitating the extrudate by contacting with a coagulant. The invention is characterized in that at least two polymeric solutions are formed. At least one of the two polymeric solutions contains one or more finely distributed additives and the at least two polymeric solutions are simultaneously extruded forming a combined extrudate.Type: GrantFiled: February 24, 2000Date of Patent: April 19, 2005Assignee: Ostthuringische Materialprufgesellschaft fur Textil und Kunststoffe mbHInventors: Thomas Schulze, Eberhard Taeger, Dieter Vorbach
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Patent number: 6875397Abstract: An apparatus for forming a fiber from a biocompatible biopolymer includes a fiber-formation tube that defines a bore extending generally vertically from an upper end to a lower end. Coagulation fluid enters the tube through a fluid inlet coupled to its upper end and establishes a laminar flow of coagulation fluid within the tube. A spinneret introduces a stream of liquid biopolymer into the laminar flow of coagulation fluid so that the stream is surrounded and swept downstream by the coagulation fluid as it coagulates into a biopolymer fiber. The laminar flow of coagulation fluid surrounding the biopolymer stream maintains the shape of the stream so that the resulting fiber is homogeneous in both geometry and structure. The laminar flow of coagulation fluid also prevents the resulting fiber from contacting the inner wall of the fiber-formation tube.Type: GrantFiled: October 19, 2001Date of Patent: April 5, 2005Assignee: TEI Biosciences, Inc.Inventor: Timothy W. Fofonoff
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Patent number: 6821591Abstract: The present invention provides a seamless tubular film on a cellulose base, being produced by extruding an aqueous cellulose N-methyl-morpholine-N-oxide spinning solution. The maximum degree of roughness Rmax is from greater than 0.1 &mgr;m to 0.5 &mgr;m and an average degree of roughness Rm is from 0.005 to 0.014 &mgr;m. On the surface of the tubular film is formed in contact with an electrolyte an electrokinetic potential, the size of which depends on the pH value of the electrolyte.Type: GrantFiled: July 20, 2001Date of Patent: November 23, 2004Assignee: Kalle GmbH & Co. KGInventors: Herbert Gord, Klaus-Dieter Hammer, Rainer Neeff, Klaus Berghof, Markus Eilers, Reinhard Maron
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Patent number: 6699549Abstract: A polyester-surfaced heat-shrinkable multilayer film exhibiting good printability and adaptability to various automatic packaging processes is provided, including an outer surface layer (a) comprising a polyester resin, an intermediate layer (b) comprising a polyamide resin and an inner surface layer (c) comprising a sealable resin. The film exhibits a heat-shrinkable stress at 50° C. of at most 3 MPa both in longitudinal direction and in transverse direction, and a hot water shrinkability at 90° C. of at least 20%.Type: GrantFiled: October 24, 2000Date of Patent: March 2, 2004Assignee: Kureha Kagaku Kogyo Kabushiki KaishaInventors: Takahisa Ueyama, Tadayoshi Itoh, Eiichi Hayashi, Hajime Tsukamoto
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Publication number: 20030160348Abstract: The invention relates to a method for producing extruded, cellulosic continuous shaped bodies from an extrusion solution containing cellulose, water and tertiary amino-oxide. In order to improve the textile properties of the extruded continuous shaped bodies with regard to the prior art, the invention provides that the continuous shaped body (5) is conveyed, with essentially no tensile stress, on a conveying device (11) between an extrusion nozzle opening and a take-off unit (24). To this end, the speed of conveyance of the interconnected conveying device (11) is preferably less than the extrusion rate and less than the take-off rate of the take-off unit (24). By employing these measures, the textile properties such as loop strength and tendency to fibrillate can be considerably improved.Type: ApplicationFiled: April 22, 2003Publication date: August 28, 2003Inventors: Stefan Zikeli, Friedrich Ecker
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Publication number: 20030094409Abstract: A method of producing a hollow fiber membrane includes discharging a polyvinylidene fluoride solution comprising a polyvinylidene fluoride resin and a poor solvent at a temperature above a phase separation temperature into a cooling bath at a temperature below the phase separation temperature to coagulate the polyvinylidene fluoride resin. The hollow fiber membrane comprises a polyvinylidene fluoride resin having spherical structures that have an average diameter in the range of 0.3 to 30 &mgr;m.Type: ApplicationFiled: September 27, 2002Publication date: May 22, 2003Applicant: Toray Industries, Inc.Inventors: Shin-ichi Minegishi, Masahiro Henmi, Toshiyuki Ishizaki, Koichi Dan
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Patent number: 6436319Abstract: A method for preparing a hollow fiber-type separation membrane from high density polyethylene is provided, which includes the steps of: melt-spinning a mixture of a high density polyethylene and a diluting agent to produce a phase-separated undrawn hollow fiber; detecting a tensile strength of the undrawn fiber during an alternative and repetitive winding and unwinding procedure between two bobbins, said undrawn fiber being drawn during the alternative and repetitive winding and unwinding procedure; reducing a rotation speed of one of the two bobbins when the detected tensile strength is larger than a predetermined value; and increasing a rotation speed of one of the two bobbins when the detected tensile strength is smaller than the predetermined value to yield the hollow fiber-type separation membrane.Type: GrantFiled: January 13, 2000Date of Patent: August 20, 2002Assignee: Agency for Technology and StandardsInventors: Hyang Sun, Yong Sang Yi, Kyu Bong Rhee
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Patent number: 6403016Abstract: A vacuum extrusion line of the horizontal barometric leg type includes a vacuum chamber having an extrusion die at one end and a water baffle immersion cooler at the other end for extracting the extrudate to atmosphere, extrudate shaping and sizing equipment downstream of the die, a large diameter fixed bulkhead at the die, and first and second large diameter movable sections surrounding the shaping and sizing equipment, a smaller fixed section of the chamber. The first section sealing against the second section and the fixed section and telescoping over the fixed section to form a gap with the second section being movable within the limits of the gap. The second section also seals against the large diameter fixed bulkhead. In this manner the downstream equipment can be fully exposed by movement of one or both movable sections and adequate volume and spatial working environment is provided for large through-put. A simplified lock mechanism facilitates the quick opening and closing of the chamber.Type: GrantFiled: December 23, 1999Date of Patent: June 11, 2002Assignee: Owens Corning Fiberglas Technology, Inc.Inventor: Robert L. Sadinski
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Publication number: 20020056682Abstract: A method and apparatus for purifying an aqueous suspension comprising feeding an aqueous suspension containing fine particles comprising an inorganic component from the outer surface of a wavy hollow fiber membrane having an outer diameter of from 0.5 to 3.1 mm to filter, followed by physical wash of the hollow fiber membrane. The purifying method can reduce the damage of the membrane outer surface during the physical wash step, prevent open pores on the surface from covering and achieve stable filtration. The hollow fiber membrane bundle can be produced by having a pulsation flow contacted with the hollow fiber material being extruded from the double spinning nozzle under specific conditions and cooling and solidifying or coagulating it while shaking.Type: ApplicationFiled: September 14, 2001Publication date: May 16, 2002Applicant: Asahi Kasei Kabushiki KaishaInventors: Tohru Taniguchi, Nobuhiko Suga, Takehiko Otoyo
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Publication number: 20020034610Abstract: Fibers and microfibrillated articles are provided by imparting fluid energy to at least one surface of a highly oriented, voided, melt-processed polymeric film. The fibers and microfibrillated articles are useful as tape backings, filters, thermal and acoustical insulation and as reinforcement fibers for polymers or cast building materials such as concrete.Type: ApplicationFiled: September 20, 2001Publication date: March 21, 2002Applicant: 3M Innovative Properties CompanyInventors: Mario A. Perez, Sundaravel Damodaran, Michael D. Swan
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Publication number: 20020022100Abstract: The present invention that also possesses provides a method for producing a seamless tubular film based on cellulose comprising extruding an aqueous cellulose-N-methyl-morpholine-N-oxide (NMMO) spinning solution through an annular die in a spinning bath, wherein the spinning solution forms the tubular film. The film is laterally drawn in an air gap between the annular die and the spinning bath by stabilizing air pressure in the tubular film. The level of hydrostatic pressure from an inner spinning solution formed inside the tubular film extends above the spinning bath, the inner spinning solution comprising an aqueous NMMO solution that supports and intensifies said lateral drawing. The tubular film that has been expanded by the lateral drawing process is passes by a turning point in the spinning bath, and directed out of the spinning bath.Type: ApplicationFiled: July 20, 2001Publication date: February 21, 2002Inventors: Herbert Gord, Klaus-Dieter Hammer, Rainer Neeff, Klaus Berghof, Markus Eilers, Reinhard Maron
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Patent number: 6213752Abstract: A vacuum extrusion line of the horizontal barometric leg type includes a vacuum chamber 10 having an extrusion die 18 at one end and a water baffle immersion cooler 20 at the other end for extracting the extrudate to atmosphere, extrudate shaping and sizing equipment downstream of the die 18, a large diameter fixed bulkhead 16 a the die 18, and first 44 and second 46 large diameter movable sections surrounding the shaping and sizing equipment, a smaller fixed section of the chamber. The first section sealing against the second section and the fixed section and telescoping over the fixed section to form a gap 68 with the second section being movable within the limits of the gap 68. The second section also seals against the large diameter fixed bulkhead 16. In this manner the downstream equipment can be fully exposed by movement of one or both movable sections and adequate volume and spatial working environment is provided for large through-put.Type: GrantFiled: December 23, 1999Date of Patent: April 10, 2001Assignee: Owens Corning Fiberglas Technology, Inc.Inventor: Robert L. Sadinski
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Patent number: 6113842Abstract: The invention is directed to a method of manufacturing oriented cellulose films by spinning non-derivated cellulose dissolved in amino oxides into a precipitating bath. The cellulose solution is extruded downward through a film-blowing nozzle and an external air gap into the precipitating bath. The spun cellulose film can be inflated after exiting the film-blowing nozzle.Type: GrantFiled: February 28, 1997Date of Patent: September 5, 2000Assignee: Fraunhofer-Gesellschaft Zur Forderung Der Angewandten Forschung E. V.Inventors: Peter Weigel, Hans-Peters Fink, Konrad Frigge, Wolfgang Schwarz
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Patent number: 6096258Abstract: A method and apparatus is disclosed for forming a cellulose film suitable for direct food contact by precipitation from a solution of cellulose water and a tertiary amine oxide cellulose solvent. After precipitation of a cellulose gel from the solution, the gel is washed at ever increasing temperatures and then dried to provide a cellulose film having a solvent level to not more than 40 ppm. Portions of the wash water is collected and treated to recover the solvent for reuse.Type: GrantFiled: January 20, 1998Date of Patent: August 1, 2000Assignee: Viskase CorporationInventors: Paul Edmund DuCharme, Jr., Edward Makoto Kajiwara, Norman Abbye Portnoy
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Patent number: 6033618Abstract: A seamless cellulose-based tubular film is produced by extrusion of an aqueous cellulose-N-methylmorpholine N-oxide solution.Type: GrantFiled: August 24, 1998Date of Patent: March 7, 2000Assignee: Kalle Nalo GmbH & Co. KGInventors: Herbert Gord, Klaus-Dieter Hammer, Helmut Sattler
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Patent number: 6017474Abstract: Formulation polymer dopes and development of processes for preparing asymmetric polyethersulfone hollow fiber membranes for gas separation are provided. Polyethersulfone hollow fiber membranes which exhibit improved gas permeability and selectivity have been produced from a formulated polymer dope containing N-methyl-2-pyrrolidone (NMP) and suitable nonsolvent-additives (NSA). The nonsolvent-additives are water and the mixture of ethanol and water. The dopes were tailored to be close to the point of phase separation, and have moderate polymer concentration with moderate viscosity. The hollow fibers were spun by the dry-wet phase inversion processes using water as both the internal and external coagulant. The dried hollow fibers are then coated with silicone rubber, a highly permeable material and the coated hollow fiber membranes exhibit excellent permeability and selectivity compared to those of the state-of-the-art polyethersulfone membranes.Type: GrantFiled: June 19, 1998Date of Patent: January 25, 2000Assignee: National University of SingaporeInventors: Wah Koon Teo, Kang Li, Dongliang Wang
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Patent number: 6015516Abstract: A process for forming ultrathin dense-layer asymmetric hollow fiber membranes with a dense layer of less than 500 .ANG. from a binary solution system comprising a polymer and a solvent. In this process, the spinning polymeric solution has a high viscosity and exhibits chain entanglement at the spinning temperature. The solubility parameter difference between the bore fluid and the spinning dope is less than 2.5 (cal/cm.sup.3).sup.0.5 and the volume ratio of bore-fluid flow rate to the dope flow rate is between 0.45 to 0.75. The dope is wet-spun into hollow fibers using water as external coagulant. The ultrathin dense-layer asymmetric hollow fiber membranes are suitable for air and other gas separations.Type: GrantFiled: June 19, 1998Date of Patent: January 18, 2000Assignee: National University of SingaporeInventors: Tai-Shung Chung, Xudong Hu, Soo Khean Teoh
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Patent number: 6001288Abstract: A process for producing a hollow fiber membrane, a hollow fiber membrane, and a dialyzer of hollow fiber membrane type is provided. The hollow fiber membrane is highly biocompatible, and the production process is quite simple and inexpensive. In the process of the invention, the hollow fiber membrane is produced in a system wherein a polymer-containing spinning solution is extruded from a tube-in-tube type orifice of a spinner in a coagulation solution to form the hollow fiber membrane. The polymer-containing spinning solution is extruded from the outer tube of the orifice to form a cylindrical filament having an inner bore and a core solution is ejected from the inner tube of the orifice into the inner bore of the filament for coagulation of the filament. The filament is directly extruded into the coagulation solution or extruded into air and then drawn to the coagulation solution.Type: GrantFiled: December 24, 1997Date of Patent: December 14, 1999Assignee: Terumo Kabushiki KaishaInventors: Makoto Saruhashi, Masatomi Sasaki
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Patent number: 5925307Abstract: A method and apparatus for forming an oriented plastic pipe from a plastic tubular material includes a first heated liquid bath for heating the plastic material to the glass transition temperature and a cooled liquid bath downstream of the heated liquid bath for cooling the plastic pipe after orientation of same.Type: GrantFiled: May 12, 1997Date of Patent: July 20, 1999Assignee: Intevep, Sa.Inventors: Sarkis J. Kakadjian, Carlos A. Villamizar, Nelson F. Torres
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Patent number: 5910274Abstract: Improved anisotropic fluid separation membranes are prepared from blends of polymers with surface energy differences. The membranes are formulated by processes wherein low surface energy polymer with desirable fluid separation and permeation characteristics is preferentially concentrated in the surface discriminating layer of the membrane.Type: GrantFiled: September 4, 1997Date of Patent: June 8, 1999Assignee: Praxair Technology, Inc.Inventors: James Timothy Macheras, Benjamin Bikson, Joyce Katz Nelson
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Patent number: 5856426Abstract: A para-oriented polyamide porous film comprising a fibril having a diameter of not more than 1.mu., with fibrils planarly arranged as a network or nonwoven fabric and laminated in a layer, the thermal linear expansion coefficient at 200.degree.-300.degree. C. within .+-.50.times.10.sup.-6 /.degree.C. and 30-95% vacant spaces. Also, a battery separator using the porous film. Also, a production process of: (a) forming a film-like material from a solution containing 1-10% of a para-oriented aromatic polyamide having an inherent viscosity of 1.0-2.8 dl/g and 1-10% of a chloride of an alkali metal or an alkali earth metal in a polar amide or polar urea solvent; (b) maintaining the film-like material at not less than 20.degree. C. and not more than -5.degree. C.Type: GrantFiled: November 25, 1996Date of Patent: January 5, 1999Assignee: Sumitomo Chemical Company, LimitedInventors: Tsutomu Takahashi, Tatsuo Tateno, Yoshifumi Tsujimoto
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Patent number: 5820934Abstract: The present invention relates to a method for the production of a fiber-reinforced cellulose tube by continuous coating of a fibrous non-woven fabric with an alkaline viscose solution which is neutralized by means of an acid-containing precipitating liquid and is converted into regenerated cellulose, wherein on the path between viscose coating and immersion in the precipitating bath, aqueous, acid-containing precipitating agents are caused to act upon the fresh viscose tube within the tube for the purpose of stiffening and regeneration to form regenerated cellulose, the process being begun with the application of the precipitating liquid directly after conclusion of the embedding of fiber in viscose and the precipitating liquid being guided together with the tube with the aid of optionally fixed internal devices which are designed in such a way that they support the tube that has had precipitating bath applied to it and in the process maintain it in rounded shape, that the length of the inner preliminary precType: GrantFiled: May 9, 1997Date of Patent: October 13, 1998Assignee: Wolff Walsrode AGInventor: Klaus Basfeld
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Patent number: 5811038Abstract: This invention relates to the manufacture of flexible porous plastic irrigation and aeration pipe having an essentially uniform porosity throughout its length. The process for making the porous pipe includes volumetrically delivering to a mixing hopper for preblending thermoset polymer particles and a thermoplastic binder for the particles, preblending the components in the hopper, volumetrically feeding from the hopper the preblended components for controlled discharge into an extruder, and extruding the preblended components to produce the porous plastic pipe.Type: GrantFiled: September 27, 1996Date of Patent: September 22, 1998Assignee: Plastic Specialties and Technologies Investments, Inc.Inventor: William S. Mitchell
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Patent number: 5795523Abstract: The present invention relates to an improved method for producing tubular sausage casings of regenerated cellulose wherein viscose is extruded through an annular extrusion die submerged in an aquarium to form a tubular product and coagulation and regeneration of the tubular product is initiated in said aquarium, continued by spray application of an intermediate regenerating solution in an intermediate regeneration zone after the tubular product has exited the aquarium, and completed in one or more coagulation/regeneration baths which includes the step of heating the tubular product to a temperature above the boiling point of carbon bisulphide in the intermediate reaction zone.Type: GrantFiled: October 30, 1996Date of Patent: August 18, 1998Assignee: Alfacel s.a.Inventor: Alexander Rozenberg
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Patent number: 5766540Abstract: The tubular extrusion of a thermoplastic nonderivatized cellulose solution about a mandrel and through a long air gap in excess of 304 mm is facilitated by use of a mandrel which is extensible from the extrusion die. On extrusion start-up, the mandrel extends a short length from the die. For steady-state operation, the mandrel is extended its full length from the die. Also disclosed is a mandrel structure to facilitate the introduction of a nonsolvent liquid into the interior of the extruded tube at a high location on start-up of extrusion and at a lower location during steady-state operation.Type: GrantFiled: March 27, 1997Date of Patent: June 16, 1998Assignee: Viskase CorporationInventors: Edward Makoto Kajiwara, Joseph Robert Walta, Ronald Joseph Jerantowski
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Patent number: 5759478Abstract: The tubular extrusion of a thermoplastic nonderivatized cellulose solution about a mandrel and through a long air gap in excess of 304 mm is facilitated by use of a mandrel which is extensible from the extrusion die. On extrusion start-up, the mandrel extends a short length from the die. For steady-state operation, the mandrel is extended its full length from the die. Also disclosed is a mandrel structure to facilitate the introduction of a nonsolvent liquid into the interior of the extruded tube at a high location on start-up of extrusion and at a lower location during steady-state operation. The mandrel also includes a sizing portion having circumferential grooves which gather gas bubbles that may evolve at the interface between the extruded tube and the sizing portion. Vertical channels in the sizing portion connect these grooves and provide the passage of gas bubbles into a volume below the mandrel.Type: GrantFiled: March 27, 1997Date of Patent: June 2, 1998Assignee: Viskase CorporationInventors: Edward Makoto Kajiwara, Brant Anton Loichinger
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Patent number: 5658524Abstract: In a method for forming a cellulose tube suitable for use as a food casing or as cellophane film, in which a solution of nonderivatized cellulose, tertiary amine N-oxide and water is extruded through an air gap of at least five inches, and into a water bath, such that a wet cellulose tube is formed. The wet tube is inflated from about 55% to 140% or more and dried thereby substantially retaining its work-to-rupture characteristics, especially when compared to viscose-derived tubes.Type: GrantFiled: May 4, 1995Date of Patent: August 19, 1997Assignee: Viskase CorporationInventors: Norman Abbye Portnoy, Edward Makoto Kajiwara, Paul Edmund Ducharme, Jr.
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Patent number: 5658525Abstract: 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 is downwardly drawn through an air gap while being internally cooled and then is passed into a water bath, the tube transverse direction tensile strength being increased by drawing the extruded tube through an air length of at least about five inches and exposing the exterior surface of the extruded tube to cooling air in the air gap.Type: GrantFiled: August 4, 1995Date of Patent: August 19, 1997Assignee: Viskase CorporationInventors: Edward Makoto Kajiwara, Norman Abbye Portnoy, Paul Edmund Ducharme, Jr.
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Patent number: 5648102Abstract: A vacuum calibrator tool for use with a vacuum chamber is provided to accurately size and shape the outer surface of molten plastic extrudate entering the vacuum chamber. The tool provides water passages to introduce water into the extrudate receiving opening of the tool at several positions along the extrudate receiving opening so that an extended zone of water within the extrudate receiving opening provides a film of water between the vacuum calibrator tool and the extrudate passing through it to lubricate the extrudate and to permit accurate sizing and shaping of the extrudate. The vacuum calibrator tool is preferably formed of a low coefficient of friction plastic material such as glass filled polytetrafluroethylene solid commercially under the registered trademark TEFLON.RTM..Type: GrantFiled: August 7, 1995Date of Patent: July 15, 1997Assignee: The Conair Group, Inc.Inventor: David H. Czarnik
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Patent number: 5630982Abstract: A method and apparatus for extruding thermoplastic tubing of reduced eccentricity, in which tubing is extruded into a vacuum calibration box containing a cooling fluid and a sizing collar. An ultrasonic device for measuring wall thicknesses around the periphery of the tubing is located downstream of the sizing collar. The wall measurements are used to determine a critical parameter, and if this critical parameter is outside of a predetermined range, the vacuum calibration box is moved in the direction of greater wall thickness. After a delay which allows the product of the correction to reach the ultrasonic device, the box is again moved if necessary, until the critical parameter is within the predetermined range.Type: GrantFiled: December 12, 1995Date of Patent: May 20, 1997Assignee: Sonoco Products CompanyInventor: David E. Boring
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Patent number: RE36585Abstract: 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: GrantFiled: May 7, 1998Date of Patent: February 29, 2000Assignee: C.A. Greiner & Sohne Gesellschaft m.b.H.Inventor: Franz Purstinger