Utilizing Fluent Extracting Medium Patents (Class 164/36)
  • Patent number: 10000021
    Abstract: There is provided a method for manufacturing a three-dimensional shaped object. The method of the present invention comprises the repeated steps of: (i) forming a solidified layer by irradiating a predetermined portion of a powder layer with a light beam, thereby allowing a sintering of the powder in the predetermined portion or a melting and subsequent solidification thereof; and (ii) forming another solidified layer by newly forming a powder layer on the resulting solidified layer, followed by the irradiation of a predetermined portion of the powder layer with the light beam; wherein only the surface portion of the solidified layer, to which a force is applied when the three-dimensional shaped object is used, is subjected to a machining process.
    Type: Grant
    Filed: June 23, 2010
    Date of Patent: June 19, 2018
    Assignee: PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO., LTD.
    Inventors: Satoshi Abe, Yoshikazu Higashi, Isao Fuwa, Masataka Takenami
  • Patent number: 9162279
    Abstract: The present disclosure relates to a system for fabricating a mold positive via additive manufacturing to form a casting mold. The mold positive material may have a first portion that undergoes a solid to gas phase transformation at a first temperature and a second portion that undergoes a solid to gas phase transformation at a second temperature. The first portion may be formed within the second portion, and the first temperature may be low relative to the second temperature. The first portion of the mold positive may thermally decompose at a lower temperature than the second portion, which may create voids within the mold positive so that during the higher temperature combustion of the second portion of the material, the second portion may expand into the newly empty spaces instead of into a ceramic casting mold. This may greatly reduce stress on the casting mold.
    Type: Grant
    Filed: February 26, 2015
    Date of Patent: October 20, 2015
    Assignee: MADESOLID, INC.
    Inventor: Lance Robert Pickens
  • Publication number: 20120085507
    Abstract: A method for controlling the dewaxing of a ceramic investment casting shell assembly is provided whereby the shells are immersed in a fluid having a relatively low boiling point, e.g., below about 230° F. The fluid must be hot enough to transfer heat though the shell assembly so as to melt the wax pattern, but low enough so as to limit steam generation as a result of moisture in the shell. By controlling the rate of immersion of the shell in the hot fluid bath, shell cracking can be greatly reduced.
    Type: Application
    Filed: October 10, 2011
    Publication date: April 12, 2012
    Applicant: BUNTROCK INDUSTRIES, INC.
    Inventor: Thomas M. BRANSCOMB
  • Patent number: 7926542
    Abstract: A system and method for dewaxing is provided. The system includes a ceramic shell mold having a wall. Water is present within the wall of the ceramic shell mold. A wax pattern assembly is located within the ceramic shell mold. A heat source is configured for heating at least a portion of the wall of the ceramic shell mold in order to convert at least a portion of the water within the wall of the ceramic shell mold into steam for use in melting at least a portion of the wax pattern.
    Type: Grant
    Filed: September 29, 2008
    Date of Patent: April 19, 2011
    Inventor: Xi Yang
  • Publication number: 20090294086
    Abstract: A system and method for dewaxing is provided. The system includes a ceramic shell mold having a wall. Water is present within the wall of the ceramic shell mold. A wax pattern assembly is located within the ceramic shell mold. A heat source is configured for heating at least a portion of the wall of the ceramic shell mold in order to convert at least a portion of the water within the wall of the ceramic shell mold into steam for use in melting at least a portion of the wax pattern.
    Type: Application
    Filed: September 29, 2008
    Publication date: December 3, 2009
    Inventor: Xi Yang
  • Publication number: 20080292745
    Abstract: Disclosed are a mold gate insert as well as a mold assembly and an injection molding machine incorporating such a mold gate insert. The mold gate insert comprises a base structure formed of a wear resistant material having a first thermal conductivity. The base structure defines a mold cavity, at least in part, a nozzle assembly alignment portion for aligning a nozzle assembly with respect to the base structure, and a gate for communication between the mold cavity and the nozzle assembly. The mold gate insert further comprises a heat dam being completely enclosed by the base structure. The heat dam is made of a material having a second thermal conductivity being less than the first thermal conductivity and arranged within the base structure in proximity to the nozzle assembly alignment portion such that the heat flow between the nozzle assembly and the base structure is impeded. Furthermore, a method of producing the mold gate insert is disclosed.
    Type: Application
    Filed: May 23, 2007
    Publication date: November 27, 2008
    Applicant: HUSKY INJECTION MOLDING SYSTEMS LTD.
    Inventor: Ralf Hubert SHMITZ
  • Publication number: 20080142183
    Abstract: A sprue former of the type used to produce a casting mold includes a generally hollow body or a body having hollow sections. The body includes an inlet forming member and at least one first interface member. The inlet forming member is configured to provide an inlet cavity in the casting mold to enable casting material to enter the casting mold. The first interface members are configured to couple to casting patterns. The casting patterns represent items to be cast. The body can also includes a reservoir forming member and at least one connecting member coupling the reservoir forming member to the inlet forming member.
    Type: Application
    Filed: November 7, 2007
    Publication date: June 19, 2008
    Inventors: Michael Craig Marshall, Kerry Glewwe
  • Publication number: 20080035294
    Abstract: The invention relates to water-soluble salt cores for die casting, said salt cores being produced by compressing, and then sintering, a mixture of water-soluble salts. According to the invention, there are between 4 and 5 parts by weight of borax, between 2 and 3 parts by weight of magnesium, and between 0.5 and 2 parts by weight of graphite or talc, in the mixture, for 100 parts by weight of salt. The compression is carried out under a pressure of between 300 and 900 N/mm2.
    Type: Application
    Filed: February 17, 2005
    Publication date: February 14, 2008
    Inventor: Dieter Grozinger
  • Patent number: 6880618
    Abstract: Method of making a subcutaneous melt flow-channel in the surface of a fugitive foam pattern used in lost-foam casting process. After a refractory skin has been formed on the surface of a foam pattern, a strip of the skin is treated so as to cause the foam underlying the strip to recede from the strip and leave a groove in its stead. Suitable treatments include (1) heating the strip, or (2) applying a foam solvent thereto that soaks through the skin. In each case, the treatment is such as to cause the foam underlying the treated strip to soften and recede from the strip.
    Type: Grant
    Filed: July 15, 2003
    Date of Patent: April 19, 2005
    Assignee: General Motors Corporation
    Inventors: David Douglas Goettsch, Bob Ross Powell, Jr.
  • Publication number: 20030041992
    Abstract: An investment casting or molding method comprises encasing a consumable pattern in a no-bake material that hardens without the application of heat. The encased pattern is then transformed to a fluid state and evacuated, thereby forming a mold cavity. Preferably, the pattern is coated with a refractory material prior to encasement, so that the resulting mold cavity is lined with the refractory material. Coating the pattern with one and only one layer of refractory material is preferred, resulting in a refractory coating that is not self-supporting. In another embodiment, a refractory-coated consumable pattern is located in a container, and a granular backing material is packed in the container around the coated pattern. The pattern is then transformed to a fluid state and evacuated to form a refractory-lined mold cavity in the container. The refractory coating again preferably comprises one and only one layer of refractory material, thereby resulting in a coating that is not self-supporting.
    Type: Application
    Filed: August 28, 2001
    Publication date: March 6, 2003
    Inventors: David M. Fee, Carl E. Fidler
  • Patent number: 6109333
    Abstract: Housing frames for use in electromechanical machines may be advantageously produced using a novel pattern form in a lost foam casting process. The pattern form is made from a cast dissolvable material, and is configured to permit easy modification prior to casting. The pattern form may be adapted to produce footed or footless housing frames, or housing frames of various axial lengths. In addition, the frame area on which a conduit box will be attached can be easily modified prior to casting. After the pattern form has been modified, it is placed in a casting medium of dry particulate material, such as sand. Upon contact with molten metal, the pattern form vaporizes. The molten metal fills the space where the pattern form had been, assuming the desired shape. After the molten metal has cooled to rigidity, the resulting housing frame can be removed from the casting medium.
    Type: Grant
    Filed: July 15, 1998
    Date of Patent: August 29, 2000
    Assignee: Reliance Electric Technologies, LLC
    Inventor: Joseph H. Pontzer
  • Patent number: 6029738
    Abstract: A core for use in a die casting process has a wood fiber material as a main ingredient. The core can be disintegrated by exerting an external force subsequent to the die casting process. The core can also be disintegrated by applying a softening agent to soften it subsequent to the die casting process. Further, the core can be made up of a stack of paper layers that are peelably removable from each other.
    Type: Grant
    Filed: May 15, 1998
    Date of Patent: February 29, 2000
    Assignee: Kioritz Corporation
    Inventors: Fujihiro Matuura, Kazuo Sasaki, Masashi Sano
  • Patent number: 5996682
    Abstract: A mold for a prototype metal casting or the like may advantageously be made by forming a casting pattern of adhesively bonded aggregate particles using a binder containing a principle constituent that is soluble in supercritical carbon dioxide; forming a rigid shell mold about the pattern of materials that are unaffected by supercritical carbon dioxide; thereafter exposing the pattern and mold combination to supercritical carbon dioxide to remove the pattern binder adhesive and leave unbonded aggregate particles in the mold and removing the aggregate particles from the mold to leave a mold cavity that faithfully defines the pattern shape.
    Type: Grant
    Filed: March 9, 1998
    Date of Patent: December 7, 1999
    Assignee: General Motors Corporation
    Inventors: Mei Cai, June-Sang Siak, Richard Michael Schreck, Nicholas Edward Sargent
  • Patent number: 5927373
    Abstract: A method of constructing a fully dense metal part or a metal mold half for matin with another mold half to form a mold for casting multiple parts. Steps include placing a pattern having critical pattern surfaces in a flask having an open end. The critical pattern surfaces face upward. Other steps involve covering the critical pattern surfaces with a concentrated heat reversible gel solution added to the flask, and cooling the gel solution to form an elastic solid gel mold. Further steps include removing the flask and the pattern from the elastic gel mold, and casting a ceramic mold around the solid gel mold. In other steps the gel mold is liquified for removal from the ceramic mold and the ceramic mold is inverted so that its critical ceramic surfaces face upward.
    Type: Grant
    Filed: February 12, 1997
    Date of Patent: July 27, 1999
    Assignee: The Procter & Gamble Company
    Inventor: James R. Tobin
  • Patent number: 5893405
    Abstract: A mold assembly and sprue configuration for dental investment casting includes a ring shaped casing, a base and a cover all made of resilient plastic material and fictionally engaged with each other. The base includes a raised neck having a top surface with a sighting bead for use in mounting wax forms on the sprue, positioned within the casing. The sprue includes a post for engaging a blind bore in a hub of the base. The cover includes a downwardly extending plug which extends into the body of the casing, and a curved lip with recess for facilitating the pouring of investment solution into the mold. The sprue has three spokes and a ring which are all triangular in cross-section to reduce the amount of metal needed in the precision casting to be made with the invention and also to provide a convenient flat upper surface for mounting wax forms to the sprue.
    Type: Grant
    Filed: October 24, 1997
    Date of Patent: April 13, 1999
    Assignee: Belle de St. Claire
    Inventor: Robert P Berger
  • Patent number: 5832981
    Abstract: A one-piece cast metal heat-exchanging forming tool is prepared using an expendable porous preform that is cast in place within a cast metal forming tool. The expendable preform is thereafter extracted to leave behind a network of inter-connected pores and passages within the body of the tool through which a heat transferring fluid may be circulated to transfer heat to or from a substantially non-porous contoured shaping surface of the tool. Fluid distribution/collection lines and vacuum lines may be incorporated in the tool during casting.
    Type: Grant
    Filed: March 19, 1997
    Date of Patent: November 10, 1998
    Assignee: Metallamics, Inc.
    Inventors: Robert R. McDonald, William O. Jones
  • Patent number: 5678624
    Abstract: An investment casting process which includes: attaching a gate to a pattern made of a plastic to form a pattern assembly; forming a mold by applying a plaster slurry on an outer surface of the pattern assembly; dissolving and removing the pattern assembly in the mold by applying an organic solvent; burning the mold from which the pattern has been removed; casting by pouring a molten metal into the burned mold; and breaking the mold to take out a cast product.
    Type: Grant
    Filed: October 3, 1995
    Date of Patent: October 21, 1997
    Assignee: Sakurai Art Casting, Ltd.
    Inventor: Junichi Sakurai
  • Patent number: 5679270
    Abstract: A method of removing ceramic material, such as for example a ceramic core, from a metallic cast or other component involves contacting the metallic cast component and a caustic ceramic leaching medium at elevated temperature for a time effective to substantially remove the ceramic material from the component and providing an oxygen getter in the caustic ceramic leaching medium in an amount effective to avoid deleterious surface corrosion of the component while the ceramic material is being removed therefrom.
    Type: Grant
    Filed: July 1, 1996
    Date of Patent: October 21, 1997
    Assignee: Howmet Research Corporation
    Inventors: Thomas J. Thornton, Julie A. Faison, Neil E. Paton
  • Patent number: 5494096
    Abstract: An investment casting process utilizes a temporary mold which is formed by pouring a liquid over a positive pattern, and cooling the liquid until it solidifies. The positive pattern is removed, and a temporary pattern is formed by pouring another liquid into the cavity of the temporary mold, and cooling the second liquid until it solidifies. The temporary mold may then be melted or dissolved to leave a temporary pattern, which may be coated with a ceramic slurry to form a ceramic shell. The temporary pattern may then be melted or dissolved in order to remove the temporary pattern from the ceramic shell. The ceramic shell may be filled with molten metal which is allowed to solidify to form the final cast piece.
    Type: Grant
    Filed: April 11, 1994
    Date of Patent: February 27, 1996
    Inventors: Juan De Antonio Gonalons, Ricardo Insausti Martinez De Lahidalga
  • Patent number: 5178673
    Abstract: This invention relates to investment casting compositions comprising (i) a refractory material, e.g., a ceramic material, and (ii) a soluble core material comprising one or more block polymers characterized by an ABCBA structure. This invention also relates to methods for investment casting and to the manufacture of molded articles. The soluble core materials exhibit desirable breaking strength, dissolution rate and surface characteristics.
    Type: Grant
    Filed: April 12, 1991
    Date of Patent: January 12, 1993
    Assignee: Union Carbide Chemicals & Plastics Technology Corporation
    Inventors: Sandra A. Caster, Clayton E. Higginbotham
  • Patent number: 5089186
    Abstract: A method of removing a core from a molded product in which the core is formed of a particulate inert material, such as sand, bound together by a cured binder of a water soluble carbohydrate alone or mixed with a silicate is disclosed. The silicate is preferably an alkali earth metal silicate, preferably sodium silicate, and the carbohydrate is preferably a saccharide or starch. The binder is cured by heat. The core and molded product are exposed to water, preferably heated water in a bath or steam, to rapidly disintegrate the core and remove it from the molded product.
    Type: Grant
    Filed: July 11, 1990
    Date of Patent: February 18, 1992
    Assignee: Advanced Plastics Partnership
    Inventors: Timothy M. Moore, Gerbrig W. Van Der Woude
  • Patent number: 4951732
    Abstract: An iron metal traverse drum having extremely thin walls is formed by instantaneously injecting a molten metal into a limited cavity of a mold having a form corresponding to the traverse drum in an oxygen-free atmosphere.
    Type: Grant
    Filed: April 18, 1989
    Date of Patent: August 28, 1990
    Assignee: Murata Kikai Kabushi Kaisha
    Inventor: Shoji Yamada
  • Patent number: 4922991
    Abstract: Disclosed is a method for making metal castings wherein a composite core assembly is utilized. The composite core assembly comprises at least one casting core and one temporary core which are in intimate contact wherein the temporary core is removed prior to casting. The improvement of the present invention comprises forming the temporary core comprising an aggregate and binder of materials such that the temporary core is sufficiently soluble in aqueous solvent for its removal prior to metal casting. The casting core is not removed by the aqueous solvent.
    Type: Grant
    Filed: September 3, 1986
    Date of Patent: May 8, 1990
    Assignee: Ashland Oil, Inc.
    Inventors: Michael A. Pitcher, Albert L. Haugse, Richard L. Pelfrey, Gregory P. Sturtz
  • Patent number: 4812278
    Abstract: A cast article having a complicated shape of the appearance and the hollow can be obtained by forming a coating film on the surface of a pattern from a solvent-insoluble material to prepare a mold pattern, filling and hardening a molding material around the mold pattern, dissolving the pattern with a solvent, and removing the residue of dissolution and the coating film outside the mold.
    Type: Grant
    Filed: February 25, 1987
    Date of Patent: March 14, 1989
    Assignee: Hitachi, Ltd.
    Inventors: Tatsuo Natori, Susumu Hioki, Takashi Shimaguchi, Toshihiro Yamada, Akihide Watanabe, Kensuke Kanekatsu
  • Patent number: 4809761
    Abstract: In an investment casting process wherein molds or cores are prepared by forming them around a polymer pattern and then dissolving the pattern with a solvent, solvent losses can be reduced by heating the mold or core before contacting it with the solvent to reduce the amount of solvent adsorbed in the mold or core. An improved process comprises: (a) forming the mold or core around the pattern; (b) heating the mold or core; (c) dunking or spraying the mold or core with the solvent until the pattern is dissolved; (d) placing the mold or core in a drying chamber in the path of circulating heated air; (e) cooling the air to condense the solvent; (f) recovering the condensed solvent; and (g) reheating the air until it is no longer saturated with solvent and recycling the air to the drying chamber. The preliminary heating step can reduce solvent losses by 66 percent and the entire improved process can reduce solvent losses by about 90 percent.
    Type: Grant
    Filed: January 12, 1988
    Date of Patent: March 7, 1989
    Assignee: The Dow Chemical Company
    Inventors: Robert J. Nankee, E. Richard Randolph
  • Patent number: 4808360
    Abstract: A mold forming method in which a pattern is made of an organic material such as foamed polystyrene and at least a portion of the outer or inner surface of the mold pattern is covered by a thin coating, and surrounded with a mold material. The pattern is then dissolved by a solvent, leaving the coating undissolved. The coating is finally removed by a solvent contained in a slip which is poured into the cavity provided with the coating.
    Type: Grant
    Filed: April 27, 1987
    Date of Patent: February 28, 1989
    Assignee: Hitachi, Ltd.
    Inventors: Tatsuo Natori, Takashi Shimaguchi, Toshihiro Yamada, Kazuaki Yokoi
  • Patent number: 4556528
    Abstract: A method and apparatus for casting of fragile complex shapes by the formation of a two layer wax mold about a pattern of the shape to be cast. Thereafter, the pattern is removed from the mold and the outer layer of wax dissolved. The slip is then poured into the mold and allowed to solidify before the inner layer of the mold is completely removed from the cast article.
    Type: Grant
    Filed: June 16, 1983
    Date of Patent: December 3, 1985
    Assignee: The Garrett Corporation
    Inventors: Herbert M. Gersch, Glenn W. Brown
  • Patent number: 4499940
    Abstract: A casting process for making and utilizing an elastomeric pattern that is coated with a non-metallic material to form a non-metallic shell mold and thereafter removed from the non-metallic shell mold by thermal decomposition or mechanical stripping.
    Type: Grant
    Filed: August 1, 1983
    Date of Patent: February 19, 1985
    Assignee: Williams International Corporation
    Inventor: Robert T. Hall
  • Patent number: 4481999
    Abstract: In a method of forming a thin (<2 .mu.m) unbacked metal foil having a desired curviplanar shape, a soluble polymeric film, preferably comprising polyvinyl alcohol, is formed on a supporting structure having a shape that defines the desired shape of the foil product. A layer of metal foil is deposited onto one side of the soluble film, preferably by vacuum vapor deposition. The metallized film is then immersed in a suitable solvent to dissolve the film and thereby leave the metal foil as an unbacked metal foil element mounted on the supporting structure. Aluminum foils less than 0.2 .mu.m (2,000 .ANG.) thick and having an areal density of less than 54 .mu.g/cm.sup.2 have been obtained.
    Type: Grant
    Filed: February 23, 1982
    Date of Patent: November 13, 1984
    Assignee: The United States of America as represented by the United States Department of Energy
    Inventors: David V. Duchane, Barry L. Barthell
  • Patent number: 4462453
    Abstract: A core assembly for use in the casting of molten metal is formed by fabricating a first core, molding a plastic layer around the first core, and molding a second core around the plastic layer. The plastic layer is interlocked with an irregular outer surface of the first core, and the second core is interlocked with an irregular outer surface of the plastic layer. The plastic layer is then dissolved with a suitable solvent prior to placing the core assembly into a mold and molten iron being poured.
    Type: Grant
    Filed: June 4, 1979
    Date of Patent: July 31, 1984
    Assignee: Deere & Company
    Inventor: David V. Trumbauer
  • Patent number: 4434835
    Abstract: A method of making at least the aerofoil of a blade for a gas turbine engine in which the cooling air exit passages, whether at the trailing edge or in other parts of the aerofoil, are cast rather than machined subsequently. In the method a disposable piece is formed with holes of the shape of the holes eventually required in the blade aerofoil. The piece is placed in a die and used to define part of the ceramic core required in the casting process, the die being arranged to produce a channel portion interconnecting the otherwise free ends of the parts of the core which will form the passages. The ceramic core thus formed in a lost-wax casting process to form the blade aerofoil, the channel portion being embedded in the shell mould to support the parts which define the passages.
    Type: Grant
    Filed: March 9, 1982
    Date of Patent: March 6, 1984
    Assignee: Rolls-Royce Limited
    Inventor: Kenneth Willgoose
  • Patent number: 4384607
    Abstract: A method of casting a blade or vane for a gas turbine engine which enables the production of more complex internal shapes than those which may be made by prior art methods. The method of the invention includes the steps of:making a temporary filler piece from a disposable material,holding the filler piece in place in a die,injecting the core material into the die and causing it to solidify round the filler piece,removing the core from the die,causing the filler to be removed from the core to leave within the core a cavity having the shape of the filler, andusing the core thus produced in an investment casting process to form the blade or vane shape.
    Type: Grant
    Filed: July 13, 1978
    Date of Patent: May 24, 1983
    Assignee: Rolls-Royce Limited
    Inventors: Andrew G. B. Wood, Anthony G. Gale
  • Patent number: 4287932
    Abstract: The material used for the production of cores for precision molds is a metal which is oxidizable at relatively low temperatures, i.e., below the solidification temperature of the melts for pouring, and which passes directly from the solid state to the gas state by oxide sublimation. This greatly speeds up the dissolving of cores, particularly small diameter cores, out of the castings.
    Type: Grant
    Filed: August 20, 1980
    Date of Patent: September 8, 1981
    Assignee: Sulzer Brothers Limited
    Inventor: Hans Schneider
  • Patent number: 4235277
    Abstract: A three-dimensional network porous metallic structure is formed by filling the internal cavity of a mold, which has been prepared by making use of a three-dimensional network resin pattern, through driving the molten metal into the cavity by a pressure or through sucking the molten metal into the cavity by reducing the pressure in the cavity. The porous metallic structure thus obtained is characterized by a large specific surface area, as well as a reduced pressure drop of fluid passing through this structure, and, therefore, is fit for various uses such as the material of fins of heat exchangers, various filters and so forth.
    Type: Grant
    Filed: September 27, 1978
    Date of Patent: November 25, 1980
    Assignee: Hitachi, Ltd.
    Inventors: Tatsushi Aizawa, Tatsuo Natori, Masakatsu Hayashi, Takeo Tanaka
  • Patent number: 4108931
    Abstract: A system of making molds for investment casting in which the patterns are formed from, and the sprue form is coated with, polyethylene glycol having a molecular weight in the range of from approximately 1,300 to approximately 1,600, or its equivalent and having admixed therein as a filler powdered graphite, in which the graphite comprises in the range of from about 35 per cent to 60 per cent by weight of the pattern forming material. The patterns are molded to the desired shape, and to include a gate section, and they are adhered to the sprue form in spaced apart relation by fluidizing the gate section end to make a welded connection with the sprue form coating. The mold is then formed about the patterns that are adhered to the sprue form, leaving the pour cup end of the sprue form exposed, to which heat is subsequently applied to sufficiently fluidize the sprue form coating so that the sprue form can be drawn out of the mold thereby leaving the sprue opening.
    Type: Grant
    Filed: August 23, 1976
    Date of Patent: August 22, 1978
    Inventor: Ralph Ogden
  • Patent number: 4106548
    Abstract: Composition for production of cores and casting molds comprises 100 parts by weight of grain base, particularly quartz sand, 0.5 - 30 parts of alkal metal hydroxides, 1 - 40 parts of alkali metal carbonates, 1 - 15 parts of water as well as 0.2 - 10 of known hydrophilic binders. The composition according to the invention is removed from the cast or mold by subjecting the core in the cast or mold to the action of solvent, particularly water, preferably by dipping.
    Type: Grant
    Filed: November 3, 1976
    Date of Patent: August 15, 1978
    Assignee: Politechnika Warszawska
    Inventors: Pawel Murza-Mucha, Zbigniew Koszarewski, Wojciech Ostaszewski, Stanislaw Peksa
  • Patent number: RE35334
    Abstract: A method of removing a core from a molded product in which the core is formed of a particulate inert material, such as .[.sand-bound.]. .Iadd.sand, bound .Iaddend.together by a cured binder of a water soluble carbohydrate alone or mixed with a silicate is disclosed. The silicate is preferably an alkali earth metal silicate, preferably sodium silicate, and the carbohydrate is preferably a saccharide or starch. The binder is cured by heat. The core and molded product are exposed to water, preferably heated water in a bath or steam, to rapidly disintegrate the core and remove it from the molded product.
    Type: Grant
    Filed: February 17, 1994
    Date of Patent: September 24, 1996
    Assignee: Advanced Plastics Partnership
    Inventors: Timothy M. Moore, Gerbrig W. Van Der Woude