EP0017902B1 - Process for producing a refractory foundry mould - Google Patents

Process for producing a refractory foundry mould Download PDF

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Publication number
EP0017902B1
EP0017902B1 EP19800101883 EP80101883A EP0017902B1 EP 0017902 B1 EP0017902 B1 EP 0017902B1 EP 19800101883 EP19800101883 EP 19800101883 EP 80101883 A EP80101883 A EP 80101883A EP 0017902 B1 EP0017902 B1 EP 0017902B1
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EP
European Patent Office
Prior art keywords
shell
pattern
sand
model
quartz sand
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
EP19800101883
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German (de)
French (fr)
Other versions
EP0017902A1 (en
Inventor
Christian Schönenborn
Ulrich Dr. Dipl.-Chem. Mennenga
H. Prof. Dipl.-Ing. Jaeger
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Kloeckner Humboldt Deutz AG
Huettenes Albertus Chemische Werke GmbH
Original Assignee
Kloeckner Humboldt Deutz AG
Huettenes Albertus Chemische Werke GmbH
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Application filed by Kloeckner Humboldt Deutz AG, Huettenes Albertus Chemische Werke GmbH filed Critical Kloeckner Humboldt Deutz AG
Publication of EP0017902A1 publication Critical patent/EP0017902A1/en
Application granted granted Critical
Publication of EP0017902B1 publication Critical patent/EP0017902B1/en
Expired legal-status Critical Current

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22C—FOUNDRY MOULDING
    • B22C15/00—Moulding machines characterised by the compacting mechanism; Accessories therefor
    • B22C15/23—Compacting by gas pressure or vacuum
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22C—FOUNDRY MOULDING
    • B22C9/00—Moulds or cores; Moulding processes
    • B22C9/02—Sand moulds or like moulds for shaped castings
    • B22C9/03—Sand moulds or like moulds for shaped castings formed by vacuum-sealed moulding

Definitions

  • the invention relates to a method for producing a refractory foundry mold, in which a free-flowing quartz sand, quartz material or a similar refractory mineral substance, the grains of which are encased by an organic substance or by an inorganic substance, by the action of a pressure difference between model and sand or if necessary, molded onto the model between the core box and sand and compacted into a shell on the surface thereof, in which the shell is backfilled with conventional molding material, for example a wet casting molding sand, and this is compacted and in which the model is subsequently removed from the foundry mold.
  • a free-flowing quartz sand, quartz material or a similar refractory mineral substance the grains of which are encased by an organic substance or by an inorganic substance
  • AT-A-370 075 discloses a method of the type mentioned, in which a shell is produced on a model by sucking air through it from a layer of molding sand applied to the model, the binder contained in the molding sand hardening by evaporation of a component of the solution. A backfilling of the shell made of binder-free molding sand is compressed after a film has been placed on the molding sand surface by sucking air out of the molding box.
  • the object on which the invention is based is to provide a method in which the difficulties described above are avoided and in which, while maintaining optimum dimensional accuracy and dimensional accuracy and improved curing of the molding material in the area of the model, foundry molds with a uniformly constructed molded shell and a stable one Backfill can be shown.
  • the solution to this lies in a method in which the covering of the quartz sand or the like consists of a thermosetting material, the model is heated to the appropriate hardening temperature when the formwork is sheathed, and after the shells have been formed, the quartz sand or the like which is not hardened to form the sheathing or the like the back of the shell is removed.
  • thermosetting coating of the quartz sand according to the invention which e.g. can consist of a synthetic resin, whereby, for example, a water glass solution can be mixed into the molding sand, forms a hardened shell of uniform wall thickness under the influence of the model surface brought to the curing temperature of the covering, the height of the total poured molding sand layer being irrelevant.
  • the shell of uniform wall thickness is then prepared for the application of the self-supporting backfill.
  • This consists of a conventional molding material that is compressed only mechanically or with the support of pressure differences, the shell being supported in accordance with the invention in a favorable manner on the model and can therefore be subjected to high forces.
  • a negative pressure can be maintained in the area of the model.
  • the resulting solidified form is self-supporting and can, if necessary, be removed from the core box or molding box before joining two mold halves. This significantly simplifies handling.
  • the excess quartz sand can be removed in any way. This is advantageously done by tilting the mold or core box by 180 °. The vacuum between the model and the shell can also be maintained to hold the shape.
  • An essential advance of the invention is that air is sucked out of the molded product from the model during the entire process up to the separation of the foundry mold, and thus annoying and endangering the working personnel by gases and vapors forming during the hardening process is prevented.
  • 1 denotes a foundry model, which is preferably provided in the transition area from the model to the flat plate with suction openings 2, which are only indicated in the simplified illustration.
  • the model 1 is arranged on a heated plate 3, on the back of which there is a space 4 which is connected to the suction openings 2.
  • a molding box 5 is placed on the device, which is filled with a free-flowing quartz sand, quartz material or similar refractory mineral material 6.
  • the plate 3 is heated.
  • a pressure difference between the surface of the model 1 and the free-flowing quartz sand 6 is generated by creating a negative pressure in the space 4, while atmospheric pressure prevails on the surface of the quartz sand.
  • the negative pressure in the space 4 can also be increased by an excess pressure on the surface of the quartz sand 6.
  • This hard shell 7 is, as further shown in FIG. 4, backfilled with a conventional molding material 8, for example wet casting molding sand, this backfilling 8 in turn being compressed under the action of a differential pressure between the surface of the model 1 and the backfilling 8.
  • This pressure differential compression of the backfill can also be supplemented by mechanical compression, not shown.

Description

Die Erfindung bezieht sich auf ein Verfahren zur Herstellung einer feuerfesten Giessereiform, bei dem ein rieselfähiger Quarzsand, Quarzgut oder ein ähnlicher feuerfester mineralischer Stoff, dessen Körner von einem organischen Stoff oder von einem anorganischen Stoff umhüllt sind, durch Einwirkung einer Druckdifferenz zwischen Modell und Sand bzw. ggf. zwischen Kernkasten und Sand an das Modell angeformt und an dessen Oberfläche zu einer Schale verdichtet wird und bei dem die Schale mit üblichem Formmaterial, beispielsweise einem Nassgussformsand, hinterfüllt und dieser verdichtet wird und bei dem anschliessend das Modell aus der Giessereiform entfernt wird.The invention relates to a method for producing a refractory foundry mold, in which a free-flowing quartz sand, quartz material or a similar refractory mineral substance, the grains of which are encased by an organic substance or by an inorganic substance, by the action of a pressure difference between model and sand or if necessary, molded onto the model between the core box and sand and compacted into a shell on the surface thereof, in which the shell is backfilled with conventional molding material, for example a wet casting molding sand, and this is compacted and in which the model is subsequently removed from the foundry mold.

Durch die AT-A-370 075 ist ein Verfahren der genannten Art bekannt, bei dem eine Schale auf einem Modell mittels Durchsaugen von Luft aus einer auf das Modell aufgetragene Formsandschicht erzeugt wird, wobei im Formsand enthaltenes Bindemittel durch Verdunsten eines Lösungsbestandteiles erhärtet. Eine Hinterfüllung der Schale aus bindemittelfreiem Formsand wird nach Auflegen einer Folie auf die Formsandoberfläche durch Absaugen von Luft über den Formkasten verdichtet.AT-A-370 075 discloses a method of the type mentioned, in which a shell is produced on a model by sucking air through it from a layer of molding sand applied to the model, the binder contained in the molding sand hardening by evaporation of a component of the solution. A backfilling of the shell made of binder-free molding sand is compressed after a film has been placed on the molding sand surface by sucking air out of the molding box.

Nachteile dieses Verfahrens bestehen darin, dass der bindemittelhaltige Formsand in gleichmässiger Schicht auf das Modell aufgebracht werden muss, dies jedoch beispielsweise an vertikalen Partien nicht durch einfaches Aufschütten oder durch Aufschiessen aus einer Richtung möglich ist. Die Herstellung einer gleichmässigen Schale erfordert damit einen besonderen manuellen oder maschinellen Aufwand. Die Verwendung der bindemittelfreien Hinterfüllung bedingt eine Abdichtung des Formkastens mittels einer luftdichten Folie und gewährt einen Zusammenhalt der Hinterfüllung nur Innerhalb des aus Folie, Formkasten und Schale gebildeten Raumes unter Beibehaltung des Unterdruckes. Die Handhabung von Formhälften wird dadurch erschwert und ihre Entnahme aus den Formkästen vor dem Guss wird unmöglich.Disadvantages of this method are that the binder-containing molding sand has to be applied to the model in a uniform layer, but this is not possible, for example, on vertical parts by simply pouring it on or by blowing it up from one direction. The production of a uniform shell therefore requires special manual or mechanical effort. The use of the binder-free backfilling requires the molding box to be sealed by means of an airtight film and only guarantees that the backfilling is held together within the space formed by the film, molding box and shell while maintaining the negative pressure. This makes it difficult to handle mold halves and makes it impossible to remove them from the mold boxes before casting.

Die der Erfindung zugrunde liegende Aufgabe besteht darin, ein Verfahren zu schaffen, bei dem die vorstehend beschriebenen Schwierigkeiten vermieden werden und bei dem unter Einhaltung einer optimalen Masshaltigkeit und Formtreue und verbesserter Aushärtung des Formmaterials im Bereich des Modells Giessereiformen mit einer gleichmässig aufgebauten Formschale und einer tragfähigen Hinterfüllung dargestellt werden können.The object on which the invention is based is to provide a method in which the difficulties described above are avoided and in which, while maintaining optimum dimensional accuracy and dimensional accuracy and improved curing of the molding material in the area of the model, foundry molds with a uniformly constructed molded shell and a stable one Backfill can be shown.

Die Lösung hierfür besteht in einem Verfahren, bei dem die Umhüllung des Quarzsandes oder dergleichen aus einem warm aushärtenden Material besteht, das Modell beim Einschalen auf die entsprechende Aushärtetemperatur erwärmt ist und nach der Schalenbildung der nicht zur Schale ausgehärtete, mit Umhüllung versehene Quarzsand oder dergleichen von der Rückseite der Schale entfernt wird.The solution to this lies in a method in which the covering of the quartz sand or the like consists of a thermosetting material, the model is heated to the appropriate hardening temperature when the formwork is sheathed, and after the shells have been formed, the quartz sand or the like which is not hardened to form the sheathing or the like the back of the shell is removed.

Durch die Erzeugung einer Druckdifferenz, insbesondere eines Unterdrucks zwischen Sand und Modell beim Einfüllen des Formsandes in den Formkasten ergibt sich eine gute und fehlerlose Anformung und Verdichtung an der Modelloberfläche. Die erfindungsgemässe warm aushärtende Umhüllung des Quarzsandes, die z.B. aus einem Kunstharz bestehen kann, wobei dem Formsand ggf. beispielsweise eine Wasserglaslösung zugemischt werden kann, bildet unter dem Einfluss der auf die Aushärttemperatur der Umhüllung gebrachten Modelloberfläche eine erhärtete Schale gleichmässiger Wandstärke aus, wobei die Höhe der insgesamt aufgeschütteten Formsandschicht keine Rolle spielt. Durch die fortwährende Aufrechterhaltung eines Unterdruckes unmittelbar am Modell können dabei entstehende Dämpfe oder Gase, insbesondere von toxischer Zusammensetzung, bei nur geringer Absaugmenge vom Arbeitsplatz ferngehalten werden. Durch das erfindungsgemässe Entfernen nicht ausgehärteten Formsandes wird dann die Schale gleichmässiger Wandstärke für das Aufbringen der selbsttragenden Hinterfüllung vorbereitet. Diese besteht aus einem üblichen Formmaterial, das ausschliesslich mechanisch oder mit Unterstützung von Druckdifferenzen verdichtet wird, wobei sich die Schale erfindungsgemäss in günstiger Weise am Modell abstützt und daher mit hohen Kräften belastet werden kann. Dabei kann ein Unterdruck im Bereich des Modells beibehalten werden. Die so entstandene verfestigte Form ist selbsttragend und kann ggf. vor dem Zusammenfügen zweier Formhälften aus dem Kernkasten bzw. Formkasten entfernt werden. Dadurch ist die Handhabung wesentlich vereinfacht.The generation of a pressure difference, in particular a negative pressure between the sand and the model when the molding sand is poured into the molding box, results in good and flawless molding and compression on the model surface. The thermosetting coating of the quartz sand according to the invention, which e.g. can consist of a synthetic resin, whereby, for example, a water glass solution can be mixed into the molding sand, forms a hardened shell of uniform wall thickness under the influence of the model surface brought to the curing temperature of the covering, the height of the total poured molding sand layer being irrelevant. By continuously maintaining a negative pressure directly on the model, vapors or gases, in particular those of a toxic composition, can be kept away from the workplace with only a small amount of suction. By removing uncured molding sand according to the invention, the shell of uniform wall thickness is then prepared for the application of the self-supporting backfill. This consists of a conventional molding material that is compressed only mechanically or with the support of pressure differences, the shell being supported in accordance with the invention in a favorable manner on the model and can therefore be subjected to high forces. A negative pressure can be maintained in the area of the model. The resulting solidified form is self-supporting and can, if necessary, be removed from the core box or molding box before joining two mold halves. This significantly simplifies handling.

Die Entfernung des überschüssigen Quarzsandes kann auf beliebige Art erfolgen. In vorteilhafter Weise geschieht dies durch Kippen des Form- bzw. Kernkastens um 180°. Hierbei kann der Unterdruck zwischen Modell und Schale auch zum Festhalten der Form aufrechterhalten werden.The excess quartz sand can be removed in any way. This is advantageously done by tilting the mold or core box by 180 °. The vacuum between the model and the shell can also be maintained to hold the shape.

Ein wesentlicher Fortschritt der Erfindung besteht darin, dass während des gesamten Verfahrens bis zur Trennung der Giessereiform von dem Modell aus dem Formgut Luft abgesaugt wird und damit eine Belästigung und Gefährdung des arbeitenden Personals durch sich beim Härtevorgang bildende Gase und Dämpfe verhindert wird.An essential advance of the invention is that air is sucked out of the molded product from the model during the entire process up to the separation of the foundry mold, and thus annoying and endangering the working personnel by gases and vapors forming during the hardening process is prevented.

Durch die DE-C-1 088 669 ist eine Trennung von Giessereiform und Modell durch Erzeugen eines Überdrucks zwischen diesen beiden Teilen an sich bekannt. Gemäss einer günstigen Ausgestaltung der Erfindung wird dieses Verfahren auch hier angewandt.From DE-C-1 088 669 a separation of the foundry mold and the model by generating an overpressure between these two parts is known per se. According to a favorable embodiment of the invention, this method is also used here.

Zur weiteren Erläuterung der Erfindung wird auf die Zeichnung verwiesen, in der ein Ausführungsbeispiel des erfindungsgemässen Verfahrens vereinfacht dargestellt ist.To further explain the invention, reference is made to the drawing, in which an embodiment of the method according to the invention is shown in simplified form.

Es zeigen:

  • Fig. 1 das Modell zu Beginn des Verfahrens,
  • Fig. 2 die Befüllung und anschliessende Verdichtung und Erhärtung des rieselfähigen Quarzsandes oder dergleichen am beheizten Modell,
  • Fig. 3 das Entfernen nicht zur Schale ausgehärteten Quarzsandes und dergleichen von der Rückseite der Schale,
  • Fig. 4 die Hinterfüllung der Schale mit üblichem Formmaterial und anschliessende Verdichtung der Hinterfüllung und
  • Fig. 5 die Entfernung des Modells aus der Giessereiform.
Show it:
  • 1 shows the model at the beginning of the method,
  • 2 the filling and subsequent compression and hardening of the free-flowing quartz sand or the like on the heated model,
  • 3 the removal of quartz sand and the like not hardened to the shell from the back of the shell,
  • Fig. 4 the backfilling of the shell with the usual molding material and subsequent compression of the backfill and
  • 5 shows the removal of the model from the foundry mold.

In den Fig. 1 bis 5 ist mit 1 ein Giessereimodell bezeichnet, das vorzugsweise im Übergangsbereich vom Modell zur ebenen Platte mit Saugöffnungen 2 versehen ist, welche in der vereinfachten Darstellung nur angedeutet sind. Ausserdem ist das Modell 1 auf einer beheizten Platte 3 angeordnet, an deren Rückseite sich ein mit den Saugöffnungen 2 in Verbindung stehender Raum 4 befindet.1 to 5, 1 denotes a foundry model, which is preferably provided in the transition area from the model to the flat plate with suction openings 2, which are only indicated in the simplified illustration. In addition, the model 1 is arranged on a heated plate 3, on the back of which there is a space 4 which is connected to the suction openings 2.

In Fig. 2 ist auf die Vorrichtung ein Formkasten 5 aufgesetzt, welcher mit einem rieselfähigen Quarzsand, Quarzgut oder ähnlichem feuerfestem, mineralischem Stoff 6 gefüllt wird. Vor bzw. während des Befüllens des das Modell 1 umgebenden Formkastens 5 wird die Platte 3 erwärmt. Gleichzeitig wird eine Druckdifferenz zwischen der Oberfläche des Modells 1 und dem rieselfähigen Quarzsand 6 dadurch erzeugt, dass im Raum 4 ein Unterdruck geschaffen wird, während an der Oberfläche des Quarzsandes atmosphärischer Druck herrscht. Der Unterdruck im Raum 4 kann jedoch auch durch einen Überdruck an der Oberfläche des Quarzsandes 6 verstärkt werden.In Fig. 2, a molding box 5 is placed on the device, which is filled with a free-flowing quartz sand, quartz material or similar refractory mineral material 6. Before or during the filling of the molding box 5 surrounding the model 1, the plate 3 is heated. At the same time, a pressure difference between the surface of the model 1 and the free-flowing quartz sand 6 is generated by creating a negative pressure in the space 4, while atmospheric pressure prevails on the surface of the quartz sand. However, the negative pressure in the space 4 can also be increased by an excess pressure on the surface of the quartz sand 6.

Die Folge ist, dass sich an der Oberfläche des Modells 1 eine harte und plastische Schale 7 bildet, von der nach Fig. 3 der überschüssige Quarzsand 6 unter Beibehaltung einer Druckdifferenz durch Kippen der gesamten Vorrichtung um etwa 180° entfernt wird.The result is that a hard and plastic shell 7 forms on the surface of the model 1, from which, according to FIG. 3, the excess quartz sand 6 is removed while maintaining a pressure difference by tilting the entire device by approximately 180 °.

Diese harte Schale 7 wird, wie weiterhin in Fig.4 dargestellt, durch ein übliches Formmaterial8, beispielsweise Nassgussformsand, hinterfüllt, wobei diese Hinterfüllung 8 wiederum unter Einwirkung eines Differenzdruckes zwischen der Oberfläche des Modells 1 und der Hinterfüllung 8 verdichtet wird. Diese Druckdifferenzverdichtung der Hinterfüllung lässt sich, auch durch eine nichtdargestellte mechanische Verdichtung ergänzen.This hard shell 7 is, as further shown in FIG. 4, backfilled with a conventional molding material 8, for example wet casting molding sand, this backfilling 8 in turn being compressed under the action of a differential pressure between the surface of the model 1 and the backfilling 8. This pressure differential compression of the backfill can also be supplemented by mechanical compression, not shown.

Im weiteren Verfahrensschritt gemäss Fig. 5 wird im Raum 4 ein Überdruck geschaffen, der zur Trennung der Schale 7 gemeinsam mit der Hinterfüllung 8 vom Modell 1 führt.In the further process step according to FIG. 5, an overpressure is created in the space 4, which leads to the separation of the shell 7 together with the backfill 8 from the model 1.

Claims (4)

1. A method of preparing a refractory casting mould, in which fluid quartz sand, quartz material or a similar refractory mineral substance, the granules of which are encased by an organic substance or an unorganic substance, is shaped around a pattern and compacted on the surface thereof so as to form a shell by subjecting the pattern and the sand or, if applicable, a core box and the sand to different air pressures, and in which the shell is backed by a conventional moulding material, for example by a green-mould casting sand, and thereafter the pattern removed from the casting mould, characterized in that the encasing of the quartz sand (6) or the like is a thermosetting substance, that while the shell is formed the pattern (1) is heated to the appropriate setting temperature, and in that after the shell has been formed the encased quartz sand (6) or the like which has not set to form the shell (7) is removed from the rear of the shell (7).
2. A method according to claim 1, characterized in that the encased quartz sand (6) or the like which has not been compacted to form the shell (7) is removed by tilting the pattern (1) together with, if applicable, the casting (5) or core box through substantially 180°, and in that during removal air pressure below atmospheric pressure is maintained in the region of the pattern (1).
3. A method according to claim 1 or claim 2, characterized in that the pattern (1) and the shell (7) are separated from each other by applying air pressure above atmospheric pressure between the pattern (1) and the shell (7).
4. A method according to any of the preceding claims, characterized in that toxic or nontoxic gases or the like are removed from the air which is sucked off the region of the pattern (1) and which produces the pressure below the atomospheric one.
EP19800101883 1979-04-21 1980-04-09 Process for producing a refractory foundry mould Expired EP0017902B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE2916211 1979-04-21
DE19792916211 DE2916211C2 (en) 1979-04-21 1979-04-21 Process for making a foundry mold

Publications (2)

Publication Number Publication Date
EP0017902A1 EP0017902A1 (en) 1980-10-29
EP0017902B1 true EP0017902B1 (en) 1983-05-18

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JP (1) JPS55141354A (en)
DE (1) DE2916211C2 (en)

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DE2923044C2 (en) * 1979-06-07 1987-05-27 Eugen Dipl.-Ing. 8877 Burtenbach Bühler Method and apparatus for making split composite sand block casting molds
GB2116889B (en) * 1982-03-23 1985-11-13 Acme Conveyors & Constr A process of moulding a metal casting mould
DE3318112A1 (en) * 1983-05-18 1984-11-22 Achinger, Michael, 8900 Augsburg METHOD AND DEVICE FOR PRODUCING CASTING MOLDS
FR2724336B1 (en) * 1994-09-14 1996-10-31 Chardon Michel Georges SILICA SAND MOLDING PROCESS COMBINING THE USE OF CHEMICAL TAKED SAND AND BINDERLESS UNDERPRESSURE
CN104325075A (en) * 2014-10-08 2015-02-04 柳州金茂机械有限公司 V method casting process
CN105562623B (en) * 2015-12-31 2017-10-24 华中科技大学 A kind of waterglass sand mold quick forming method
CN113400649B (en) * 2021-06-30 2023-07-04 山东威高骨科材料股份有限公司 Method for solving thermal deformation of 3D printing PEEK material part

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DE945717C (en) * 1943-11-14 1956-07-12 Siemens Ag Process for the production of casting molds for metal casting, iron casting or the like.
DE1097621B (en) * 1956-03-23 1961-01-19 Fritz Hansberg Process and molding machine for the pneumatic production of foundry cores and foundry molds as well as boxes for this
DE1129660B (en) * 1956-04-20 1962-05-17 Gen Motors Corp Method and device for backfilling molded masks during casting
DE1167488B (en) * 1959-06-17 1964-04-09 Shell Moulding Foundry Ltd Process for the production of casting molds
US3293703A (en) * 1962-11-13 1966-12-27 Arthur R Taccone Vacuum molding apparatus
GB1151237A (en) * 1966-07-20 1969-05-07 Barnett Levy Method for Removing Sand Cores and Pattern Shells from Core Boxes and Patterns
BE789785A (en) * 1971-10-08 1973-02-01 Akita Kk MOLD PRODUCTION APPARATUS
JPS5519958B2 (en) * 1972-08-15 1980-05-29
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JPS5138230A (en) * 1974-09-30 1976-03-30 Mitsubishi Heavy Ind Ltd Igatano genatsuzokeihoho
JPS5160629A (en) * 1974-11-22 1976-05-26 Mitsubishi Heavy Ind Ltd Genatsuzokeiigatano seisakuhoho
AT340075B (en) * 1975-04-21 1977-11-25 Mitsubishi Heavy Ind Ltd METHOD OF MAKING A MOLD
DE2619529A1 (en) * 1975-05-01 1976-11-18 Baker Perkins Holdings Ltd METHOD AND DEVICE FOR FILLING FOUNDRY SHAPES OR CORE BOXES WITH A MOLD-BASED MIX
DE2608740C2 (en) * 1976-03-03 1978-05-11 Eugen Dipl.-Ing. 8871 Burtenbach Buehler Process for compacting molding sand
DE2609274A1 (en) * 1976-03-05 1977-09-08 Buehler Eugen Compacting sand into mould or core boxes - in which partial vacuum is applied via holes in pattern plate to aid compaction
DE2833999C2 (en) * 1978-08-03 1981-11-19 Eugen Dipl.-Ing. 8871 Burtenbach Bühler Method and device for the production of casting molds and cores
DE2844464C2 (en) * 1978-10-12 1983-03-24 Bühler, Eugen, Dipl.-Ing., 8871 Burtenbach Method and device for compacting casting molds

Also Published As

Publication number Publication date
JPS6321576B2 (en) 1988-05-07
EP0017902A1 (en) 1980-10-29
DE2916211A1 (en) 1980-10-30
JPS55141354A (en) 1980-11-05
DE2916211C2 (en) 1983-11-24

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