WO1991012881A1 - Process for treating a powder and device therefor - Google Patents

Process for treating a powder and device therefor Download PDF

Info

Publication number
WO1991012881A1
WO1991012881A1 PCT/EP1991/000315 EP9100315W WO9112881A1 WO 1991012881 A1 WO1991012881 A1 WO 1991012881A1 EP 9100315 W EP9100315 W EP 9100315W WO 9112881 A1 WO9112881 A1 WO 9112881A1
Authority
WO
WIPO (PCT)
Prior art keywords
powder
oxide
pressure plasma
low
ceramics
Prior art date
Application number
PCT/EP1991/000315
Other languages
German (de)
French (fr)
Inventor
Stefan Schulz
Wolfgang MÖHL
Original Assignee
Krauss Maffei Ag
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Krauss Maffei Ag filed Critical Krauss Maffei Ag
Publication of WO1991012881A1 publication Critical patent/WO1991012881A1/en

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J19/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
    • B01J19/08—Processes employing the direct application of electric or wave energy, or particle radiation; Apparatus therefor
    • B01J19/12—Processes employing the direct application of electric or wave energy, or particle radiation; Apparatus therefor employing electromagnetic waves
    • B01J19/122—Incoherent waves
    • B01J19/126—Microwaves
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J19/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
    • B01J19/08—Processes employing the direct application of electric or wave energy, or particle radiation; Apparatus therefor
    • B01J19/087—Processes employing the direct application of electric or wave energy, or particle radiation; Apparatus therefor employing electric or magnetic energy
    • B01J19/088—Processes employing the direct application of electric or wave energy, or particle radiation; Apparatus therefor employing electric or magnetic energy giving rise to electric discharges
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J2/00—Processes or devices for granulating materials, e.g. fertilisers in general; Rendering particulate materials free flowing in general, e.g. making them hydrophobic
    • B01J2/006—Coating of the granules without description of the process or the device by which the granules are obtained
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F1/00—Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties
    • B22F1/10—Metallic powder containing lubricating or binding agents; Metallic powder containing organic material
    • B22F1/102—Metallic powder coated with organic material
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B13/00—Oxygen; Ozone; Oxides or hydroxides in general
    • C01B13/14—Methods for preparing oxides or hydroxides in general
    • C01B13/145—After-treatment of oxides or hydroxides, e.g. pulverising, drying, decreasing the acidity
    • C—CHEMISTRY; METALLURGY
    • C03—GLASS; MINERAL OR SLAG WOOL
    • C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
    • C03B32/00—Thermal after-treatment of glass products not provided for in groups C03B19/00, C03B25/00 - C03B31/00 or C03B37/00, e.g. crystallisation, eliminating gas inclusions or other impurities; Hot-pressing vitrified, non-porous, shaped glass products
    • C—CHEMISTRY; METALLURGY
    • C03—GLASS; MINERAL OR SLAG WOOL
    • C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
    • C03B37/00—Manufacture or treatment of flakes, fibres, or filaments from softened glass, minerals, or slags
    • C03B37/10—Non-chemical treatment
    • C03B37/14—Re-forming fibres or filaments, i.e. changing their shape
    • C03B37/15—Re-forming fibres or filaments, i.e. changing their shape with heat application, e.g. for making optical fibres
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/515—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics
    • C04B35/56—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics based on carbides or oxycarbides
    • C04B35/565—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics based on carbides or oxycarbides based on silicon carbide
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/622—Forming processes; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/626—Preparing or treating the powders individually or as batches ; preparing or treating macroscopic reinforcing agents for ceramic products, e.g. fibres; mechanical aspects section B
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
    • B01J2219/08—Processes employing the direct application of electric or wave energy, or particle radiation; Apparatus therefor
    • B01J2219/0894—Processes carried out in the presence of a plasma

Definitions

  • inorganic powders are used, from which canen is mixed in a mixture with up to about 20% by weight of organic auxiliaries.
  • This route via green bodies is chosen because the green body can be given a desired shape, while the raggedly honey to extreme extreme hardness of the end product prevents post-processing.
  • the organic auxiliaries are removed from the green cores by prying out, whereby end products with irreversible windows can be obtained. It is obvious that for these Fenler i.a. the rneological properties of the mixture of inorganic powder and organic auxiliary materials can be appropriately demonstrated.
  • the object of the invention is now to provide a method with which powders can be conditioned in such a way that there is no segregation of the organic component which is necessary for shaping and with which the proportion of the organic auxiliary can be nero-set.
  • the object of the invention is also a device for
  • a method for conditioning a powder in which the powder is exposed to a low-pressure plasma in the presence of a polymerizable organic and / or organometallic monomer.
  • the procedure according to the invention achieves a coating of the discrete powder particles or a distribution of the polymer formed on the powders.
  • the polymer formed by plasma polymerization is deposited on the discrete particles from the gasonase, preferably in the area of the standard. This polymer can be seen as one of the finishes used to impart adhesion.
  • an optimal improvement of the rheological flow properties of ceramic materials e.g.
  • silicon powder including the required inorganic sintering additives (e.g. AI 2 O 3 ) for injection molding and hot isostatic pressing.
  • AI 2 O 3 required inorganic sintering additives
  • the homogeneity and thus the strength, density and resistance to oxidation of ceramic components with complex geometry is directly dependent on the rheological flow properties of the starting materials during the shaping process of the so-called green compacts.
  • Tecnnik for low-pressure plasmas can be found, for example, in Rutscher & Deutsch, Plasma Technology, Carl-Hanser-Verlag
  • the low pressure plasma is ignited or maintained in a low pressure atmosphere which consists of the desired monomer to be polymerized or comprises this monomer.
  • the monomer can also be a monomer mixture.
  • suitable monomers the person skilled in the art can stick to polymers which are already common in the prior art in connection with the powder to be used.
  • the process according to the invention can be carried out at a negative pressure in the range from 0.001 to 5 mear and in particular 0.01 to 0.5 mdar.
  • the low-pressure plasma is preferably ignited and maintained with microwaves at a frequency of approximately 2.45 GHz.
  • the powder is allowed to fall freely through the low-pressure plasma, ie on ballistic paths.
  • a dren mixing drum which is arranged in the low-pressure plasma or in the vacuum chamber.
  • the term powder is not to be understood narrowly, but is intended to encompass a general bulk material made of discrete particles, for example also fibers (such as glass fibers) of a short length (for example from 0.1 to 1 mm).
  • the powder or bulk material should consist of discrete parts which can fall through the plasma on ballistic tracks and which, after their conditioning, either as a mass (if appropriate in the presence of auxiliaries) of a shaping or as an addition (for example as a reinforcing or extending agent) to one formoaren mass can be subjected to a shaping process.
  • conditionable powders are inorganic powders, for example Graomt, ceramic, glass or metal, such as hard metal.
  • ceramic powders are powders for technical ceramics, for example for oxide ceramics such as aluminum oxide, magnesium oxide, zirconium oxide or beryllium oxide, or for non-oxide ceramics such as carbides, e.g. Boron carbide or silicon carbide, or such as nitrides, e.g. Boron nitride, silicon nitride or aluminum nitride.
  • oxide ceramics such as aluminum oxide, magnesium oxide, zirconium oxide or beryllium oxide
  • non-oxide ceramics such as carbides, e.g. Boron carbide or silicon carbide, or such as nitrides, e.g. Boron nitride, silicon nitride or aluminum nitride.
  • a device for carrying out the method according to the invention in which the vacuum chamber in which the low-pressure plasma is ignited and maintained comprises a mixing drum in which the powder used can fall freely through the low-pressure plasma.
  • a device according to P 37 38 352.3 with a 100-1 low pressure chamber was used. in which a mixing drum (about 20 Liter volume) was arranged with ejection. This mixing drum was charged with 10 kg of graphite and, after the low-pressure plasma had been ignited, was driven by an electric motor. Methyl methacrylate was chosen as the plasma atmosphere, the low-pressure plasma being maintained at a pressure of 0.4 mbar with microwaves at a frequency of approximately 2.45 GHz.
  • Example 1 According to Example 1, the exception was that 5 kg of silicon carbide was subjected to the plasma polymerization. 100 pieces of green foils were punched out of the conditioned powder obtained in order to produce ceramic heat exchangers. These green sheets were burned out in the usual way. Their mechanical strength corresponded to the requirements applicable to Kerarm heat exchangers.

Abstract

The invention relates to a process for treating powder in low-pressure plasma and a suitable device therefor.

Description

Verfanran zur Konditionierung eines Pulvers und Vorrichtung dafür Processor for conditioning a powder and device therefor
Zur Herstellung von tachnischer Keramik, auch High-tach-Keramik, verwendet man anorgamsche Pulver, aus canen man im Gemisch mit bis zu etwa 20 Gew. -% organischen Hilfssteffen Grünkörper herstellt. Dieser Weg über Grünkörper wird gewählt, da man dem Grünkörper eine gewünschte Form geben kann, während die ragelmäßig hone bis teilweise extreme Härte des Endprodukts eine Nachbearbeitung vereietet. Die organischen Hilfsstoffe werden aus den Grunkorpern duren Ausprennen entfernt, wobei EndproduKte mit irreversiblen Fenlern anfallen können. Es ist einleuchtand, daß für diese Fenler u.a. die rneologischen Eigenschaften des Gemischs aus anorganischem Pulver und organischen H i l fsstpffen verantwertlich gemacnt werden können. Zum Stand der Technik sei beispielsweise auf Felcht, Die chemische Produktion, Mai/Juni (1988) 19 bis 20, und Helnrich et al., VDI Berichte, 550 (1988) 669 bis 682, verwiesen. For the production of tachnical ceramics, also high-tach ceramics, inorganic powders are used, from which canen is mixed in a mixture with up to about 20% by weight of organic auxiliaries. This route via green bodies is chosen because the green body can be given a desired shape, while the raggedly honey to extreme extreme hardness of the end product prevents post-processing. The organic auxiliaries are removed from the green cores by prying out, whereby end products with irreversible windows can be obtained. It is obvious that for these Fenler i.a. the rneological properties of the mixture of inorganic powder and organic auxiliary materials can be appropriately demonstrated. With regard to the prior art, reference is made, for example, to Felcht, Die chemische Produktion, May / June (1988) 19 to 20, and Helnrich et al., VDI reports, 550 (1988) 669 to 682.
Analog ist der Stand der Technik, der sich mit der Herstellung von Formkörpern aus Metallbulvern. beispieIsweise Hartmetallpulvern, besenäftigt. Dazu sei beiseielsweise auf Haworth & James, MPR , Februar (1986) 1 6 bis 149, und Martyn et al., MPR , Dezember (1988) 816 bis 823, verwiesen. Nach dem angesprochenen Stand der Technik ist also sowohl für das Flleßvernalten als auch für die Formoarkeit von Pulvermischungen ein hoher organischer HiIfsmittelanteil üblich. Es ist gut vorstellbar, daß eine ungleiche Verteilung dieses honen organischen Hilfsmittelanteils zu den angesprochehen irreversiblen Fehlern, insbesondere auch zu einem unbefriedigenden mechanischen Vereund des Endprodukts beitragen kann. So ist es beispielsweise bisher noch nicht gelungen, aus Graphitpulver allein durch Extrusion Bleistiftminen herzustellen, die ohne einem Brennprozeß unterwerfen zu werden befriedigen. The prior art dealing with the production of molded articles from metal powders is analogous. for example hard metal powders, occupied. For example, see Haworth & James, MPR, February (1986) 16 to 149, and Martyn et al., MPR, December (1988) 816 to 823. According to the state of the art mentioned, a high proportion of organic auxiliaries is therefore customary both for flow curing and for the formability of powder mixtures. It is conceivable that an unequal distribution of this high proportion of organic auxiliaries can contribute to the irreversible errors referred to, in particular also to an unsatisfactory mechanical bonding of the end product. So far, for example, it has not yet been possible to produce pencil leads from graphite powder by extrusion alone, which are satisfactory without being subjected to a firing process.
Im vorliegenden Zusammenhang ist schließlich auch der Stand der Technik relevant, der sien mit der Verstärkung von Polyolefin oder Polycarbonat duren Glasfasern und Spritzgießen der Finally, in the present context, the state of the art is also relevant, which is the reinforcement of polyolefin or polycarbonate by means of glass fibers and injection molding
verstärkten Massen befaßt. reinforced masses.
Aufgabe der Erfindung ist es nun, ein Verfanren vorzusehen, mit dem sich Pulver derart konditiomeren lassen, daß es zu keiner Entmischung der organischen Komponente kommt, die zur Formgebung erforderlich ist, und mit dem der Anteil des organischen Hilfsmittels neraogesetzt werden Kann. The object of the invention is now to provide a method with which powders can be conditioned in such a way that there is no segregation of the organic component which is necessary for shaping and with which the proportion of the organic auxiliary can be nero-set.
Aufgabe der Erfindung ist es ferner, eine Vorrichtung zur The object of the invention is also a device for
Durchführung des genannten Verfahrens vorzusenen.  Perform the above procedure.
Erfindungsgemäß wird nun ein Verfahren zur Konditionierung eines Pulvers vorgesehen, bei dem man das Pulver in Gegenwart eines polymerisierbaren organischen und/oder metallorganischen Monomeren einem Niederdruckplasma aussetzt. Durch das erfindungsgemäße Vorgehen wird eine Ummantelung der diskreten Pulverteilchen bzw. eine Femstverteilung des gepildeten Polymeren auf den Pulvern erreicht. Das duren Plasmapolymerisation gebildete Polymere wird aus der Gasonase auf den diskreten Teilchen abgeschieden, und zwar vorzugsweise im Prormllebereich. Man Kann dieses Polymere als eine der Haftungsvermittlung d i enende Appretur betrachten. Abgesehen von der Lösung der Aufgabe der Erfindung kann man erfindungsgemäß im Vergleich zum Stand der Technik mit geringerem Energie- und Materialverbrauch eine optimale Verpesserung der rheologischen Fließeigenschaften keramischer Massen (z. B. von Sιliziumpulver) einschließlich der erforderlichen anorganischen Sinteradditive (z. B. AI2O3) für Spritzgußverarpeitung und heißisostatisches Pressen erreichen. Die Homogenität und damit die Festigkeit, Dichte und Oxydationsbeständigkeit keramischer Bauteile mit komplexer Geometrie ist unmittelbar abhängig von den rheologisehen Fließeigenschaften der Ausgangsmateri a l l en während des Formgeoungsprozeßes der sogenannten Grünlinge. According to the invention, a method for conditioning a powder is now provided, in which the powder is exposed to a low-pressure plasma in the presence of a polymerizable organic and / or organometallic monomer. The procedure according to the invention achieves a coating of the discrete powder particles or a distribution of the polymer formed on the powders. The polymer formed by plasma polymerization is deposited on the discrete particles from the gasonase, preferably in the area of the standard. This polymer can be seen as one of the finishes used to impart adhesion. Apart from the solution to the problem of the invention, according to the invention, compared to the prior art with lower energy and material consumption, an optimal improvement of the rheological flow properties of ceramic materials (e.g. silicon powder) including the required inorganic sintering additives (e.g. AI 2 O 3 ) for injection molding and hot isostatic pressing. The homogeneity and thus the strength, density and resistance to oxidation of ceramic components with complex geometry is directly dependent on the rheological flow properties of the starting materials during the shaping process of the so-called green compacts.
Zum Stand der Tecnnik für Niederdruckplasmen sei beispielsweise auf Rutscher & Deutsch, Plasmatechnik, Carl-Hanser-Verlag The booth of Tecnnik for low-pressure plasmas can be found, for example, in Rutscher & Deutsch, Plasma Technology, Carl-Hanser-Verlag
(1984), sowie die Patentanmeldungen/Patente P 37 38 352.3 und P 38 43 028.3 verwiesen. (1984), as well as the patent applications / patents P 37 38 352.3 and P 38 43 028.3.
Das Niederdruckplasma wird cadei in einer Niederdruckatmosphäre gezündet oder unterhalten, die aus dem gewünschten zu polymerisierenden Monomeren besteht oder dieses Monomere umfaßt. Bei dem Monomeren kann es sich auch um ein Monomergemisch nandeln. Zur Wahl von geeigneten Monomeren Kann sich der Fachmann an Polymere halten, die in Verbindung mit dem einzusetzenden Pulver im Stand der Technik bereits üblien sind. The low pressure plasma is ignited or maintained in a low pressure atmosphere which consists of the desired monomer to be polymerized or comprises this monomer. The monomer can also be a monomer mixture. For the selection of suitable monomers, the person skilled in the art can stick to polymers which are already common in the prior art in connection with the powder to be used.
Man kann das erfindungsgemäße Verfanren bei einem Unterdruck im Bereich von 0,001 bis 5 mear und insbesondere 0,01 bis 0,5 mdar durchführen. Vorzugsweise zündet und unterhält man das Niederdruckplasma mit Mikrowellen einer Frequenz von etwa 2,45 GHz. The process according to the invention can be carried out at a negative pressure in the range from 0.001 to 5 mear and in particular 0.01 to 0.5 mdar. The low-pressure plasma is preferably ignited and maintained with microwaves at a frequency of approximately 2.45 GHz.
Gemäß einer speziellen Ausführungsform läßt man das Pulver frei, d.h. auf ballistischen Bahnen, durch das Niederdruckplasma fallen. Für den freien Fall Kann man sich eine sien drenende Mischtrommel vorstellen, die im Niederoruckplasma bzw. in der Vakuumkammer angeordnet ist. Im vorliegenden Zusammenhang ist der Ausdruck Pulver nicht eng zu verstehen, soll vielmenr allgemeines Schüttgut aus diskreten Teilchen umfassen, beispielsweise auch Fasern (wie Glasfasern) einer geringen Länge (z.B. von 0,1 bis 1 mm). Das Pulver bzw. Schüttgut soll aus diskreten Teilcnen bestehen, die auf ballistischen Bahnen durch das Plasma fallen können und die nach ihrer Konditiomerung entweder als Masse (gegebenenfalls in Gegenwart von Hilfsmitteln) einer Formgebung oder als Zusatz (beispielsweise als Verstärkungs- oder Streckmittel) zu einer formoaren Masse einem Formgebungsvorgang unterworfen werden können. According to a special embodiment, the powder is allowed to fall freely through the low-pressure plasma, ie on ballistic paths. For free fall you can imagine a dren mixing drum, which is arranged in the low-pressure plasma or in the vacuum chamber. In the present context, the term powder is not to be understood narrowly, but is intended to encompass a general bulk material made of discrete particles, for example also fibers (such as glass fibers) of a short length (for example from 0.1 to 1 mm). The powder or bulk material should consist of discrete parts which can fall through the plasma on ballistic tracks and which, after their conditioning, either as a mass (if appropriate in the presence of auxiliaries) of a shaping or as an addition (for example as a reinforcing or extending agent) to one formoaren mass can be subjected to a shaping process.
Beispiele für konditionierpare Pulver sind anorganiscne Pulver, beispielsweise Graomt, Keramik, Glas oder Metall, wie Hartmetall. Beispiele für Keramikpulver sind Pulver für tecnnische Keramik, beispielsweise für Oxidkeramik, wie Aluminiumoxid, Magnesiumoxid, Zirkonoxid oder Berylliumoxid, oder für Nicht- Oxidkeramik, wie Carbide, z.B. Borcarbid oder Siliciumcarbid, oder wie Nitride, z.B. Bornitrid, Siliciumnitrid oder Aluminiumnitrid. Ergänzend sei hier auf den eingangs angeführten Stand der Technik verwiesen. Examples of conditionable powders are inorganic powders, for example Graomt, ceramic, glass or metal, such as hard metal. Examples of ceramic powders are powders for technical ceramics, for example for oxide ceramics such as aluminum oxide, magnesium oxide, zirconium oxide or beryllium oxide, or for non-oxide ceramics such as carbides, e.g. Boron carbide or silicon carbide, or such as nitrides, e.g. Boron nitride, silicon nitride or aluminum nitride. In addition, reference is made to the prior art mentioned at the beginning.
Erfindungsgemäß wird schließlion eine vorrichtung zur Durchführung des erfindungsgemäßen Verfanrens vorgesenen, bei der die Vakuumkammer, in der das Niederdruckplasma gezündet und unterhalten wird, eine Mischtrommel umfaßt, in der das eingesetzte Pulver in freiem Fall durch das Niederdruckplasma fallen kann. According to the invention, a device for carrying out the method according to the invention is provided, in which the vacuum chamber in which the low-pressure plasma is ignited and maintained comprises a mixing drum in which the powder used can fall freely through the low-pressure plasma.
Nachstehend wird die Erfindung durch zwei Beispiele näher erläutert. The invention is explained in more detail below by means of two examples.
Beispiel 1 example 1
Es wurde eine Vorrichtung gemäß P 37 38 352.3 mit einer 100-1- Niederdruckkammer verwendet. in der eine Mischtrommel (etwa 20 Liter Rauminhalt) mit Auswurf angeordnet war. Diese Mischtrommel wurde mit 10 kg Graphit beschickt und nach dem Zünden des Niederdruckplasmas mit Hilfe eines Elektromotors angetrieben. Als Plasmaatmosphäre wählte man Methylmethacryl at, wobei das Niederdruckplasma bei einem Druck von 0,4 mbar mit Mikrowellen einer Frequenz von etwa 2,45 GHz unterhalten wurde. A device according to P 37 38 352.3 with a 100-1 low pressure chamber was used. in which a mixing drum (about 20 Liter volume) was arranged with ejection. This mixing drum was charged with 10 kg of graphite and, after the low-pressure plasma had been ignited, was driven by an electric motor. Methyl methacrylate was chosen as the plasma atmosphere, the low-pressure plasma being maintained at a pressure of 0.4 mbar with microwaves at a frequency of approximately 2.45 GHz.
Nachdem die gesamte Graphitmenge in freiem Fall das Niederdruckplasma passiert hatte, wurde es der Mischtrommel entnommen. After the entire amount of graphite had passed through the low-pressure plasma in free fall, it was removed from the mixing drum.
Das so behandelte PZW. oescnichtete Graphitpulver wurde in an sich bekannter Weise stranggeoreßt und zur Herstellung von nicht georannten Minen für Bleistifte herangezogen, die hinsichtlich ihrer Schreibeigenschaften befriedigten. The PZW treated in this way. Unsealed graphite powder was extruded in a manner known per se and used for the production of unorganized leads for pencils which were satisfactory in terms of their writing properties.
Beispiel 2 Example 2
Es wurde gemäß Beispiel 1 mit der Ausnanme verfanren, daß man 5 kg Siliciumcarbid der Plasmapolymerisation unterwarf. Aus dem erhaltenen konditionierten Pulver wurden 100 Stück Grünfolien zur Herstellung keramischer Wärmeaustauscher gestanzt. Diese Grünfolien wurden in übliener Weise ausgebrannt. Ihre mechanische Festigkeit entsprach den für kerarmsche Wärmeaustauscher geltenden Anforderungen. According to Example 1, the exception was that 5 kg of silicon carbide was subjected to the plasma polymerization. 100 pieces of green foils were punched out of the conditioned powder obtained in order to produce ceramic heat exchangers. These green sheets were burned out in the usual way. Their mechanical strength corresponded to the requirements applicable to Kerarm heat exchangers.

Claims

Patentansprüche Claims
1 . Verfahren zur Kondi ti on i erung ei nes Pu l vers , daduren gekennzeichnet, daß man das Puiver in Gegenwart eines polymerisierbaren organischen und/oder metallorganischen Monomeren einem Niederdruckplasma aussetzt. 1 . Process for conditioning a powder, characterized in that the powder is exposed to a low-pressure plasma in the presence of a polymerizable organic and / or organometallic monomer.
2. Verfahran nach Anspruch 1, dadurch gekennzeichnet, daß man bei einem Unterdruck im Bereich von 0,001 bis 5 mbar und insbesondere 0,01 bis 0,5 mbar ardeitet. 2. Verfahran according to claim 1, characterized in that ardeiten at a negative pressure in the range of 0.001 to 5 mbar and in particular 0.01 to 0.5 mbar.
3. Verfanren nach Anspruch 1 oder 2, daduron gekennzeichnet, daß man das Niederdruckplasma mit Mikrowellen einer Frequenz von etwa 2,45 GHz erzeugt. 3. Verfanren according to claim 1 or 2, daduron characterized in that the low pressure plasma is generated with microwaves of a frequency of about 2.45 GHz.
4. Verfanren nach einem der vornergenenden Ansorüche, dadurch gekennzeichnet, daß man das Pulver frei durch das Niedereruck- plasma fallen läßt. 4. Method according to one of the foregoing claims, characterized in that the powder is allowed to fall freely through the low-pressure plasma.
5. Verfanren nach einem der vornergenenden Ansprüche, dadurch gekennzeichnet, daß man das Puiver in einer sich drehenden Mischtrommel frai durch das Niederdruckplasma fallen läßt. 5. Verkanren according to one of the vornergenenden claims, characterized in that the Puiver frai in a rotating mixing drum may fall through the low pressure plasma.
5. Verfahren nach einem der vornergehenden Anserüche, dadurch gekennzeichnet, daß man ein anorgamsches Pulver konditioniert. beispielsweise Grapnit, Keramik, Glas oder Metall, wie 5. The method according to any one of the preceding claims, characterized in that an inorganic powder is conditioned. for example grapnite, ceramic, glass or metal, such as
Hartmetal 1. Hard metal 1.
7. Verfahren nach Anspruch 5, dadurch gekennzeichnet, daß man ein Pulver für tachnische Keramik konditioniert, beispielsweise für Oxidkeramik, wie Aluminiumoxid, Magnesiumoxid, Zirkonoxid oder Berylliumoxid, od er für Nicht-Oxidkeramik, wie Carbide, z.B. Borcarbid oder Siliciumcarbid, oder wie Nitride, z.B. Boinitrid, Siliciumnitrid oder AIuminiumnitrid. 7. The method according to claim 5, characterized in that a powder for Tachnic ceramics is conditioned, for example for oxide ceramics, such as aluminum oxide, magnesium oxide, zirconium oxide or beryllium oxide, or it for non-oxide ceramics, such as carbides, e.g. Boron carbide or silicon carbide, or such as nitrides, e.g. Boinitride, silicon nitride or aluminum nitride.
8. Vorrichtung zur Durchführung ces Verfanrens gemäß einem der vorhergehenden Ansprüche, gekennzeichnet durch sine Vakuumkammer mit eingekoppeltan Mikrowellen, die eine Mischtrommel umfaßt. 8. Device for carrying out the process according to one of the preceding claims, characterized by a vacuum chamber with coupled-in microwaves, which comprises a mixing drum.
PCT/EP1991/000315 1990-02-20 1991-02-20 Process for treating a powder and device therefor WO1991012881A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DEP4005328.8 1990-02-20
DE4005328A DE4005328A1 (en) 1990-02-20 1990-02-20 METHOD FOR CONDITIONING A POWDER AND DEVICE THEREFOR

Publications (1)

Publication Number Publication Date
WO1991012881A1 true WO1991012881A1 (en) 1991-09-05

Family

ID=6400583

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/EP1991/000315 WO1991012881A1 (en) 1990-02-20 1991-02-20 Process for treating a powder and device therefor

Country Status (2)

Country Link
DE (1) DE4005328A1 (en)
WO (1) WO1991012881A1 (en)

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1995009044A1 (en) * 1993-09-29 1995-04-06 E.I. Du Pont De Nemours And Company Melt granulation with dielectric heating
US8858210B2 (en) 2009-09-24 2014-10-14 Mcneil-Ppc, Inc. Manufacture of variable density dosage forms utilizing radiofrequency energy
US8865204B2 (en) 2009-09-24 2014-10-21 Mcneil-Ppc, Inc. Manufacture of lozenge product with radiofrequency
US8968769B2 (en) 2007-10-31 2015-03-03 Mcneil-Ppc, Inc. Orally disintegrative dosage form
US9233491B2 (en) 2012-05-01 2016-01-12 Johnson & Johnson Consumer Inc. Machine for production of solid dosage forms
US9445971B2 (en) 2012-05-01 2016-09-20 Johnson & Johnson Consumer Inc. Method of manufacturing solid dosage form
US9511028B2 (en) 2012-05-01 2016-12-06 Johnson & Johnson Consumer Inc. Orally disintegrating tablet
US9789066B2 (en) 2014-01-10 2017-10-17 Johnson & Johnson Consumer Inc. Process for making tablet using radiofrequency and lossy coated particles
US10493026B2 (en) 2017-03-20 2019-12-03 Johnson & Johnson Consumer Inc. Process for making tablet using radiofrequency and lossy coated particles

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2011306A1 (en) * 1969-03-10 1970-09-17 Fa. Progil, Paris Process for wrapping or encapsulating powdery materials
JPS63242906A (en) * 1987-03-30 1988-10-07 Hitachi Ltd Production of oxide ultrafine particle
DE3738352A1 (en) * 1987-11-11 1989-05-24 Technics Plasma Gmbh FILAMENTLESS MAGNETRON ION BEAM SYSTEM

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2011306A1 (en) * 1969-03-10 1970-09-17 Fa. Progil, Paris Process for wrapping or encapsulating powdery materials
JPS63242906A (en) * 1987-03-30 1988-10-07 Hitachi Ltd Production of oxide ultrafine particle
DE3738352A1 (en) * 1987-11-11 1989-05-24 Technics Plasma Gmbh FILAMENTLESS MAGNETRON ION BEAM SYSTEM

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
Patent Abstracts of Japan, Band 13, Nr. 49 (C-565)(3397), 3. Februar 1989; & JP-A-63242906 (HITACHI LTD) 7. Oktober 1988 *

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1995009044A1 (en) * 1993-09-29 1995-04-06 E.I. Du Pont De Nemours And Company Melt granulation with dielectric heating
US8968769B2 (en) 2007-10-31 2015-03-03 Mcneil-Ppc, Inc. Orally disintegrative dosage form
US8858210B2 (en) 2009-09-24 2014-10-14 Mcneil-Ppc, Inc. Manufacture of variable density dosage forms utilizing radiofrequency energy
US8865204B2 (en) 2009-09-24 2014-10-21 Mcneil-Ppc, Inc. Manufacture of lozenge product with radiofrequency
US8871263B2 (en) 2009-09-24 2014-10-28 Mcneil-Ppc, Inc. Manufacture of tablet in a die utilizing radiofrequency energy and meltable binder
US9107807B2 (en) 2009-09-24 2015-08-18 Mcneil-Ppc, Inc. Machine for the manufacture of dosage forms utilizing radiofrequency energy
US9610224B2 (en) 2009-09-24 2017-04-04 Johnson & Johnson Consumer Inc. Manufacture of tablet in a die utilizing powder blend containing water-containing material
US9233491B2 (en) 2012-05-01 2016-01-12 Johnson & Johnson Consumer Inc. Machine for production of solid dosage forms
US9445971B2 (en) 2012-05-01 2016-09-20 Johnson & Johnson Consumer Inc. Method of manufacturing solid dosage form
US9511028B2 (en) 2012-05-01 2016-12-06 Johnson & Johnson Consumer Inc. Orally disintegrating tablet
US9789066B2 (en) 2014-01-10 2017-10-17 Johnson & Johnson Consumer Inc. Process for making tablet using radiofrequency and lossy coated particles
US10493026B2 (en) 2017-03-20 2019-12-03 Johnson & Johnson Consumer Inc. Process for making tablet using radiofrequency and lossy coated particles

Also Published As

Publication number Publication date
DE4005328A1 (en) 1991-08-22
DE4005328C2 (en) 1991-12-12

Similar Documents

Publication Publication Date Title
DE3318832C2 (en)
DE2648459C3 (en) Process for the production of refractory workpieces
EP1368286B1 (en) Composite material and method for the production thereof
EP1044179B1 (en) Ceramic network, method for the production and utilization thereof
DE10019447A1 (en) An inorganic material binder useful for preparation of metallic and ceramic molded bodies removable in two stages without residue, giving green body and metallic or ceramic molded bodies devoid of pores and cracks
CH653954A5 (en) METHOD FOR PRODUCING SHAPED COMPOSITES FROM A FIBER REINFORCED GLASS MATRIX OR GLASS CERAMIC MATRIX.
EP2043802A1 (en) Thermoplastic masses containing binding agents for the production of metallic molds
WO1991012881A1 (en) Process for treating a powder and device therefor
DE3103167A1 (en) Flocculant beta -silicon carbide, method for its preparation, and use thereof
EP3450128B1 (en) Method for the preparation of an intermediate product for the manufacture of a fibre-reinforced part
KR102275122B1 (en) Binder Composition for Metal Injection Molding
DE102004016874C5 (en) Composite material, process for its preparation and its use
DE2651311A1 (en) COMPOSITE BODY MADE OF CERAMICS AND THE PROCESS FOR ITS PRODUCTION
EP0314142A2 (en) Process for the fabrication of a porous shaped body
EP0752978A1 (en) Heat insulating mouldings
DE3611271C2 (en)
DE3220559C2 (en)
EP3093305B1 (en) Batch for producing a green body for producing a refractory carbon-bonded product, method for producing such a green body and a green body obtained through this method
WO2011117137A2 (en) Method and device for producing a product by casting from liquid, pulpy, paste-like, powdery, granular, solid material and/or composition additives thereof
EP0595099B1 (en) Process for the production of sintered bodies
DE60316080T2 (en) Process for producing a refractory material, protective coating obtainable therewith and their uses
DE19508959C2 (en) Shaped body made of ceramic, powder metallurgical or composite material and process for its production
DE2141029C3 (en) Process for the manufacture of refractory materials
DE2014312C3 (en) Process for the production of objects from heat-resistant materials
SU834181A1 (en) Method of producing sintered articles

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): JP US

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): AT BE CH DE DK ES FR GB GR IT LU NL SE