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EP0343038A1 - Surface cleaning method with a transported plasma - Google Patents

Surface cleaning method with a transported plasma Download PDF

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Publication number
EP0343038A1
EP0343038A1 EP89401297A EP89401297A EP0343038A1 EP 0343038 A1 EP0343038 A1 EP 0343038A1 EP 89401297 A EP89401297 A EP 89401297A EP 89401297 A EP89401297 A EP 89401297A EP 0343038 A1 EP0343038 A1 EP 0343038A1
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EP
European Patent Office
Prior art keywords
plasma
fluorinated
mixture
cleaning
nitrogen
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EP89401297A
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German (de)
French (fr)
Inventor
Odile Dessaux
Brigitte Mutel
Daniel Szurminski
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Prestations De Services Sps Ste
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Prestations De Services Sps Ste
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Publication of EP0343038A1 publication Critical patent/EP0343038A1/en
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    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23G—CLEANING OR DE-GREASING OF METALLIC MATERIAL BY CHEMICAL METHODS OTHER THAN ELECTROLYSIS
    • C23G5/00—Cleaning or de-greasing metallic material by other methods; Apparatus for cleaning or de-greasing metallic material with organic solvents
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B08—CLEANING
    • B08B—CLEANING IN GENERAL; PREVENTION OF FOULING IN GENERAL
    • B08B7/00—Cleaning by methods not provided for in a single other subclass or a single group in this subclass
    • B08B7/0035—Cleaning by methods not provided for in a single other subclass or a single group in this subclass by radiant energy, e.g. UV, laser, light beam or the like

Definitions

  • the present invention relates to surface cleaning of objects, for example the pickling of metal surfaces by removing oils or greases which cover them in whole or in part, for example the cleaning of ceramic objects or optical fibers based of glass, this list not being limiting.
  • the present invention relates more particularly to the treatment of such objects with a view to cleaning their surface with a plasma.
  • a plasma is given to various media containing simultaneously neutral particles - atoms or molecules - positive ions and electrons.
  • a plasma can be produced artificially by carrying a gas at high temperature or by subjecting it to an intense electric field.
  • Type I plasma commonly called plasma without any other qualifier
  • plasma is a highly ionized medium, in which a very high temperature prevails, and which is in thermodynamic equilibrium. It is obtained for example using a plasma torch type material. Its temperature is around 10,000 to 15,000 ° K. The surface cleaning of objects with type I plasmas is obtained by the destructive action due to high temperatures. These plasmas being confined in the restricted volume of the discharge, only small surfaces can be treated. A plasma of this type is described in US Pat. No. 4,555,303.
  • Type II plasma commonly called cold plasma
  • Cold plasma is a poorly ionized medium. Its temperature is lower, since it is less than 1000 ° K. It is however poorly defined because the environment is in strong thermodynamic imbalance. Cold plasma is obtained in electrical discharges with or without electrodes, in a gas under low pressure, less than 100 mbar, for example in electrical discharges, microwave or high frequency discharges. A plasma of this type is described in Patent FR.2.368.308.
  • Type III plasma will be called in the remainder of this text deferred plasma; in scientific literature, it is sometimes referred to as "activated gas” or "post-luminescence" when the plasma gas is nitrogen.
  • the deferred plasma is obtained by dynamic expansion of a cold plasma outside the discharge. This expansion can be carried out in very large volumes, of the order of several cubic meters. It is generally formed at pressures below 100 mbar but can be obtained up to pressures above atmospheric pressure. It is an environment in a state of very strong thermodynamic non-equilibrium, where the average temperature is that of the ambient atmosphere, for example 298 ° K.
  • Deferred plasma is known in the treatment of plastic surfaces, in particular by European patent applications No. 84.101.926.8 and 84.101.935.9, with a view to increasing the bonding power of said surfaces, resulting in particular in an increase in wettability, characterized by a decrease in the angle of contact of water on the surface of the material.
  • European patent applications No. 84.101.926.8 and 84.101.935.9 with a view to increasing the bonding power of said surfaces, resulting in particular in an increase in wettability, characterized by a decrease in the angle of contact of water on the surface of the material.
  • no particular applications of deferred plasmas are known.
  • deferred plasma has a cleaning action on the surface of certain objects which are not themselves altered. or modified by said plasma, in particular objects made of stainless steel, ceramic, procelaine, glass.
  • pollutants such as oils, fats, organic materials, deposited on the surface of said objects were degraded when subjected to the action of a delayed plasma for a given time. This time is a function of the pressure prevailing in the plasma expansion chamber and the surface condition of the object. This degradation occurs even when the plasma temperature is close to ambient temperature.
  • the delayed plasmas used in the context of the invention involve pure or mixed gases, in particular argon, dioxygen (O2), dinitrogen (N2) and even air, called plasma gas.
  • the plasmagenic medium is a mixture of gases, comprising in a proportion at most equal to 10%, a fluorinated or chlorinated compound. It has in fact been observed that the presence of such a gas has an amplifying effect on the action of cleaning the delayed plasma.
  • the fluorinated compound is in particular chosen from nitrogen trifluoride (NF3), carbon tetrafluoride (CF4), sulfur hexafluoride (SF6) or fluorine (F2).
  • the chlorinated compound is in particular chosen from nitrogen trichloride (NCl3), carbon tetrachloride (CCl4), trichloromethane (CHCl3), dichloromethane (CH2Cl2) or chlorine (Cl2).
  • the preferred composition of the plasma medium is as follows: dioxygen 75%, dinitrogen 23.5% and nitrogen trifluoride 1.5% for a pressure of 12 mbar.
  • the treatment time necessary for the complete cleaning of the surface of the object is of the order of 1 to 15 minutes if said surface is smooth; it is around 90 to 100 minutes if the surface is granite. This time is sufficient to carry out the complete degradation of all the polluting materials deposited on the surface of the object, whatever the shape of the object and even if the polluting materials would be located in indentations or interior cavities.
  • FIG. 1 is a schematic view of said installation
  • Figure 2 is a schematic view of a large capacity expansion chamber.
  • the cleaning installation of the invention comprises a plasma generator 1.
  • This is a microwave generator, operating at a frequency of 2450 MHz and delivering a variable, adjustable power, up to 1500 W.
  • a coupler 2 of parallelepiped shape, which allows a very good adaptation, thanks to the piston 11, to the screws 12, and to an inner iris not shown in the figure.
  • This coupler is described with precision in J. Phys.E.Sc.inst.16-1983 pages 1160-1161.
  • the quartz tube 3 has a diameter of 15 mm.
  • the plasma produced in tube 3 is type II cold plasma.
  • the tube 3 is connected to three gas bottles 13, 14, 15: respectively nitrogen, oxygen and nitrogen trifluoride in the preferred composition of the invention .
  • the tube 3 further comprises a gauge 4 for measuring the pressure.
  • the other end of the tube 3, on the right in the figure, is connected to the expansion chamber 7 by means of the male 6 and female 19 spherical connections.
  • This chamber 7 is moreover connected, by means of the male 20 and female spherical connections. 21, to a trap 8 containing a copper sponge and to a second liquid nitrogen trap 9 placed in series after the first trap 8, and connected to a vacuum pump not shown.
  • the vacuum pump has a flow rate of 35 m3 / h at atmospheric pressure.
  • the spherical connections make it possible to interchange the expansion chambers according to the volume of the objects to be cleaned.
  • the expansion chamber 7, shown in Figure 1 has a capacity of 2.5 l, it is suitable for objects of small dimensions, for example pliers or other hand tools.
  • the expansion chamber 7, shown in FIG. 2 which has a capacity of 125 l.
  • This chamber is composed of two separate parts, which can be separated to allow the introduction of the object or objects to be cleaned, each part being equipped with closing means capable of preserving the tightness of the expansion chamber 7 once the object or objects were introduced there.
  • the cleaning operation consists in introducing into the expansion chamber 7 the soiled tool 10 to be cleaned, in connecting the chamber 7 by its spherical connections 19 and 20 on the one hand to the tube 3 and on the other hand to the traps 8 and 9, to supply the tube 3 with one and / or the other of the gases, in the desirable proportion by acting on the regulators 16,17,18, and to create the cold plasma in the tube 3 by actuating the generator 1 and by adjusting the coupler 2.
  • the cold plasma, generated in the tube 3 is dynamically, by the gas flow which crosses the tube 3, transferred into the expansion chamber 7. There, the deferred plasma attacks the materials organic, oils or greases staining the surface of the tool.
  • the tool 10 must be kept in the activated gas flow for a sufficient time so that all the surface materials are degraded and are themselves evacuated from the chamber 7 and retained by the two successive traps 8 and 9.
  • the optimal composition of the plasma gas is the following, at a total pressure of 12 mbar: oxygen (WHERE) 75% nitrogen (N2) 23.5% nitrogen trifluoride 1.5%
  • the microwave power introduced via the coupler 2 was less than 160W.
  • the nitrogen trifluoride promotes the pickling of surfaces, in particular stainless steel, by reducing the processing time required to remove pollutants.
  • the duration of the treatment was 15 min; for tools with a granite surface, 90 min were required.
  • the time required is much shorter, less than a minute and in some cases less than a second.
  • the invention is not limited to the embodiment which has just been described, but covers all its variants. What has been said for the stripping of metallic surfaces is also true for the cleaning of ceramic materials, porcelains, glass objects (in particular glass fibers), ceramic composites - glasses-metals. Similarly, it is possible, without departing from the invention, to modify the conditions for obtaining deferred plasma: pressure, power, volume of the expansion chamber, plasma generated by electrical discharge, microwave or high frequency. Finally, oils and fats are not the only pollutants degradable by deferred plasma, they can be inks, more generally organic materials, or even certain metallic deposits.

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  • Chemical & Material Sciences (AREA)
  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • General Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Optics & Photonics (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Cleaning And De-Greasing Of Metallic Materials By Chemical Methods (AREA)
  • Cleaning In General (AREA)
  • Electrical Discharge Machining, Electrochemical Machining, And Combined Machining (AREA)
  • Detergent Compositions (AREA)
  • Polishing Bodies And Polishing Tools (AREA)
  • Drying Of Semiconductors (AREA)
  • Cleaning Or Drying Semiconductors (AREA)

Abstract

The invention consists in subjecting the object (10) to be cleaned to the action of a transported cold plasma, by placing it in the expansion chamber (7) of an installation producing a cold plasma, for example under the action of a microwave discharge. The plasma-forming gas is preferably a mixture of nitrogen and oxygen containing a small proportion of a fluorinated or chlorinated compound, in particular nitrogen trifluoride. The invention applies to the cleaning of objects made from stainless steel, ceramic, porcelain, or glass by destroying their polluting substances, for example mechanical oils or greases. It applies, in particular, to the decontamination of tools used in the nuclear industry. <IMAGE>

Description

La présente invention concerne le nettoyage en surface d'objet, par exemple le décapage de surfaces métalliques par élimination des huiles ou des graisses qui les recouvrent en totalité ou en partie, par exemple le nettoyage d'objet en céramique ou de fibres optiques à base de verre, cette énumération n'étant pas limitative. La présente invention concerne plus particulièrement le traitement de tels objets en vue du nettoyage de leur surface par un plasma.The present invention relates to surface cleaning of objects, for example the pickling of metal surfaces by removing oils or greases which cover them in whole or in part, for example the cleaning of ceramic objects or optical fibers based of glass, this list not being limiting. The present invention relates more particularly to the treatment of such objects with a view to cleaning their surface with a plasma.

L'appellation plasma est donnée à divers milieux contenant simultanément des particules neutres - atomes ou molécules - des ions positifs et des électrons. On peut réaliser artificiellement un plasma en portant un gaz à haute température ou en le soumettant à un champ électrique intense.The name plasma is given to various media containing simultaneously neutral particles - atoms or molecules - positive ions and electrons. A plasma can be produced artificially by carrying a gas at high temperature or by subjecting it to an intense electric field.

Le plasma de type I, couramment appelé plasma sans autre qualificatif , est un milieu fortement ionisé, au sein duquel il règne une température très élevée, et qui est en équilibre thermodynamique . Il est obtenu par exemple à l'aide d'un matériel de type torche à plasma. Sa température est de l'ordre de 10.000 à 15.000°K. Le nettoyage en surface d'objets par des plasmas du type I est obtenu par l'action destructrice due aux hautes températures. Ces plasmas étant confinés dans le volume restreint de la décharge, seules de petites surfaces peuvent être traitées.Un plasma de ce type est décrit dans le brevet US.4,555,303.Type I plasma, commonly called plasma without any other qualifier, is a highly ionized medium, in which a very high temperature prevails, and which is in thermodynamic equilibrium. It is obtained for example using a plasma torch type material. Its temperature is around 10,000 to 15,000 ° K. The surface cleaning of objects with type I plasmas is obtained by the destructive action due to high temperatures. These plasmas being confined in the restricted volume of the discharge, only small surfaces can be treated. A plasma of this type is described in US Pat. No. 4,555,303.

Le plasma de type II, couramment appelé plasma froid, est un milieu peu ionisé. Sa température est plus faible, puisqu'elle est inférieure à 1000°K. Elle est toutefois mal définie car le milieu est en fort déséquilibre thermodynamique. Le plasma froid est obtenu dans des décharges électriques avec ou sans électrodes, dans un gaz sous faible pression, inférieure à 100 mbar, par exemple dans des décharges électriques, des décharges micro-onde ou haute fréquence.Un plasma de ce type est décrit dans le brevet FR.2.368.308.Type II plasma, commonly called cold plasma, is a poorly ionized medium. Its temperature is lower, since it is less than 1000 ° K. It is however poorly defined because the environment is in strong thermodynamic imbalance. Cold plasma is obtained in electrical discharges with or without electrodes, in a gas under low pressure, less than 100 mbar, for example in electrical discharges, microwave or high frequency discharges. A plasma of this type is described in Patent FR.2.368.308.

Le plasma de type III sera appelé dans la suite du présent texte plasma différé; dans la littérature scientifique , on le désigne parfois sous le terme "gaz activé" ou encore de "postluminescence" quand le gaz plasmagène est l'azote. Le plasma différé est obtenu par expansion en régime dynamique d'un plasma froid en dehors de la décharge. Cette expansion peut être réalisée dans des volumes très importants, de l'ordre de plusieurs mètres cubes. Il est en général formé à des pressions inférieures à 100 mbar mais peut être obtenu jusqu'à des pressions supérieures à la pression atmosphérique. Il s'agit d'un milieu en état de très fort non-équilibre thermodynamique, où la température moyenne est celle de l'atmosphère ambiant, par exemple 298°K.Type III plasma will be called in the remainder of this text deferred plasma; in scientific literature, it is sometimes referred to as "activated gas" or "post-luminescence" when the plasma gas is nitrogen. The deferred plasma is obtained by dynamic expansion of a cold plasma outside the discharge. This expansion can be carried out in very large volumes, of the order of several cubic meters. It is generally formed at pressures below 100 mbar but can be obtained up to pressures above atmospheric pressure. It is an environment in a state of very strong thermodynamic non-equilibrium, where the average temperature is that of the ambient atmosphere, for example 298 ° K.

Le plasma différé est connu dans les traitements des surfaces plastiques, notamment par les demandes de brevets européens N°84.101.926.8 et 84.101.935.9, en vue d'augmenter le pouvoir d'accrochage desdites surfaces, se traduisant en particulier par une augmentation de la mouillabilité , se caractérisant par une diminution de l'angle de contact de l'eau à la surface du matériau. Par contre , en dehors des matériaux plastiques, on ne connaît pas d'applications particulières des plasmas différés.Deferred plasma is known in the treatment of plastic surfaces, in particular by European patent applications No. 84.101.926.8 and 84.101.935.9, with a view to increasing the bonding power of said surfaces, resulting in particular in an increase in wettability, characterized by a decrease in the angle of contact of water on the surface of the material. On the other hand, apart from plastic materials, no particular applications of deferred plasmas are known.

Or on a trouvé et c'est ce qui fait l'objet de l'invention que, de manière tout-à-fait inattendue , le plasma différé a une action de nettoyage en surface de certains objets qui ne sont pas eux-mêmes altérés ou modifiés par ledit plasma, notamment les objets en acier inoxydable, en céramique, procelaine, verre. Il a été trouvé que les matières polluantes, du type huiles , graisses, matières organiques, déposées à la surface desdits objets étaient dégradées lorsqu'on les soumettait à l'action d'un plasma différé pendant un temps donné . Ce temps est fonction de la pression régnant dans l'enceinte d'expansion du plasma et de l'état de surface de l'objet. Cette dégradation intervient alors même que la température du plasma est proche de la température ambiante.Now we have found, and this is what is the subject of the invention, that, quite unexpectedly, deferred plasma has a cleaning action on the surface of certain objects which are not themselves altered. or modified by said plasma, in particular objects made of stainless steel, ceramic, procelaine, glass. It has been found that pollutants, such as oils, fats, organic materials, deposited on the surface of said objects were degraded when subjected to the action of a delayed plasma for a given time. This time is a function of the pressure prevailing in the plasma expansion chamber and the surface condition of the object. This degradation occurs even when the plasma temperature is close to ambient temperature.

Les plasmas différés utilisés dans le cadre de l'invention font intervenir des gaz purs ou en mélange, en particulier l'argon, le dioxygène (O₂), le diazote (N₂) et même l'air, appelé gaz plasmagène.The delayed plasmas used in the context of the invention involve pure or mixed gases, in particular argon, dioxygen (O₂), dinitrogen (N₂) and even air, called plasma gas.

De préférence, le milieu plasmagène est un mélange de gaz, comportant dans une proportion au plus égale à 10 % un composé fluoré ou chloré. Il a en effet été remarqué que la présence d'un tel gaz avait un effet amplificateur de l'action de nettoyage du plasma différé. Le composé fluoré est en particulier choisi parmi le trifluorure d'azote (NF₃), le tétrafluorure de carbone (CF₄), l'hexafluorure de soufre (SF₆) ou le fluor (F₂). Le composé chloré est en particulier choisi parmi le trichlorure d'azote (NCl₃), le tétrachlorure de carbone (CCl₄), le trichlorométhane (CHCl₃), le dichlorométhane (CH₂Cl₂) ou le chlore (Cl₂).Preferably, the plasmagenic medium is a mixture of gases, comprising in a proportion at most equal to 10%, a fluorinated or chlorinated compound. It has in fact been observed that the presence of such a gas has an amplifying effect on the action of cleaning the delayed plasma. The fluorinated compound is in particular chosen from nitrogen trifluoride (NF₃), carbon tetrafluoride (CF₄), sulfur hexafluoride (SF₆) or fluorine (F₂). The chlorinated compound is in particular chosen from nitrogen trichloride (NCl₃), carbon tetrachloride (CCl₄), trichloromethane (CHCl₃), dichloromethane (CH₂Cl₂) or chlorine (Cl₂).

La composition préférée du milieu plasmagène est la suivante : dioxygène 75 %, diazote 23,5 % et trifluorure d'azote 1,5 % pour une pression de 12 mbar.The preferred composition of the plasma medium is as follows: dioxygen 75%, dinitrogen 23.5% and nitrogen trifluoride 1.5% for a pressure of 12 mbar.

Dans une telle composition et à une telle pression, pour des objets en acier inoxydable le temps de traitement nécessaire au nettoyage complet de la surface de l'objet est de l'ordre de 1 à 15 minutes si ladite surface est lisse ; il est de l'ordre de 90 à 100 minutes si la surface est granitée. Ce temps est suffisant pour réaliser la dégradation complète de toutes les matières polluantes déposées à la surface de l'objet, quelle que soit la forme de l'objet et quand bien même les matières polluantes seraient situées dans des échancrures ou cavités intérieures.In such a composition and at such a pressure, for stainless steel objects the treatment time necessary for the complete cleaning of the surface of the object is of the order of 1 to 15 minutes if said surface is smooth; it is around 90 to 100 minutes if the surface is granite. This time is sufficient to carry out the complete degradation of all the polluting materials deposited on the surface of the object, whatever the shape of the object and even if the polluting materials would be located in indentations or interior cavities.

Ainsi le nettoyage complet d'un objet est obtenu sans manipulation difficile, simplement en plaçant ledit objet dans l'enceinte d'expansion où il est soumis à l'action du plasma froid différé. Ceci est particulièrement intéressant dans le cas de la décontamination d'outils de l'industrie nucléaire souillés par des graisses ou des huiles contenant des éléments radioactifs.Thus, the complete cleaning of an object is obtained without difficult handling, simply by placing said object in the expansion enclosure where it is subjected to the action of delayed cold plasma. This is particularly interesting in the case of the decontamination of nuclear industry tools contaminated with fats or oils containing radioactive elements.

L'invention sera mieux comprise, ainsi que les avantages qu'elle procure , à la lecture de la description qui va maintenant être faite d'un exemple de mise en oeuvre du procédé de nettoyage d'objet en surface, dans l'enceinte d'expansion d'une installation de production de plasma froid, illustré par le dessin annexé dans lequel la figure 1 est une vue schématique de ladite installation et la figure 2 est une vue schématique d'une chambre d'expansion de grande capacité.The invention will be better understood, as well as the advantages which it provides, on reading the description which will now be made of an example of implementation of the method of cleaning an object on the surface, in the enclosure of expansion of a cold plasma production installation, illustrated by the appended drawing in which FIG. 1 is a schematic view of said installation and Figure 2 is a schematic view of a large capacity expansion chamber.

L'installation de nettoyage de l'invention comporte un générateur 1 de plasma. Il s'agit ici d'un générateur micro-onde, fonctionnant à une fréquence de 2450 MHz et débitant une puissance variable, réglable, jusqu'à 1500 W. Entre le générateur 1 et le tube de quartz 3, dans lequel est produite la décharge induite par l'énergie électrique micro-onde, est placé un coupleur 2, de forme parallélépipède, qui permet une très bonne adaptation, grâce au piston 11, aux vis 12 , et à un iris intérieur non représenté sur la figure. Ce coupleur est décrit avec précision dans J.Phys.E.Sc.inst.16-1983 pages 1160-1161. Le tube de quartz 3 a un diamètre de 15 mm.The cleaning installation of the invention comprises a plasma generator 1. This is a microwave generator, operating at a frequency of 2450 MHz and delivering a variable, adjustable power, up to 1500 W. Between the generator 1 and the quartz tube 3, in which the discharge induced by microwave electrical energy, is placed a coupler 2, of parallelepiped shape, which allows a very good adaptation, thanks to the piston 11, to the screws 12, and to an inner iris not shown in the figure. This coupler is described with precision in J. Phys.E.Sc.inst.16-1983 pages 1160-1161. The quartz tube 3 has a diameter of 15 mm.

Le plasma produit dans le tube 3 est un plasma froid du type II. A une de ses extrémités, à gauche sur la figure, le tube 3 est relié à trois bouteilles 13,14,15 de gaz : respectivement d'azote, d'oxygène et de trifluorure d'azote dans la composition préférée de l'invention. Entre chacune de ces bouteilles 13,14,15 et le tube 3 sont disposés trois régulateurs , respectivement 16,17,18, de débits massiques destinés à réguler et connaître les débits de gaz alimentés dans le tube 3 et donc leurs proportions. Le tube 3 comporte de plus une jauge 4 de mesure de la pression.The plasma produced in tube 3 is type II cold plasma. At one of its ends, on the left in the figure, the tube 3 is connected to three gas bottles 13, 14, 15: respectively nitrogen, oxygen and nitrogen trifluoride in the preferred composition of the invention . Between each of these bottles 13,14,15 and the tube 3 are arranged three regulators, respectively 16,17,18, of mass flow rates intended to regulate and know the gas flow rates supplied in the tube 3 and therefore their proportions. The tube 3 further comprises a gauge 4 for measuring the pressure.

L'autre extrémité du tube 3 , à droite sur la figure, est raccordée, à la chambre d'expansion 7 grâce aux raccords sphériques mâle 6 et femelle 19. Cette chambre 7 est par ailleurs raccordée , grâce aux raccords sphériques mâle 20 et femelle 21, à un piège 8 renfermant une éponge de cuivre et à un second piège 9 à azote liquide placé en série après le premier piège 8, et reliée à une pompe à vide non représentée. La pompe à vide a un débit de 35 m3/h à la pression atmosphérique.The other end of the tube 3, on the right in the figure, is connected to the expansion chamber 7 by means of the male 6 and female 19 spherical connections. This chamber 7 is moreover connected, by means of the male 20 and female spherical connections. 21, to a trap 8 containing a copper sponge and to a second liquid nitrogen trap 9 placed in series after the first trap 8, and connected to a vacuum pump not shown. The vacuum pump has a flow rate of 35 m3 / h at atmospheric pressure.

Les raccords sphériques permettent d'interchanger les chambres d'expansion en fonction du volume des objets à nettoyer. La chambre 7 d'expansion , montrée sur la figure 1, a une capacité de 2,5 l, elle est adaptée pour des objets de petites dimensions, par exemple des pinces ou autres outils à main. Dans le cas d'objets plus volumineux par exemple un corps de pompe 10, on utilise avantageusement la chambre 7 d'expansion, montrée sur la figure 2, qui a une capacité de 125 l. Cette chambre est composée de deux parties distinctes , séparables pour permettre l'introduction du ou des objets à nettoyer , chaque partie étant équipée de moyens de fermeture aptes à préserver l'étanchéité de la chambre d'expansion 7 une fois que le ou les objets y ont été introduits.The spherical connections make it possible to interchange the expansion chambers according to the volume of the objects to be cleaned. The expansion chamber 7, shown in Figure 1, has a capacity of 2.5 l, it is suitable for objects of small dimensions, for example pliers or other hand tools. In in the case of larger objects, for example a pump body 10, use is made of the expansion chamber 7, shown in FIG. 2, which has a capacity of 125 l. This chamber is composed of two separate parts, which can be separated to allow the introduction of the object or objects to be cleaned, each part being equipped with closing means capable of preserving the tightness of the expansion chamber 7 once the object or objects were introduced there.

L'opération de nettoyage consiste à introduire dans la chambre d'expansion 7 l'outil 10 souillé à nettoyer, à raccorder la chambre 7 par ses raccords sphériques 19 et 20 d'une part au tube 3 et d'autre part aux pièges 8 et 9, à alimenter le tube 3 avec l'un et/ou l'autre des gaz, dans la proportion souhaitable en agissant sur les régulateurs 16,17,18 , et à créer le plasma froid dans le tube 3 en actionnant le générateur 1 et en ajustant le coupleur 2. Le plasma froid, généré dans le tube 3, est de façon dynamique, par le flux gazeux qui traverse le tube 3, transféré dans la chambre d'expansion 7. Là, le plasma différé attaque les matières organiques, les huiles ou graisses souillant la surface de l'outil. Il faut maintenir l'outil 10 dans le flux gazeux activé pendant un temps suffisant pour que toutes les matières en surface soient dégradées et soient elles-mêmes évacuées de la chambre 7 et retenues par les deux pièges successifs 8 et 9.The cleaning operation consists in introducing into the expansion chamber 7 the soiled tool 10 to be cleaned, in connecting the chamber 7 by its spherical connections 19 and 20 on the one hand to the tube 3 and on the other hand to the traps 8 and 9, to supply the tube 3 with one and / or the other of the gases, in the desirable proportion by acting on the regulators 16,17,18, and to create the cold plasma in the tube 3 by actuating the generator 1 and by adjusting the coupler 2. The cold plasma, generated in the tube 3, is dynamically, by the gas flow which crosses the tube 3, transferred into the expansion chamber 7. There, the deferred plasma attacks the materials organic, oils or greases staining the surface of the tool. The tool 10 must be kept in the activated gas flow for a sufficient time so that all the surface materials are degraded and are themselves evacuated from the chamber 7 and retained by the two successive traps 8 and 9.

Parmi tous les mélanges gazeux qui ont été essayés sur l'installation décrite ci-dessus, à partir d'azote, d'air, d'oxygène, d'argon, avec ou sans composé halogène, la composition optimale du gaz plasmagène est la suivante, à une pression totale de 12 mbar : oxygène (O₂) 75 % azote (N₂) 23,5 % trifluorure d'azote 1,5 % Among all the gas mixtures which have been tested on the installation described above, using nitrogen, air, oxygen, argon, with or without halogen compound, the optimal composition of the plasma gas is the following, at a total pressure of 12 mbar: oxygen (WHERE) 75% nitrogen (N₂) 23.5% nitrogen trifluoride 1.5%

La puissance micro-onde introduite par l'intermédiaire du coupleur 2 était inférieure à 160W.The microwave power introduced via the coupler 2 was less than 160W.

Le trifluorure d'azote, de manière surprenante, favorise le décapage des surfaces notamment en acier inoxydable, en diminuant le temps de traitement nécessaire à l'élimination des matières polluantes. Pour des outils ayant une surface lisse et souillée par des graisses et huiles mécaniques, la durée du traitement a été de 15 mn ; pour des outils dont la surface est granitée, 90 mn ont été nécessaires. Pour des objets en céramique ou en verre, le temps nécessaire est beaucoup plus court, inférieure à la minute et dans certains cas inférieure à la seconde.The nitrogen trifluoride, surprisingly, promotes the pickling of surfaces, in particular stainless steel, by reducing the processing time required to remove pollutants. For tools with a smooth surface and soiled with mechanical greases and oils, the duration of the treatment was 15 min; for tools with a granite surface, 90 min were required. For ceramic or glass objects, the time required is much shorter, less than a minute and in some cases less than a second.

L'invention n'est pas limitée à l'exemple de réalisation qui vient d'être décrit, mais en couvre toutes les variantes. Ce qui a été dit pour le décapage des surfaces métalliques est également vrai pour le nettoyage des matériaux céramiques, porcelaines, objets en verre (notamment fibres de verre), composites céramiques - verres-métaux. De même il est possible sans sortir de l'invention de modifier les conditions d'obtention du plasma différé : pression, puissance, volume de la chambre d'expansion, plasma généré par décharge électrique , micro-onde ou haute fréquence. Enfin, les huiles et graisses ne sont pas les seules matières polluantes dégradables par le plasma différé, il peut s'agir d'encres, plus généralement de matières organiques, voire même de certains dépôts métalliques.The invention is not limited to the embodiment which has just been described, but covers all its variants. What has been said for the stripping of metallic surfaces is also true for the cleaning of ceramic materials, porcelains, glass objects (in particular glass fibers), ceramic composites - glasses-metals. Similarly, it is possible, without departing from the invention, to modify the conditions for obtaining deferred plasma: pressure, power, volume of the expansion chamber, plasma generated by electrical discharge, microwave or high frequency. Finally, oils and fats are not the only pollutants degradable by deferred plasma, they can be inks, more generally organic materials, or even certain metallic deposits.

Claims (9)

1. Procédé de nettoyage en surface d'objet caractérisé en ce que, ledit objet (10) étant en acier inoxydable, en verre, porcelaine, céramique, en pur ou en mélange, il consiste à soumettre ledit objet (10) à l'action d'un plasma froid différé, pendant un temps suffisant pour décomposer les matières polluantes déposées sur la surface de l'objet.1. A method of cleaning the surface of an object, characterized in that, said object (10) being made of stainless steel, glass, porcelain, ceramic, in pure or mixed form, it consists in subjecting said object (10) to action of a delayed cold plasma, for a time sufficient to decompose the pollutants deposited on the surface of the object. 2. Procédé selon la revendication 1 caractérisé en ce que le gaz plasmagène est un mélange de dioxygène et de diazote.2. Method according to claim 1 characterized in that the plasma gas is a mixture of dioxygen and dinitrogen. 3. Procédé selon l'une des revendications 1 et 2 caractérisé en ce que le gaz plasmagène est un mélange comportant un composé fluoré ou chloré dans une proportion au plus égale à 10 %.3. Method according to one of claims 1 and 2 characterized in that the plasma gas is a mixture comprising a fluorinated or chlorinated compound in a proportion at most equal to 10%. 4. Procédé selon la revendication 3 caractérisé en ce que le composé fluoré est choisi parmi le trifluorure d'azote, le tétrafluorure de carbone, l'hexafluorure de soufre ou le fluor.4. Method according to claim 3 characterized in that the fluorinated compound is chosen from nitrogen trifluoride, carbon tetrafluoride, sulfur hexafluoride or fluorine. 5. Procédé selon la revendication 3 caractérisé en ce que le composé chloré est choisi parmi le trichlorure d'azote, le tétra ou le tri ou le dichlorométhane, ou le chlore.5. Method according to claim 3 characterized in that the chlorinated compound is chosen from nitrogen trichloride, tetra or tri or dichloromethane, or chlorine. 6. Procédé selon la revendication 1 caractérisé en ce que le gaz plasmagène est à une pression de l'ordre de 12 mbar et est un mélange de 75 % environ de dioxygène , de 23,5 % environ de diazote et de 1,5 % environ d'un composé fluoré ou chloré.6. Method according to claim 1 characterized in that the plasma gas is at a pressure of the order of 12 mbar and is a mixture of about 75% of oxygen, about 23.5% of dinitrogen and 1.5% about a fluorinated or chlorinated compound. 7. Procédé selon la revendication 6 caractérisé en ce que, l'objet étant en acier inoxydable, le temps de traitement est de l'ordre de une à 100 minutes en fonction de son état de surface.7. Method according to claim 6 characterized in that, the object being made of stainless steel, the treatment time is of the order of one to 100 minutes depending on its surface condition. 8. Procédé selon la revendication 1 caractérisé en ce que les matières polluantes sont des matières organiques, notamment des graisses ou des huiles mécaniques.8. Method according to claim 1 characterized in that the polluting materials are organic materials, in particular greases or mechanical oils. 9. Procédé de décontamination d'outils de l'industrie nucléaire selon la revendication 1 caractérisé en ce que les matières polluantes comportent des éléments radioactifs.9. A method of decontaminating tools from the nuclear industry according to claim 1 characterized in that the polluting materials include radioactive elements.
EP89401297A 1988-05-10 1989-05-10 Surface cleaning method with a transported plasma Withdrawn EP0343038A1 (en)

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FR8806607A FR2631258B1 (en) 1988-05-10 1988-05-10 DELAYED PLASMA SURFACE CLEANING PROCESS
FR8806607 1988-05-10

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Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0618017A1 (en) * 1993-03-30 1994-10-05 Bridgestone Corporation Method for cleaning curing mold
FR2733437A1 (en) * 1995-04-27 1996-10-31 Aubert Bruno Separating free chemical element(s) from other materials
FR2750348A1 (en) * 1996-06-28 1998-01-02 Conte PROCESS FOR INCREASING THE WET RESISTANCE OF A BODY, BODY THUS PROCESSED AND ITS APPLICATIONS
EP0828618A1 (en) * 1995-06-02 1998-03-18 The University Of Tennessee Research Corporation Method and apparatus for cleaning surfaces with a glow discharge plasma at one atmosphere of pressure
EP0924282A1 (en) * 1997-12-18 1999-06-23 Central Glass Company, Limited Gas for removing a deposit and its use
US6125859A (en) * 1997-03-05 2000-10-03 Applied Materials, Inc. Method for improved cleaning of substrate processing systems
WO2000078123A1 (en) * 1999-06-24 2000-12-28 Wisconsin Alumni Research Foundation Cold-plasma treatment of seeds to remove surface materials
US6274058B1 (en) 1997-07-11 2001-08-14 Applied Materials, Inc. Remote plasma cleaning method for processing chambers
CN104148334A (en) * 2014-07-02 2014-11-19 太仓华德石太工业设备有限公司 Method for performing industrial local cleaning through hydrocarbon/ plasmas
DE102020131832A1 (en) 2020-12-01 2022-06-02 Universität Kassel, Körperschaft des öffentlichen Rechts Process for the manufacture of casting molds or casting cores

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
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US20110108058A1 (en) * 2009-11-11 2011-05-12 Axcelis Technologies, Inc. Method and apparatus for cleaning residue from an ion source component
CN101837357B (en) * 2010-05-04 2011-10-05 宁波大学 A plasma cleaning device
JP2012152855A (en) * 2011-01-26 2012-08-16 Osg Corp Method of removing diamond film or hard carbon film
CN104353643B (en) * 2014-12-02 2017-07-25 上海华虹宏力半导体制造有限公司 A kind of maintenance system and maintaining method for reducing ultrasonic cleaner

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2368308A1 (en) * 1976-10-19 1978-05-19 Kernforschungsanlage Juelich METHOD AND DEVICE FOR CLEANING SURFACES, ESPECIALLY METAL SURFACES
US4555303A (en) * 1984-10-02 1985-11-26 Motorola, Inc. Oxidation of material in high pressure oxygen plasma
WO1987002603A1 (en) * 1985-10-29 1987-05-07 Hughes Aircraft Company Method and apparatus for atomic beam irradiation

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2368308A1 (en) * 1976-10-19 1978-05-19 Kernforschungsanlage Juelich METHOD AND DEVICE FOR CLEANING SURFACES, ESPECIALLY METAL SURFACES
US4555303A (en) * 1984-10-02 1985-11-26 Motorola, Inc. Oxidation of material in high pressure oxygen plasma
WO1987002603A1 (en) * 1985-10-29 1987-05-07 Hughes Aircraft Company Method and apparatus for atomic beam irradiation

Cited By (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0618017A1 (en) * 1993-03-30 1994-10-05 Bridgestone Corporation Method for cleaning curing mold
FR2733437A1 (en) * 1995-04-27 1996-10-31 Aubert Bruno Separating free chemical element(s) from other materials
EP0828618A4 (en) * 1995-06-02 2001-01-03 Univ Tennessee Res Corp Method and apparatus for cleaning surfaces with a glow discharge plasma at one atmosphere of pressure
EP0828618A1 (en) * 1995-06-02 1998-03-18 The University Of Tennessee Research Corporation Method and apparatus for cleaning surfaces with a glow discharge plasma at one atmosphere of pressure
FR2750348A1 (en) * 1996-06-28 1998-01-02 Conte PROCESS FOR INCREASING THE WET RESISTANCE OF A BODY, BODY THUS PROCESSED AND ITS APPLICATIONS
US6197234B1 (en) 1996-06-28 2001-03-06 Conte Sa Method for increasing the anti-wettability of a body
EP0815937A1 (en) * 1996-06-28 1998-01-07 Conte S.A. Process for increasing the anti-wettability of a body, body thus treated and use thereof
US6125859A (en) * 1997-03-05 2000-10-03 Applied Materials, Inc. Method for improved cleaning of substrate processing systems
US6274058B1 (en) 1997-07-11 2001-08-14 Applied Materials, Inc. Remote plasma cleaning method for processing chambers
EP0924282A1 (en) * 1997-12-18 1999-06-23 Central Glass Company, Limited Gas for removing a deposit and its use
US6673262B1 (en) 1997-12-18 2004-01-06 Central Glass Company, Limited Gas for removing deposit and removal method using same
US7168436B2 (en) 1997-12-18 2007-01-30 Central Glass Company, Limited Gas for removing deposit and removal method using same
US7744769B2 (en) 1997-12-18 2010-06-29 Central Glass Company, Limited Gas for removing deposit and removal method using same
WO2000078123A1 (en) * 1999-06-24 2000-12-28 Wisconsin Alumni Research Foundation Cold-plasma treatment of seeds to remove surface materials
US6543460B1 (en) 1999-06-24 2003-04-08 Wisconsin Alumni Research Foundation Cold-plasma treatment of seeds to remove surface materials
CN104148334A (en) * 2014-07-02 2014-11-19 太仓华德石太工业设备有限公司 Method for performing industrial local cleaning through hydrocarbon/ plasmas
DE102020131832A1 (en) 2020-12-01 2022-06-02 Universität Kassel, Körperschaft des öffentlichen Rechts Process for the manufacture of casting molds or casting cores

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FR2631258B1 (en) 1991-04-05
NO173921B (en) 1993-11-15
FR2631258A1 (en) 1989-11-17
NO173921C (en) 1994-02-23
NO891827D0 (en) 1989-05-03
NO891827L (en) 1989-11-13
JPH0252084A (en) 1990-02-21
DK226989D0 (en) 1989-05-09
DK226989A (en) 1989-11-11
CN1038036A (en) 1989-12-20
ZA893473B (en) 1990-01-31

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