EP0114280A2 - Method of manufacturing abrasive bodies - Google Patents
Method of manufacturing abrasive bodies Download PDFInfo
- Publication number
- EP0114280A2 EP0114280A2 EP83112342A EP83112342A EP0114280A2 EP 0114280 A2 EP0114280 A2 EP 0114280A2 EP 83112342 A EP83112342 A EP 83112342A EP 83112342 A EP83112342 A EP 83112342A EP 0114280 A2 EP0114280 A2 EP 0114280A2
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- Prior art keywords
- binder
- synthetic resin
- fillers
- grinding
- additives
- 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.)
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Classifications
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B24—GRINDING; POLISHING
- B24D—TOOLS FOR GRINDING, BUFFING OR SHARPENING
- B24D3/00—Physical features of abrasive bodies, or sheets, e.g. abrasive surfaces of special nature; Abrasive bodies or sheets characterised by their constituents
- B24D3/34—Physical features of abrasive bodies, or sheets, e.g. abrasive surfaces of special nature; Abrasive bodies or sheets characterised by their constituents characterised by additives enhancing special physical properties, e.g. wear resistance, electric conductivity, self-cleaning properties
- B24D3/342—Physical features of abrasive bodies, or sheets, e.g. abrasive surfaces of special nature; Abrasive bodies or sheets characterised by their constituents characterised by additives enhancing special physical properties, e.g. wear resistance, electric conductivity, self-cleaning properties incorporated in the bonding agent
- B24D3/344—Physical features of abrasive bodies, or sheets, e.g. abrasive surfaces of special nature; Abrasive bodies or sheets characterised by their constituents characterised by additives enhancing special physical properties, e.g. wear resistance, electric conductivity, self-cleaning properties incorporated in the bonding agent the bonding agent being organic
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B24—GRINDING; POLISHING
- B24D—TOOLS FOR GRINDING, BUFFING OR SHARPENING
- B24D3/00—Physical features of abrasive bodies, or sheets, e.g. abrasive surfaces of special nature; Abrasive bodies or sheets characterised by their constituents
- B24D3/02—Physical features of abrasive bodies, or sheets, e.g. abrasive surfaces of special nature; Abrasive bodies or sheets characterised by their constituents the constituent being used as bonding agent
- B24D3/20—Physical features of abrasive bodies, or sheets, e.g. abrasive surfaces of special nature; Abrasive bodies or sheets characterised by their constituents the constituent being used as bonding agent and being essentially organic
- B24D3/28—Resins or natural or synthetic macromolecular compounds
Definitions
- the invention relates to a method for producing grinding wheels in a casting mold, using a cold-curing synthetic resin as a binder in an abrasive grain-binder mixture, to which additives are optionally added.
- Such methods are used to manufacture hard abrasive grits, i.e. Grinding wheels, slip rings, cups, honing tools etc.
- the known hard abrasives are made using ceramic, phenolic, magnesite or epoxy binders (the less frequently used binders such as metal-silicate-polyester and others are not considered).
- Ceramic bonded abrasives are mainly used in precision grinding. Their production is complex because of the multi-day burning at temperatures above 90C P C. In addition, because of the warping that occurs during firing, these bodies must be provided with a considerable excess, which necessitates appropriate reworking.
- the phenolic resin bond is based on the simultaneous use of phenolic resoles and novolaks.
- curing for up to two days at temperatures around 175C is also an environmental burden in that considerable amounts of free phenol, formaldehyde and ammonia are released in addition to water.
- free phenol, formaldehyde and ammonia are released in addition to water.
- the structure of the abrasive body is porous, namely highly porous in the coarse grain area and less porous in the fine area. It is difficult, if not impossible, to adjust the abrasive grain density to the respective use with such abrasives over the entire grain spectrum and to provide a sufficient chip gap volume, particularly in the fine and very fine grain range.
- the phenolic resin bond has the disadvantage that it is not very resistant to the alkaline coolants, which is why this bond is mainly used only in dry grinding.
- abrasive particles in magnesite bond are cast and therefore tight, i.e. practically non-porous. Nevertheless, they offer an extremely cool cut, especially for hardened steels with high stock removal rates. That is why such grinding tools are primarily used for grinding knives, scissors, pliers and other tools, the ends of spiral springs, etc.
- magnesite bonded abrasives are manifold. So they are only approved for working speeds up to 20 m / sec, furthermore they change their hardness over time, so that they only work optimally in the period from 1 month to 4 months after production can be used.
- a significant disadvantage is the magnesium chloride liberated during grinding, which leads to severe corrosion, in particular to the protective hoods of the machines, and represents a considerable waste water load.
- epoxy resin bonding has become increasingly popular in the past few years, particularly in the cutlery industry with lower stock removal rates and in the fine grain area.
- a handicap of epoxy resins is their high viscosity. Base resins with a high proportion of reactive thinners are available with viscosities of approx. 1000 mPa.s, but because of the thinning they show insufficient heat resistance. That is why such abrasives always compromise between just enough castability, resin content (which is inevitably 40% by weight and higher), heat resistance and performance. Because of these necessary compromises with regard to heat resistance, such grinding tools can only be used in wet grinding.
- the invention solves this problem by using a synthetic resin with a dynamic viscosity of 1-10 mPa.s as the binder and adding a radical-forming starter system to the resin and / or the additives in a manner known per se.
- the abrasive grain / filler / binder mixtures are highly thixotropic due to their composition according to the invention and can be easily liquefied by vibration. Your consistency. is under appropriate vibration such that they easily pass the outlet of a funnel and fill even complex molds cleanly. It is possible, for example, to manufacture cup wheels with a wall thickness of only 3 mm and a cup diameter of 250 mm, which is not possible with the binders known to date.
- the addition of the starter system can be metered in such a way that a sufficient pot life is achieved, but the hardened grinding wheel can be removed from the mold no later than two hours after the start of filling and the hardening takes place essentially at room temperature. Only in the case of small grinding wheels, where the large relative mold volume inevitably absorbs a lot of reaction heat compared to the small relative grinding wheel volume, it is advisable to warm the molds to 60 ° C briefly before or after filling.
- the starter system expediently consists of an organic peroxide and an aromatic tertiary amine. It has proven advantageous to add a powdered organic peroxide to polymeric methacrylate and to dissolve the aromatic tertiary amine in the binder.
- the hardening shrinkage of the abrasive articles produced according to the invention is extremely low and averages 0.02%. This fact makes it possible to design the respective shape in such a way that the parts of the grinding wheel which are in contact with the shape are no longer machined. This even applies to the bore, provided the bore mandrel has a correspondingly small oversize. Compared to the known methods, considerable manufacturing costs can be saved.
- the abrasive bodies show practically no imbalance and no differences in density or hardness within the finished body, provided that the casting mold is geometrically perfect.
- the abrasive article produced according to the invention competes in various areas of metal-cutting surface processing with ceramic, phenolic resin, magnesite and epoxy resin bonding.
- the table below gives an overview of the relevant conditions for the manufacture and use of the various grinding tools, with a plus sign representing a positive rating and a minus sign representing a negative rating. From this compilation, the overall positive properties of the method according to the invention compared to the known methods are clear.
- thermoplastics can also be used for the production of hard abrasive articles, the polymerization being carried out from the monomer in the abrasive article mixture in the casting mold, the monomers optionally being stabilized with 3 to 20 ppm hydroquinone or other.
- monomers are mainly methacrylic acid esters and / or vinyl acetate in question, other monomers are conceivable alone or as an additive, but it must be taken into account that some of the other monomers in question are unsafe in terms of work hygiene.
- the binder according to the invention expediently contains bifunctional or trifunctional methacrylates as crossing agents.
- Fillers are necessary to create the necessary chip gap volume and to enable polymerization at all. On the one hand, these fillers must be softer than the materials to be machined, but on the other hand they must be so pressure-resistant that they fix the grinding bodies rigidly and give the grinding body as a whole the necessary hardness.
- Fillers with a Mohs hardness of less than 6 or a Knoop hardness of less than 500 are available here, are available in various grades and are environmentally friendly and may refine the grinding pattern created by the abrasive grain as a polishing agent.
- the granulometric composition of the abrasive grain-filler combination should essentially correspond to the respective fuller curve. This ensures that the inorganic constituents are packed as densely as possible.
- the fuller curve begins, for example, in the range from 150 to 60 ⁇ m with a filler which is neutral in grinding, the range from 60 to 20 ⁇ m with the 280 F abrasive grain, and subsequently from 20 to 2 ⁇ m again a grinding-neutral filler. It is expedient that the fillers are surface-treated, primarily in the fine range 20 ... 2 ⁇ m.
- the extensive setting of the fuller curve corresponding to the respective abrasive grain size makes it possible to keep the binder content relatively low, in extreme cases 8% or 20% by volume.
- the binder content is 16% by weight or 40% by volume.
- the "hardness” can be adjusted to the respective use in a similar way to that of the abrasive bodies of hard bonds, where one also speaks of “hard” and “soft” ceramic or Bakelite discs. Here is more with the “hardness” or less the strength of the grain binding meant.
- glass fabrics or rovings as reinforcing materials is also possible.
- atmospheric oxygen inhibits the polymerization, the abrasive articles according to the invention must be essentially leakproof.
- grinding heat-sensitive steels it can be useful to create a more open surface of the grinding wheel to take away more water-based coolant. This is achieved very well by adding water-soluble powder substances.
- ground water glass is ideal, which not only has a corrosion-inhibiting effect, but is also environmentally friendly and does not impair the coolant.
- All known types can be used as abrasive grain, i.e. glass, flint, garnet, the various corundums, silicon carbide, etc., alone or as a mixture. As already mentioned, all grain sizes are possible, for example from 8 - 1200 according to FEPA.
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- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Polishing Bodies And Polishing Tools (AREA)
- Finish Polishing, Edge Sharpening, And Grinding By Specific Grinding Devices (AREA)
Abstract
Description
Die Erfindung betrifft ein Verfahren zur Herstellung von Schleifkörpern in einer Gießform, unter Verwendung eines kalthärtenden Kunstharzes als Bindemittel in einem Schleifkorn-Bindemittel-Gemisch, dem gegebenenfalls Zuschlagstoffe zugesetzt sind.The invention relates to a method for producing grinding wheels in a casting mold, using a cold-curing synthetic resin as a binder in an abrasive grain-binder mixture, to which additives are optionally added.
Derartige Verfahren werden zur Herstellung von harten Schleifkörpem eingesetzt, d.h. Schleifscheiben, Schleifringe, Schleiftöpfe, Honwerkzeuge usw.Such methods are used to manufacture hard abrasive grits, i.e. Grinding wheels, slip rings, cups, honing tools etc.
In der Schleifmittel herstellenden Industrie wird die Auffassung vertreten, daß als Bindemittel für derartige harte Schleifkörper ("hart" hier im Gegensatz zu elastomer) mit hohen Abtragsleistungen nur anorganische oder duroplastische mit hoher wärmebeständigkeit infrage kommen wegen der beim Schleifen, auch unter Kühlung auftretenden Temperaturen.In the abrasive manufacturing industry, the view is taken that only inorganic or thermosetting plastics with high heat resistance can be considered as binders for such hard abrasive bodies ("hard" here in contrast to elastomeric) with high removal rates because of the temperatures that occur during grinding, even under cooling.
Die bekannten, harten Schleifkörper werden hergestellt unter Verwendung von keramischen, Phenolharz-, Magnesit- oder Epoxidharz Bindemitteln (die seltener eingesetzten Bindemittel wie Metall- Silikat-Polyester- und andere bleiben außer Betracht).The known hard abrasives are made using ceramic, phenolic, magnesite or epoxy binders (the less frequently used binders such as metal-silicate-polyester and others are not considered).
Keramisch gebundene Schleifkörper finden hauptsächlich im Präzisionsschliff Anwendung. Ihre Herstellung ist wegen des mehrtägigen Brennens bei Temperaturen über 90CP C aufwendig. Darüber hinaus müssen diese Körper wegen des beim Brennen eintretenden Verzugs mit erheblichem Übermaß versehen werden, was eine entsprechende Nacharbeit notwendig macht.Ceramic bonded abrasives are mainly used in precision grinding. Their production is complex because of the multi-day burning at temperatures above 90C P C. In addition, because of the warping that occurs during firing, these bodies must be provided with a considerable excess, which necessitates appropriate reworking.
Die Phenolharzbindung geht von der gleichzeitigen Verwendung von Phenolresolen und -novolaken aus. Abgesehen von den notwendigen arbeitshygienischen Maßnahmen bei der Herstellung stellt auch das bis zu zwei Tage dauernde Härten bei Temperaturen um 175C eine Umweltbelastung dar insofern, als hierbei erhebliche Mengen an freiem Phenol, an Formaldehyd und Ammoniak neben Wasser freigesetzt werden. Beim Reinigen der Mischer gelangen solche Stoffe auch zusammen mit den Lösungsmitteln ins Abwasser, was eine aufwendige Reinigung notwendig macht.The phenolic resin bond is based on the simultaneous use of phenolic resoles and novolaks. In addition to the necessary work hygiene measures during production, curing for up to two days at temperatures around 175C is also an environmental burden in that considerable amounts of free phenol, formaldehyde and ammonia are released in addition to water. When cleaning the mixer, such substances also get into the wastewater together with the solvents, which makes complex cleaning necessary.
Beiden vorstehend beschreibenden Bindungsarten ist eigen, daß die Struktur des Schleifkörpers porös ist, und zwar stark porös im groben Kornbereich und wenig porös im Feinbereich. Es ist schwierig wenn nicht unmöglich, bei solchen Schleifkörpern über das gesamte Körnungsspektrum hinweg die Schleifkorndichte auf die jeweilige Verwendung einzustellen und besonders im Fein- und Feinstkombereich ein ausreichendes Spanlückenvolumen bereitzustellen.It is a feature of both types of bond described above that the structure of the abrasive body is porous, namely highly porous in the coarse grain area and less porous in the fine area. It is difficult, if not impossible, to adjust the abrasive grain density to the respective use with such abrasives over the entire grain spectrum and to provide a sufficient chip gap volume, particularly in the fine and very fine grain range.
Darüber hinaus hat die Phenolharzbindung den Nachteil, daß sie wenig beständig ist gegen die alkalischen Kühlmittel, weshalb diese Bindung hauptsächlich nur im Trockenschliff eingesetzt wird.In addition, the phenolic resin bond has the disadvantage that it is not very resistant to the alkaline coolants, which is why this bond is mainly used only in dry grinding.
Schleifkörper in Magnesitbindung sind im Gegensatz zu solchen in keramischer oder Phenolharzbindung, gegossen und damit dicht, d.h. praktisch porenfrei. Trotzdem bieten sie gerade bei gehärteten Stählen bei hohen Abtragsleistungen einen extrem kühlen Schliff. Deshalb werden solche Schleifkörper vornehmlich eingesetzt zum Schleifen von Messern, Scheren, Zangen und anderen Werkzeugen, den Enden von Spiralfedern u.a.In contrast to those in ceramic or phenolic resin bond, abrasive particles in magnesite bond are cast and therefore tight, i.e. practically non-porous. Nevertheless, they offer an extremely cool cut, especially for hardened steels with high stock removal rates. That is why such grinding tools are primarily used for grinding knives, scissors, pliers and other tools, the ends of spiral springs, etc.
Die Nachteile der Schleifkörper in Magnesitbindung sind mannigfach. So sind sie nur für Arbeitsumfanggeschwindigkeiten bis zu 20 m/sec zugelassen, ferner ändern sie ihre Härte mit der Zeit, so daß sie nur im Zeitraum von 1 Monat bis 4 Monate nach der Herstellung optimal eingesetzt werden können. Ein bedeutender Nachteil ist das beim Schleifen freiwerdende Magnesium-Chlorid, welches zu starker Korrosion, insbesondere der Schutzhauben der Maschinen, führt und eine erhebliche Abwasserbelastung darstellt.The disadvantages of magnesite bonded abrasives are manifold. So they are only approved for working speeds up to 20 m / sec, furthermore they change their hardness over time, so that they only work optimally in the period from 1 month to 4 months after production can be used. A significant disadvantage is the magnesium chloride liberated during grinding, which leads to severe corrosion, in particular to the protective hoods of the machines, and represents a considerable waste water load.
Wegen dieser Nachteile der Magnesitbindung führte sich in den letzten Jahren zunehmend die Epoxidharzbindung ein, besonders in der Schneidwarenindustrie bei geringeren Abtragsleistungen und im Feinkornbereich. Ein Handikap der Epoxidharze ist ihre hohe Viskosität. Basisharze mit hohem Anteil an reaktiven Verdünner sind zwar mit Viskositäten von ca. 1000 mPa.s erhältlich, zeigen jedoch wegen der Verdünnung eine unzureichende Wärmebeständigkeit. Darum stellen solche Schleifkörper immer einen Kompromiß dar zwischen noch eben ausreichender Gießfähigkeit, Harzanteil (der zwangsläufig bei 40 Gew% und höher liegt), wärmebeständigkeit und Leistung. Wegen dieser notwendigen Kompromisse hinsichtlich der Wärmebeständigkeit können solche Schleifkörper nur im Naßschliff eingesetzt werden.Because of these disadvantages of magnesite bonding, epoxy resin bonding has become increasingly popular in the past few years, particularly in the cutlery industry with lower stock removal rates and in the fine grain area. A handicap of epoxy resins is their high viscosity. Base resins with a high proportion of reactive thinners are available with viscosities of approx. 1000 mPa.s, but because of the thinning they show insufficient heat resistance. That is why such abrasives always compromise between just enough castability, resin content (which is inevitably 40% by weight and higher), heat resistance and performance. Because of these necessary compromises with regard to heat resistance, such grinding tools can only be used in wet grinding.
Hinzu kommen die bei den zumeist kalthärtenden Harzsystemen durch die organischen Amine, Epichlorhydrinreste und Reaktivverdünner im Epoxidharz bestehenden arbeitshygienischen Gefahren.Added to this are the occupational hygiene risks associated with the mostly cold-curing resin systems due to the organic amines, epichlorohydrin residues and reactive thinners in the epoxy resin.
Der Rohstoffeinsatz und die damit verbundenen Kosten sind für Schleifkörper mit Epoxidharzbindung sehr' hoch.The use of raw materials and the associated costs are very high for grinding wheels with epoxy resin bond.
Es ist daher Aufgabe der Erfindung, das gattungsgemäße Verfahren so weiterzuentwickeln, daß ein vielseitiger einsetzbarer Schleifkörper einfacher und kostengünstiger herzustellen ist.It is therefore an object of the invention to further develop the generic method so that a versatile grinding wheel is easier and cheaper to manufacture.
Diese Aufgabe löst die Erfindung dadurch, daß als Bindemittel ein Kunstharz mit einer dynamischen Viskosität von 1-10 mPa.s verwendet wird und dem Harz und/oder den Zuschlagstoffen in an sich bekannter Weise ein Radikale bildendes Startersystem zugesetzt wird.The invention solves this problem by using a synthetic resin with a dynamic viscosity of 1-10 mPa.s as the binder and adding a radical-forming starter system to the resin and / or the additives in a manner known per se.
Die Schleifkorn- Füllstoff- Bindemittelmischungen sind auf Grund ihrer erfindungsgemäßen Zusammensetzung stark thixotrop und lassen sich durch Vibration leicht verflüssigen. Ihre Konsistenz. ist unter entsprechender Vibration derart, daß sie den Auslauf eines Trichters leicht passieren und auch komplizierte Gießformen sauber ausfüllen. Dabei ist es beispielsweise möglich, Schleiftöpfe mit einer Wandstärke von nur 3mm bei einem Topfdurchmesser von 250 mm herzustellen, was mit den bisher bekannten Bindemitteln nicht möglich ist.The abrasive grain / filler / binder mixtures are highly thixotropic due to their composition according to the invention and can be easily liquefied by vibration. Your consistency. is under appropriate vibration such that they easily pass the outlet of a funnel and fill even complex molds cleanly. It is possible, for example, to manufacture cup wheels with a wall thickness of only 3 mm and a cup diameter of 250 mm, which is not possible with the binders known to date.
Der Zusatz des Startersystems kann so dosiert werden, daß eine ausreichende Topfzeit erzielt wird, die Entformung des ausgehärteten Schleifkörpers jedoch spätestens zwei Stunden nach Beginn der Befüllung erfolgen kann und die Aushärtung im wesentlichen bei Raumtemperatur erfolgt. Nur im Falle kleiner Schleifkörper, wo zwangsläufig das große relative Formvolumen gegenüber dem kleinen relativen Schleifkörpervolumen viel Reaktionswärme aufnimmt, ist es zweckmäßig, die Formen vor dem Befüllen oder nachher kurz auf 60°C aufzuwärmen.The addition of the starter system can be metered in such a way that a sufficient pot life is achieved, but the hardened grinding wheel can be removed from the mold no later than two hours after the start of filling and the hardening takes place essentially at room temperature. Only in the case of small grinding wheels, where the large relative mold volume inevitably absorbs a lot of reaction heat compared to the small relative grinding wheel volume, it is advisable to warm the molds to 60 ° C briefly before or after filling.
Das Startersystem besteht zweckmäßigerweise aus einem organischen Peroxid und einem aromatischen tertiären Amin. Hierbei hat es sich als günstig erwiesen, ein pulverförmiges organisches Peroxid polymerem Methacrylat beizumischen und das aromatische tertiäre Amin im Bindemittel zu lösen.The starter system expediently consists of an organic peroxide and an aromatic tertiary amine. It has proven advantageous to add a powdered organic peroxide to polymeric methacrylate and to dissolve the aromatic tertiary amine in the binder.
Der Härtungsschrumpf der erfindungsgemäß hergestellten Schleifkörper ist außerordentlich gering und beträgt im Durchschnitt 0,02%. Diese Tatsache gestattet es, die jeweilige Form so zu gestalten, daß die der Form anliegenden Teile des Schleifkörpers nicht mehr bearbeitet werden messen. Dies gilt selbst für die Bohrung, sofern der Bohrungsdorn ein entsprechend geringes Übermaß hat. So sind gegenüber den bekannten Verfahren erhebliche Herstellungskosten einsparbar.The hardening shrinkage of the abrasive articles produced according to the invention is extremely low and averages 0.02%. This fact makes it possible to design the respective shape in such a way that the parts of the grinding wheel which are in contact with the shape are no longer machined. This even applies to the bore, provided the bore mandrel has a correspondingly small oversize. Compared to the known methods, considerable manufacturing costs can be saved.
Wegen des geringen Härtungsschrurrpfes ist es auch sehr gut möglich, Metallteile direkt zu integrieren. Hierbei kann es sich um Verstärkungen handeln wie auch um Gewindebuchsen, Schäfte bei Kleinschleifkörpern usw.Because of the low hardening shrinkage, it is also very possible to integrate metal parts directly. These can be reinforcements as well as threaded bushings, shanks for small grinding wheels, etc.
Auf Grund der erfindungsgemäßen Herstellung zeigen die Schleifkörper praktisch keine Unwucht und keine Dichte- bzw. Härteunterschiede innerhalb des fertigen Körpers, sofern die Gießform geometrisch einwandfrei ist.On account of the production according to the invention, the abrasive bodies show practically no imbalance and no differences in density or hardness within the finished body, provided that the casting mold is geometrically perfect.
Der erfindungsgemäß hergestellte Schleifkörper tritt in verschiedenen Bereichen der spangebenden Oberflächenbearbeitung in Konkurrenz zur keramischen, Phenolharz-, Magnesit- und Epoxidharzbindung. In der beigefügten Tabelle wird eine Übersicht über die relevanten Bedingungen bei Herstellung und Anwendung der verschiedenen Schleifkörper gegeben, wobei ein Pluszeichen .eine positive Bewertung und ein Minuszeichen eine negative Bewertung darstellt. Aus dieser Zusammenstellung gehen die insgesamt positiven Eigenschaften des erfindungsgemäßen Verfahrens gegenüber den bekannten Verfahren deutlich hervor.The abrasive article produced according to the invention competes in various areas of metal-cutting surface processing with ceramic, phenolic resin, magnesite and epoxy resin bonding. The table below gives an overview of the relevant conditions for the manufacture and use of the various grinding tools, with a plus sign representing a positive rating and a minus sign representing a negative rating. From this compilation, the overall positive properties of the method according to the invention compared to the known methods are clear.
Überraschenderweise hat sich ferner ergeben, daß zur Herstellung harter Schleifkörper auch Thermoplaste verwendbar sind, wobei die Polymerisation vom Monomer aus in der Schleifkörpermischung in der Gießform erfolgt, wobei die Monomere gegebenenfalls mit 3 bis 20 ppm Hydrochinon oder anderem stabilisiert sind. Als solche Monomere kommen in der Hauptsache Methacrylsäureester und/oder Vinylacetat in Frage, andere Monomere sind allein oder als Zusatz denkbar, wobei jedoch berücksichtigt werden muß, daß einige der anderen in Frage kommenden Monomere arbeitshygienisch bedenklich sind.Surprisingly, it has also been found that thermoplastics can also be used for the production of hard abrasive articles, the polymerization being carried out from the monomer in the abrasive article mixture in the casting mold, the monomers optionally being stabilized with 3 to 20 ppm hydroquinone or other. As such monomers are mainly methacrylic acid esters and / or vinyl acetate in question, other monomers are conceivable alone or as an additive, but it must be taken into account that some of the other monomers in question are unsafe in terms of work hygiene.
Das erfindungsgemäße Bindemittel enthält zweckmäßigerweise bi- oder trifunktionelle Methacrylate als crossing agens.The binder according to the invention expediently contains bifunctional or trifunctional methacrylates as crossing agents.
Zur Schaffung des notwendigen Spanlückenvolumens und zur Ermöglichung der Polymerisation überhaupt sind Füllstoffe notwendig. Diese Füllstoffe müssen einerseits weicher sein als die zu bearbeitenden Werkstoffe, andererseits aber so druckfest, daß sie die Schleifkörper starr fixieren und dem Schleifkörper als Ganzes die notwendige Härte geben.Fillers are necessary to create the necessary chip gap volume and to enable polymerization at all. On the one hand, these fillers must be softer than the materials to be machined, but on the other hand they must be so pressure-resistant that they fix the grinding bodies rigidly and give the grinding body as a whole the necessary hardness.
Hier bieten sich solche Füllstoffe an, die eine Härte nach Mohs von unter 6 bzw. nach Knoop von unter 500 besitzen, in verschiedenen Körnungsabstufungen erhältlich und umweltfreundlich sind und die evtl. das durch das Schleifkorn erzeugte Schliffbild als Poliermittel verfeinern. Hier kommen bevorzugt wasserunlösliche Kalziumverbindungen in Betracht wie Calcit, Dolomit, Aragonit, Gips, Selenit und/oder Estrichgips.Fillers with a Mohs hardness of less than 6 or a Knoop hardness of less than 500 are available here, are available in various grades and are environmentally friendly and may refine the grinding pattern created by the abrasive grain as a polishing agent. Water-insoluble calcium compounds, such as calcite, dolomite, aragonite, gypsum, selenite and / or screed gypsum, are preferred here.
Zur Minimierung des Bindemittelbedarfs und zur gleichzeitigen optimalen Stützung und starren Fixierung des Schleifkorns sollte die granulometrische Zusammensetzung der Schleifkorn-Füllstoff-Kombination, bezogen auf das Volumen, im wesentlichen der jeweiligen Fullerkurve entsprechen. Damit ist eine möglichst dichte Packung der anorganischen Bestandteile gegeben.In order to minimize the need for binding agents and at the same time to optimally support and rigidly fix the abrasive grain, the granulometric composition of the abrasive grain-filler combination, based on the volume, should essentially correspond to the respective fuller curve. This ensures that the inorganic constituents are packed as densely as possible.
Es kann sich hierbei durchaus als nützlich erweisen, daß die Fullerkurve beispielsweise im Bereich von 150...60 µm mit einem schleifneutralgen Füllstoff beginnt, der Bereich 60...20 µm das Schleifkorn 280 F, und nachfolgend von 20...2 µm wiederum ein schleifneutraler Füllstoff. Zweckmäßig ist es, daß, vornehmlich im Feinbereich 20...2 µm, die Füllstoffe oberflächenbehandelt sind.It can prove to be useful here that the fuller curve begins, for example, in the range from 150 to 60 μm with a filler which is neutral in grinding, the range from 60 to 20 μm with the 280 F abrasive grain, and subsequently from 20 to 2 μm again a grinding-neutral filler. It is expedient that the fillers are surface-treated, primarily in the fine range 20 ... 2 µm.
Die weitgehende Einstellung der der jeweiligen Schleifkorngröße entsprechenden Fullerkurve ermöglicht es, den Bindemittelgehalt relativ niedrig zu halten, im Extremfall bei 8 Gew% bzw. 20 Vol%. Im Bereich mittlerer "Härte" liegt der Bindemittelgehalt bei 16 Gew% bzw. 40 Vol%. Hiermit soll gesagt werden, daß sich die "Härte" hier ähnlich auf die jeweilige Verwendung einstellen läßt, wie bei den Schleifkörpern harter Bindungen, wo man auch von "harten" und "weichen" keramischen oder Bakelitescheiben spricht. Hier ist mit der "Härte" mehr oder weniger die Festigkeit der Korneinbindung gemeint.The extensive setting of the fuller curve corresponding to the respective abrasive grain size makes it possible to keep the binder content relatively low, in extreme cases 8% or 20% by volume. In the medium "hardness" range, the binder content is 16% by weight or 40% by volume. Hereby it should be said that the "hardness" can be adjusted to the respective use in a similar way to that of the abrasive bodies of hard bonds, where one also speaks of "hard" and "soft" ceramic or Bakelite discs. Here is more with the "hardness" or less the strength of the grain binding meant.
Wie bei den bekannten Schleifkörpern, beispielsweise in Phenolharzbindung, üblich, ist es auch bei der erfindungsgemäßen Mischung möglich, diese durch Zusatzstoffe zu modifizieren. Hierher gehören z.B. Schleifhilfsmittel wie Kryolith, Pyrit oder ähnliche, sofern sie bei der Berechnung der Fullerkurve berücksichtigt werden.As is customary in the case of the known grinding wheels, for example in a phenolic resin bond, it is also possible with the mixture according to the invention to modify it by means of additives. This subheading includes Grinding aids such as cryolite, pyrite or similar, provided that they are taken into account when calculating the fuller curve.
Beim Trockenschliff läßt sich das Zusetzen der Schleiffläche unterdrücken durch Zusatz entsprechender Metall- oder Aminseifen. Auch hier ist die Fullerkurve zu beachten.With dry sanding, the clogging of the sanding surface can be suppressed by adding appropriate metal or amine soaps. The fuller curve must also be observed here.
Entsprechendes gilt, falls kurze Glas- oder Kohlenstoff-Fasern zugesetzt werden zur Erhöhung der zulässigen Arbeitsumfangsgeschwindigkeit. Selbstverständlich ist auch der Einsatz von Glasgeweben oder -rovings als Verstärkungsstoffe möglich. Da Luftsauerstoff die Polymerisation inhibiert, müssen die erfindungsgemäßen Schleifkörper im wesentlichen dicht sein. Beim Schleifen wärmeempfindlicher Stähle kann es aber nützlich sein, zur verstärkten Mitnahme von Kühlmittel auf wässriger Basis eine offenere Oberfläche des Schleifkörpers zu erzeugen. Dies gelingt sehr gut durch den Zusatz wasserlöslicher Pulverstoffe. Hier bietet sich hervorragend gemahlenes Wasserglas an, welches nicht nur korrosionsinhibierend wirkt, sondern auch umweltfreundlich ist und die Kühlmittel nicht beeinträchtigt.The same applies if short glass or carbon fibers are added to increase the permissible scope of work. Of course, the use of glass fabrics or rovings as reinforcing materials is also possible. Since atmospheric oxygen inhibits the polymerization, the abrasive articles according to the invention must be essentially leakproof. When grinding heat-sensitive steels, however, it can be useful to create a more open surface of the grinding wheel to take away more water-based coolant. This is achieved very well by adding water-soluble powder substances. Here, ground water glass is ideal, which not only has a corrosion-inhibiting effect, but is also environmentally friendly and does not impair the coolant.
Als Schleifkorn kommen alle bekannten Arten in Frage, also Glas, Flint, Granat, die verschiedenen Korunde, Siliciumkarbid u.a., für sich allein oder in Mischung. Wie bereits erwähnt, sind alle Kömungsgrößen möglich, nach FEPA also beispielsweise von 8 - 1200.All known types can be used as abrasive grain, i.e. glass, flint, garnet, the various corundums, silicon carbide, etc., alone or as a mixture. As already mentioned, all grain sizes are possible, for example from 8 - 1200 according to FEPA.
Claims (8)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| AT83112342T ATE45908T1 (en) | 1983-01-21 | 1983-12-08 | PROCESS FOR THE MANUFACTURE OF ABRASIVES. |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19833301925 DE3301925A1 (en) | 1983-01-21 | 1983-01-21 | METHOD FOR PRODUCING ABRASIVE BODIES |
| DE3301925 | 1983-10-21 |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| EP0114280A2 true EP0114280A2 (en) | 1984-08-01 |
| EP0114280A3 EP0114280A3 (en) | 1985-09-18 |
| EP0114280B1 EP0114280B1 (en) | 1989-08-30 |
Family
ID=6188838
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| EP83112342A Expired EP0114280B1 (en) | 1983-01-21 | 1983-12-08 | Method of manufacturing abrasive bodies |
Country Status (4)
| Country | Link |
|---|---|
| US (1) | US4541843A (en) |
| EP (1) | EP0114280B1 (en) |
| AT (1) | ATE45908T1 (en) |
| DE (2) | DE3301925A1 (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0242410A1 (en) * | 1986-04-17 | 1987-10-28 | Carborundum Schleifmittelwerke GmbH | Method of manufacturing an elastic grinding body |
| EP0285369A2 (en) * | 1987-04-02 | 1988-10-05 | Minnesota Mining And Manufacturing Company | Coated abrasive binder containing ternary photoinitiator system |
| EP0280756B1 (en) * | 1987-03-06 | 1990-06-27 | Carborundum Schleifmittelwerke GmbH | Process for improving the grinding efficiency of grinding and honing tools |
| EP0381662A2 (en) * | 1989-01-30 | 1990-08-08 | MAGINDAG Steirische Magnesit-Industrie Aktiengesellschaft | Process for the manufacture of abrasive bodies |
| DE19614401B4 (en) * | 1996-04-12 | 2004-08-19 | Saint-Gobain Diamantwerkzeuge Gmbh & Co. Kg | Base for grinding and honing tools |
| CN102699826A (en) * | 2012-06-16 | 2012-10-03 | 大连理工大学 | Soft grinding material sand wheel with bonding agent solidified at normal temperature |
Families Citing this family (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4681600A (en) * | 1984-09-05 | 1987-07-21 | Extrude Hone Corporation | Cutting tool fabrication process |
| US4736548A (en) * | 1986-02-11 | 1988-04-12 | Arkansas Hones, Inc. | Vitrified composite washita stone and process for producing same |
| US4662897A (en) * | 1986-02-11 | 1987-05-05 | Arkansas Hones Inc. | Vitrified composite novaculite and process for producing same |
| US5116392A (en) * | 1988-12-30 | 1992-05-26 | Tyrolit - Schleifmittelwerke Swarovski K.G. | Abrasive article and abrasive |
| US5209023A (en) * | 1990-05-18 | 1993-05-11 | Jerry Bizer | Thermoplastic polymer optical lap and method of making same |
| US5089032A (en) * | 1990-07-05 | 1992-02-18 | Moran Joseph F | Grinding wheel |
| NL9300927A (en) * | 1993-05-28 | 1994-12-16 | Terra Ijssel Bv | Method for processing waste materials and body obtained with the method. |
| NL9300919A (en) * | 1993-05-28 | 1994-12-16 | Terra Ijssel Bv | Method for processing waste materials. |
| DE9411326U1 (en) * | 1994-07-13 | 1994-09-15 | Zahnradpraezision Horst Reinek | Toothed honing tool |
| US5779529A (en) * | 1996-11-25 | 1998-07-14 | Bizer Industries | Thermoplastic optical lap with reinforced webbing |
| US6050573A (en) * | 1998-09-30 | 2000-04-18 | Kwikee Products Co., Inc. | Automatic leveling system for vehicles |
| JP2000351960A (en) * | 1999-06-10 | 2000-12-19 | Nisca Corp | Abrasive grain body for grinding |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2189733A (en) * | 1938-01-28 | 1940-02-06 | Norton Co | Resin bonded abrasive article |
| FR1194373A (en) * | 1959-11-09 | |||
| FR1257770A (en) * | 1960-02-24 | 1961-04-07 | Somata Sa | Abrasive product and its manufacturing process |
| DE2028891A1 (en) * | 1970-06-12 | 1971-12-16 | Gold U Silberscheideanstalt De | Abrasive articles - contng acrylic resins as binders |
| FR2242344A1 (en) * | 1973-08-30 | 1975-03-28 | Touati Roger | Mortar bonded with a urea resin - and set rapidly with vibration and-or centrifuging to give high strength |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2901337A (en) * | 1956-07-31 | 1959-08-25 | Union Carbide Corp | Abrasive articles and method of making the same |
| US2943926A (en) * | 1958-07-18 | 1960-07-05 | Cincinnati Milling Machine Co | Abrasive wheel composition |
| US3208836A (en) * | 1960-09-09 | 1965-09-28 | Borden Co | Cold press method of making abrasive articles |
| CH532452A (en) * | 1970-07-02 | 1973-01-15 | Esterol Ag | Process for the production of synthetic resin-bonded molded articles, in particular polyester-bonded abrasive articles |
| NL7013165A (en) * | 1970-09-05 | 1972-03-07 |
-
1983
- 1983-01-21 DE DE19833301925 patent/DE3301925A1/en not_active Withdrawn
- 1983-12-08 AT AT83112342T patent/ATE45908T1/en not_active IP Right Cessation
- 1983-12-08 DE DE8383112342T patent/DE3380484D1/en not_active Expired
- 1983-12-08 EP EP83112342A patent/EP0114280B1/en not_active Expired
-
1984
- 1984-01-20 US US06/572,544 patent/US4541843A/en not_active Expired - Fee Related
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR1194373A (en) * | 1959-11-09 | |||
| US2189733A (en) * | 1938-01-28 | 1940-02-06 | Norton Co | Resin bonded abrasive article |
| FR1257770A (en) * | 1960-02-24 | 1961-04-07 | Somata Sa | Abrasive product and its manufacturing process |
| DE2028891A1 (en) * | 1970-06-12 | 1971-12-16 | Gold U Silberscheideanstalt De | Abrasive articles - contng acrylic resins as binders |
| FR2242344A1 (en) * | 1973-08-30 | 1975-03-28 | Touati Roger | Mortar bonded with a urea resin - and set rapidly with vibration and-or centrifuging to give high strength |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0242410A1 (en) * | 1986-04-17 | 1987-10-28 | Carborundum Schleifmittelwerke GmbH | Method of manufacturing an elastic grinding body |
| EP0280756B1 (en) * | 1987-03-06 | 1990-06-27 | Carborundum Schleifmittelwerke GmbH | Process for improving the grinding efficiency of grinding and honing tools |
| EP0285369A2 (en) * | 1987-04-02 | 1988-10-05 | Minnesota Mining And Manufacturing Company | Coated abrasive binder containing ternary photoinitiator system |
| EP0285369A3 (en) * | 1987-04-02 | 1990-12-05 | Minnesota Mining And Manufacturing Company | Coated abrasive binder containing ternary photoinitiator system |
| EP0381662A2 (en) * | 1989-01-30 | 1990-08-08 | MAGINDAG Steirische Magnesit-Industrie Aktiengesellschaft | Process for the manufacture of abrasive bodies |
| EP0381662A3 (en) * | 1989-01-30 | 1990-09-26 | Magindag Steirische Magnesit-Industrie Aktiengesellschaft | Process for the manufacture of abrasive bodies |
| DE19614401B4 (en) * | 1996-04-12 | 2004-08-19 | Saint-Gobain Diamantwerkzeuge Gmbh & Co. Kg | Base for grinding and honing tools |
| CN102699826A (en) * | 2012-06-16 | 2012-10-03 | 大连理工大学 | Soft grinding material sand wheel with bonding agent solidified at normal temperature |
Also Published As
| Publication number | Publication date |
|---|---|
| DE3380484D1 (en) | 1989-10-05 |
| EP0114280A3 (en) | 1985-09-18 |
| ATE45908T1 (en) | 1989-09-15 |
| EP0114280B1 (en) | 1989-08-30 |
| US4541843A (en) | 1985-09-17 |
| DE3301925A1 (en) | 1984-07-26 |
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