WO2006125612A1 - Verfahren zur trocknung von wasserschlichten - Google Patents
Verfahren zur trocknung von wasserschlichten Download PDFInfo
- Publication number
- WO2006125612A1 WO2006125612A1 PCT/EP2006/004909 EP2006004909W WO2006125612A1 WO 2006125612 A1 WO2006125612 A1 WO 2006125612A1 EP 2006004909 W EP2006004909 W EP 2006004909W WO 2006125612 A1 WO2006125612 A1 WO 2006125612A1
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- WIPO (PCT)
- Prior art keywords
- water
- combustible liquid
- coating composition
- weight
- based coating
- Prior art date
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Classifications
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22C—FOUNDRY MOULDING
- B22C9/00—Moulds or cores; Moulding processes
- B22C9/12—Treating moulds or cores, e.g. drying, hardening
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22C—FOUNDRY MOULDING
- B22C3/00—Selection of compositions for coating the surfaces of moulds, cores, or patterns
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22C—FOUNDRY MOULDING
- B22C1/00—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22C—FOUNDRY MOULDING
- B22C5/00—Machines or devices specially designed for dressing or handling the mould material so far as specially adapted for that purpose
- B22C5/08—Machines or devices specially designed for dressing or handling the mould material so far as specially adapted for that purpose by sprinkling, cooling, or drying
Definitions
- the present invention relates to a process for drying waterborne coating compositions (water sizing) without the use of drying aggregates.
- the present invention relates to a process for drying water-based coating compositions, comprising applying a combustible liquid to a coated, optionally-matted, waterborne coating composition and completely burning off the combustible liquid.
- Casting transforms molten bath materials into geometrically determined objects with specific workpiece properties.
- Most products of the iron and steel industry as well as the materials of the non-ferrous metal industry go through casting processes for the first shaping.
- a prerequisite for the production of castings is, among other things, the production of partly very complicated casting molds for receiving the melt.
- the casting molds are subdivided into lost molds, which usually consist of a mineral, refractory, granular base material with a binder and often still further various additives, eg to achieve good casting surfaces, and are destroyed after each casting, and permanent molds, each with a large Number of castings can be made.
- lost molds refractory, granular ground substance is predominantly washed, classified quartz sand, in certain cases also chromite, zircon and olivine sand are used.
- moldings based on fireclay, magnesite, sillimanite, corundum and others are used.
- the binders for the molding sands may be inorganic or organic in nature.
- Lost molds are predominantly made from bentonite-bonded molded materials for smaller molds or resin-bonded molded materials for larger molds, which must be mechanically compacted to achieve sufficient stability.
- cast iron, unalloyed and alloyed steels, as well as copper, aluminum, graphite, sintered metals and ceramic materials have proven successful as mold material for permanent molds.
- the permanent molding processes include the mold, printing, spinning and Continuous casting.
- a method for producing molds and cores of resin-bonded molding sand includes making a master mold from the foundry sand and applying a refractory inorganic ingredient-containing coating (mold coating), which is also called “sizing," at least to those Surfaces of the basic shape and / or the basic core which come into contact with the cast metal
- mold coating which is also called "sizing”
- the purpose of the coating compositions is to influence the molding surface, to improve the casting appearance, to metallurgically influence the casting and / or to avoid casting defects these coatings or sizing function to chemically isolate the mold from the molten metal during casting, thereby preventing any adhesion and allowing or facilitating subsequent separation of the mold and cast parts Mold and casting.
- a metal mold is exposed during the successive casting processes such thermal stresses that it is prematurely destroyed.
- the heat transfer can be used selectively to influence the cooling of the casting.
- metal parts such as cast iron
- the large-scale casting and the centrifugal casting process are used.
- enormous metallostatic pressures prevail on the mold and core, which are exposed to the temperature load for a very long time. Therefore, especially in this process, the sizing assumes a very exposed protective function in order to avoid penetration of the metal into the molding sand (penetration), cracking of the cores (sheet ribs) or reaction with the foundry sand (mineralization).
- the casting metal In centrifugal casting, the casting metal is filled into a rotating around its axis, tubular or annular mold in which it is formed under the action of centrifugal force, for example, to cans, rings and pipes. It is imperative that the casting be fully solidified before demolding so that a fairly long contact time between mold and casting is required.
- the mold In this case, the mold is coated with an insulating size in the form of a single-layer or multi-layer coating.
- the commonly used sizings contain as basic materials such as clays, quartz, kieselguhr, cristobalite, tridymite, aluminum silicate, zirconium silicate, mica, chamotte and also coke and graphite. These bases are the purportive portion of the sizings which cover the mold surface and close the pores against the penetration of the cast metal.
- the carrier liquid component (solvent component) of coating compositions or sizes usually comprises water or one or more volatile, preferably aliphatic alcohols or mixtures of alcohol (s) and water and optionally as further component one or more organic, volatile solvents which differ from the alcohols. Finishes whose carrier fluid consists mainly of water are commonly referred to as “water finishes.” Finishes whose carrier liquid consists mainly of alcohol or mixtures of alcohols are called “alcohol sizing.” Alcohol sizing often contains isopropanol as a carrier liquid for the coating components.
- Alcohol sizing often use isopropanol as a carrier liquid for Due to its low flash point of + 12 ° C, isopropanol is classified as a highly flammable liquid and compelling regulations governing its use are present in many countries.Isopropanol shows a tendency to burn violently and with high flame, so that if an alcohol sizing is applied to a mold or core and ignited, the flames spread rapidly over the surface of the mold or core from the point of ignition Alcohols of a Wegschlichte very difficult to control.
- alcohol sizing causes higher production costs than water sizing.
- the necessary burning is thus a very costly factor in all casting methods known today. Costs are accounted for by the significant energy consumption, and the investment and investment costs that are necessary and high-cost must be taken into account, and the burning-off must be carried out with great care, thus increasing labor costs. Since it is very difficult to control alcohol burn-off, small defects caused, for example, by too rapid burning of the alcohol sizing or rapid cooling of the flamed sizing, can increase the small initial cracks and micro-cracks during flaming to such an extent that at the end an unusable Form is present. This will increase scrap, which in turn increases production costs.
- An object of the present invention is to replace alcohol sizing, which are used in particular for average shape and core sizes, by water-sizing, and thus to reduce the amount of VOC to be removed. Another object of the present invention is to provide a water sizing drying process which does not require drying equipment.
- One aspect of the present invention relates to a process for drying waterborne coating compositions comprising
- the waterborne coating composition is applied to at least a portion of the surface of an uncoated casting mold.
- the waterborne coating composition is applied to at least a portion of the surface of the primer layer previously applied to at least a portion of the surface of an uncoated casting mold. It is also possible to use casting molds in which a priming layer is applied only on certain surface parts. Another embodiment of the present invention relates to the use of such molds wherein the waterborne coating composition is applied to at least a portion of the uncoated surface of the mold as well as to at least a portion of the surface of the primer layer.
- the main component of the carrier liquid of the water-based coating used in the present invention is water.
- the water-based coating composition comprises as particulate matter particulate refractory materials commonly used in foundry technology for the preparation of sizings and commonly used binders.
- the water-based coating composition comprises 20-79.9% by weight of water, 79.9-20% by weight of particle-like, refractory materials, 0.1-5% by weight of binder and 0-18% by weight of further additives such as other particulate materials, wetting agents, defoamers, dyes and pigments, biocides and dispersants, based on all components of the water-based coating composition.
- flammable liquids When flammable liquids are used in the present invention typically flammable liquids with a flash point of -60 ° C to 100 ° C, preferably from -20 0 C to 60 0 C.
- the combustible liquids are selected from commonly used combustible solvents, preferably from combustible, preferably aliphatic, alcohols, aliphatic, cycloaliphatic and aromatic hydrocarbons, esters of aliphatic carboxylic acids, ethers, ketones and mixtures thereof.
- the combustible liquid is preferably applied to the mold by spraying, in a preferred embodiment, the combustible liquid is ignited immediately after application and completely burned. In a further embodiment, additional combustible liquid is additionally sprayed on during the burning off.
- the waterborne coating composition may be applied in multiple layers.
- the individual applied layers can be individually dried by applying and completely burning off a combustible liquid according to the present invention before applying a next layer of water-based coating material.
- a plurality of mutually differing waterborne coating compositions may be applied to an uncoated or primed coating surface of a casting mold.
- the individual applied layers of the water-based coating compositions can be separated from one another with the same or differing flammable liquids according to the process according to the invention before the application of a further layer be dried.
- the layers of the water-based finishes can also be applied without drying each individual layer, with the finishing composite then being dried by application and subsequent burning off of a combustible liquid.
- the dried layer of the coating composition or layers of the coating compositions obtained after complete combustion of the combustible liquid preferably has a residual moisture content of less than 8%, preferably less than 6%, more preferably less than 5%, even more preferably less than 2%, most preferably less than 1%, determined according to CM by Riedel de Häen, Seelze.
- the water-based coating compositions which can be used in the present invention include, as main components, a solid component and a carrier liquid component.
- the main constituent of the solid component is formed by particulate refractory materials, the main constituent of the carrier liquid component being water.
- the solid component of the water-based coating composition comprises, as a main component, particulate refractory materials selected from the refractories commonly used for water-based finishes.
- particulate refractory materials which can be used in waterborne coating compositions in the present invention include diatomite, kaolins, calcined kaolins, kaolinite, metakaolinite, pyrophyllite, mica, zirconia, zirconium silicate (zircon, zircon, zircon, zircon, alumina), chamotte , Iron oxides, kyanite, bauxite, olivine, quartzes, talc, graphites and carbon blacks, as well as clays and minerals containing them.
- zirconium silicate zirconium flour
- bauxite bauxite
- MetakaoHnit pyrophyllite
- graphite hectorite
- bentonite attapulgite
- the water-based coating composition usually comprises 20-79.9 wt.%, Preferably 30-75 wt.%, More preferably 40-70 wt.%, Even more preferably 50-70 wt.%, And most preferably 60-70 wt. % of the particulate refractory materials.
- the coating compositions used in the present invention may further optionally further contain other particulate materials such as commonly used two-layer silicates and three-layer silicates such as attapulgite, serpentine, smectites such as saponite, montmorillonite, beidellite and nontronite, Vermiculite, illite and mica, in smaller amounts, for example, 0.5-4.0 wt.%, Preferably 1.0-2.0 wt.% Contain.
- particulate materials such as commonly used two-layer silicates and three-layer silicates such as attapulgite, serpentine, smectites such as saponite, montmorillonite, beidellite and nontronite, Vermiculite, illite and mica, in smaller amounts, for example, 0.5-4.0 wt.%, Preferably 1.0-2.0 wt.% Contain.
- Useful coating compositions may further optionally comprise one or more further components, such as e.g. Binders, wetting agents, defoamers, pigments, dyes, biocides and dispersants.
- Binders such as e.g. Binders, wetting agents, defoamers, pigments, dyes, biocides and dispersants.
- a binder is to allow binding of the ingredients of the sizing composition after drying the sizing applied to a casting mold.
- the binder cures irreversibly and thus provides an abrasion resistant coating on the mold.
- the abrasion resistance is of great importance for the finished coating, since the coating can be damaged in the absence of abrasion resistance.
- the binder should not be softened by atmospheric moisture.
- curing of the binder is carried out in a manner known per se. For example, in acrylate systems, curing can be accomplished using free radical generators that form, for example, under the irradiation of UV light.
- all binders which are conventionally used in aqueous systems can be used.
- the binder consists of a dispersion of an alkyd resin which is soluble in water.
- alkyd resins are unmodified water-dispersible alkyd resins based on a natural oil or its fatty acids with polyalcohols, as described, for example, in US Pat. No.
- binders are polyvinyl alcohols and polyvinyl acetate copolymers. The binders are preferably used in an amount of 0.1-5% by weight, more preferably 0.5-2% by weight, based on all components of the water-based coating.
- Wetting agents which may be used are preferably anionic and non-anionic surfactants of medium and high polarity (HSB value of 7 and higher) known to the person skilled in the art.
- An example of a wetting agent that can be used in the present invention is disodium dioctylsulfosuccinate.
- the wetting agents are preferably used in an amount of 0.01-1% by weight, more preferably 0.05-0.3% by weight, based on all the components of the water-based coating composition.
- Defoamers or antifoam agents are used to prevent foaming during preparation of the coating composition and application of same. Foaming on application of the sizing composition can result in uneven layer thickness and holes in the coating.
- defoamers for example, silicone or mineral oil can be used.
- defoamers are used in an amount of 0.01-1 wt%, more preferably 0.05-0.3 wt%.
- pigments and dyes may optionally be used. These are optionally added to provide a different contrast, e.g. between different layers, or to achieve a greater separation effect of the sizing of the casting.
- pigments are red and yellow iron oxide and graphite.
- dyes are commercially available dyes such as the Luconyl color series from BASF. The dyes and pigments are usually used in an amount of 0.01-10% by weight, preferably 0.1-5% by weight.
- Coating compositions whose carrier liquid mainly consists of water, so-called water sizing, are usually added biocides in order to prevent bacterial attack and thus to avoid a negative impact on the rheology and the binding force of the binding agents.
- biocides to be used are formaldehyde, 2-methyl-4-isothiazolin-3-one (MIT), 5-chloro-2-methyl-4-isotbiazolin-3-one (CIT) and 1,2-benzisothiazolin-3-one on (BIT).
- MIT, BIT or a mixture thereof are used.
- the biocides are usually used in an amount of 0.01-0.5 wt% or 10-1000 ppm, preferably 50-500 ppm.
- dispersants can be added to the water-based coating.
- the dispersants are preferably used in an amount of 0.01-1.5 wt%, more preferably 0.02-0.5 wt%.
- examples of dispersants which can be used are hexasodium tetrapolyphosphate or sodium polyacrylate.
- the proportion of water is preferably at least 80% by weight, more preferably at least 90% by weight, even more preferably at least 95% by weight and most preferably at least 97% by weight, based on all constituents of the carrier liquid component.
- the carrier liquid consists only of water.
- the coating composition contains 20-79.9 weight percent, more preferably 25-70 weight percent, even more preferably 30-50 weight percent, and most preferably 30-40 weight percent water, based on all ingredients the water-based coating.
- the carrier liquid component of the coating composition may further optionally contain as further component one or more organic volatile solvents, such as volatile, preferably aliphatic, aliphatic, cycloaliphatic or aromatic hydrocarbons, esters, ethers and ketones, which are commonly used as solvents, for example the solution of dispersants, binders, Netzmittehi, defoamers, dyes and biocides easier.
- organic volatile solvents such as volatile, preferably aliphatic, aliphatic, cycloaliphatic or aromatic hydrocarbons, esters, ethers and ketones, which are commonly used as solvents, for example the solution of dispersants, binders, Netzmittehi, defoamers, dyes and biocides easier.
- Ethanol, isopropanol, methoxypropanol, ethylene glycol, and aliphatic, isoaliphatic, cycloaliphatic and aromatic hydrocarbons are preferably used here.
- the carrier liquid component contains less than 20% by weight, preferably less than 10% by weight, more preferably less than 5% by weight, and most preferably less than 3% by weight of organic volatile solvents.
- the water-based coating composition preferably contains less than 5 wt%, more preferably less than 3 wt%, even more preferably less than 2 wt%, and most preferably less than 1 wt% or no organic solvents, based on all components of the water-based coating.
- a water-based coating composition contains, in addition to the particulate refractory materials, the following further components: 0.02-0.5% by weight of dispersant,
- binder 0.5-3.0% by weight of binder
- coating compositions based on water can be used, as described in the German patent application with the file reference 10 2004 060 649.8.
- An example of a preferred highly filled water-sizing comprises the following components:
- Zirconium silicate (particle size ⁇ 90 ⁇ m) 40.0-60.0% by weight
- Attapulgite 0.0-2.0% by weight preferably 0.2-2.0% by weight
- Hectorite 0.0-1.0% by weight (preferably 0.1-1.0% by weight)
- Bentonite 0.0-2.0% by weight preferably 0.2-2.0% by weight
- Dispersant 0.02-0.1% by weight
- the water-based compounds are prepared by conventional methods.
- a water sizing is prepared by a major part of the total amount of the carrier liquid component, preferably the total amount of water, presented here and clay minerals, such as bentonite and hectorite, by using a high-shear stirrer (eg 400-2000 U / min) are digested.
- the refractory components are stirred individually or as a mixture and pigments and dyes until a homogeneous mixture is formed.
- the Order of addition here plays no role or only a minor role, which can then be easily determined by a person skilled in the art.
- wetting agents, anti-foaming agents, biocides and binders are stirred in.
- the appropriate amount of the carrier liquid component (water) necessary to adjust the required viscosity and density characteristics of the size must be added.
- water-based coatings used to coat molds and cores in foundry technology have a viscosity of 12-25 seconds, more preferably 14-16 seconds (determined according to DIN 53211, 4 mm Auslaufbecher, Ford Cup)
- Preferred densities of a ready-water coating are in the range of 20-7O 0 Be, more preferably from 30- 50 0 Be (Baume-determined by the buoyancy method; DIN 12791).
- the combustible liquid which can be used for drying of the coating composition, water-based has a flash point of -60 0 C to 100 0 C, preferably from -20 0 C to 60 0 C, more preferably from 10 0 C to 55 ° C and most preferably from 10 0 C to 40 0 C.
- the flashpoint is the lowest temperature, corrected to a barometric pressure of 101.3 kPa (760 Torr) at which, with the use of a pilot flame under the prescribed test conditions, the vapors of the sample are ignited.
- the flash point of flammable liquids is determined in the "closed crucible" according to Pensky-Martens, DIN EN 22 719 (1993), ISO 2719 (1988) For petroleum products with a flash point of + 5-65 ° C also the device according to Abel -Pensky, DIN 51 755 (1974), be used.
- the flash points of the most common solvents are conventional literature sources removed (see, eg, Ullmann's Encyclopedia of Industrial Chemistry, 4th ed. (1978), Vol. 16, pp. 305-307).
- Examples of combustible liquids which can be used in the present invention are flammable alcohols, hydrocarbons, esters, ethers and ketones, which are also commonly used as solvents.
- flammable liquid combustible aliphatic alcohols having preferably 1 to 10 carbon atoms and C 1 -C 4 alkyl derivatives thereof may be used.
- Preferred examples of alcohols which can be used are methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, tert-butanol, amyl alcohols, pentanols and hexanols, and mixtures thereof.
- Particularly preferred are methanol, ethanol, n-propanol, isopropanol and mixtures of these alcohols.
- Alcohols are preferably used in an amount of 0-100% by weight, preferably 20-100% by weight, more preferably 60-90% by weight, based on all constituents of the combustible liquid.
- flammable hydrocarbon solvents may be used as the flammable liquid.
- flammable aliphatic, cycloaliphatic and aromatic hydrocarbons having 5-12 carbon atoms are used.
- useful hydrocarbons are various specialty gases with a flash point of -60 ° C to -5 ° C, pentane, hexane and various types of gasolines.
- Suitable gasolines are, for example, petroleum ether [DIN 51 630 (11/1986)], petroleum benzine [DIN 51 631 (01/1988)] of type 1, type 2 or type 3 and white spirit [DIN 51 632 (01/1988)] of the boiling ranges Type 1, Type 2, Type 3, Type 4 or Type 5.
- cycloaliphatic hydrocarbons are cyclohexane and methylcyclohexane.
- the hydrocarbons are used in the form of hydrocarbon mixtures.
- the hydrocarbons may also be used in admixture with alcohols, esters, ethers and ketones.
- the proportion of hydrocarbons in the combustible liquid is 0-100%, preferably 10-40 wt.%.
- flammable esters may be used as the flammable liquid.
- Flammable C 1 -C 4 -EStCr aliphatic C 2 -Cio-carboxylic acids are preferably used.
- useful esters are methyl, ethyl, propyl, isopropyl and butyl esters of acetic, propionic, butyric and isobutyric acid and mixtures thereof.
- the esters of aliphatic carboxylic acids are preferably used in a proportion of 10-20 wt.%, Based on all components of the combustible liquid. Also, mixtures of these esters with alcohols, hydrocarbons, ethers and ketones as described herein are useful.
- ethers and glycol ethers may be used as the combustible liquid.
- Useful ethers are, for example, diethyl, diisopropyl and dibutyl ethers, methyl tert-butyl ether, tetrahydrofuran and dioxane.
- Useful glycol ethers are mono- and di-alkyl ethers of a polyhydric alcohol such as the methyl, ethyl, propyl, isopropyl and butyl ethers of glycol and diglycol, preferably the monoalkyl ethers of a polyhydric alcohol such as ethylene glycol monoethyl ether, diethylene glycol monoethyl ether, triethylene glycol monoethyl ether, ethylene glycol monomethyl ether and ethylene glycol monobutyl ether ,
- the ethers can be used as ether mixtures and mixtures of ethers with the abovementioned alcohols, hydrocarbons and esters.
- ketones which are usually used as a solvent can be used as the combustible liquid.
- Preferred ketones are acetone, methyl ethyl ketone, methyl propyl ketone, methyl isopropyl ketone, methyl butyl ketone, methyl isobutyl ketone, diethyl ketone,
- Ethyl butyl ketone, diisopropyl ketone, diisobutyl ketone, cyclohexanone, methylcyclohexanone and acetylacetone can be used as ketone mixtures or as a mixture with the abovementioned alcohols, hydrocarbons, esters and ethers.
- the ketones are used in the flammable liquid in an amount of 0-100 wt.%, Preferably 10-40 wt.%.
- the combustible liquid consists of a mixture of at least one aliphatic C 2 -C 3 -AlkOhOl and at least one aliphatic or cycloaliphatic C 5 -C 12 hydrocarbon or hydrocarbon mixture.
- the alcohol is selected from ethanol, propanol and isopropanol.
- the Cs-C ⁇ -hydrocarbon is preferably used in the form of a hydrocarbon mixture, which is preferably selected from petroleum ether, light, middle and white spirits.
- a preferred mixture of a combustible liquid preferably consists of 20-90% by weight of at least one alcohol, preferably a C 2 -C 3 alcohol, 10-40% by weight of at least one hydrocarbon, preferably an aliphatic or cycloaliphatic Cs-C ⁇ hydrocarbon or a mixture of mainly Cs-Cn hydrocarbons, and / or 10-40 wt.% Of at least one carboxylic acid ester, preferably a C 1 -C 4 alkyl esters of aliphatic C 2 -C 1 o-carboxylic acids, based on all components of the combustible liquid ,
- the water-based finishes can be used to coat molds.
- the term "mold” includes all types of bodies necessary to make a casting, such as cores, molds and molds.
- the use of the water sizing also includes partial coating of molds. Preferably, the surfaces of a mold are coated, which come into contact with the casting metal.
- the water-based sizings are suitable for all conceivable applications in which coating of casting molds with sizing is desired.
- sand cores may be mentioned which are PUR cold box, water glass CO 2 , MF resole, resole CO 2 , furan resin, phenolic or water glass / ester bonded.
- Other examples of preferred casting molds that can be coated with water-based coatings are described, for example, in “Forming and Forming Methods,” Eckart Flemming and Werner Tuch, Wiley VCH, 1993, ISBN 3-527-30920-9.
- a method for coating a casting mold with a water-based coating comprises, for example, the steps:
- the size in several passes i. Layers, wherein the applied sizing layer is usually partially or completely dried before applying the next sizing layer. As a rule, 2-5 layers are applied.
- the sizing composition is usually applied only once, whereby a priming layer can be applied beforehand at critical points. Light (casting up to 2 tons) and medium casting (up to 2-1 tons) are generally not primed.
- the application of a basecoat, if desired, to the uncoated casting mold may be accomplished by any conventional method of application in the art.
- the basecoats may contain as base materials, for example, clays, talc, quartz, mica, zirconium silicate, alumina, aluminum silicate, bauxite, andalusites, chamotte and graphite. These base materials are the purportive part of the basecoat. They cover the mold surface, close the sand pores against the penetration of the casting metal and serve u.a. also as a thermal insulation against the mold. Commonly used application methods are dipping, flooding, spraying and brushing.
- the basecoat has a dry film thickness of at least 0.1 mm, preferably at least 0.2 mm, more preferably at least 0.45 mm, and most preferably in the range from 0.3 mm to 1.5 mm. Both water-based and alcohol-based sizing may be used as the basecoat, with water-based sizing being preferred.
- the application of a water-based finish to produce a top coat may be accomplished by any conventional application method.
- Examples of preferred application methods are dipping, flooding, spraying and brushing.
- conventional Application methods are described, for example, in "Forming Materials and Forming Methods", Eckart Fnellrning and Werner Tilch, Wiley VCH, 1993, ISBN 3-527-30920-9.
- the casting mold optionally containing a base coat is immersed in a container of ready-to-use water-based wash for about 2 seconds to 2 minutes. After a sufficient expiration time, the coated casting mold is subjected to drying.
- spraying as the application method commercial pressure sprayers are used.
- the water-based size is filled in a dilute state in a pressure vessel.
- the sizing can be pressed into a spray gun via the overpressure to be set, where it is sprayed with the aid of separately adjustable atomizing air.
- the application of the water-based sizing can take place in one or more layers. When applying several layers, each individual layer can be completely or partially dried after application.
- the wet layer thickness of the water-based sizing to produce a topcoat is applied as a function of the desired dry film thickness of the topcoat.
- the dry layer thickness of the topcoat is at least 0.1 mm, preferably at least 0.2 mm, more preferably at least 0.3 mm, even more preferably at least 0.45 mm, more preferably at least 0.55 mm, and most preferably within a range from 0.3 mm to 1, 5 mm.
- the dry layer thickness in this case is the layer thickness of the dried water wash, which was obtained by drying the size and, if appropriate, subsequent curing.
- the dry layer thickness of the base coat and the top coat is determined, for example, by measurement with the wet film thickness comb.
- the comb can determine the layer thickness by scraping the sizing off at the end marks of the comb until the substrate is revealed. On the markings of the teeth you can then read off the layer thickness.
- the applied water-based coating can optionally be partially or completely abschmattet, depending on the elapsed time, a part of the carrier liquid of the coating composition passes into the ground (infiltrated).
- a "matted" layer is a non-flowable layer in which the proportion of the Carrier liquid is so greatly reduced that the surface no longer has gloss.
- the drying of the applied water-based sizing is accomplished by applying a combustible liquid as described above and completely burning off the applied combustible liquid.
- the combustible liquid is here preferably applied in an amount of 10-5000 g / m 2, more preferably 20-2000 g / m 2, even more preferably 50 1000 g / m 2 and most preferably 80-500 g / m 2 ,
- the application of the flammable liquid can be done by flooding, dipping or spraying. Particularly preferred is the spraying of the combustible liquid.
- the combustible liquid can be applied by means of a commercially available hand sprayer (eg Gloria garden sprayer for spraying pesticides).
- the spray angle with the adjustable nozzle is preferably set to about 30 ° and the material pressure to about 2 bar (200 kPa).
- Another means for applying are commercially available spray guns (eg Sicmo spray gun), wherein the application is carried out for example with a 0.7 mm nozzle, a material pressure of 2 bar (200 kPa) and a spray pressure of 0.5 bar (50 kPa).
- a metallic pressure vessel should be used to prevent the organic liquids from becoming electrostatically charged and from being ignited prematurely due to discharge and the associated sparking.
- the combustible liquid is preferably ignited with a burning flame (eg lighter or gas flame).
- the flammable liquid is used as a heating source for burning off the carrier liquid (water) of the water wash. Complete burning is required to fully utilize the heat. If the heat development is large and the edge burning (burning of the resin binder in the sand), the coated amount can be reduced, or the proportion of hydrocarbons and esters reduces be.
- Increasing the content of high boiling components in the combustible liquid prolongs the burning time and reduces the firing temperature, while increasing the level of low boiling components shortens the firing time but increases the firing temperature. Soot formation, which is undesirable for occupational safety reasons, can be achieved optionally suppress by reducing the hydrocarbon content. Infiltration of the liquid into the water sizing prior to burning is undesirable.
- the amount of heat energy provided by the amount and composition of the combustible liquid is sufficient to remove the water from the applied sizing.
- temperatures between 100 and 180 ° C are desirable.
- the drying process by burning can be supported by a slight air flow. Additional use of high oxygen content gases is possible to improve or control burning.
- the dried layer of coating composition obtained after burning off the combustible liquid has a residual moisture content of less than 8% (which may be sufficient for gray cast iron), preferably less than 6%, more preferably less than 5%, even more preferably less than 2%, most preferably less than 1%.
- the residual moisture should be less than 1-2%.
- the residual moisture can be determined according to the carbide method (CM) by Riedel de Häen, Seelze. The carbide method is based on the principle that dry carbide reacts with water to form acetylene gas:
- Moisture determination can be carried out by a known method in the laboratory or with a CM meter directly in place. If the desired residual moisture of the applied water-based size is not reached after the first burn-off operation, then the above-mentioned drying process may be repeated several times by spraying a combustible liquid and burning it off, until the desired residual moisture is obtained. In a preferred embodiment, additional combustible liquid may additionally be sprayed onto the burning mold surface during the burning process. In a further embodiment of the invention, different parts of a mold may be treated with different amounts and / or different compositions of a combustible liquid. In the case of multiple application, it may be possible to change the amount and composition of the combustible liquid to be applied.
- the steps of applying a water sizing and drying the water sizing by applying and burning off a combustible liquid may be repeated if desired.
- the water-based coating compositions used, the combustible liquids used or both may differ from the water-based coating composition or the flammable liquid used for the first time.
- a post-drying using an air flow, a hot air blower, a gas flame or an infrared radiator can be done.
- the dried sizing may optionally be further cured. All known curing methods can be used. Added hardeners can be activated by heat or electromagnetic radiation. Depending on the temperature generated upon burning of the combustible liquid, drying and curing of the sizing may be carried out in one step or in separate steps. Also conceivable would be radical and ionic curing processes.
- Molds comprising a topcoat made according to the method of the present invention are used, inter alia, for the manufacture of pipes, cylinder liners, engine and engine components, machine beds, turbines, and general machine components.
- wetting agent usual wetting agent of the company Henkel AG, D 40589 Dusseldorf
- the biocides, starch and thickener were added to the total amount of water submitted.
- Zirconium silicate (particle size ⁇ 45 ⁇ m) and graphite were added to the resulting mixture.
- the flow time of the water-sizing thus obtained was set at 12.6 seconds. determined according to DIN 53211, outlet cup 4mm, Ford Cup.
- the molds were flooded in a metal flood basin. After draining the water-sizing, the average wet-film thickness was about 125 ⁇ m as measured by wet-film thickness crest.
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Chemical & Material Sciences (AREA)
- Materials Engineering (AREA)
- Application Of Or Painting With Fluid Materials (AREA)
- Mold Materials And Core Materials (AREA)
- Paints Or Removers (AREA)
Abstract
Description
Claims
Priority Applications (6)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
MX2007014675A MX2007014675A (es) | 2005-05-25 | 2006-05-23 | Metodo para secar recubrimientos a base de agua. |
JP2008512756A JP2009525872A (ja) | 2005-05-25 | 2006-05-23 | 水性塗型剤の乾燥方法 |
EP06753814A EP1888273A1 (de) | 2005-05-25 | 2006-05-23 | Verfahren zur trocknung von wasserschlichten |
CA002610372A CA2610372A1 (en) | 2005-05-25 | 2006-05-23 | Method for drying water-based coatings |
BRPI0610305-7A BRPI0610305A2 (pt) | 2005-05-25 | 2006-05-23 | processo para secagem de revestimentos a base de água |
NO20076407A NO20076407L (no) | 2005-05-25 | 2007-12-12 | Fremgangsmate for a torke vannbaserte belegg |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE102005024207.3 | 2005-05-25 | ||
DE102005024207A DE102005024207A1 (de) | 2005-05-25 | 2005-05-25 | Verfahren zur Trocknung von Wasserschlichten |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2006125612A1 true WO2006125612A1 (de) | 2006-11-30 |
Family
ID=36802171
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/EP2006/004909 WO2006125612A1 (de) | 2005-05-25 | 2006-05-23 | Verfahren zur trocknung von wasserschlichten |
Country Status (10)
Country | Link |
---|---|
EP (1) | EP1888273A1 (de) |
JP (1) | JP2009525872A (de) |
KR (1) | KR20080027787A (de) |
BR (1) | BRPI0610305A2 (de) |
CA (1) | CA2610372A1 (de) |
DE (1) | DE102005024207A1 (de) |
MX (1) | MX2007014675A (de) |
NO (1) | NO20076407L (de) |
RU (1) | RU2007148506A (de) |
WO (1) | WO2006125612A1 (de) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2009012764A1 (de) * | 2007-07-26 | 2009-01-29 | Ava Anhaltinische Verfahrens- Und Anlagentechnik Gmbh | Vorrichtung und verfahren zur trocknung von formschlichte auf giessereiformen und/oder -kernen |
CN102248120A (zh) * | 2011-04-11 | 2011-11-23 | 中方阀业淅川制造有限公司 | 一种薄壁铸件消失模铸造用低导热涂料 |
CN104475669A (zh) * | 2014-10-08 | 2015-04-01 | 铜陵瑞莱科技有限公司 | 一种抗粘砂铸造涂料及其制作方法 |
Families Citing this family (13)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE102009032668A1 (de) | 2009-07-09 | 2011-01-13 | Hüttenes-Albertus Chemische Werke GmbH | Schlichte zur Herstellung von Formüberzügen |
PL2364795T3 (pl) * | 2010-03-08 | 2012-12-31 | Foseco Int | Kompozycja powłoki odlewniczej |
KR101287146B1 (ko) * | 2011-01-20 | 2013-07-17 | 현대메티아 주식회사 | 이중 코팅공정을 통한 주형재료, 주형, 주형품, 주형재료의 제조방법 및 주형의 제조방법 |
JP5784399B2 (ja) * | 2011-07-20 | 2015-09-24 | 花王株式会社 | 砂型鋳造用塗型剤組成物 |
DE102011114626A1 (de) * | 2011-09-30 | 2013-04-04 | Ask Chemicals Gmbh | Beschichtungsmassen für anorganische Giessformen und Kerne und deren Verwendung |
DE102013101249A1 (de) * | 2013-02-08 | 2014-08-14 | Neue Halberg-Guss Gmbh | Gießverfahren und Gußteil |
DE102014113017A1 (de) * | 2014-09-10 | 2016-03-10 | Buderus Guss Gmbh | Sandkern, Beschichtungsvorrichtung und Verfahren zur Herstellung eines Sandkerns jeweils für die Herstellung von belüfteten Bremsscheiben |
ITUB20153502A1 (it) * | 2015-09-09 | 2017-03-09 | Altea S R L | Processo per il trattamento superficiale di componenti per fonderia per processi di colata in getti e dispositivo a letto fluido per eseguire tale processo |
CN105964894A (zh) * | 2016-06-22 | 2016-09-28 | 湖北星源科技有限公司 | 一种消失模铸造用涂料 |
KR101943874B1 (ko) * | 2016-10-13 | 2019-01-30 | 주식회사 산화 | 풀 몰드용 도형재 및 이의 제조방법 |
DE102018004234A1 (de) * | 2018-05-25 | 2019-11-28 | Ask Chemicals Gmbh | Schlichtezusammensetzung, Verfahren zur Beschichtung einer Gießform und Verwendung der Schlichtezusammensetzung zur Beschichtung einer Gießform |
CN108941446B (zh) * | 2018-07-31 | 2020-11-27 | 铜陵旭时新材料科技有限公司 | 一种圆盘浇铸机用脱模剂 |
JP2022133052A (ja) * | 2021-03-01 | 2022-09-13 | 明智セラミックス株式会社 | 高熱伝導性断熱材 |
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GB1208511A (en) * | 1967-08-08 | 1970-10-14 | Howmet Corp | Improvements in eliminating patterns from and hardening of shell molds |
GB1354822A (en) * | 1971-02-11 | 1974-06-05 | Ahlstroem Oy | Process for hardening with combustion gases a casting mould or core |
Family Cites Families (3)
Publication number | Priority date | Publication date | Assignee | Title |
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GB1198363A (en) * | 1968-01-16 | 1970-07-15 | Foseco Int | Coating Processes |
AT301059B (de) * | 1970-06-17 | 1972-08-25 | Reichhold Chemie Ag | Schlichte für Gießereiformen und Kerne |
DD110619A1 (de) * | 1974-03-11 | 1975-01-05 |
-
2005
- 2005-05-25 DE DE102005024207A patent/DE102005024207A1/de not_active Withdrawn
-
2006
- 2006-05-23 JP JP2008512756A patent/JP2009525872A/ja not_active Withdrawn
- 2006-05-23 MX MX2007014675A patent/MX2007014675A/es unknown
- 2006-05-23 WO PCT/EP2006/004909 patent/WO2006125612A1/de active Search and Examination
- 2006-05-23 RU RU2007148506/02A patent/RU2007148506A/ru not_active Application Discontinuation
- 2006-05-23 KR KR1020077030201A patent/KR20080027787A/ko not_active Application Discontinuation
- 2006-05-23 BR BRPI0610305-7A patent/BRPI0610305A2/pt not_active Application Discontinuation
- 2006-05-23 CA CA002610372A patent/CA2610372A1/en not_active Abandoned
- 2006-05-23 EP EP06753814A patent/EP1888273A1/de not_active Withdrawn
-
2007
- 2007-12-12 NO NO20076407A patent/NO20076407L/no unknown
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB1208511A (en) * | 1967-08-08 | 1970-10-14 | Howmet Corp | Improvements in eliminating patterns from and hardening of shell molds |
GB1354822A (en) * | 1971-02-11 | 1974-06-05 | Ahlstroem Oy | Process for hardening with combustion gases a casting mould or core |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2009012764A1 (de) * | 2007-07-26 | 2009-01-29 | Ava Anhaltinische Verfahrens- Und Anlagentechnik Gmbh | Vorrichtung und verfahren zur trocknung von formschlichte auf giessereiformen und/oder -kernen |
ES2354790A1 (es) * | 2007-07-26 | 2011-03-18 | Ava Anhaltinische Verfahrens- Und Anlagentechnik G | Dispositivo de método para secar recubrimientos de moldes en moldes y/o núcleos de fundición. |
CN102248120A (zh) * | 2011-04-11 | 2011-11-23 | 中方阀业淅川制造有限公司 | 一种薄壁铸件消失模铸造用低导热涂料 |
CN102248120B (zh) * | 2011-04-11 | 2013-05-15 | 中方阀业淅川制造有限公司 | 一种薄壁铸件消失模铸造用低导热涂料 |
CN104475669A (zh) * | 2014-10-08 | 2015-04-01 | 铜陵瑞莱科技有限公司 | 一种抗粘砂铸造涂料及其制作方法 |
Also Published As
Publication number | Publication date |
---|---|
KR20080027787A (ko) | 2008-03-28 |
NO20076407L (no) | 2008-02-12 |
EP1888273A1 (de) | 2008-02-20 |
CA2610372A1 (en) | 2006-11-30 |
DE102005024207A1 (de) | 2006-11-30 |
RU2007148506A (ru) | 2009-06-27 |
JP2009525872A (ja) | 2009-07-16 |
MX2007014675A (es) | 2008-02-11 |
BRPI0610305A2 (pt) | 2010-06-15 |
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