Classifications

• • 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
  • B22C1/16—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds characterised by the use of binding agents; Mixtures of binding agents
  • B22C1/18—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds characterised by the use of binding agents; Mixtures of binding agents of inorganic agents
  • B22C1/186—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds characterised by the use of binding agents; Mixtures of binding agents of inorganic agents contaming ammonium or metal silicates, silica sols
  • B22C1/188—Alkali metal silicates
• • 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
  • B22C1/16—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds characterised by the use of binding agents; Mixtures of binding agents
  • B22C1/162—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds characterised by the use of binding agents; Mixtures of binding agents use of a gaseous treating agent for hardening the binder
• • 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
  • B22C1/16—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds characterised by the use of binding agents; Mixtures of binding agents
  • B22C1/18—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds characterised by the use of binding agents; Mixtures of binding agents of inorganic agents
  • B22C1/181—Cements, oxides or clays
• • 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
  • B22C1/16—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds characterised by the use of binding agents; Mixtures of binding agents
  • B22C1/18—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds characterised by the use of binding agents; Mixtures of binding agents of inorganic agents
  • B22C1/183—Sols, colloids or hydroxide gels
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B22—CASTING; POWDER METALLURGY
  • B22C—FOUNDRY MOULDING
  • B22C15/00—Moulding machines characterised by the compacting mechanism; Accessories therefor
  • B22C15/23—Compacting by gas pressure or vacuum
  • B22C15/24—Compacting by gas pressure or vacuum involving blowing devices in which the mould material is supplied in the form of loose particles
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B22—CASTING; POWDER METALLURGY
  • B22C—FOUNDRY MOULDING
  • B22C9/00—Moulds or cores; Moulding processes
  • B22C9/02—Sand moulds or like moulds for shaped castings
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B22—CASTING; POWDER METALLURGY
  • B22C—FOUNDRY MOULDING
  • B22C9/00—Moulds or cores; Moulding processes
  • B22C9/10—Cores; Manufacture or installation of cores

Definitions

• the invention relates to the production of lost cores or moldings for casting molds for the production of cast components (casting production).
• Lost cores are needed in the foundry industry for the realization of voids inside castings and can have an extremely complex structure, e.g. B. cores for car cylinder heads.
• the lost cores are produced from a granular and dry base material, a sand, often quartz sand, but also chromite, zirconium, olivine, feldspar, mullite or other sands and a chemically curing binder system. These components are mixed, optionally introduced with the addition of further additives and by pressurization (compressed air) in the mold (core or molding box).
• the subsequent solidification of the still loose molding material mixture can be carried out by various means, for example by passing a hardening gas, e.g. Carbon dioxide or thermal solidification by a heated, d. H. metallic, archetype tool.
• Water-glass-based binders are known, which mostly consist of multicomponent systems of the waterglass component and of a usually powdery additive component. Blended with mold bases and formed into cores or core moldings, such moldings can be solidified by physical consolidation (dehydration, dehydration, drying) or chemical hardening (chemical hardening).
• the INOTEC process which uses a binder mixture based on sodium silicate as a binder, wherein in this binder by adding additives to the so-called inotec promoters different molding properties are improved.
• the curing takes place via a stepwise proceeding dehydration of the core molding material by mold temperatures between 150 to 250 ° C and a subsequent hot air flushing in the same temperature range.
• binder contents between 1.8 and 2.5% and promoter contents between 0.1% and 1.0% are used.
• the promoter improves the flowability and strength of the core molding material and the core, by bonding together individual binder particles and building up a three-dimensional network.
• the main areas of application of the INOTEC process and the INOTEC binders are light metal and non-ferrous metal alloys, for example for the production of cylinder heads as well as fittings castings.
• CORDIS binder system in which the binder has a matrix of a combination of phosphate, borate and silicate groups.
• the CORDIS binder system is a two-component inorganic system composed of the binder CORDIS and the additive Anorgit.
• a heated core box 130 to 180 ° C
• a H exertluftbegasung 100 to 200 ° C
• Binder contents used can be between 1.5 and 3.0%, depending on the binder type. In this case, bending strengths of 350 to 550 N / cm 2 are achieved.
• the CORDIS binder system is also used to make inorganic bonded cores in tempered core-making tools.
• the Cordis binder system is composed of water as a solvent and an inorganic binder matrix. Depending on the application, this binder matrix consists of a combination of modified phosphate, silicate and borate groups.
• this binder matrix consists of a combination of modified phosphate, silicate and borate groups.
• inorganic substances directly in the binders or as an additive in the core production properties can be specifically controlled. These include, for example, the flowability, the reactivity of the molding material mixture, the wetting of the core by the melt or the storage stability.
• the problem with this binder is that due to its hydrophilicity, the shelf life of bound cores is limited. For example, when stored for 24 hours, the strengths drop by about 1/3 of the initial strength.
• the Cordis binder systems for aluminum gravity chill casting are preferred.
• AWB inorganic warm box
• the AWB process also uses heated core boxes (160 to 200 ° C).
• a negative pressure is applied to the core box, which serves to deduct the resulting water vapor.
• Curing is purely physical, which positively influences the regeneration of the molding material after casting. After the core in the core box has a certain machining strength, it is completely cured in a microwave at low power.
• the AWB process is based on the thermal hardening of water-glass-bonded molded materials in a tempered tool with subsequent microwave drying.
• the binder used is a modified water glass, which receives a low viscosity by dilution with sodium hydroxide solution.
• the flowability of the molding mixtures prepared therewith and thus their ductility allows a good production of the core or molding.
• the solidification of the molding material in the AWB process takes place exclusively by dehydration, ie drying at mold temperatures between 160 and 200 ° C, with an additional negative pressure can be created.
• the final drying is then ensured by low power microwave ovens.
• the binder additions are between 1.5 and 2.5%. Additives are dispensed with.
• Out DE 103 21 106 A1 is a molding material for moldings of casting molds for casting of light metal melts is known, as a molding material, a quartz-free sand (olivine) and an inorganic binder based on water glass is used.
• a quartz-free sand (olivine) and an inorganic binder based on water glass is used.
• Two-component binder systems are known from the prior art.
• the DE 20 2008 017 975 U1 discloses a two component system comprising a first liquid, water glass and a second solid particulate metal oxide containing component.
• a surfactant preferably added to the liquid component.
• the metal oxide has a particle size of less than 100 microns and greater than 10 microns.
• the disadvantage of adding a surface-active substance to this binder is necessary.
• the binder is provided as a two-component system and must first be laboriously mixed together before use.
• DE 2434431 A1 discloses a water glass based binder system wherein the molding mixtures prepared therewith contain a number of additional components besides the molding base and the binder.
• the binder has a ratio of silica to alkali oxide of between 3.5: 1 and 10: 1 and is added to the molding base in proportions of between 3 and 15% by weight.
• the additives used in this multicomponent system are clay or alumina, carbonaceous materials (eg pitch or soot) and film-forming resin adhesives (eg polyvinyl acetate dispersions or vinyl acetate-ethylene copolymers).
• DE 10 2012 020 510 A1 discloses a molding material mixture of a refractory base molding material, a water glass based inorganic binder and particulate amorphous SiO 2 . Furthermore, this system using a two-component binder contains additional organic additives as well as various surfactants. The particulate amorphous SiO 2 is added here as a powder.
• the molding material mixture used contains a hardener (eg an ester or phosphate compound) and is suitable for use in cast aluminum suitable. The curing of the molding material mixture is carried out with the aid of hot tools, which are preferably heated to 120 to 250 ° C.
• DE 10 2007 027 577 A1 discloses a molding material mixture containing in addition to the binder on alkali silicate based 0.1 to 10% sodium hydroxide solution and a surcharge between 0.1 and 3% by weight of a suspension having a solids content between 30 and 70% of amorphous, spherical SiO 2 .
• this method uses microwave energy.
• CN 1721103 A discloses an inorganic binder for molding with improved disintegration performance after casting of the castings.
• the binder contains dextrose powder, calcium carbonate powder, a suspending agent and other additives.
• DE 10 2007 023 883 A1 discloses a shot gas supply device for supplying a core shooter with a humidified gas having a certain humidity, wherein the temperature of this gas can also be varied.
• a microwave radiator can be used for tempering the humidified gas.
• EP 2 163 328 A1 discloses a process in which the masterbatch is coated with a waterglass binder in the range of 0.25 to 0.9% based on the total fabric weight, in addition the binder contains at least one additive from the groups of adhesion promoters, flow improvers, surface improvers, desiccants or release agents , Furthermore, at least one curing agent is contained in the molding material mixture, which cures, for example, by contact with water vapor. The curing of the molded parts is carried out in a heated mold, which is preferably heated to temperatures between 60 and 120 ° C.
• EP 1 095 719 A2 describes a binder system for molding sands for the production of cores.
• the waterglass-based binder system consists of an aqueous alkali silicate solution and a hygroscopic base, such as sodium hydroxide, added in a ratio of 1: 4 to 1: 6.
• the water glass has a modulus SiO 2 / M 2 O of 2.5 to 3.5 and a solids content of 20 to 40%.
• the binder system also contains a surface-active substance, such as silicone oil, which has a boiling point ⁇ 250 ° C.
• the binder system is mixed with a suitable refractory material, such as quartz sand, and can then be shot into a core box with a core shooter.
• a suitable refractory material such as quartz sand
• the curing the molding material mixture takes place by the withdrawal of the water still contained.
• the drying or hardening of the casting mold can also take place under the action of microwaves.
• WO 2006/024540 A2 describes that through the use of a binder containing an alkali water glass as well as a particulate metal oxide selected from the group consisting of silica, alumina, titania and zirconia, the strength of molds both immediately after molding and curing and under elevated conditions Humidity can be significantly improved.
• the particle size of these metal oxides is preferably less than 300 microns, more preferably less than 100 microns.
• the procedure is generally such that initially the refractory molding base material is introduced and then the binder is added with stirring.
• the water glass and the particulate metal oxide can be added per se in any order.
• WO 2008/046651 A1 discloses a carbohydrate-containing molding material mixture for the production of molds for metal processing, a process for the production of molds, casting molds obtained by the process and their use.
• a refractory molding material and a water glass based binder is used for the production of the molds.
• a proportion of a particulate metal oxide is added to the binder.
• the oligosaccharides or polysaccharides used for the molding material mixture are intended to increase the strength of the casting mold and its releasability.
• the molding material mixture can be shot by means of a core shooting machine with the aid of compressed air into the mold. The curing of the molds can be accelerated by blowing heated air into the mold.
• the present invention is based on the object to develop a process for the production of lost cores or moldings for casting molds that with an environmentally and workplace friendly binder system using original molds made of wood, plastic, metal or combinations thereof without active heating the production complicated shaped lost cores or moldings using inorganic binder systems.
• the object is achieved by a method for producing lost cores or moldings for casting molds for casting production with the features of claim 1. Further embodiments of the method according to the invention include the subclaims 2 to 14.
• a molding base is mixed with an alkali silicate or waterglass binder, and a lost core or molding for a casting mold is formed in a core box with a core shooter.
• the process is characterized in that the alkali metal silicate or waterglass binder comprises an alkali silicate or waterglass solution having a modulus of from 1.5 to 3.5 and natural and / or synthetic additives containing from 0.1 to 25% by mass.
• the natural and / or synthetic additives at least, each to 1 to 5% by mass, based on the total content of the binder, aluminum silicate, magnesium silicate and sodium aluminum silicate are the lost core or molding is molded in an unheated core box, and the resulting core or molding is cured with hot air.
• a modified alkali silicate or water glass solution is used in conventional sands as the molding material as a binder, wherein the binder according to the invention contains additives based on natural or synthetic minerals with a particle size of less than 5 microns and wherein the core shooter produced lost core with hot air , which may be enriched with CO 2 , is cured.
• Lost cores designate molded parts that are used in the production of castings, for example, to act as a placeholder for complex contours, mostly cavities, in casting. On the one hand, these must be strong and strong enough to retain their shape during the casting process, on the other hand they should be easily removable from the finished casting after the casting process and cooling of the casting. For this reason, the lost cores consist of a molding material and a binder, which provides sufficient stability to withstand the above claims.
• Moldings according to the invention designate parts of a casting mold, which correspond, for example, in their outer shape to the later casting.
• Water glass solution is not a uniform chemical compound but a collective name for glassy solidified melts of alkali silicates of varying composition in solution.
• Aqueous alkali silicate solutions are known in the art as water glass solutions.
• Waterglass solutions have the general composition xSiO 2 * yM 2 O * zH 2 O, where M is an alkali metal, preferably selected from sodium, potassium and lithium.
• M is an alkali metal, preferably selected from sodium, potassium and lithium.
• the ratio of silica to alkali oxide is referred to as a module.
• the module denotes the molar ratio of the two components.
• the binder according to the invention ensures that the molding material mixture is held together in the desired shape and a lost core or a molded part is formed after the curing of the binder.
• the lost core or the molded part is intended to be dimensionally stable at least until the casting to be produced has solidified and cooled sufficiently that it no longer suffers any deformation.
• the binder may be present as a one-component or multicomponent system, i. it may be mixed together shortly before use or present as a ready-made formulation.
• the fine-grained natural and / or synthetic additives are present in the binder in proportions of from 0.1 to 25% by mass, preferably in proportions of from 0.5 to 15% by mass.
• the proportion of the binder to that of the molding material mixture in the core production is less than 5% by mass and is preferably from 0.5 to 3.5% by mass, particularly preferably from 1.0 to 2.0% by mass.
• the natural and / or synthetic additives have a particle size of less than 5 microns, which advantageously prevents settling of the additives in the binder.
• the binder is shelf stable for several months, but at least 2 months.
• a core shooter is a device for producing lost cores.
• the person skilled in common core shooting machines are known.
• the core shooter is used for shooting the mixed with binder molding base in a core box.
• the core boxes are the forms that give the lost core its later form.
• the core box according to the invention itself is not heated, which is why the material of the core box can be selected from plastic, wood and metal or metal alloys, such as aluminum.
• the core box points at least at the first use Room temperature.
• energy is saved, since it is not necessary to first heat a complete core box and to keep it constantly warm over the time of use.
• the core box consists of a heatable material, preferably of steel.
• the core box heats up when the lost mold is cured by means of hot air, thus contributing to faster hardening of the following lost cores into this core box.
• air designates the naturally occurring gas mixture of the earth's atmosphere, the composition of which varies slightly and is known to the person skilled in the art, but contains at least nitrogen, oxygen, argon and smaller proportions, for example, of other noble gases and carbon dioxide in the main components.
• the aluminum silicate is preferably natural aluminum silicate
• the magnesium silicate is a natural magnesium silicate
• the sodium aluminum silicate is a synthetic sodium aluminum silicate.
• the skilled person is aware of the various sources and types of natural and synthetic additives.
• the binder is preferably mixed in proportions of less than 5% by weight, based on the amount of the molding base material, with the molding base material.
• At least one sand selected from quartz, zirconium, chromite, olivine feldspar, mullite, chamotte, bauxite or rutile sand is preferably used as the molding base material.
• sand denotes all mineral substances having a particle diameter in a size range from 0.02 to 2 mm.
• the binder preferably contains at least one further natural and / or synthetic additive selected from zirconium silicate, aluminum oxide, aluminum hydroxide, magnesium oxide, magnesium hydroxide, titanium oxide, titanium hydroxide, sodium aluminate, potassium aluminate, lithium aluminate, sodium germanate, potassium germanate, lithium germanate, aluminum silicate, magnesium silicate, aluminum magnesium silicate, magnesium iron silicate, iron oxide , Iron hydroxide and silicon dioxide in a proportion of 0 to 3 wt .-%, measured on the total content of the binder.
• the natural or synthetic materials added to the binder system may include alumina, aluminum hydroxide, magnesium oxide, magnesium hydroxide, titanium oxide, titanium hydroxide, sodium aluminate, potassium aluminate or lithium aluminate, sodium germanate, potassium germanate, lithium germanate, aluminum silicate, magnesium silicate, aluminum magnesium silicate, Magnesium iron silicate, iron oxide, iron hydroxide or silicon dioxide.
• the following materials are particularly suitable: magnesium hydroxide, lithium aluminate, aluminum silicate, magnesium silicate, aluminum magnesium silicate and / or silicon dioxide.
• a mono-component binder is preferably used as the alkali silicate or water glass binder.
• One-component binder designates a one-component system in the sense of the invention.
• One-component systems are characterized by the fact that all components which are required for later setting or hardening of the binder (one-component system) are already contained in the one-component binder. Mixing before its use is thus advantageously no longer necessary.
• a hot air generator is used for curing with hot air, which is integrated mechanically or pressure-tight in or on the core shooting machine.
• Hot air generators are devices that can heat air and other gases or gas mixtures to a desired temperature by sucking and passing them through the heated device.
• the person skilled in various hot air heaters are known.
• heat losses are minimized by integrating the hot air generator in or on the core shooter or in its immediate vicinity.
• the molding material mixture, mixed with the binder can be cured by contacting with hot air to form a lost core or molding.
• the hot air generator is connected by a permanent mechanical connection with the core shooting machine.
• connection of hot air generator and core shooter can be done for example via a fixed line or a flexible hose.
• the person skilled in methods for connecting the two devices are known.
• control of the hot air generator is integrated into the control of the core shooting machine.
• the hot air at a temperature up to 500 ° C, more preferably from 150 to 300 ° C, most preferably from 150 to 200 ° C used.
• the degree of hardening can be increased.
• pure carbon dioxide is used to cure the binder.
• hot air is used with a volume flow of up to 40,000 l / min, more preferably with a volume flow of 20,000 l / min up to 35,000 l / min for curing of the binder.
• the hot air is preferably used at a pressure of up to 10 bar, preferably at a pressure of 2 to 5 bar, very particularly preferably at a pressure of 2 to 4 bar.
• the lost core can be cured in a short time at relatively low energy consumption.
• the known in the prior art heating the entire core boxes requires a much higher energy consumption.
• a directed suction of the hot air by a negative pressure of up to 1 bar Preferably, a directed suction of the hot air by a negative pressure of up to 1 bar.
• the solid lost core or molding is removed from the core box and used for casting production.
• a hot air generator is integrated mechanically or pressure-tight in or on a core shooter or in the immediate vicinity in order to minimize heat losses.
• the integration of the hot air generator is preferably carried out by a permanent mechanical connection with the core shooter.
• the control of the hot air generator is integrated into the control of the core shooting machine.
• hot air with a temperature of up to 500 ° C and an overpressure of up to 10 bar is used.
• the hot air can also be sucked in by a negative pressure of up to 1 bar.
• the control and regulation of the volume flow takes place in the range up to 40,000 l / min.
• the inventive method allows the production of lost cores or moldings for casting molds with an environmentally and workplace friendly binder system.
• the binder system is a one-component system, which allows a simplified application.
• the binder can be used in small amounts, preferably 2 Ma-% binder, measured on the mass of the molding material.
• core boxes can also be used made of heat-sensitive materials.
• the lost cores or moldings produced by the method according to the invention in addition to a high primary strength and a low secondary strength after de casting.
• primary strength refers to the strength of the lost cores or molded parts after production.
• the primary strength is high so that the lost cores or moldings are long lasting and shelf stable and do not disintegrate during use.
• Secondary strength refers to the strength according to the invention after the production of a casting by means of a lost core or molded part.
• the secondary strength is low, so that the lost core or molding can be quickly and easily released from the mold.
• the invention also includes an alkali or water glass binder for bonding a mold base for lost cores or moldings for casting molds for casting production containing an alkali silicate or water glass solution with a modulus of 1.5 to 3.5 and natural and / or synthetic additives with a Proportion of 0.1 to 25 wt .-%, measured on the total content of the binder, with a particle size of less than 5 microns, wherein the natural and / or synthetic additives at least, in each case to 1 to 5% by mass, measured on the total content of the binder , Aluminum silicate, magnesium silicate and sodium aluminosilicate.
• the binders of the invention have a higher flowability and a lower water absorption compared to known binders.
• Advantageously lost cores or moldings can be made with a higher strength than with conventional binders.
• the binder preferably contains at least one further natural and / or synthetic additive selected from zirconium silicate, aluminum oxide, aluminum hydroxide, magnesium oxide, magnesium hydroxide, titanium oxide, titanium hydroxide, sodium aluminate, potassium aluminate, lithium aluminate, sodium germanate, potassium germanate, lithium germanate, aluminum silicate, magnesium silicate, aluminum magnesium silicate, magnesium iron silicate, iron oxide , Iron hydroxide and silicon dioxide in a proportion of 0 to 3 wt .-%, measured on the total content of the binder.
• the alkali silicate or waterglass binder is a one-component binder.
• all ingredients of the binder are in a formulation and need not be mixed together prior to application of the binder, which facilitates application of the binder.
• the invention also includes the use of the alkali silicate or water glass binder for producing lost cores or moldings for casting molds for casting production.
• quartz sand mixed as a molding material on the one hand with a known binder "binder old 1" and on the other with a known binder "binder old 2".
• molding material mixtures are prepared with a molding material content of 98% by mass and 98.5% by mass.
• the binder content of the molding material mixture was 2% by mass and 1.5% by mass, respectively.
• the percentage by weight refers to the total content of the mixture of molding material and binder.
• a batch mixer was used for mixing.
• Binder alt 1 is a known alkali metal silicate binder with a modulus of 2.3 containing only organic additives in minor proportions (1.5% oxoanion, 0.5% polyol and 2% sodium hydroxide)
• Binder alt 2 is a known alkali metal silicate binder with a modulus of 2.3 containing minor amounts of organic additives (1.5% oxoanion, 0.5% polyol and 2% sodium hydroxide) and 0.5% flow improver.
• the finished molding material mixture is then transferred to the reservoir of a core shooter (DISA Core EP 20). Subsequently, the filling of the unheated core box with the molding material mixture by short-term (2 s) compressed air (2.5 bar).
• the core box is separated from the shooting head of the machine and a hot air generator (type DISA, power 8 KW) is connected. Then the formed lost core is flowed through with hot air according to the values for temperature, pressure and time given in the tables.
• a hot air generator type DISA, power 8 KW
• the core box Upon completion of the hot air fumigation, the core box is disconnected from the heat source and withdrawn from the core shooter. After opening the core box, the core can be removed and processed further.
• quartz sand is used as a molding material.
• the quartz sand is mixed with a proportion of 98% by mass with 2.0% binder and in a second experiment with 98.5% quartz sand and 1.5% binder with a batch mixer.
• Waterglass solutions (modulus 2.0 to 3.5) with the following additives are used as one-component binders:
• the residual compressive strength is determined analogously to the compressive strength.
• the bending strength is according to DIN 52404 and the rule for determining the bending strength is the VDG (Association of German Foundry Experts) - "Binder Testing - Testing of Cold-curing, Resin-Bonded Wet Forming Materials with Aerosol and / or Gas Curing", P73, August 1972 certainly.
• Tables 1 and 2 document the values for flexural strength and compressive strength for Examples 1 and 2. Flexural strength and compressive strength were determined with the Multiserv LRu-2e universal strength tester.
• Table 3 documents the residual compressive strength values for Examples 1 and 2 after simulated casting at 400 ° C and at 800 ° C.
• Tables 4 to 9 document the experimental results achieved using binder neu1 with a binder content of 1.5 Ma% and 2.0 Ma% at different fumigation temperatures and times.
• Tables 4-9 firing pressure 2.5 bar, firing time 2.0 s, flexural bending test, times in the table indicate the test time after test specimen removal from the core box; for residual compressive strength 20 minutes annealing of the samples at test temperature, testing 1 hour after end annealing, all measured values mean values from 3 individual measurements.
• lost cores are at least as good
• Table 1 shows the flexural strengths of the lost cores. It will be appreciated that the lost cores made with the one-component binder of the present invention have significantly higher flexural strengths both immediately and after 1 hour and 24 hours than lost cores made with the conventional binders. This trend can also be seen in the compressive strengths.
• test values in Tables 4 to 9 document that with binder proportions of 1.5 and 2.0% by mass at gassing temperatures of 150-170 ° C and gassing times of 1 to 3 minutes both very high values for flexural strength and also very low values be achieved for the residual compressive strength. This behavior proven on test specimens comes very close to the practical requirement of very high primary and very low secondary strengths (ideally 0).

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Chemical & Material Sciences (AREA)
• Materials Engineering (AREA)
• Dispersion Chemistry (AREA)
• Mold Materials And Core Materials (AREA)
• Molds, Cores, And Manufacturing Methods Thereof (AREA)
• Adhesives Or Adhesive Processes (AREA)

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• 2014
  • 2014-10-17 JP JP2016548428A patent/JP6141539B2/ja active Active
  • 2014-10-17 ES ES14786500.0T patent/ES2628255T3/es active Active
  • 2014-10-17 EP EP14786500.0A patent/EP2916976B1/de active Active
  • 2014-10-17 US US15/030,052 patent/US10092947B2/en active Active
  • 2014-10-17 WO PCT/EP2014/072361 patent/WO2015055838A1/de active Application Filing
  • 2014-10-17 CN CN201480057450.2A patent/CN105658352B/zh active Active
  • 2014-10-17 PL PL14786500T patent/PL2916976T3/pl unknown
  • 2014-10-20 DE DE201410221237 patent/DE102014221237A1/de not_active Withdrawn

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