Manufacturing method, casting mold, core or riser, kit, and method for manufacturing metal castings.

Abstract

Manufacturing methods, casting molds, cores or risers, kits, and methods for producing metal castings are provided. The present invention provides a method for producing an article selected from the group consisting of a casting mold, a core, a feeder, and a molding compound for producing a portion of a casting mold, a core, or a feeder, the method comprising: (S1) At the foundry, a first component (A) comprising a first binder component (b1) of a binder system and an amount of a first mold base material; Spatially separated from it, a second binder component (b2) of the binder system and a second component (B) comprising an amount of a second mold base material; generating or providing the first binder component (b1) and the second binder component (b2) are suitable for chemical reaction with each other and for hardening of the mixture of the first component (A) and the second component (B), Steps and (S2) contacting and mixing the first component (A) and the second component (B) in a predetermined mass ratio to obtain a self-hardening molding compound; The present invention relates to a method comprising:

Description

Technical Field

[0001] The present invention relates to a method for manufacturing an article selected from the group consisting of a casting mold, a core, a riser, and a self-hardening or curing molding compound for manufacturing a part of the casting mold, the core, or the riser. Further details of the method of the present invention will become apparent from the appended claims and the following description. The present invention further relates to a casting mold, a core, and a riser. The present invention further relates to a kit for use in the method of the present invention. The present invention further relates to a method for manufacturing a metal casting by metal casting in a casting mold. The present invention is defined in the appended claims and will be described in detail in the following description.

Background Art

[0002] Casting in a lost mold is a widely practiced method for manufacturing near-net shape components. After casting, the mold is destroyed and the casting is removed. A lost mold is a casting mold and thus a negative mold. A lost mold includes a cavity to be cast, and the cavity surrounds the casting to be manufactured. The inner contour of the future casting is formed by a core. In the manufacture of a casting mold, the cavity is shaped in a molding material by a model of the casting to be manufactured. For related details, see paragraphs

[0001] to

[0005] of German Patent Application Publication No. 10 2017 107 531 A1.

[0003] In the manufacture of metal castings (cast articles) in the casting industry, liquid metal is poured into a casting mold and solidifies there. The solidification operation involves a reduction in the metal volume. Therefore, a riser in or on the casting mold is regularly used to compensate for the volume deficiency during solidification of the casting and thus prevent the formation of cavities in the casting. The riser is connected to a dangerous casting or casting area and is usually present above and / or on the side of the mold cavity. For related details, see paragraph

[0003] of German Patent Application Publication No. 10 2012 200 967 A1.

[0004] European Patent No. 0 913 215B1 discloses a composition suitable for the manufacture of heat-insulating or heat-exciting risers and other filling funnels and feed elements for casting molds by blow molding and cold-box curing, the composition comprising (i) hollow alumina silicate microbeads having an alumina content of less than 38% by weight, (ii) a binder for cold-box curing, and optionally (iii) a filler in a non-fibrous form.

[0005] German Patent No. 10 104 289B4 discloses a moldable exothermic composition for manufacturing risers for the casting industry, comprising an easily oxidizable metal, an oxidizer for the easily oxidizable metal, a granular filler, and a binder, and containing a certain ratio of lithium silicate that affects the ignition properties.

[0006] German Patent No. 69716 Specification No. 248T2 relates to a riser having exothermic properties, thermal insulation properties, or both, which can be obtained by a cold box method, the cold box method comprising the steps of (A) introducing a riser mixture into a riser casting mold to produce an uncured riser, wherein the riser mixture comprises (1) a riser composition capable of producing a riser, comprising (a) an oxidizing metal and oxidizing agent capable of generating an exothermic reaction, or (b) an insulating refractory material, or (c) a mixture of (a) and (b), and (2) an effective amount of a chemically reactive cold box binder selected from phenolic resins, phenolic urethane binders, furan binders, alkaline phenol resol binders, and epoxy acrylic binders, (B) contacting the uncured riser produced in (A) with a vapor curing catalyst, (C) curing the riser obtained in (B) until it can be handled, and (D) removing the riser from the casting mold.

[0007] German Patent No. 10 065 270B1 discloses a moldable exothermic composition for manufacturing risers for the casting industry, comprising particulate (granular) fillers, an organic binder system, and an oxidizing agent for the binder system, wherein the composition contains 0% to 4% by weight of an easily oxidizable metal and the proportion of the oxidizing agent is in the range of 5% to 40% by weight. Also disclosed is a method for manufacturing a moldable exothermic composition for manufacturing risers for the casting industry, comprising the step of mixing an easily oxidizable metal, an oxidizing agent for the easily oxidizable metal, particulate fillers, a binder, and a certain amount of lithium silicate that affects the ignition properties.

[0008] German Patent Application Publication No. 196 17 938A1 discloses a riser insert comprising a mixture of thermal and / or heat-generating components bound together by a binder to give a molded body and conventional admixtures, wherein a polyurethane-based binder is used, the composition comprising a phenolic resin containing free OH groups and a polyisocyanate as a co-reactant, at least one of which is dissolved mainly or completely in a solvent consisting of a vegetable oil methyl ester.

[0009] The technical paper “Struktures of Cold-Box Binder Systems and the Possibility of Changes Thereto” by the authors F. Iden, U. Pohlmann, W. Tilch, and H. J. Wojtas, published in the technical journal Giesserei-Rundschau, 58, 1 / 2 (2011), discloses the fundamentals regarding the strength of cold-box binders.

[0010] Therefore, the prior art already discloses methods for manufacturing casting molds, cores, risers, and molded compounds.

[0011] The prior art further discloses that a riser section having insulating or heat-generating properties can be manufactured.

[0012] In the technical field of the present invention, it is generally required to manufacture casting molds, cores, risers, and molded compounds in a foundry with a low level of equipment complexity. In many cases, particularly in the manufacture of prototypes in the field of the present invention, the use of complex metering and mixing devices is undesirable.

[0013] Furthermore, it is necessary to avoid equipment complexity with respect to the curing of the molded compound. In many cases, in the field of the present invention, particularly in the iterative manufacturing of prototypes and the repair of surface defects, or in filling intended recesses in casting molds, cores, or risers, it is especially desirable that no equipment is required for metering, mixing, and curing.

[0014] Cavities frequently occur in the manufacturing of casting prototypes. Even with the use of appropriate risers, cavity formation cannot be prevented in all cases. In the field of the present invention, it is known that cavity formation can often be avoided by installing exothermic heating pads in appropriate locations on the corresponding casting mold or core. Such exothermic heating pads are known in the prior art, for example, in European Patent No. 1 728 571B1, German Patent Application Publication No. 199 205 70A1, or in Giesserei Lexikon [Foundry Lexikon] ("exothermes Heizkissen" [exothermic heating pad], page 198 in the Giesserei Lexikon, published by Simone Franke, Verlag Schiele und Schoen, Berlin; 20th edition, 2019; ISBN: 978-3-7949-0916-2).

[0015] The manufacture of heat-generating heating pads is costly and time-consuming, which is recognized as a disadvantage in the field of the casting industry. Furthermore, especially in the case of complex molding prototypes, it is often impossible to reliably predict the area and size where corresponding heat-generating heating pads must be provided, or whether cavity formation can be completely avoided by heat-generating heating pads in specific individual cases. Therefore, in the context of the present invention, it is particularly desirable to determine the location and amount in which heat-generating heating pads can be used in a particular casting mold to prevent cavity formation without incurring high costs and / or spending a lot of time.

[0016] In particular, there is a need for a method that fully or partially satisfies the aforementioned requirements and can be implemented in a foundry with high resource efficiency.

[0017] Furthermore, in the field of the present invention, there is a growing need for methods that can be implemented with high energy efficiency and environmentally friendly resource use. [Overview of the project] [Means for solving the problem]

[0018] The present invention - A method for manufacturing an article selected from the group consisting of a casting mold, a core, a riser, a molding compound for manufacturing a part of the casting mold, core, or riser, preferably a molding compound for manufacturing a prototype of the casting mold, core, or riser, or a molding compound for manufacturing a casting mold, core, or riser by repairing or completing a corresponding defective or incomplete article. - Articles selected from the group consisting of casting molds, cores, and risers, - A kit for use in the method of the present invention, - A method for manufacturing metal castings by metal casting in a casting mold. Regarding.

[0019] Specific embodiments, aspects, or features described or identified as preferred in connection with one of these categories are considered to be correspondingly applicable or equally applicable to each other category, and vice versa.

[0020] Unless otherwise stated, the preferred aspects or embodiments of the present invention and their various categories can be combined with other aspects or embodiments of the present invention and their various categories, particularly with other preferred aspects or embodiments. By combining the respective preferred aspects or embodiments with each other, further preferred aspects or embodiments of the present invention are generated.

[0021] In a main aspect of the present invention, there is provided a method for manufacturing an article selected from the group consisting of a casting mold, a core, a riser, and a self-hardening or curing molding compound for manufacturing a part of the casting mold, a core, or a riser, comprising: (S1) at a casting site, - a first component (A) containing a first binder component (b1) of a binder system and an amount of a first mold base material, and spatially separated therefrom, - a second component (B) containing a second binder component (b2) of the binder system and an amount of a second mold base material are generated or provided, wherein - the first binder component (b1) and the second binder component (b2) are suitable for mutual chemical reaction and for curing the mixture of the first component (A) and the second component (B), step, and (S2) mixing at least the first component (A) and the second component (B) by contacting them in a specific mass ratio to obtain a self-hardening molding compound The above problems are solved and the object is achieved by a method comprising at least the above steps.

[0022] In step (S2), the first component (A) and the second component (B) are mixed by contact in a predetermined mass ratio to obtain a self-hardening molding compound. Simultaneously or thereafter, one (third) or more additional components can also be brought into contact with the mixture of these two components. However, in many cases, in step (S2), it is preferred to use only the first component (A) and the second component (B). In some other cases, a third component is added during the mixing of the first component (A) and the second component (B) or after the mixing of these components. The preferred third component or additional components used are quite conventional admixtures (additives) already used in the practice of casting in the manufacture of the molding material mixture. For example, the third component used may be a coloring pigment. In some cases, it is preferred that the third component contains a catalyst (for curing the first binder component (b1) and the second binder component (b2) with each other). In other cases, it is preferred that the third component is a catalyst (for curing the first binder component (b1) and the second binder component (b2) with each other). The one or more additional components used become part of the self-hardening molding compound.

[0023] The first component (A) includes the first binder component (b1) of the binder system and a certain amount of the first mold base material. If appropriate, further constituent components are further present. The second binder component (b2) of the binder system is not present in the first component (A).

[0024] The second component (B) includes the second binder component (b2) of the binder system and a certain amount of the second mold base material. If appropriate, further constituent components are further present. The first binder component (b1) of the binder system is not present in the second component (B).

[0025] A self-hardening moldable compound is obtained only when the first component (A) and the second component (B) are mixed by contact in step (S-2), and the first binder component (b1) and the second binder component (b2) come into contact. In contrast, the first component (A1) contains only the binder component (b1) and does not contain the binder component (b2), and is therefore not a self-hardening moldable compound. Similarly, the second component (B1) contains only the binder component (b2) and does not contain the binder component (b1), and is therefore not a self-hardening moldable compound.

[0026] In many cases, one of the two components (A) and (B) contains (as a further component) a catalyst for curing the first binder component (b1) and the second binder component (b2) to each other.

[0027] The "manufacturing" of casting molds, cores, and risers preferably refers to manufacturing by repairing or completing the corresponding precursors.

[0028] The binder system used in the method of the present invention includes, or consists of, the two binder components described above, namely a first binder component (b1) and a second binder component (b2). In step (S1) of the method of the present invention, the first binder component (b1) and the second binder component (b2) each exist in spatially separated containers as components of either a first component (A) (containing the first binder component (b1)) or a second component (B) (containing the second binder component (b2)).

[0029] Preferred configurations of the method of the present invention are defined in the following description and in the appended claims.

[0030] Conventionally, methods known from the prior art required the addition of at least one mold base material and two binder components at the foundry site, even for simple self-hardening moldable compounds. As a result, such methods were often impractical due to unacceptable time requirements or equipment requirements, particularly in relation to the need for prototype manufacturing and repair (see above). Herein, the method of the present invention enables the production of self-hardening moldable compounds by mixing only two pre-manufactured or provided components, namely a first component (A) and a second component (B), by contacting them in a predetermined mixing ratio, eliminating the need for a dosing step at the foundry site involving individual substances (especially binder components) present in the first component (A) or the second component (B). Components (A) and (B) are, respectively, preferably non-self-hardening and have storage stability for several weeks.

[0031] In the method of the present invention, it is possible to use a number of binder systems, the components of which take the form of a first binder component (b1) and a second binder component (b2), and which are suitable for curing a mixture of the first component (A) and the second component (B) through chemical reactions with each other. In each case, the above binder components (b1) and (b2) can be combined with different mold base materials and, optionally, with further substances, and thus, even in the manufacture and / or provision of the first component (A) and the second component (B), a skilled selection of composition can result in the appropriate viscosity and curing time of the self-hardening molded compound produced in step (S2). In this way, according to the respective needs of each individual case, the requirements for the articles obtained as intermediates or products in the method of the present invention are met particularly easily and efficiently by the method of the present invention.

[0032] Components (A) and (B) manufactured or provided in step (S1), namely the first component (A) and the second component (B), each include, as one of several constituent components, amounts of the first and second mold base materials, respectively.

[0033] In the method of the present invention, it is preferable to use a refractory mold base material and / or an insulating filler as the mold base material. In some cases, it is preferable to use a combination of an insulating filler and a refractory mold base material as the mold base material in the method of the present invention. The appropriate selection of the mold base material used in the method of the present invention as a component of the first component (A) or the second component (B) allows the thermal conductivity or insulating properties of the molded compound produced in step (S2) and the article manufactured therefrom to be controlled.

[0034] In this text, “refractory” means, according to the customary understanding of those skilled in the art, not only a compound, material, and especially mold base material that can withstand thermal stress at least for a short time during casting operations or during the solidification of molten metal, preferably steel, iron, or cast iron molten metal, but also a compound, material, and especially mold base material defined as “refractory” in accordance with DIN 51060, June 2000, preferably bronze or aluminum molten metal. Suitable refractory mold base materials are natural and synthetic refractory mold base materials, such as quartz sand, zircon sand or chromite sand, olivine, vermiculite, bauxite or refractory clay.

[0035] The thermal insulation filler used is preferably a material having a lower thermal conductivity than the refractory mold base material described above. A thermal insulation filler suitable for use in the method of the present invention, selected from the group consisting of the following, is particularly preferred. - Hollow body, preferably a hollow sphere of fly ash, -Porous material, preferably perlite, or burnt rice husk ash, or burnt diatomaceous earth, closed-pore microspheres, - Core-shell particles, -and mixtures thereof.

[0036] Suitable calcined diatomaceous earth used in the context of the method of the present invention is described, for example, in German Patent Application Publication No. 10 2012 200 967A1. Suitable closed-pore hollow microspheres used in the context of the method of the present invention are described, for example, in International Publication No. 2017 / 174826A1.

[0037] A suitable insulating core-shell particle for use in the context of the method of the present invention is described, for example, in European Patent No. 2 139 626B1.

[0038] A first component (A) manufactured or provided in step (S1) comprises a certain amount of a first mold base material, and a second component (B) manufactured or provided spatially separately from the first component (A) in step (S1) comprises a certain amount of a second mold base material. In many cases, the first mold base material and the second mold base material used are different mold base materials. However, in many cases, it is also preferable to use the same mold base material as the first and second mold base materials.

[0039] In many cases, it is preferable that the first binder component (b1) in the first component (A) is partially or completely pre-mixed with the amount of the first mold base material, preferably completely pre-mixed, and the second binder component (b2) in the second component (B) is partially or completely pre-mixed with the amount of the second mold base material, preferably completely pre-mixed.

[0040] The term "molding compound" includes both "self-hardening molding compounds" and "hardened molding compounds." A "self-hardening molding compound" is an intermediate in the manufacture of a "hardened molding compound" or "hardened molded product" (of the first component (A) and the second component (B)). Casting dies, cores, and risers are articles containing or comprising a "hardened molding compound" or "hardened molded product" (of the first component (A) and the second component (B)) for the purpose of repairing or completing a corresponding (incomplete or defective) precursor (substrate). Self-hardening or hardened molding compounds are suitable for the manufacture of parts of casting dies, cores, or risers.

[0041] The "mixing by contact" between the first component (A) and the second component (B) in step (S2) begins as soon as the first component (A) comes into contact with the second component (B) and ends when the mixing operation yields a self-hardening moldable compound.

[0042] The term "self-hardening" means that the hardening proceeds without further means, but does not exclude further means to assist the hardening. Those skilled in the art will determine, according to the requirements of each individual case, whether or not the self-hardening of a self-hardening molded compound is assisted, or should be assisted, by a method to assist hardening in the implementation of the method of the present invention.

[0043] In step (S2), when the first component (A) and the second component (B) are mixed by contacting each other in a predetermined mass ratio, the mixing of the first component (A) and the second component (B) means that a predetermined mass of each individual component is used (for example, according to the formulation). In many cases, it is preferable that the first component (A) and the second component (B) in step (S1) are already manufactured or provided in their respective predetermined masses, so that the predetermined masses of components (A) and (B) are all used in step (S2). In these cases, there is no additional dosing step between the manufacturing or provision in step (S1) and the mixing of the first component (A) and the second component (B) in contact in step (S2) in a predetermined mass ratio.

[0044] These methods allow the aforementioned articles or parts of casting molds, cores, and risers to be manufactured particularly efficiently, saving time and resources, especially as prototypes and / or in the manufacture of repairs or completions of precursors.

[0045] The present invention relates, more particularly, to a method (as identified above as preferred and suitable) by which the self-hardening molding compound produced in step (S2) is kneaded mechanically and / or manually, preferably manually, and preferably homogeneously mixed in one or more subsequent steps (see also the details below relating to further step (S3)).

[0046] In many cases, in carrying out the method of the present invention, it is preferable that the obtained self-hardening molded compound is mixed by kneading, preferably homogeneously mixed by kneading, preferably by hand. In such cases, the material is a deformable, preferably manually deformable, modelable plastic mass. Therefore, preferably, the molded compound can be irreversibly deformed beyond its yield point by applying force, preferably by hand, and maintain the shape achieved after the force is applied. The self-hardening molded compound kneaded in the preferred method of the present invention is non-free flowable.

[0047] Following the mixing by contact in step (S2), preferably by manual kneading (preferably by kneading), in one development of the method of the present invention, a step of manual molding of the self-hardening molded compound, preferably onto another article, particularly preferably onto a molded body, for example, to complete or repair an incomplete or defective precursor (substrate). For example, manual filling of surface defects with the self-hardening molded compound, or manual modeling of the self-hardening molded compound onto the surface of a mold part, is also considered to be covered by manual molding, provided that these methods include manual compression and molding. The kneading operation, and preferably the molding operation of the molded compound, is preferably completed before the curing process of the molded compound is finished, or (even better) before curing. In this way, the breakdown of binder crosslinks already formed in the molded compound is avoided.

[0048] When the self-hardening moldable compound is mixed using the method of the present invention, it is often possible to work with fewer resources and, in some cases, to perform the method faster. For example, in the method of the present invention, mixing the self-hardening moldable compound in manual modeling of the self-hardening moldable compound onto the surface of a mold prototype results in a replica of the contour of these mold prototypes, eliminating the need to fabricate a mold for this purpose and eliminating the need to combine anything other than the first component (A) and the second component (B) on the foundry floor.

[0049] (S3) The self-hardening compound produced in step (S2) is shaped (preferably by hand) and cured to obtain a cured molded product of the first component (A) and the second component (B), wherein the cured molded product preferably forms an article or a region of an article upon completion of the manufacturing method. Includes, The method is preferably a manufacturing method by repair or completion. A preferred method of the present invention (as identified above as preferably suitable) for manufacturing an article selected from the group consisting of a casting mold, a core, and a riser is preferred.

[0050] In particular, in manufacturing methods involving restoration or completion, the hardened molded product forms a region of the article.

[0051] The self-hardening moldable compound produced in step (S2) by mixing the first component (A) and the second component (B) in a predetermined mass ratio is molded and hardened in step (S3) to become a hardened molded product of the first component (A) and the second component (B).

[0052] Preferably, the shaping of the self-hardening compound produced in step (S2) in step (S3) is a mixing operation, preferably a manual mixing operation, preferably mixing by manual mixing (see above).

[0053] The curing in step (S3) may be exclusively self-hardening, or may be assisted by, for example, the curing method described later or other curing methods known to those skilled in the art.

[0054] In many cases, the self-hardening of self-hardening molded compounds in the method of the present invention is not assisted by a method to aid in hardening. In particular, hardening does not occur in the presence of a gaseous catalyst and / or gaseous co-reactants.

[0055] However, in some cases, the curing of the self-hardening molded compound in the method of the present invention is assisted by the use of appropriate equipment and / or apparatus. The auxiliary means should be suited to the properties and curing mechanism of the first and second binder components (b1) and (b2).

[0056] Auxiliary treatment may also be carried out by controlled gas treatment of the molded material mixture (preferably formed by manual mixing) with air at a controlled temperature, as is known to those skilled in the art by the high-temperature curing (thermosetting) process. The air temperature is preferably 100°C to 250°C, more preferably 110°C to 180°C. Depending on the selected binder type (for example, when using a phenolic resin (phenol resol) condensed under alkaline conditions in combination with an oxyanion ("resol-CO2 method"), or when using water glass as a binder), the curing of the molded compound may also be assisted by gas treatment with CO2 or a mixture of CO2 and air.

[0057] The curing of the formed self-hardening compound is, in some preferred cases, also assisted by the action of microwaves or electromagnetic radiation, particularly infrared radiation. For this purpose, to accelerate the curing operation, the formed self-hardening compound can be stored in an oven or exposed to another heat source, such as an IR source or an open flame.

[0058] In some cases, the hardening of the fabricated self-hardening compound is also assisted by passing an electric current through the fabricated self-hardening compound. Further details are disclosed, for example, in German Patent No. 10 2017 217 098B3 and the documents cited herein.

[0059] The curing of the molded self-hardening compound is, in some cases, also assisted by the use of carbon dioxide, as described in chapter 1.5.3 of the textbook Buehring-Polaczek, Michael and Spur: Handbuch Urformen [Primary Forming Handbook] (2013), Carl Hanser Verlag GmbH & Co.KG, ISBN 978-3-446-42035-9.

[0060] The curing of the molded self-hardening compound is, in some cases, also assisted by the use of esters, for example, in British Patent No. 1029057 or in chapter 1.5.3 of the textbook Buehring-Polaczek, Michael and Spur: Handbuch Urformen (2013), Carl Hanser Verlag GmbH & Co.KG, ISBN 978-3-446-42035-9.

[0061] It is also possible to combine the low-temperature curing method and its applications in the additive manufacturing sector with the method of the present invention.

[0062] To say that the hardened product of the first component (A) and the second component (B) forms an article or a region of an article upon completion of the manufacturing method means that (i) the article consists only of the hardened product of the first component (A) and the second component (B), or (ii) the hardened product of the first component (A) and the second component (B) forms a region of the article, preferably a region of the article that comes into contact with the cast metal during casting, and the rest of the article consists of different materials.

[0063] In some cases, during the manufacture of a casting mold or core, undesirable defects occur on the surface of the casting mold or core intended to come into contact with the casting mold. Preferably, in such cases, the self-hardening molding compound produced in step (S2) is kneaded in the manner of the present invention, preferably by hand, and used for repair, i.e., for filling such surface defects, regardless of whether the casting mold or core is made of the same material as the hardened molded product formed from the self-hardening molding compound. If the defective casting mold or core is made of a different material than the hardened molded product, the hardened molded product forms a region in the finished article (e.g., the casting mold), i.e., a region created by the repair (e.g., a filled cavity). More preferably, the hardened molded product forms a region of the article that comes into contact with the liquid casting metal during casting.

[0064] In a preferred configuration of the method of the present invention, the article produced thereby, which consists essentially, preferably entirely, of a cured molded product of a first component (A) and a second component (B), is a contour pad. In the context of the present invention, the term “contour pad” is understood to mean a mold insert manufactured from a molding compound or molding material that forms a region of a casting mold that conforms at least partially to the contour of a subsequent casting. Contour pads that, due to their component materials, are capable of thermite reaction after activation by contact with liquid casting metal are also referred to herein as “exothermic heating pads,” according to the customary understanding of those skilled in the art. See also the further details regarding exothermic heating pads described herein. "Insulation pads" ("Isolierkissen" [insulation pads], pages 387-388 in the Giesserei Lexikon, edited by Simone Franke, Verlag Schiele und Schoen, Berlin; 20th edition, 2019; ISBN: 978-3-7949-0916-2), known to those skilled in the art, are similarly contour pads.

[0065] Such contour pads are preferably manufactured in a foundry, particularly by a molding box, using apparatus aids. Such separately manufactured contour pads are manufactured independently of the casting mold used for casting the workpiece.

[0066] Using the self-hardening compound produced in step (S2), such contour pads can be easily manufactured in a foundry, or even manually, as needed.

[0067] In many cases, the method of the present invention involves manually forming the self-hardening compound onto a model, preferably before manual forming. In these cases, the use of additional equipment and auxiliary tools is preferably avoided.

[0068] One or more contour pads, which are automatically manufactured on-site or manually formed (preferably by mixing), are preferably positioned or formed in recesses present in the substrate (i.e., precursor) of the casting mold. One or more corresponding contour pads preferably form an area of ​​the casting mold used to manufacture the casting, which comes into contact with the liquid casting metal during the casting operation.

[0069] In order to define at least a portion of the cavity for containing a cast metal, the method of the present invention (as identified above as preferably preferred) is preferred, wherein the article has a first boundary region and an adjacent, preferably adjacent, second boundary region of different composition, and the first boundary region is formed from a hardened product of a first component (A) and a second component (B). The second boundary region may be, for example, a portion of the substrate (precursor) of a casting mold. The first boundary region may be a portion of a filled recess in such a substrate. Such recesses are preferably filled during the manufacture of the article by repair or completion of the precursor.

[0070] Further details will become clear from the attached drawings and the explanations provided later in the text.

[0071] The method of the present invention (as identified above as preferably preferred) is preferred, wherein the first component (A) and / or the second component (B) comprises components present in at least one of the cured molded product after step (S3) or in the article after completion of the manufacturing method, and the components can be reacted with each other by heating in a thermite reaction, such as an aluminothermite reaction.

[0072] In many cases, it is preferable that the article after the manufacturing method is completed is in a form in which, by appropriate activation, at least the component materials of individual regions can react with each other in a strong exothermic reaction, preferably a thermite reaction, such as an aluminothermie reaction. In particular, it is preferable that these are regions of the article formed by the method according to the present invention.

[0073] The thermite reaction is known to those skilled in the art. In the method of the present invention, it is preferable that the thermite reaction is activated by a liquid metal during casting. In some cases, it is preferable that the thermite reaction occurs by casting using a liquid casting metal. In that case, the substances used in the method of the present invention are substances known to those skilled in the art that react with each other in a thermite reaction after appropriate activation, as components of one or both of the first component (A) and the second component (B) produced or provided in step (S1). For example, those skilled in the art may use aluminum for the first component (A) and / or the second component (B), and iron oxide for the same and / or other components of components (A) and (B), respectively. Similarly, other metals such as copper, nickel, titanium, chromium, and manganese may be added to enable the thermite reaction with aluminum. The specific components in the first component (A) and / or the second component (B) produced or provided, and their respective mass ratios, are selected by those skilled in the art according to the needs of each individual case.

[0074] The method of the present invention is more suitable for the manufacture of cast prototypes. This method allows for individual manual fitting of geometric shapes (particularly the first boundary region), thereby simplifying the iterative optimization of the manufacturing method. For example, in individual casting experiments, it is possible to test whether the use of a heat-generating pad is feasible for subsequent mass production, and if so, where it is possible, without incurring unfavorablely long time and / or high costs.

[0075] For example, in a first casting operation using a casting mold of a casting prototype, if cavity formation is present in or on the casting prototype, preferably, individual or multiple regions of the corresponding casting mold are reconfigured by the method of the present invention so that they essentially correspond functionally to a heat-generating heating pad.

[0076] In many cases, the method according to the present invention allows for the reproduction of the contours of the substrates by the molding compound through manual modeling and mixing of the self-hardening molding compound onto the surface of the mold substrate, eliminating the need to create a molding box and the need to administer anything other than the first component (A) and the second component (B) on-site at the foundry. Simultaneously, subject to the appropriate selection of materials (see above), heating, preferably by contact with liquid casting metal, yields a hardened molded product or a region of an article that can be reacted by a thermite reaction. Thus, in such a method configuration, individual or multiple regions of the mold are constructed in a way that saves time, cost, and resources, and functionally correspond to essentially exothermic heating pads.

[0077] Therefore, (without the complex separate manufacture of the heat-generating pads), a casting mold is manufactured, and one or more areas come into contact with the cast metal to release thermal energy, thus controlling and influencing the solidification properties of the cast metal in those areas. Conventional drawbacks associated with the manufacture of heat-generating pads are often completely or partially avoided when implementing the method of the present invention. These drawbacks include, for example, (i) the high cost of manufacturing tools suitable for manufacturing heat-generating pads and / or creating accurate geometric data of models tailored to the needs of individual cases, (ii) the long time required for manufacturing heat-generating pads, often unacceptably long in the field of industrial casting operations, and (iii) the high overall cost associated with manufacturing heat-generating pads. The method of the present invention often yields comparable, preferably equivalent, results while completely or partially avoiding the aforementioned drawbacks.

[0078] Preferably, the method of the present invention determines, in the form of a test method, whether the use of a heat-generating heating pad can avoid cavity formation without undesirably high costs and / or long time.

[0079] Furthermore, if the procedure proves to be fundamentally appropriate, the method of the present invention can determine the points, volume, and number of exothermic heating pads to be used in each casting mold for the casting prototype to avoid cavity formation, preferably without incurring high costs and / or long periods of time.

[0080] Therefore, the method of the present invention is performed before mass production of the heat-generating heating pads in that case.

[0081] In the method of the present invention, the molding compound, which is often composed of the first component (A) and the second component (B) produced in step (S2), is preferably kneaded before curing (preferably molded during or after the kneading process, and particularly molded or modeled into an article), and is then present in the cured molding product after step (S3), or in the article at the completion of the manufacturing method, and can be reacted by a thermite reaction by heating.

[0082] - The molding in step (S3) is done manually or automatically, preferably manually. and / or (preferably "and") -The manufacturing of the second boundary region involves using an automated molding system to fabricate a molding material (i.e., a molding material mixture including a mold base material (e.g., refractory mold base material or thermal filler), a binder, and optionally additives). The methods of the present invention (as described above and identified above as preferred) are preferred.

[0083] In some cases, in step (S3), the formation of the self-hardening molded compound produced in step (S2) is preferably automated, more preferably using apparatus aids, particularly a molding device. The molding device is preferably supplied with the self-hardening molded compound produced in step (S2) in a repeating sequence. In such cases, the self-hardening molded compound is used to produce a curable article in a continuous sequence. It is preferable to automatically produce “exotablets” or “exothermic lids” from the self-hardening molded compound, which are used, for example, in combination with natural risers. The term “exotablet” refers to a solid tablet produced from a molded compound or molding material, such as those sold as “exotablets” by HA KOVOCHEM. Exotablets may periodically lose strength under the action of heat released during casting with cast metal, and may even decompose to produce exothermic powder, thus functioning as exothermic riser covers.

[0084] The manufactured "exotablet" or "heat-generating lid" allows the casting operation to close the riser over the top surface of the molten material, thus providing insulation, and its preferably heat-generating action prevents premature cooling of the molten material within the riser.

[0085] However, in many cases, especially when a self-hardening compound is being mixed, it is preferable that the shaping in step (S3) be done manually, regardless of how the subsequent processing steps are carried out.

[0086] In an alternative or optional configuration of the method of the present invention, the generation of the second boundary region includes forming the molded compound using an automated molding system, preferably a molding system employing vertical shape separation. This preferably results in a portion of the mold forming a second boundary region adjacent to the first boundary region for containing the casting metal.

[0087] Such a molding system preferably has two model halves, one of which is specifically fixed to or attached to an essentially movable, more preferably linearly movable, plunger, and the second model half is preferably pivotable and simultaneously attached to a linearly movable mold plate. The first and second model halves at least form the lateral boundary of the molding chamber in the molding system, where molding material is introduced to form a second boundary region of the article to be manufactured. The second boundary region, which at least partially forms the article, can be molded using or without the self-hardening molding compound that forms the first boundary region to provide a part of the casting mold.

[0088] - Preferably, the first boundary region of the article is formed by creating a first boundary region on the model, and then the second boundary region is created on top of the first boundary region. or - First, the second boundary region of the article is formed, and then the first boundary region is formed on top of the second boundary region. The methods of the present invention (as described above and identified above as preferred) are preferred.

[0089] Further details will become clear from the attached drawings and the explanations provided later in the text.

[0090] The mixing of the first component (A) and the second component (B) by contact in step (S2) - At least partially manual, preferably entirely manual, and / or - At least partially, without electrical assistance for the mixing operation, The methods of the present invention (as described above and identified above as preferred) are preferred.

[0091] In a preferred configuration, the mixing by contact in step (S2) leads directly to a subsequent method step, such as a molding step (preferably step (S3)). In each case, mixing by contact by hand is preferred. However, mixing by contact can also be assisted or performed by machine.

[0092] Preferably, in the method of the present invention, contact mixing is performed manually, particularly when a self-hardening molding compound is kneaded by this method, preferably by hand. More preferably, contact mixing is performed manually.

[0093] - A step of filling intended or unintended recesses (i.e., completion or repair) in a surface area of ​​a mold component, preferably an area defining at least a portion of the cavity for housing the cast metal, with the self-hardening molding compound produced in step (S2). The method of the present invention, which includes (as described above, preferably identified above as preferred), is preferable.

[0094] This method is used, for example, when the repair of surface defects in a casting mold should be carried out particularly quickly, and especially when it is undesirable to transport the casting mold for repair. In many cases, in carrying out the method of the present invention, it is preferable that the mixing of the first component (A) and the second component (B) by contact in step (S2) be done manually (see above). The method of the present invention is then often carried out on-site so as not to delay the operating sequence. A contributing factor to this is the mixing, preferably by hand, of only the two components by bringing them into contact with each other in a predetermined mass ratio, preferably by kneading. In this way, the method can be carried out particularly easily by hand.

[0095] Furthermore, the method of the present invention can be used quickly and with high resource efficiency when it is necessary to impart heat-insulating or heat-generating properties only to individual areas of a casting mold. For example, such areas of a casting mold are first intentionally recessed or removed and then filled, i.e., completed, with a self-hardening molding compound in the method of the present invention.

[0096] Filling recesses in mold parts for repair or completion with a self-hardening molding compound preferably retrospectively forms a first boundary region. The molding compound is directly adjacent to the molding material forming a second boundary region. Recesses in the surface area of ​​the article are preferably filled using model sections or shape gauges that can be placed in this area. This ensures that a predetermined contour is created in the article, particularly in the casting mold, in the area of ​​the recess filled with the self-hardening molding compound, thereby producing the desired shape of the casting.

[0097] The method of the present invention (as described above, preferably identified above as preferred) is preferred, wherein the first component (A) and / or the second component (B) comprises a catalyst (c) for catalyzing the chemical reaction between the first binder component (b1) and the second binder component (b2).

[0098] In many cases, it is preferable that the first component (A) and / or the second component (B) include a catalyst (c) that catalyzes the chemical reaction between the first binder component (b1) and the second binder component (b2).

[0099] In many cases, the use of appropriate catalysts allows for acceleration of curing or adjustment of curing time, providing a reproducible period for curing of self-hardening molded compounds, and thus enabling this method to be carried out in many cases, particularly predictably, resource-efficiently, and without delay to other operational sequences, especially in foundries.

[0100] The components of the mold base material used in step (S1), preferably as the mold base material in the first component (A) and / or second component (B), are fire-resistant mold base materials designated as fire-resistant according to DIN 51060, and preferably, - Natural and synthetic mold base materials, and mixtures thereof Selected from the group consisting of, Preferably, all or partly, - Quartz sand, zircon sand or chromite sand, olivine, vermiculite, bauxite, refractory clay, and mixtures thereof Selected from the group consisting of, and / or The components of the mold base material used in step (S1), preferably as the mold base material, in the first component (A) and / or second component (B), are thermal insulation fillers, preferably - Hollow body, preferably a hollow sphere of fly ash, -Porous material, preferably perlite, or burnt rice husk ash, or burnt diatomaceous earth, closed-pore microspheres, - Core-shell particles Selected from the group consisting of, and / or - A first component (A) containing a binder component (b1), and / or -The second component (B) contains a binder component (b2), - Metallic materials selected from the group consisting of aluminum, magnesium, silicon, titanium, their alloys, and mixtures thereof with each other or with other metallic materials. - Preferably a metal oxide selected from the group consisting of iron oxide, manganese oxide, and mixtures thereof. - Lithium silicate, - Cordierite, and - Preferably an alkali metal nitrate selected from the group consisting of sodium nitrate, potassium nitrate, and mixtures thereof. Further comprising one, two, three, or four or more additional component materials independently selected from the group consisting of, The methods of the present invention (as described above and identified above as preferred) are preferred.

[0101] The enumerated component materials, and their use in molding compounds or articles manufactured therefrom, are known to those skilled in the art. The independent selection of one, two, three, or four or more additional component materials from the above group means that the selection of the first material does not affect the selection of one or more subsequent materials. Similarly, the selection of any further material does not affect the selection of subsequent materials.

[0102] A person skilled in the art will select the materials to be used according to the requirements of each individual case.

[0103] The binder system is (G1) Polyurethane no-bake type, The first binder component (b1) is preferably a polyol component, preferably selected from the group consisting of phenol resins, preferably ortho- ortho-condensed phenol resols, and aliphatic polyol compounds, and the second binder component (b2) is a polyisocyanate component, preferably a polyisocyanate component containing methylenedi(phenylisocyanate). The first component (A) and / or the second component (B) preferably comprises a catalyst (c) selected from the group consisting of 4-phenylpropylpyridine and liquid amines, preferably methylimidazole or vinylimidazole. Polyurethane no-bake type, (G2) Acid-curing cold resin, The first binder component (b1) is preferably, -Furan resin, phenolic resin, or a combination thereof Selected from, The second binder component (b2) is -Sulfonic acid, more preferably p-toluenesulfonic acid, xylenesulfonic acid, benzenesulfonic acid, methanesulfonic acid, - A mixture of sulfonic acid and an organic acid, more preferably a mixture of sulfonic acid and lactic acid, - A mixture of inorganic acids, preferably containing one or more sulfonic acids and / or one or more phosphoric acids in the mixture, Containing one or more acidic components independently selected from, Acid-curing cold resin and (G3) Inorganic binder system, Preferably an inorganic binder system containing water glass, more preferably (i) water glass and ester, or (ii) an inorganic binder system containing water glass and amorphous silicon dioxide. (G4) An epoxy resin wherein the first binder component (b1) preferably comprises an epoxy compound selected from the group consisting of glycidyl-based epoxy resins, bisphenol-based epoxy resins, novolac epoxy resins, aliphatic epoxy resins, and / or halogenated epoxy resins, and the second binder component (b2) comprises a polyfunctional amine selected from the group consisting of a polyfunctional aromatic amine, preferably 1,3-diaminobenzene, a polyfunctional aliphatic amine, preferably diethylenetriamine or 4,4'-methylenebis(cyclohexylamine), and / or dicarboxylic anhydride, preferably hexahydrophthalic anhydride. Selected from the group consisting of, The methods of the present invention (as described above and identified above as preferred) are preferred.

[0104] The use of the polyurethane no-bake system (G1) in the method of the present invention is often preferred. The polyurethane no-bake system (G1) is advantageous over the polyurethane cold-box binder system used in the prior art, for example, German Patent No. 10104289B1, as it eliminates the need for gas treatment with a gaseous catalyst (tertiary amine) and therefore does not require the complexity of the corresponding apparatus.

[0105] Generally, it is preferable to carry out the method of the present invention such that the hardening of the self-hardening molded compound produced in step (S2) does not occur in the presence of a gaseous catalyst and / or gaseous co-reactants.

[0106] The first binder component (b1) of the polyurethane no-bake binder system (G1) defined above does not contain polyisocyanate, and the second binder component (b2) of the polyurethane no-bake binder system (G1) defined above does not contain polyol.

[0107] However, depending on the requirements of each individual case, in some cases, the use of a different binder system may be preferable.

[0108] The first binder component (b1) of the acid-curing cold resin (G2) defined above does not include any acidic component selected from sulfonic acid, mixtures of sulfonic acid and organic acid, and mixtures of inorganic acid. The second binder component (b1) of the acid-curing cold resin (G2) defined above does not include any component selected from furan resin, phenolic resin, and combinations thereof.

[0109] The use of acid-curing cold resins in the method of the present invention is undesirable in embodiments in which the component materials are reacted by a thermite reaction through self-curing or appropriate activation after curing. Basically, the formulation should be designed so that the components of the binder system do not react undesirably with other components of the molding compound. Aluminum, for example, reacts with acids and alkalis to release hydrogen. Therefore, corresponding combinations should be avoided.

[0110] When the inorganic binder system (G3) is used in the method of the present invention, it is preferable that the first binder component (b1) comprises water glass, preferably water glass and a surfactant, and the second binder component (b2) comprises an ester, preferably an ester and fine amorphous SiO2. In this preferred variant, the first binder component of the inorganic binder system (G3) does not contain an ester or fine amorphous SiO2, and the second binder component of the inorganic binder system (G3) does not contain water glass.

[0111] The first binder component (b1) of the epoxy resin binder system (G4) defined above does not contain a polyfunctional amine, and the second binder component (b2) of the epoxy resin binder system (G4) defined above does not contain epoxy resin.

[0112] Those skilled in the art will preferably select the chemical compositions of the first binder component (b1) and the second binder component (b2) such that the reaction between the component material of the first binder component (b1) and the component material of the second binder component (b2) occurs only when the first component (A) and the second component (B) are mixed in contact in step (S2).

[0113] The self-hardening molding compound produced in step (S2) -82-98% by weight, preferably 84-96% by weight, more preferably 86-96% by weight, most preferably 92-95% mold base material. and / or -2 to 18% by weight, preferably 4 to 16% by weight, more preferably 4 to 14% by weight, and most preferably 5 to 8% by weight of components other than the mold base material. Includes, The weight percentage is based on the total mass of the self-hardening moldable compound. The methods of the present invention (as described above and identified above as preferred) are preferred.

[0114] Those skilled in the art will select the minimum ratio of the mold base material in the first component (A) and the second component (B), and in the self-hardening molded compound produced in step (S2), according to the requirements of each individual case.

[0115] In many cases, the methods of the present invention (as described above and identified above as preferably suitable) preferably use a refractory mold base material. Here, the self-hardening molding compound produced in step (S2) preferably includes the following: -Refractory mold base material up to 84% by weight, preferably 40% to 80% by weight, more preferably 60% to 80% by weight. This is preferably, - Natural and synthetic mold base mixtures, and their materials Selected from the group consisting of, Preferably, all or partly, - Quartz sand, zircon sand or chromite sand, olivine, vermiculite, bauxite, refractory clay, and mixtures thereof It is selected from the group consisting of the following.

[0116] In many cases, the methods of the present invention (as identified above as preferably suitable) prefer to use an insulating filler. Here, the self-hardening molding compound produced in step (S2) preferably includes the following: - Up to 84% by weight, preferably 40% to 80% by weight, more preferably 60% to 80% by weight of thermal filler. This is preferably, - Hollow body, preferably a hollow sphere of fly ash, -Porous material, preferably perlite, or burnt rice husk ash, or burnt diatomaceous earth, closed-pore microspheres, - Core-shell particles It is selected from the group consisting of the following.

[0117] Those skilled in the art will select the composition of the self-hardening compound produced in step (S2) according to the requirements of each individual case, so that articles having preferred properties in each case are obtained. More specifically, attention will be paid to the reactivity of the materials used, the density of the substances used, the thermal conductivity (thermal insulation), and the thermal stability.

[0118] The first mold base material and the second mold base material are - Having essentially the same or identical chemical composition, or - Having different chemical compositions, The methods of the present invention (as described above and identified above as preferred) are preferred.

[0119] Both variations are preferable depending on the requirements of the individual case and can be appropriately selected by those skilled in the art.

[0120] - The first mold base material and the second mold base material have different average particle sizes. or - The first mold base material and the second mold base material are, - Having essentially the same average particle size, and / or Having an average particle size of less than -1.3 mm, preferably 0.1 to 0.7 mm, more preferably 0.1 mm to 0.5 mm. The methods of the present invention (as described above and identified above as preferred) are preferred.

[0121] The (average) particle size is determined by sieving according to the worksheet from VDG Merkblatt (i.e., “Verein deutscher Giessereifachleute” [Society of German Foundry Experts]) p. 27 dated October 1999, point 4.3. This specifies the use of test sieves in accordance with DIN ISO 3310.

[0122] - The first and / or second mold base material is selected from the group consisting of natural and synthetic mold base materials and mixtures thereof, preferably all or partly selected from the group consisting of quartz sand, zircon sand or chromite sand, olivine, vermiculite, bauxite, refractory clay, and mixtures thereof. and / or - The first and / or second mold base material consists of at least a portion of recycled mold base material, preferably at least 30% by weight, more preferably at least 60% by weight, and most preferably at least 90% by weight of recycled mold base material. The methods of the present invention (as described above and identified above as preferred) are preferred.

[0123] The method of the present invention (as described above and identified above as preferred) is preferable in which, at the time of contact in step (S2), the temperatures of the first component (A) and the second component (B) are each in the range of 5 to 40°C.

[0124] In particular, the temperature range specified herein is preferred in step (S2) when there is manual mixing by contact between the first component (A) and the second component (B) in the method of the present invention in step (S2), preferably when there is manual mixing by contact between the first component (A) and the second component (B) in the method of the present invention in step (S2), and preferably when the self-hardening moldable compound is manually kneaded in one or more subsequent steps in step (S3). Thus, manual kneading can be performed without requiring heating or cooling between the mixing by contact in step (S2) and the manual kneading in one or more subsequent steps to generate desirable working conditions for manual processing. However, the specified temperature range is also preferred in many other cases, for example, when the self-hardening moldable compound is in a free-flowing form, or when there is no manual mixing in the method of the present invention.

[0125] - The cured compound contains components that can react with each other in a thermite reaction (preferably by heating), and / or (preferably "and") - The curing compound is 100 N / cm 2 Exceeding 200 N / cm², preferably 200 N / cm² 2 More preferably 300 N / cm² 2It has a bending strength exceeding (the bending strength is determined by a +GF+ test bar and by a MOREK Multiserw bending strength tester, preferably by referring to VDG-Merkblatt P72, October 1999 edition, points 4 and 5.3, using a GF test bar), and / or (preferably "and") - The self-hardening compound produced in step (S2) undergoes shaping and hardening in step (S3) within a period of 1 to 60 minutes, preferably 2 to 30 minutes, more preferably 5 to 20 minutes, and most preferably 5 to 10 minutes. The methods of the present invention (as described above and identified above as preferred) are preferred.

[0126] For details on the thermite reaction and the substances to be used, please refer to the above information.

[0127] After the mixing of the first component (A) and the second component (B) by contact in step (S2), - A step of placing a self-hardening moldable compound in a molding chamber or molding box, preferably in contact with a model or model plate, wherein the placement preferably includes the formation of the self-hardening moldable compound. -The next step is to introduce a molding material into a molding chamber or molding box during or after the curing of the self-hardening molding compound, wherein the molding compound placed in the molding chamber or molding box is preferably surrounded in at least a portion of the area by the molding material. A preferred method of the present invention is one that produces an article selected from the group consisting of a casting mold, a core, and a riser (as identified above as preferably preferred).

[0128] In this configuration of the method of the present invention, the self-hardening molding compound is specifically placed within a molding chamber or molding box. A preferred configuration assumes that the self-hardening molding compound is placed within a molding chamber or molding box, and the molding compound is preferably in contact with the model or model plate. The self-hardening molding compound is preferably placed at a predetermined site or location that comes into contact with the liquid casting metal during casting using the liquid casting metal. Preferably, the self-hardening molding compound at each site or location contributes to keeping the casting metal in a liquid state for a minimum period, more preferably a predetermined minimum period.

[0129] During the curing of the self-hardening molding compound, or even after the curing of the molding compound, a molding material is introduced into the molding chamber or molding box in a subsequent step. Often, a molding material having a different chemical composition from the self-hardening molding compound disposed in the molding chamber or molding box in the previous step is used for this purpose. The molding material then added in the subsequent step forms a second boundary region in the resulting article having a different composition to define at least a portion of the cavity for containing the casting metal.

[0130] The step of placing the self-hardening compound into a molding chamber or molding box is, - A step of forming a self-hardening moldable compound on a model plate defining a molding chamber and / or on a molding model forming a mold cavity of an article to be manufactured, wherein the self-hardening moldable compound preferably comprises components that can react with each other by a thermite reaction (preferably by heating), and / or - A casting mold is manufactured by placing the riser or core inside a molding chamber or molding box, wherein the region of the riser and / or core is a hardened molded product of the first component (A) and the second component (B). The method of the present invention, which includes (as described above and identified above as preferably preferred), is preferable.

[0131] For details on the thermite reaction and the substances to be used, please refer to the above information.

[0132] The formation of the self-hardening compound onto a model plate defining the molding chamber for a casting mold, and / or onto a build model forming the mold cavity for the article to be manufactured, is preferably done manually. The self-hardening compound is formed on the intended area of ​​the model plate and / or build model after mixing by contact of a first component (A) and a second component (B). More preferably, the area of ​​the model plate and / or build model to which the self-hardening compound has been applied defines a surface area that, after removal of the model plate or build model, defines at least a portion of the cavity for containing the casting metal.

[0133] Alternatively, or optionally, the self-hardening molding compound is placed in the molding chamber or molding box by inserting a riser or core into the molding chamber or molding box. Rather than introducing a molding compound that is still mixable and then self-hardens into the molding chamber or molding box, it is preferable to place an already hardened molding compound into the molding chamber or molding box as a hardened molding product in the form of a riser or core (or part thereof). The hardened molding product is preferably formed in step (S3) of the method of the present invention.

[0134] Such risers or cores are preferably pre-fabricated products, which consist of at least a portion of a hardened molded product of a first component (A) and a second component (B), which are mixed and molded by hand or automatically, preferably by hand, to produce the product. Upon contact with the cast metal introduced into the finished casting mold, there is preferably a thermite reaction of the hardened molded product, which keeps the cast metal in a liquid state for an extended period in the cavity region to which the hardened molded product is applied. This influences the solidification properties of the casting region under control, and thus reduces, preferably avoids, undesirable material defects in the casting.

[0135] The method of the present invention (as identified above as preferably preferred) is preferred, in which the manufactured article is separated from the model plate or modeling template.

[0136] Articles can be manufactured, for example, in a molding chamber of an automated molding system. For this purpose, a molding material is injected into the molding chamber and preferably compacted therein. The molding chamber is a molding space for manufacturing articles, and its wall region defines the area of ​​the article to be manufactured. The mold base material used is preferably natural sand, semi-synthetic molding sand, or synthetic molding material, which is introduced into the molding chamber and preferably injected into the molding chamber under high pressure.

[0137] The introduction of the molding material preferably involves pre-compacting the molding material. The molding material introduced into the molding chamber is preferably further compacted by the compressive force acting on it.

[0138] Compaction can be performed, for example, using two relatively movable model plates in an automated molding system. To generate relative motion between the model plates, at least one of the model plates is moved linearly relative to the other. This reduces the distance between the model plates and compresses the molding material present. The model plates, which are essentially parallel to each other, are surrounded by fixed chamber walls. After compaction of the molding material, the article is solidified to the extent that it can be separated from the model plates or the molding model. Separating the article from the model plates and / or the molding model makes the cavity of the manufactured article accessible for housing the casting metal.

[0139] The method of the present invention is carried out using conventional molding boxes, often with a high proportion of manual labor, rather than by an automated manufacturing process.

[0140] In a further embodiment, the present invention relates to an article selected from the group consisting of casting molds, cores, and risers, which can be manufactured by the methods of the present invention described above, preferably identified above as suitable, and comprising a first region formed from a cured product of a first component (A) and a second component (B), and a second region formed from a material of a different composition.

[0141] The present invention is based on the finding that castings can be manufactured using articles of the present invention, which take the form of casting molds, cores, or risers, and which can preferably be manufactured by the methods of the preferred embodiments described above, and whose solidification characteristics can be controlled and influenced during the cooling operation, thus avoiding the generation of material defects in the castings. Articles of the present invention include at least one region, also called a first region, formed from a hardened product of a first component (A) and a second component (B). Preferably, such articles manufactured according to the present invention may have a plurality of such first regions composed of hardened products.

[0142] The second region preferably consists of materials of different compositions. The article preferably consists mainly of the above materials having different compositions, i.e., more than 50%, preferably more than 80%, and is therefore not a product of the first component (A) and the second component (B).

[0143] Preferably, the article of the present invention (as identified above as preferably preferred) has a first boundary region and an adjacent, preferably adjacent, second boundary region of different composition, wherein the first boundary region is formed from a hardened product of a first component (A) and a second component (B), in order to define at least a portion of the cavity for containing the cast metal.

[0144] In the article of the present invention, the hardened product comprising the first component (A) and the second component (B) forms at least one surface region that defines at least a portion of the cavity for housing the casting metal. The hardened product of the first component (A) and the second component (B) produced in step (S3) of the preferred method of the present invention is preferably disposed near the surface of the mold cavity or forms a portion of the surface in, for example, a casting mold, core, or riser.

[0145] In many cases, it is preferable that the hardened molded product contains components that come into contact with the liquid casting metal and react with each other in a thermite reaction. Therefore, the hardened molded product of the first component (A) and the second component (B) is preferably introduced into the cavity of the casting mold or comes into direct contact with the casting metal rising within the riser. As a result, preferably, the first boundary region of the cavity formed from the hardened molded product of the first component (A) and the second component (B) is heated by the casting metal to obtain the starting temperature to be achieved for the subsequent thermite reaction. The second boundary region defining the cavity for containing the casting metal is formed from a material of a different composition, for example, a molding material used to form the casting mold or individual mold parts of the casting mold, or for the core and / or riser. The corresponding molding materials are conventional in the field of the casting industry and are known to those skilled in the art.

[0146] The present invention further states that, at least, -As a first component of the kit, or within the first component, a certain amount of first component (A) containing a first binder component (b1) and mold base material, - As a second component of the kit, or within the second component, a certain amount of the second component (B) containing the second binder component (b2) and the mold base material. Includes, The first and second components of the kit are arranged in spatially separated positions. This relates to a kit for use in the manner described above (preferably identified above as suitable).

[0147] The advantages described above in relation to the method and article of the present invention are particularly advantageous when using the kit of the present invention.

[0148] In a further embodiment, the present invention relates to a method for manufacturing a metal casting by metal casting in a casting mold, -A step of manufacturing an article selected from the group consisting of a casting mold, a core, and a riser, by a method of the present invention as described above, preferably identified above, and inserting the article to define at least a portion of a cavity for containing a casting metal, wherein the article has a first boundary region and adjacent, preferably adjacent, second boundary regions of different compositions, the first boundary region being formed from a hardened molding product of a first component (A) and a second component (B), - The step of bringing the cast metal into contact with at least a first boundary area of ​​an article manufactured during casting. Regarding methods including

[0149] The present invention's method for manufacturing metal castings contributes to the simple manufacture of metal castings and to the influence of their solidification properties during cooling in the casting operation, thereby preventing casting defects and ensuring that the finished castings are free from material defects. For this purpose, both the casting mold and core to be used in the manufacture of the casting, and the riser conventionally used to seal the cavity of the casting mold, can be made, at least in part, of a hardened molded product (hardened molded compound) produced from a first component (A) and a second component (B). The present invention's method is particularly suitable for the manufacture of casting prototypes. This method allows for individual adjustment of the geometry (especially boundary regions) by hand, thereby simplifying the optimization of the iterative manufacturing process.

[0150] The article produced in the first method step includes a first boundary region comprising (at least) a hardened product (hardened compound), the first boundary region defining a cavity in at least a portion of the area for accommodating a cast metal. Adjacent to this, preferably adjacent, a second boundary region having a different composition is provided (at least).

[0151] At the moment the casting metal comes into contact with the first boundary region of the article being manufactured during the casting operation, the first boundary region is heated. In a preferred configuration, the thermite reaction is initiated after the hardening compound forming the first boundary region of the cavity for the casting metal reaches a predetermined starting temperature. As a result, in this configuration, a specific volume region of the casting metal remains liquid and solidifies more slowly than other volume regions of the casting metal. Therefore, the method of the present invention makes it possible to avoid or reduce the occurrence of casting defects in the casting. See the corresponding details below. Those details are also applicable here.

[0152] The preferred embodiments or developments described above with respect to the method of the present invention for manufacturing articles are also preferred embodiments of the method of the present invention for manufacturing articles, kits for use, and metal castings. At the same time, the preferred embodiments or developments described with respect to the method of the present invention for manufacturing metal castings, articles, and kits for use are also preferred embodiments of the method of the present invention for manufacturing articles and the like.

[0153] The present invention will be described in detail below with reference to examples.

[0154] The mixing ratios and materials used, namely the mold base material, binder components, catalyst, and other components, are merely examples; different concentrations, materials, and combinations of materials can also be used. Please refer to the above description for corresponding properties.

[0155] The Pentex 34V44, Pentex 35V92, Pentex 36003, and Pentex 36003B components used were sourced from HA France (ZI de Pont-Brenouille, BP 309, 60723 Pont Ste Maxence, France). The quartz sand used was Type H32 quartz sand from Quarzwerke GmbH. [Examples]

[0156] Example 1 - Manufacture and use of self-hardening moldable compound This example illustrates, as an example, the performance of the present invention's method for producing self-hardening moldable compounds with and without the use of a thermite mixture.

[0157] 1.1 Generation of the first component (A) 1.1-1 Formation of the first component (A) (which does not contain any substances that can be reacted by thermite reaction upon heating); hereafter referred to as the first component (A-0). In one experiment (at a foundry), 1000 g of H32 quartz sand (manufactured by Quarzwerke GmbH, AFS particle size number 45; as an example - other mold base materials can also be used in the method of the present invention), 70 g of Pentex 34V44 (o,o' condensed phenol resol in an aliphatic solvent; as an example of the first binder component (b1) - other substances can also be used as the first binder component (b1) in the method of the present invention), and 1.4 g of Pentex 36003 (methylimidazole in an aromatic solvent; equivalent to 2% by weight based on the amount of Pentex 34V44 used; as an example of a catalyst - other catalysts can also be used in the method of the present invention) were placed in a first container (container 1.1-1), transferred to a vibrating mixer (manufactured by KLEIN, model SM511) and mixed for 30 seconds to obtain a mixture as an example of the first component (A) containing the first binder component (b1) of the binder system and a certain amount of the first mold base material.

[0158] 1.1-2 Formation of the first component (A) (including substances that can be reacted by thermite reaction upon heating); hereinafter also referred to as the first component (AT). In the composition according to Example 1.1-1, 1000 g of quartz sand was replaced with a conventional thermite mixture containing aluminum powder, powdered Fe2O3, potassium nitrate powder, filler, and starter (as an example of substances that can react with each other in a thermite reaction upon heating), and container 1.1-2 was used instead of container 1.1-1. Thus, apart from these modifications following the procedure from Example 1.1-1, a mixture was produced as an example of a first component (A) (component (AT)) containing a first binder component (b1) of the binder system, a certain amount of first mold base material, and substances that can react with each other in a thermite reaction upon heating.

[0159] 1.2 Generation of the second component (B) 1.2-1 Formation of the second component (B) (which does not contain any substances that can be reacted by thermite reaction upon heating); hereafter referred to as the second component (B-0). In one experiment (at a foundry), 1000 g of H32 quartz sand (manufactured by Quarzwerke GmbH, AFS particle size number 45; as an example - other mold base materials can also be used in the method of the present invention) and 70 g of Pentex 35V92 (p-MDI in an aliphatic solvent; as an example of the second binder component (b2) - other substances can also be used as the second binder component (b2) in the method of the present invention) were placed in a second container (container 1.2-1) spatially separated from the first container (container 1.1-1 or 1.1-2), and mixed for 30 seconds in a vibrating mixer (manufactured by KLEIN, model SM511) to obtain a mixture (component (B-0)) as an example of the second component (B) containing the second binder component (b2) of the binder system and a certain amount of the second mold base material.

[0160] 1.2-2 Formation of the second component (B) (including substances that can be reacted by thermite reaction upon heating); hereafter referred to as the second component (BT). In the composition according to Example 1.2-1, 1000 g of quartz sand was replaced with a conventional thermite mixture containing aluminum powder, powdered Fe2O3, potassium nitrate powder, filler, and starter (as an example of substances that can react with each other in a thermite reaction upon heating), and container 1.2-2 was used instead of container 1.2-1. Thus, apart from these modifications following the procedure from Example 1.2-1, a mixture was produced as an example of a second component (B) (component (BT)) containing a second binder component (b2) of the binder system, a certain amount of second mold base material, and substances that can react with each other in a thermite reaction upon heating.

[0161] 1.3 Mixing by contact between the first component (A) and the second component (B) 1.3-1 Mixing of the generated first component (A-0) and second component (B-0) by contact. All of the first component (A) (component (A-0)) produced according to Example 1.1-1 above and the second component (B) (component (B-0)) produced according to Example 1.2-1 above were transferred under nitrogen from their respective containers (containers 1.1-1 and 1.2-1) to individual screw-top containers (containers 1.1-1N and 1.2-1N) and stored for approximately 6 weeks. To produce a self-hardening moldable compound, equal amounts of component A (component (A-0)) and component B (component (B-0)) were mixed and kneaded together by hand in a mixing container (container 1.3-1) for approximately 2 minutes to produce a self-hardening moldable compound.

[0162] 1.3-2 Mixing of the generated first components (AT) and (BT) by contact to obtain a self-hardening molding compound. All of the first component (A) (component (AT)) produced according to Example 1.1-2 above, and the second component (B) (component (BT)) produced according to Example 1.2-2 above, were transferred to separate screw-top containers (containers 1.1-2N and 1.2-2N) under nitrogen and stored for approximately 6 weeks. To produce the self-hardening moldable compound, equal amounts of component A (component (AT)) and component B (component (BT)) were mixed and kneaded together by hand in a mixing container (container 1.3-2) for approximately 2 minutes to produce the self-hardening moldable compound. Similarly, note that (A-0) and (BT) or (AT) and (B-0) can also be combined.

[0163] 1.4 Fabrication of self-hardening moldable compounds onto prototype models In each case, one self-hardening moldable compound, prepared and mixed according to Examples 1.3-1 and 1.3-2 above, was formed into a prototype model by compression mixing and allowed to harden at room temperature (approximately 20°C). After a waiting period of approximately 30 minutes, each self-hardening moldable compound had hardened to a degree suitable for use as part of a mold component in cast iron.

[0164] 1.5 Restoration of the substrate As substrates (precursors), each has surface defects (defect volume approximately 20 cm³). 3 Two casting dies having the following characteristics were prepared. One self-hardening moldable compound, produced and mixed according to Examples 1.3-1 and 1.3-2 above, was formed into the respective surface defects by compression mixing. Then, using a spatula, the contour of the introduced moldable compound was matched to the contour profile of each casting die. After a waiting time of about 30 minutes at room temperature (about 20°C), each self-hardening moldable compound hardened to a degree that a casting die usable in cast iron (as an example of an article manufactured by repair) was obtained.

[0165] Example 2 - Effect of binder amount on strength and treatment time To investigate the effect of binder quantity on strength and processing time, mixtures containing three different binder components were prepared. All examples were carried out using H32 quartz sand as the substrate (mold base material).

[0166] 2.1 Formation of the first component (A) (not containing any substance that can be reacted by thermite reaction upon heating) In this experiment, 1000 g of H32 quartz sand (Quarzwerke GmbH, AFS particle size number 45), Pentex 34V44 (o,o'-resol in an aliphatic solvent), and Pentex 36003 (methylimidazole in an aromatic solvent; equivalent to 2% by weight based on the amount of Pentex 34V44 used) were placed in appropriate amounts according to Table 1 into the first containers (containers 2.1-1, 2.1-2, and 2.1-3), transferred to a vibrating mixer (KLEIN, model SM511), and mixed for 30 seconds to obtain a mixture (component A1, component A2, or component A3) as an example of a first component (A) containing a first binder component (b1) of the binder system and a certain amount of the first mold base material. A total of three mixtures were produced according to the formulations specified in Table 1.

[0167] [Table 1]

[0168] 2.2 Generation of the second component (B) In this experiment, 1000 g of thermite mixture (Chemex) and Pentex 35V92 (p-MDI in an aliphatic solvent) were placed in appropriate amounts according to Table 2 into second containers (containers 2.2-1, 2.2-2, and 2.2-3) spatially separated from the first containers (containers 2.1-1, 2.1-2, and 2.1-3) in each case. The mixtures were then transferred to a vibrating mixer (KLEIN, model SM511) and mixed for 30 seconds to obtain a mixture in each case that served as an example of a second component (B) (component B1, component B2, or component B3) containing a second binder component (b2) of the binder system and a certain amount of second mold base material. A total of three mixtures were produced according to the formulations specified in Table 2.

[0169] [Table 2]

[0170] 2.3 Mixing of the generated first component (A) and the generated second component (B) From each container (containers 2.1-1, 2.1-2, and 2.1-3 containing component (A); containers 2.2-1, 2.2-2, and 2.2-3 containing component (B)), all of the amounts of the first component (A) produced according to Example 2.1 and the second component (B) produced according to Example 2.2 were filled into individual screw-top containers (containers 2.1-1N, 2.1-2N, and 2.1-3N containing component (A); containers 2.2-1N, 2.2-2N, and 2.2-3N containing component (B)) under nitrogen and stored for approximately 6 weeks. To produce self-hardening moldable compounds, equal parts by weight of component (A) and component (B) were brought into contact by hand for approximately 2 minutes in each of the third mixing containers (containers 2.3-1, 2.3-2, and 2.3-1) to thoroughly mix and knead them together; in each case, component (A1) (according to Table 1) was mixed with component (B1) (according to Table 2), component (A2) (according to Table 1) was mixed with component (B2) (according to Table 2), and component (A3) (according to Table 1) was mixed with component (B3) (according to Table 2) to obtain self-hardening moldable compounds in each case. That is, moldable compound material (F2-1) was obtained from components (A1) and (B1), moldable compound (F2-2) from components (A2) and (B2), and moldable compound (F2-3) from components (A3) and (B3).

[0171] 2.4 Fabrication of self-hardening moldable compounds onto prototype models In each case, one self-hardening moldable compound (molding compound (F2-1), (F2-2), and (F2-3)) mixed according to Example 2.3 above was formed into a prototype model by mixing and compression, and then left to self-harden at room temperature (approximately 20°C). After a waiting period of approximately 30 minutes, the self-hardening moldable compound had hardened to a degree that it could be used as part of a mold component in cast iron in each case.

[0172] 2.5 Restoration of the substrate As a substrate (precursor), surface defects (defect volume approximately 20 cm³) are present in each case. 3 A single casting mold having the following characteristics was prepared. In each case, one self-hardening moldable compound (molding compound (F2-1), (F2-2), and (F2-3)), mixed according to Example 2.3 above, was formed into the respective surface defects by compression mixing. Then, using a spatula, the contour of the introduced molding compound was matched to the contour profile of each casting mold. After a waiting time of about 30 minutes at room temperature (about 20°C), the self-hardening moldable compound hardened in each case to the extent that a casting mold usable in cast iron (as an example of an article manufactured by repair) was obtained.

[0173] 2.6 Study on the working time of molding material mixtures The working time of the mixture (see the value in "Working Time" in Table 3) is determined by placing one newly produced molded compound (molded compounds (F2-1), (F2-2), and (F2-3)) according to Example 2.3 above into a container (containers 2.6-1, 2.6-2, and 2.6-3), manually compacting the mixture in each case, and smoothing the surface. Immediately after smoothing, a stopwatch is started. Then, using a shape compression tester (GF80 type, manufactured by Georg Fischer AG), the surface is tested at regular intervals using the ball indentation method (ball diameter 4 mm) until a value of 80 is reached. This time is recorded in minutes (rounded) as the "Working Time" of the mixture (see the value in "Working Time" in Table 3).

[0174] 2.7 Study on the release time of molding material mixtures The peeling time of the mixture (see the values ​​in "Peeling Time" in Table 3) was determined using a testing machine (Model VC40, PROLABO) as follows: Each of the newly generated mixtures (molding compounds (F2-1), (F2-2), and (F2-3)) according to Example 2.3 above was placed in containers (containers 2.7-1, 2.7-2, and 2.7-3), and the mixture was manually compacted in each case to smooth the surface. Immediately after smoothing, a stopwatch was started. In each case, the container was placed under the needle of the testing machine (weighing 300g, with a diameter of 1mm), and the test was conducted until the needle no longer penetrated the sand mixture. At this point, the stopwatch was stopped, and the time was recorded as peeling time in minutes (rounded) (see the values ​​in "Peeling Time" in Table 3).

[0175] [Table 3]

[0176] Example 3 - Effect of catalyst amount on intensity and treatment time To determine the effect of catalyst quantity on strength and processing time, mixtures were prepared with three different amounts of catalyst. All examples were carried out using silica sand as the base material (mold base material).

[0177] 3.1 Generation of the first component (A) In one experiment (at a foundry), 1000g of H32 quartz sand (manufactured by Quarzwerke GmbH, AFS particle size number 45; as an example - other mold base materials can also be used in the method of the present invention), Pentex 34V44 (o,o' condensed phenol resol in an aliphatic solvent; as an example of the first binder component (b1) - other substances can also be used as the first binder component (b1) in the method of the present invention), and Pentex 36003B (methylimidazole in an aromatic solvent; Pentex used) Based on the amount of 34V44, an amount equivalent to 2% by weight (as an example of a catalyst - other catalysts can also be used in the method of the present invention) was placed in each of the first containers (containers 3.1-1, 3.1-2, and 3.1-3) in the amounts described for the mixtures for molding compounds F3-1, F3-2, and F3-3 in Table 4, and each was transferred to a vibrating mixer (KLEIN, model SM511) and mixed for 30 seconds to obtain a mixture as an example of a first component (A) containing a first binder component (b1) of the binder system and a certain amount of first mold base material.

[0178] 3.2 Generation of the second component (B) In one experiment (at a foundry), 1000 g of H32 quartz sand (manufactured by Quarzwerke GmbH, AFS particle size number 45) and 5 g of Pentex 35V92 (p-MDI in an aliphatic solvent) were placed in second containers (containers 3.2-1, 3.2-2, and 3.2-3) spatially separated from the first containers (containers 3.1-1, 3.1-2, and 3.1-3), and mixed for 30 seconds in a vibrating mixer (manufactured by KLEIN, model SM511) to obtain a mixture as an example of a second component (B) containing a second binder component (b2) of the binder system and a certain amount of second mold base material.

[0179] 3.3 Mixing of the generated first component (A) and the generated second component (B) From each container (containers 3.1-1, 3.1-2, and 3.1-3 containing component (A); containers 3.2-1, 3.2-2, and 3.2-3 containing component (B)), all of the amounts of the first component (A) produced according to Example 3.1 and the second component (B) produced according to Example 3.2 were filled into individual screw-top containers (containers 3.1-1N, 3.1-2N, and 3.1-3N containing component (A); containers 3.2-1N, 3.2-2N, and 3.2-3N containing component (B)) under nitrogen and stored for approximately 6 weeks. To produce the self-hardening moldable compound, equal parts by weight of component (A) and component (B) were brought into contact by hand in a mixing container (containers 3.3-1, 3.3-2, 3.3-3, 3.3-4, 3.3-5, and 3.3-6) for approximately 2 minutes, thoroughly mixed and kneaded to obtain the self-hardening moldable compound (in each case, the resulting components (A) and (B) were mixed with each other to obtain mixtures according to the formulations specified in Table 4, i.e., moldable compounds (F3-1), (F3-2), and (F3-3)).

[0180] 3.4 Fabrication of self-hardening moldable compounds onto prototype models In each case, one self-hardening moldable compound (molding compound (F3-1), (F3-2), and (F3-3)) mixed according to Example 3.3 above was formed into a prototype model by mixing and compression, and then left to self-harden at room temperature (approximately 20°C). After a waiting period of approximately 30 minutes, each self-hardening moldable compound had hardened to a degree suitable for use as part of a mold component in cast iron.

[0181] 3.5 Restoration of the substrate As a substrate (precursor), surface defects (defect volume approximately 20 cm³) are present in each case. 3A single casting mold having the following characteristics was prepared. In each case, one self-hardening moldable compound (molding compound (F3-1), (F3-2), and (F3-3)), mixed according to Example 3.3 above, was formed into the respective surface defects by compression mixing. Then, using a spatula, the contour of the introduced molding compound was matched to the contour profile of each casting mold. After a waiting time of about 30 minutes at room temperature (about 20°C), the self-hardening moldable compound hardened in each case to the extent that a casting mold usable in cast iron (as an example of an article manufactured by repair) was obtained.

[0182] 3.6 Study on the working time of molding material mixtures The working time of the mixture (see the value in "Working Time" in Table 4) is determined by placing one newly prepared mixture (molding compounds (F3-1), (F3-2), and (F3-3)) prepared according to Example 3.3 in each case into a container (containers 3.6-1, 3.6-2, and 3.6-3), manually compacting the mixture in each case, and smoothing the surface. Immediately after smoothing, a stopwatch is started. Then, using a shape compression tester (GF80 type, manufactured by Georg Fischer AG), the surface is tested at regular intervals using the ball indentation method (ball diameter 4 mm) until a value of 80 is reached. This time is recorded in minutes (rounded) as the "Working Time" of the mixture (see the value in "Working Time" in Table 4).

[0183] 3.7 Study on the peeling time of molding material mixtures The peeling time of the mixture (see the values ​​in "Peeling Time" in Table 4) was determined using a testing machine (Model VC40, PROLABO) as follows: Each of the newly generated mixtures (molding compounds (F3-1), (F3-2), and (F3-3)) according to Example 3.3 above was placed in containers (containers 3.7-1, 3.7-2, and 3.7-3), and the mixture was manually compacted in each case, and the surface was smoothed. Immediately after smoothing, the stopwatch was started. In each case, the container was placed under the needle of the testing machine (weighing 300 g, with a diameter of 1 mm) and moved downwards repeatedly until the needle no longer penetrated the sand mixture. At this point, the stopwatch was stopped, and the time was recorded as peeling time in minutes (rounded) (see the values ​​in "Peeling Time" in Table 4).

[0184] [Table 4]

[0185] The present invention will be described in detail below with reference to the attached schematic diagram and to preferred working examples of methods for manufacturing articles or castings. [Brief explanation of the drawing]

[0186] [Figure 1] This is a diagram of the provided model plate and the model placed on it. [Figure 2] This is a diagram of a model plate and other models having a self-hardening moldable compound fabricated in the critical region for metal casting in a 3D model. [Figure 3] This is a detailed view of a molding chamber or molding box, in which a model plate and a model having a self-hardening compound are arranged, and the molding chamber is filled with molding material. [Figure 4] This is a diagram of at least a portion of a manufactured article, particularly a mold component of a casting mold. [Figure 5] This is a diagram of a casting mold consisting of two mold components, the mold being filled with casting metal, and having a hardened molding compound disposed within the cavity of the casting mold. [Figure 6] This is a diagram of a completed casting removed from a casting mold. [Modes for carrying out the invention]

[0187] Figure 1 shows a model plate 2 on which a molding model 4 is arranged, used in a method for manufacturing an article 1 (Figure 4) according to the present invention, preferably a casting mold, more preferably a first mold component 10 (Figure 4) of a casting mold.

[0188] The mold plate 2 may be used, for example, in a molding box (not shown in detail) where the model 4 is placed, or it may form a component of a molding chamber in the form of a movable press plate (not shown in detail) in an automated molding system. The model plate 2 is used to define at least a portion of the area of ​​the molding box or the molding chamber of the molding system.

[0189] As shown in Figure 2, the self-hardening molding compound 6 is placed in the “critical region” of the molding model 4, and is molded therein, and the molding compound 6 is preferably molded by hand. The molding compound is produced from a first component (A) and a second component (B) by the method of the present invention (see the description above). The “critical region” refers to a region of the molding model where material defects, particularly cavities in the casting metal, may occur nearby during the solidification of the casting metal, especially if further supply is insufficient. The molding model essentially corresponds to the shape of the subsequent casting, and the molding model may be made larger than the finished casting, taking into account the degree of shrinkage. According to a preferred configuration of the present invention, the molding compound 6 produced from the first component (A) and the second component (B) contains components that can react with each other in a thermite reaction. These components are pre-existing in the first component (A) and / or the second component (B).

[0190] The molding compound 6 is preferably formed by hand-mixing it into the “critical region” of the fabricated model 4 and allowing it to harden there. In one configuration of the method of the present invention, which is not shown in detail, it is possible to place multiple amounts of such molding compound 6 in a uniform distribution around the fabricated model in order to form multiple heat-generating centers.

[0191] In further embodiments not shown in detail, the molded compound may take the form of a pre-fabricated contour pad. In this case, the self-hardening molded compound is preferably pre-fabricated in a mold intended to give a contour pad of a predetermined shape, rather than being arbitrarily fabricated by hand as a molded compound. Such a pre-fabricated, typically already cured, contour pad has a shape that matches each region of the build model 4 in which the contour pad is placed. The contour pad is set or placed in the region of the build model intended for the purpose and optionally fixed therein.

[0192] Figure 3 shows the results of the next step of the method of the present invention, in which a molding material 8 comprising a binder and a mold base material, such as natural sand, semi-synthetic molding sand, or synthetic mold base material, is introduced into a build box (not shown in detail) or molding chamber. After being introduced into the build chamber or build box, the molding material 8 is compressed. Compression is carried out by applying a compressive force acting on the molding material 8. Compression and any associated curing processes give the molding material 8 the required strength, and together with the molding compound 6, form the article 1 of the present invention, in this context, the mold component 10 of a casting mold.

[0193] As is clear from Figure 3, the molding material 8 surrounds the molded compound 6 formed on the fabrication model 4. Compression of the molding material 8 embeds the molded compound 6 into the molding material 8, thereby establishing a strong bond between the molded compound 6 and the molding material 8.

[0194] In the next step of the preferred method according to the present invention, the model plate 2, together with the molded model 4, is separated from the manufactured mold part 10. Prior to, during, or after the separation operation, the mold part 10 (containing the molding compound 6) is removed from the molding box (not shown) or molding chamber. Figure 4 shows the mold part 10 with the molding compound 6 embedded after these steps have been taken.

[0195] As further shown in Figure 4, the molding compound 6 produced from the first component (A) and the second component (B) in particular forms a first boundary region 12 of article 1, which defines a portion of the cavity 16 for housing the casting metal. The molding material 8 forms a second boundary region 14 adjacent to, and preferably adjacent to, the first boundary region 12. The second boundary region 14 of article 1, which similarly defines a portion of the cavity 16 for housing the casting metal, has a different composition from the boundary region 12 (e.g., not capable of thermite reaction). When the molded model 4 is removed from the manufactured mold part 10, a mold cavity 16 corresponding to at least a portion of the casting 24 to be manufactured is obtained (Figure 6).

[0196] In the next step, a first mold component 10 (including a molding compound 6 defining a first boundary region) as article 1 according to the present invention is joined to a further mold component 18 to obtain a complete casting mold. After joining the mold components 10 and 18, which are juxtaposed by sealing, the two mold components 10 and 18 in the illustrated implementation of the method of the present invention are rotated 180°. Thus, mold component 18 forms the top surface of article 1. Subsequently, the casting metal 22 is introduced into the cavity 16 of article 1, which is preferably in the form of a casting mold, through a mouth 20 formed in or later fabricated in the mold component 18, so that the casting metal 22 completely fills the cavity 16 and rises into the mouth 22. When the casting metal 22 comes into contact with the molding compound 6 that forms the first boundary region 12 of the cavity 16, the molding compound is heated to such an extent that an exothermic reaction, particularly a thermite reaction, proceeds within the molding compound 6. As a result, the casting metal 22 in this region of the casting mold remains in a liquid state for an extended period, which has a favorable effect on the continuous supply process of the castings 24 to be manufactured. The results of this step are shown in Figure 5.

[0197] After the casting operation is complete, the casting metal 22 has solidified, and the manufactured casting 24 has cooled at least partially, the casting 24 is removed from the mold and any casting residue is removed. Upon completion of these procedures, the finished casting 24 shown in Figure 6 is produced. [Explanation of Symbols]

[0198] 1. Articles / Casting molds 2 Model Plates 4. Model 6 Molding compound 8 Molding material 10 Mold parts 12 Boundary area 14 Boundary area 16 Cavity 18 Mold parts 20 Cast metals 22 Mouth 24 Castings

Claims

1. Casting molds and The core, Oshiyubu and A method for producing an article selected from the group consisting of by repairing or completing a corresponding defective or incomplete article, (S1) At the foundry, A first component (A) comprising a first binder component (b1) of a binder system and a certain amount of a first mold base material, Move it spatially away from there, The second component (B) comprises a second binder component (b2) of the binder system and a certain amount of a second mold base material. A step of generating or providing, The first binder component (b1) and the second binder component (b2) are suitable for mutual chemical reactions and for the curing of the mixture of the first component (A) and the second component (B). The first binder component (b1) and the second binder component (b2) are each in spatially separated containers. These exist as constituent components of the first component (A) and the second component (B), respectively. Steps and (S2) A step of mixing at least the first component (A) and the second component (B), which is produced or provided spatially separated from it, in a specific mass ratio to obtain a self-hardening moldable compound, (S3) The self-hardening moldable compound produced in step (S2) is molded and cured to obtain a cured molded product of the first component (A) and the second component (B), wherein the cured molded product forms a region of the article upon completion of the manufacturing method. A method that includes at least [something].

2. The method according to claim 1, wherein the self-hardening molding compound produced in step (S2) is kneaded by machine or by hand in one or more subsequent steps.

3. The method according to claim 1, wherein, in order to define at least a portion of the area of ​​a cavity for containing a cast metal, the article has a first boundary region (12) and an adjacent second boundary region (14) of a different composition, the first boundary region being formed from the hardened product of the first component (A) and the second component (B).

4. The method according to claim 3, wherein the first component (A) and / or the second component (B) include at least components present in the cured molded product after step (S3) or in the article after completion of the manufacturing method, and the components can be reacted with each other by a thermite reaction by heating.

5. The molding in step (S3) may be done manually or automatically. and / or The manufacturing of the second boundary region (14) includes forming the molding material using an automated molding system. The method according to claim 3.

6. First, the first boundary region (12) of the article is formed, and then the second boundary region (14) is formed on top of the first boundary region. or First, the second boundary region of the article is formed, and then the first boundary region is formed on top of the second boundary region. The method according to any one of claims 3 to 5.

7. The mixing by contact between the first component (A) and the second component (B) in step (S2) At least part of it is done by hand. or At least in part, the mixing does not involve electrical assistance. The method according to any one of claims 1 to 6.

8. Step (S2): Filling intended or unintended recesses in the surface area of ​​the mold component with the self-hardening molding compound produced in step (S2). The method according to any one of claims 1 and 3 to 6, including the method described in claim 1 and 3 to 6.

9. The constituent components of the mold base material used in step (S1) in the first component (A) and / or the second component (B) are fire-resistant mold base materials designated as fire-resistant according to DIN 51060. and / or The component of the mold base material used in step (S1) in the first component (A) and / or the second component (B) is a thermal insulation filler. and / or The first component (A) comprising a binder component (b1), and / or The second component (B) containing the binder component (b2) Metallic materials selected from the group consisting of aluminum, magnesium, silicon, titanium, their alloys, and mixtures thereof with each other or with other metallic materials. metal oxides, Lithium silicate, Cordierite, and Alkali metal nitrates It further comprises one, two, three, or four or more additional component materials independently selected from the group consisting of the following: The method according to any one of claims 1 to 8.

10. The aforementioned binder system (G1) Polyurethane no-bake type, The first binder component (b1) is a polyol component, and the second binder component (b2) is a polyisocyanate component. The first component (A) and / or the second component (B) include the catalyst (c), Polyurethane no-bake type, (G2) Acid-curing cold resin, The first binder component (b1) is Furan resin, phenolic resin, or combination thereof Selected from, The second binder component (b2) is Sulfonic acid, A mixture of sulfonic acid and organic acid, mixture of inorganic acids A mixture containing one or more acidic components independently selected from the above, Acid-curing cold resin and (G3) Inorganic binder system, (G4) An epoxy resin wherein the first binder component (b1) comprises an epoxy compound and the second binder component (b2) comprises a polyfunctional amine. Selected from the group consisting of, The method according to any one of claims 1 to 9.

11. The self-hardening molding compound produced in step (S2) 82-98% by weight of mold base material, Includes, The aforementioned weight % is based on the total mass of the self-hardening moldable compound, The method according to any one of claims 1 to 10.

12. The first mold base material and the second mold base material are Having the same chemical composition, or Having different chemical compositions, The method according to any one of claims 1 to 11.

13. In the contact in step (S2), the temperatures of the first component (A) and the second component (B) are in the range of 5 to 40°C, and / or The self-hardening compound produced in step (S2) undergoes the shaping and hardening in step (S3) within a period of 1 to 60 minutes. The method according to any one of claims 1 to 12.

14. After the mixing by contact between the first component (A) and the second component (B) in step (S2), Step (S2) involves placing the self-hardening molded compound into a molding chamber or molding box. Next, during or after the curing of the self-hardening molded compound produced in step (S2), a molding material is introduced into the molding chamber or molding box. including, The method according to any one of claims 1 to 13.

15. The method according to any one of claims 1 to 14, wherein the hardening of the self-hardening molded compound produced in step (S2) is carried out in such a way as not to occur in the presence of a gaseous catalyst and / or gaseous co-reactants.

16. A method for manufacturing metal castings by metal casting in a casting mold, A method according to any one of claims 1 to 15, comprising the steps of manufacturing an article selected from the group consisting of a casting mold, a core, and a riser, and inserting the article to define at least a portion of a cavity for containing a casting metal, wherein the article has a first boundary region (12) and an adjacent second boundary region (14) of a different composition, the first boundary region being formed from the hardened molding product of the first component (A) and the second component (B), The steps include bringing the cast metal into contact with at least the first boundary region of the article manufactured during the casting process. A method that includes this.

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