The present disclosure includes binder systems for making foundry articles. The binder systems may comprise a humic substance-containing component that comprise lignite, an isocyanate component, and a catalyst component. The binder systems may be mixed with an aggregate (e.g., sand) for making foundry articles such as molds and cores. Also disclosed herein are methods of making foundry articles using the binder systems.

A foundry core formed from a moulding sand, grains of which are bound together by a binder, and which is provided to form a cooling channel in an engine block for an internal combustion engine. The foundry core has a supporting section, two neck sections, which protrude from a lateral surface of the supporting section and are arranged at a distance from one another, and at least one bridge section which is held by the neck sections at a distance from the supporting section and a minimum thickness of which measured as the distance between its lateral surfaces is no more than 3 mm in an area which lies between the neck sections.

A foundry core formed from a moulding sand, grains of which are bound together by a binder, and which is provided to form a cooling channel in an engine block for an internal combustion engine. The foundry core has a supporting section, two neck sections, which protrude from a lateral surface of the supporting section and are arranged at a distance from one another, and at least one bridge section which is held by the neck sections at a distance from the supporting section and a minimum thickness of which measured as the distance between its lateral surfaces is no more than 3 mm in an area which lies between the neck sections.

Described is a phenolic resin composition for use in the polyurethane cold-box and/or no-bake process. The phenolic resin composition comprises an ortho-condensed phenolic resol having etherified and/or free methylol groups in a total amount of 40 to 60% by weight based on the total mass of the phenolic resin composition, free formaldehyde in an amount of less than 0.1% by weight based on the total weight of the phenolic resin composition, one or more reaction products of formaldehyde with one or more CH-acidic reactant compounds, other constituents in a total amount of at least 38% by weight, wherein the amount of water in the phenolic resin composition is not more than 1.0% by weight in each case based on the total mass of the phenolic resin composition. Also described is a two-component binder system for use in the polyurethane cold-box and/or no-bake process, a use of a CH-acidic compound as a formaldehyde scavenger for producing a phenolic resin composition for use in the polyurethane cold-box and/or no-bake process, a process for producing a phenolic resin composition, a process for producing a two-component binder system and a process for producing a feeder, a foundry mold or a foundry core from a molding material mixture and finally corresponding feeders, foundry molds and foundry cores.

A method for additive manufacturing is provided, including: mixing a hardener with a sand material, so that the hardener is evenly coated on a surface of the sand material, and then spraying a binder through a nozzle, reacting the binder sprayed through the nozzle with the surface of the sand material evenly coated with the hardener to harden a sand mold. Therefore, the problem of nozzle clogging may be overcome, and a solid with a particle size of less than 0.6 m may be obtained by the additive manufacturing. In addition, the hardening speed can be adjusted according to the size of the sand mold. Compared with a general sand mold product, the hardening speed may be increased and the storage life of the binder may be prolonged when the sand mold has a large size.

Defects can arise in a product of a metal casting process from reactions occurring at a metal-mold interface. A method that reduces the defects uses an organic binder system by introducing a separate third component to a two-part polyurethane-based binder system used in the cold box or no bake process. The third part is added only after the first two parts are mixed with a refractory molding material to provide a shapeable foundry mix. The third part is an alkyl silicate, such as tetraethyl orthosilicate (TEOS), an alkyl orthoformate, such as trimethyl orthoformate (TMOF) or triethyl orthoformate (TEOF), or combinations thereof.

Defects can arise in a product of a metal casting process from reactions occurring at a metal-mold interface. A method that reduces the defects uses an organic binder system by introducing a separate third component to a two-part polyurethane-based binder system used in the cold box or no bake process. The third part is added only after the first two parts are mixed with a refractory molding material to provide a shapeable foundry mix. The third part is an alkyl silicate, such as tetraethyl orthosilicate (TEOS), an alkyl orthoformate, such as trimethyl orthoformate (TMOF) or triethyl orthoformate (TEOF), or combinations thereof.

The object of the invention is a component system for producing a binder for metal casting on the basis of phenolic resins of the benzyl ether type and isocyanates containing non-polar solvents.

Provided are: a coated sand having improved fluidity and being capable of improving a filling rate of a casting mold to be obtained; and a coated sand for advantageously manufacturing a casting mold having excellent strength, which coated sand provides a casting mold with good mold-releasability and collapsibility, gives cast products a favorable casting surface, and effectively improves sand adhesion on cast products. The coated sand is formed as a dry granular material having fluidity at room temperature, in which the surface of a refractory aggregate is coated with a solid layer of a water-soluble inorganic binder, and spherical particles of silicone resin having binder-repellency exist on the surface of the binder layer, or form a layer on the surface of the binder layer, a part of the spherical particles being not covered with the water-soluble inorganic binder and being exposed.

A method of fabricating a casting is provided. The method includes creating a mixture of ceramic powder and a binder, pouring the mixture around sacrificial patterns, executing a first thermal treatment to set the mixture into a solid mold without damaging the sacrificial patterns, executing a second thermal treatment to remove the sacrificial patterns without removing any of the binder from the solid mold, executing at least one of a third thermal treatment and a chemical treatment to remove a quantity of the binder to transform the solid mold into a solid breakaway mold and pouring molten metallic material into the solid breakaway mold.